const Database = require('better-sqlite3');
const path = require('path');
const fs = require('fs');

// Lazy import for auditService — cannot require at top level due to circular dependency
// (auditService -> database.js -> auditService). Use getLogAudit() instead of logAudit directly.
let _logAudit = null;
function getLogAudit() {
  if (!_logAudit) {
    try { _logAudit = require('../services/auditService').logAudit; } catch { _logAudit = () => {}; }
  }
  return _logAudit;
}

const DB_PATH = process.env.DB_PATH || path.join(__dirname, 'bills.db');
const SCHEMA_PATH = path.join(__dirname, 'schema.sql');
const DEFAULT_CATEGORIES = [
  'Housing',
  'Utilities',
  'Credit Cards',
  'Food',
  'Loans',
  'Insurance',
  'Beauty',
  'Entertainment',
  'Subscriptions',
  'Pets',
  'Phone & Internet',
  'Transportation',
  'Medical',
  'Other',
];

// ── SQL Whitelist Mappings ────────────────────────────────────────────────────
// Security FIX (2026-05-08): Whitelist all allowed column names to prevent SQL injection
// in migrations that use dynamic ALTER TABLE statements.

const COLUMN_WHITELIST = new Set([
  // users table columns
  'active', 'is_default_admin', 'notification_email', 'notifications_enabled',
  'notify_3d', 'notify_1d', 'notify_due', 'notify_overdue', 'notify_amount_change',
  'display_name', 'last_password_change_at', 'auth_provider', 'external_subject',
  'email', 'last_login_at',
  // payments table columns
  'deleted_at', 'payment_source', 'transaction_id',
  // monthly_starting_amounts table columns
  'other_amount',
  // bills table columns
  'history_visibility', 'interest_rate', 'user_id',
  'current_balance', 'minimum_payment', 'snowball_order', 'snowball_include',
  'sort_order', 'snowball_exempt', 'is_subscription', 'subscription_type', 'reminder_days_before',
  'subscription_source', 'subscription_detected_at', 'deleted_at', 'drift_snoozed_until',
  // categories table columns
  'sort_order',
  // sessions table columns
  'created_at',
  // financial_accounts table columns
  'monitored',
]);

// Security validation function for column names
function isValidColumnName(col) {
  if (!col || typeof col !== 'string') return false;
  // Must be in whitelist AND match valid SQL identifier pattern
  return COLUMN_WHITELIST.has(col) && /^[a-z0-9_]+$/i.test(col);
}

// Security validation function for SQL definition fragments
function isValidSqlDefinition(def) {
  if (!def || typeof def !== 'string') return false;
  // Allow standard column definitions but reject any user input
  // This is safe because all definitions are hardcoded here
  return /^[\w\s\(\)\',!@#$%^&*+=\[\]<>\-.]+$/i.test(def);
}

// ── Subscription catalog seed ─────────────────────────────────────────────────
// [rank, name, category, subscription_type, website, domain]
const SUBSCRIPTION_CATALOG_ROWS = [
  [1,'Netflix','Video Streaming','streaming','https://www.netflix.com/','netflix.com'],
  [2,'Amazon Prime Video','Video Streaming','streaming','https://www.primevideo.com/','primevideo.com'],
  [3,'Hulu','Video Streaming','streaming','https://www.hulu.com/','hulu.com'],
  [4,'Disney+','Video Streaming','streaming','https://www.disneyplus.com/','disneyplus.com'],
  [5,'Max','Video Streaming','streaming','https://www.max.com/','max.com'],
  [6,'Peacock','Video Streaming','streaming','https://www.peacocktv.com/','peacocktv.com'],
  [7,'Paramount+','Video Streaming','streaming','https://www.paramountplus.com/','paramountplus.com'],
  [8,'Apple TV+','Video Streaming','streaming','https://tv.apple.com/','tv.apple.com'],
  [9,'YouTube Premium','Video Streaming','streaming','https://www.youtube.com/premium','youtube.com'],
  [10,'ESPN+','Sports Streaming','streaming','https://plus.espn.com/','plus.espn.com'],
  [11,'YouTube TV','Live TV Streaming','streaming','https://tv.youtube.com/','tv.youtube.com'],
  [12,'Sling TV','Live TV Streaming','streaming','https://www.sling.com/','sling.com'],
  [13,'Fubo','Live TV Streaming','streaming','https://www.fubo.tv/','fubo.tv'],
  [14,'DirecTV Stream','Live TV Streaming','streaming','https://streamtv.directv.com/','streamtv.directv.com'],
  [15,'Philo','Live TV Streaming','streaming','https://www.philo.com/','philo.com'],
  [16,'Starz','Video Streaming','streaming','https://www.starz.com/','starz.com'],
  [17,'MGM+','Video Streaming','streaming','https://www.mgmplus.com/','mgmplus.com'],
  [18,'AMC+','Video Streaming','streaming','https://www.amcplus.com/','amcplus.com'],
  [19,'BET+','Video Streaming','streaming','https://www.bet.plus/','bet.plus'],
  [20,'Crunchyroll','Video Streaming','streaming','https://www.crunchyroll.com/','crunchyroll.com'],
  [21,'HIDIVE','Video Streaming','streaming','https://www.hidive.com/','hidive.com'],
  [22,'Shudder','Video Streaming','streaming','https://www.shudder.com/','shudder.com'],
  [23,'Acorn TV','Video Streaming','streaming','https://acorn.tv/','acorn.tv'],
  [24,'BritBox','Video Streaming','streaming','https://www.britbox.com/','britbox.com'],
  [25,'The Criterion Channel','Video Streaming','streaming','https://www.criterionchannel.com/','criterionchannel.com'],
  [26,'MUBI','Video Streaming','streaming','https://mubi.com/','mubi.com'],
  [27,'Discovery+','Video Streaming','streaming','https://www.discoveryplus.com/','discoveryplus.com'],
  [28,'Hallmark+','Video Streaming','streaming','https://www.hallmarkplus.com/','hallmarkplus.com'],
  [29,'PBS Passport','Video Streaming','streaming','https://www.pbs.org/passport/','pbs.org'],
  [30,'MagellanTV','Video Streaming','streaming','https://www.magellantv.com/','magellantv.com'],
  [31,'Curiosity Stream','Video Streaming','streaming','https://curiositystream.com/','curiositystream.com'],
  [32,'Nebula','Video Streaming','streaming','https://nebula.tv/','nebula.tv'],
  [33,'WOW Presents Plus','Video Streaming','streaming','https://www.wowpresentsplus.com/','wowpresentsplus.com'],
  [34,'ViX Premium','Video Streaming','streaming','https://vix.com/','vix.com'],
  [35,'FloSports','Sports Streaming','streaming','https://www.flosports.tv/','flosports.tv'],
  [36,'DAZN','Sports Streaming','streaming','https://www.dazn.com/','dazn.com'],
  [37,'MLB.TV','Sports Streaming','streaming','https://www.mlb.com/live-stream-games/subscribe','mlb.com'],
  [38,'NBA League Pass','Sports Streaming','streaming','https://www.nba.com/watch/league-pass-stream','nba.com'],
  [39,'NHL Power Play on ESPN+','Sports Streaming','streaming','https://www.espn.com/espnplus/catalog/nhl','espn.com'],
  [40,'NFL+','Sports Streaming','streaming','https://www.nfl.com/plus/','nfl.com'],
  [41,'Spotify Premium','Music & Audio','music','https://www.spotify.com/premium/','spotify.com'],
  [42,'Apple Music','Music & Audio','music','https://www.apple.com/apple-music/','apple.com'],
  [43,'Amazon Music Unlimited','Music & Audio','music','https://music.amazon.com/','music.amazon.com'],
  [44,'Pandora Premium','Music & Audio','music','https://www.pandora.com/upgrade','pandora.com'],
  [45,'SiriusXM','Music & Audio','music','https://www.siriusxm.com/','siriusxm.com'],
  [46,'TIDAL','Music & Audio','music','https://tidal.com/','tidal.com'],
  [47,'Qobuz','Music & Audio','music','https://www.qobuz.com/us-en/music/streaming/offers','qobuz.com'],
  [48,'SoundCloud Go+','Music & Audio','music','https://soundcloud.com/go','soundcloud.com'],
  [49,'Deezer','Music & Audio','music','https://www.deezer.com/us/offers','deezer.com'],
  [50,'iHeartRadio Plus','Music & Audio','music','https://www.iheart.com/plus/','iheart.com'],
  [51,'Audible','Audiobooks','education','https://www.audible.com/','audible.com'],
  [52,'Spotify Audiobooks','Audiobooks','education','https://www.spotify.com/us/audiobooks/','spotify.com'],
  [53,'Everand','Audiobooks & Ebooks','education','https://www.everand.com/','everand.com'],
  [54,'Scribd','Documents & Ebooks','education','https://www.scribd.com/','scribd.com'],
  [55,'Kindle Unlimited','Ebooks','education','https://www.amazon.com/kindle-dbs/hz/subscribe/ku','amazon.com'],
  [56,'Kobo Plus','Ebooks & Audiobooks','education','https://www.kobo.com/us/en/plus','kobo.com'],
  [57,'Libro.fm','Audiobooks','education','https://libro.fm/','libro.fm'],
  [58,'Blinkist','Books & Learning','education','https://www.blinkist.com/','blinkist.com'],
  [59,'Pocket Casts Plus','Podcasts','music','https://pocketcasts.com/plus/','pocketcasts.com'],
  [60,'Wondery+','Podcasts','music','https://wondery.com/plus/','wondery.com'],
  [61,'The New York Times','News & Magazines','news','https://www.nytimes.com/subscription','nytimes.com'],
  [62,'The Wall Street Journal','News & Magazines','news','https://www.wsj.com/news/subscribe','wsj.com'],
  [63,'The Washington Post','News & Magazines','news','https://subscribe.washingtonpost.com/','subscribe.washingtonpost.com'],
  [64,'The Atlantic','News & Magazines','news','https://www.theatlantic.com/subscribe/','theatlantic.com'],
  [65,'The New Yorker','News & Magazines','news','https://www.newyorker.com/subscribe','newyorker.com'],
  [66,'Bloomberg.com','News & Magazines','news','https://www.bloomberg.com/subscriptions','bloomberg.com'],
  [67,'Financial Times','News & Magazines','news','https://www.ft.com/products','ft.com'],
  [68,'The Economist','News & Magazines','news','https://www.economist.com/subscribe','economist.com'],
  [69,'TIME','News & Magazines','news','https://time.com/subscribe/','time.com'],
  [70,'WIRED','News & Magazines','news','https://www.wired.com/subscribe/','wired.com'],
  [71,'Consumer Reports','News & Magazines','news','https://www.consumerreports.org/join/','consumerreports.org'],
  [72,'Politico Pro','News & Magazines','news','https://www.politicopro.com/','politicopro.com'],
  [73,'The Athletic','Sports Media','streaming','https://theathletic.com/','theathletic.com'],
  [74,'Substack','Creator Media','news','https://substack.com/','substack.com'],
  [75,'Medium','Creator Media','news','https://medium.com/membership','medium.com'],
  [76,'Patreon','Creator Media','news','https://www.patreon.com/','patreon.com'],
  [77,'Apple News+','News & Magazines','news','https://www.apple.com/apple-news/','apple.com'],
  [78,'Readly','News & Magazines','news','https://us.readly.com/','us.readly.com'],
  [79,'PressReader','News & Magazines','news','https://www.pressreader.com/','pressreader.com'],
  [80,'The Information','News & Magazines','news','https://www.theinformation.com/subscribe','theinformation.com'],
  [81,'Microsoft 365','Software & Productivity','software','https://www.microsoft.com/microsoft-365','microsoft.com'],
  [82,'Google One','Cloud & Storage','cloud','https://one.google.com/','one.google.com'],
  [83,'iCloud+','Cloud & Storage','cloud','https://www.apple.com/icloud/','apple.com'],
  [84,'Dropbox','Cloud & Storage','cloud','https://www.dropbox.com/plans','dropbox.com'],
  [85,'Box','Cloud & Storage','cloud','https://www.box.com/pricing','box.com'],
  [86,'Adobe Creative Cloud','Software & Design','software','https://www.adobe.com/creativecloud.html','adobe.com'],
  [87,'Canva Pro','Software & Design','software','https://www.canva.com/pro/','canva.com'],
  [88,'Figma','Software & Design','software','https://www.figma.com/pricing/','figma.com'],
  [89,'Notion','Software & Productivity','software','https://www.notion.so/pricing','notion.so'],
  [90,'Evernote','Software & Productivity','software','https://evernote.com/compare-plans','evernote.com'],
  [91,'Todoist','Software & Productivity','software','https://todoist.com/pricing','todoist.com'],
  [92,'Grammarly','Writing & AI','software','https://www.grammarly.com/plans','grammarly.com'],
  [93,'ChatGPT','AI','software','https://chatgpt.com/pricing','chatgpt.com'],
  [94,'Claude.ai','AI','software','https://claude.ai/upgrade','anthropic.com'],
  [95,'Perplexity','AI','software','https://www.perplexity.ai/pro','perplexity.ai'],
  [96,'Gemini Advanced','AI','software','https://one.google.com/about/google-ai-plans/','one.google.com'],
  [97,'GitHub Copilot','Developer Tools','software','https://github.com/features/copilot/plans','github.com'],
  [98,'Cursor','Developer Tools','software','https://www.cursor.com/pricing','cursor.com'],
  [99,'Replit','Developer Tools','software','https://replit.com/pricing','replit.com'],
  [100,'Setapp','Software & Productivity','software','https://setapp.com/','setapp.com'],
  [101,'1Password','Security','security','https://1password.com/pricing','1password.com'],
  [102,'Dashlane','Security','security','https://www.dashlane.com/pricing','dashlane.com'],
  [103,'NordVPN','Security','security','https://nordvpn.com/pricing/','nordvpn.com'],
  [104,'ExpressVPN','Security','security','https://www.expressvpn.com/','expressvpn.com'],
  [105,'Surfshark','Security','security','https://surfshark.com/pricing','surfshark.com'],
  [106,'Norton 360','Security','security','https://us.norton.com/products','us.norton.com'],
  [107,'McAfee+','Security','security','https://www.mcafee.com/en-us/consumer-support/pricing.html','mcafee.com'],
  [108,'QuickBooks Online','Finance Software','software','https://quickbooks.intuit.com/pricing/','quickbooks.intuit.com'],
  [109,'TurboTax Live','Finance Software','software','https://turbotax.intuit.com/personal-taxes/online/live/','turbotax.intuit.com'],
  [110,'YNAB','Finance Software','software','https://www.ynab.com/pricing','ynab.com'],
  [111,'Rocket Money Premium','Finance Software','software','https://www.rocketmoney.com/premium','rocketmoney.com'],
  [112,'Copilot Money','Finance Software','software','https://copilot.money/','copilot.money'],
  [113,'Calendly','Software & Productivity','software','https://calendly.com/pricing','calendly.com'],
  [114,'Zoom Workplace','Software & Productivity','software','https://www.zoom.com/en/pricing/','zoom.com'],
  [115,'Slack','Software & Productivity','software','https://slack.com/pricing','slack.com'],
  [116,'Xbox Game Pass','Gaming','gaming','https://www.xbox.com/en-US/xbox-game-pass','xbox.com'],
  [117,'PlayStation Plus','Gaming','gaming','https://www.playstation.com/en-us/ps-plus/','playstation.com'],
  [118,'Nintendo Switch Online','Gaming','gaming','https://www.nintendo.com/us/switch/online/','nintendo.com'],
  [119,'Apple Arcade','Gaming','gaming','https://www.apple.com/apple-arcade/','apple.com'],
  [120,'EA Play','Gaming','gaming','https://www.ea.com/ea-play','ea.com'],
  [121,'Ubisoft+','Gaming','gaming','https://www.ubisoft.com/en-us/ubisoft-plus','ubisoft.com'],
  [122,'NVIDIA GeForce NOW','Gaming','gaming','https://www.nvidia.com/en-us/geforce-now/memberships/','nvidia.com'],
  [123,'Roblox Premium','Gaming','gaming','https://www.roblox.com/premium/membership','roblox.com'],
  [124,'Fortnite Crew','Gaming','gaming','https://www.fortnite.com/fortnite-crew-subscription','fortnite.com'],
  [125,'Minecraft Realms','Gaming','gaming','https://www.minecraft.net/realms','minecraft.net'],
  [126,'Twitch Turbo','Creator & Social','news','https://www.twitch.tv/turbo','twitch.tv'],
  [127,'Discord Nitro','Creator & Social','news','https://discord.com/nitro','discord.com'],
  [128,'X Premium','Creator & Social','news','https://help.x.com/en/using-x/x-premium','help.x.com'],
  [129,'Snapchat+','Creator & Social','news','https://www.snapchat.com/plus','snapchat.com'],
  [130,'TikTok Live Subscription','Creator & Social','news','https://www.tiktok.com/live/creators/en-US/subscription/','tiktok.com'],
  [131,'Meta Verified','Creator & Social','news','https://about.meta.com/technologies/meta-verified/','about.meta.com'],
  [132,'LinkedIn Premium','Career & Social','news','https://premium.linkedin.com/','premium.linkedin.com'],
  [133,'Tinder Gold','Dating','other','https://tinder.com/feature/plus','tinder.com'],
  [134,'Bumble Premium','Dating','other','https://bumble.com/en/the-buzz/bumble-premium','bumble.com'],
  [135,'Hinge+','Dating','other','https://hinge.co/hinge-plus','hinge.co'],
  [136,'Amazon Prime','Shopping & Delivery','shopping','https://www.amazon.com/amazonprime','amazon.com'],
  [137,'Walmart+','Shopping & Delivery','shopping','https://www.walmart.com/plus','walmart.com'],
  [138,'Target Circle 360','Shopping & Delivery','shopping','https://www.target.com/circle/target-circle-360','target.com'],
  [139,'Costco','Warehouse Clubs','shopping','https://www.costco.com/join-costco.html','costco.com'],
  [140,'Sam\'s Club','Warehouse Clubs','shopping','https://www.samsclub.com/join','samsclub.com'],
  [141,'BJ\'s Wholesale Club','Warehouse Clubs','shopping','https://www.bjs.com/membership','bjs.com'],
  [142,'Instacart+','Grocery & Delivery','food','https://www.instacart.com/instacart-plus','instacart.com'],
  [143,'DoorDash DashPass','Food Delivery','food','https://www.doordash.com/dashpass/','doordash.com'],
  [144,'Uber One','Food & Rides','food','https://www.uber.com/us/en/u/uber-one/','uber.com'],
  [145,'Grubhub+','Food Delivery','food','https://www.grubhub.com/plus','grubhub.com'],
  [146,'Shipt','Grocery & Delivery','food','https://www.shipt.com/membership/','shipt.com'],
  [147,'Kroger Boost','Grocery & Delivery','food','https://www.kroger.com/pr/boost','kroger.com'],
  [148,'Thrive Market','Grocery & Delivery','food','https://thrivemarket.com/','thrivemarket.com'],
  [149,'Misfits Market','Grocery & Delivery','food','https://www.misfitsmarket.com/','misfitsmarket.com'],
  [150,'Imperfect Foods','Grocery & Delivery','food','https://www.imperfectfoods.com/','imperfectfoods.com'],
  [151,'Chewy Autoship','Pet Retail','shopping','https://www.chewy.com/app/content/autoship','chewy.com'],
  [152,'Petco Vital Care Premier','Pet Retail','shopping','https://www.petco.com/shop/en/petcostore/c/vitalcare','petco.com'],
  [153,'PetSmart Treats Rewards VIPP','Pet Retail','shopping','https://www.petsmart.com/treats-rewards-vipp.html','petsmart.com'],
  [154,'GameStop Pro','Retail Memberships','shopping','https://www.gamestop.com/pro/','gamestop.com'],
  [155,'Barnes & Noble Membership','Retail Memberships','shopping','https://www.barnesandnoble.com/membership','barnesandnoble.com'],
  [156,'HelloFresh','Food & Meal Kits','food','https://www.hellofresh.com/','hellofresh.com'],
  [157,'Blue Apron','Food & Meal Kits','food','https://www.blueapron.com/','blueapron.com'],
  [158,'Home Chef','Food & Meal Kits','food','https://www.homechef.com/','homechef.com'],
  [159,'Marley Spoon','Food & Meal Kits','food','https://marleyspoon.com/','marleyspoon.com'],
  [160,'Dinnerly','Food & Meal Kits','food','https://dinnerly.com/','dinnerly.com'],
  [161,'EveryPlate','Food & Meal Kits','food','https://www.everyplate.com/','everyplate.com'],
  [162,'Green Chef','Food & Meal Kits','food','https://www.greenchef.com/','greenchef.com'],
  [163,'Purple Carrot','Food & Meal Kits','food','https://www.purplecarrot.com/','purplecarrot.com'],
  [164,'Sunbasket','Food & Meal Kits','food','https://sunbasket.com/','sunbasket.com'],
  [165,'Factor','Prepared Meals','food','https://www.factor75.com/','factor75.com'],
  [166,'CookUnity','Prepared Meals','food','https://www.cookunity.com/','cookunity.com'],
  [167,'Fresh N Lean','Prepared Meals','food','https://www.freshnlean.com/','freshnlean.com'],
  [168,'Hungryroot','Food & Meal Kits','food','https://www.hungryroot.com/','hungryroot.com'],
  [169,'Daily Harvest','Prepared Meals','food','https://www.daily-harvest.com/','daily-harvest.com'],
  [170,'Tovala','Prepared Meals','food','https://www.tovala.com/','tovala.com'],
  [171,'MistoBox','Coffee & Tea','food','https://mistobox.com/','mistobox.com'],
  [172,'Trade Coffee','Coffee & Tea','food','https://www.drinktrade.com/','drinktrade.com'],
  [173,'Atlas Coffee Club','Coffee & Tea','food','https://atlascoffeeclub.com/','atlascoffeeclub.com'],
  [174,'Bean Box','Coffee & Tea','food','https://beanbox.com/','beanbox.com'],
  [175,'Universal Yums','Snacks','food','https://www.universalyums.com/','universalyums.com'],
  [176,'Peloton App','Fitness & Wellness','fitness','https://www.onepeloton.com/app','onepeloton.com'],
  [177,'ClassPass','Fitness & Wellness','fitness','https://classpass.com/','classpass.com'],
  [178,'Apple Fitness+','Fitness & Wellness','fitness','https://www.apple.com/apple-fitness-plus/','apple.com'],
  [179,'Strava','Fitness & Wellness','fitness','https://www.strava.com/subscribe','strava.com'],
  [180,'Fitbit Premium','Fitness & Wellness','fitness','https://www.fitbit.com/global/us/products/services/premium','fitbit.com'],
  [181,'MyFitnessPal Premium','Fitness & Wellness','fitness','https://www.myfitnesspal.com/premium','myfitnesspal.com'],
  [182,'Noom','Fitness & Wellness','fitness','https://www.noom.com/','noom.com'],
  [183,'WW','Fitness & Wellness','fitness','https://www.weightwatchers.com/us/plans','weightwatchers.com'],
  [184,'Headspace','Meditation & Wellness','fitness','https://www.headspace.com/','headspace.com'],
  [185,'Calm','Meditation & Wellness','fitness','https://www.calm.com/premium','calm.com'],
  [186,'Sleep Cycle Premium','Sleep & Wellness','fitness','https://www.sleepcycle.com/premium/','sleepcycle.com'],
  [187,'Oura Membership','Fitness & Wellness','fitness','https://ouraring.com/membership','ouraring.com'],
  [188,'Whoop','Fitness & Wellness','fitness','https://www.whoop.com/us/en/membership/','whoop.com'],
  [189,'Aaptiv','Fitness & Wellness','fitness','https://aaptiv.com/','aaptiv.com'],
  [190,'Fitbod','Fitness & Wellness','fitness','https://fitbod.me/pricing/','fitbod.me'],
  [191,'Alo Moves','Fitness & Wellness','fitness','https://www.alomoves.com/','alomoves.com'],
  [192,'Obe Fitness','Fitness & Wellness','fitness','https://obefitness.com/','obefitness.com'],
  [193,'Centr','Fitness & Wellness','fitness','https://centr.com/','centr.com'],
  [194,'Future','Fitness & Wellness','fitness','https://www.future.co/','future.co'],
  [195,'Tonal Membership','Fitness & Wellness','fitness','https://www.tonal.com/membership/','tonal.com'],
  [196,'Duolingo Super','Education','education','https://www.duolingo.com/super','duolingo.com'],
  [197,'MasterClass','Education','education','https://www.masterclass.com/','masterclass.com'],
  [198,'Coursera Plus','Education','education','https://www.coursera.org/courseraplus','coursera.org'],
  [199,'Skillshare','Education','education','https://www.skillshare.com/','skillshare.com'],
  [200,'Book of the Month','Books & Subscription Boxes','education','https://www.bookofthemonth.com/','bookofthemonth.com'],
];

const SUBSCRIPTION_CATALOG_V2_ROWS = [
  // ── AI ──────────────────────────────────────────────────────────────────────
  [201,'Suno','AI Music','music','https://suno.com/','suno.com'],
  [202,'Midjourney','AI Image Generation','software','https://midjourney.com/','midjourney.com'],
  [203,'Grok','AI','software','https://grok.com/','grok.com'],
  [204,'ElevenLabs','AI Voice','software','https://elevenlabs.io/','elevenlabs.io'],
  [205,'Character.ai Plus','AI','software','https://character.ai/','character.ai'],
  [206,'Runway','AI Video','software','https://runwayml.com/','runwayml.com'],
  [207,'Windsurf','Developer Tools','software','https://windsurf.com/','windsurf.com'],
  [208,'Leonardo.ai','AI Image Generation','software','https://leonardo.ai/','leonardo.ai'],
  // ── Home Security / Smart Home ───────────────────────────────────────────────
  [209,'Ring Protect','Home Security','other','https://ring.com/protect-plans','ring.com'],
  [210,'Nest Aware','Home Security','other','https://store.google.com/us/category/connected_home','nest.com'],
  [211,'SimpliSafe','Home Security','other','https://simplisafe.com/','simplisafe.com'],
  [212,'ADT','Home Security','other','https://www.adt.com/','adt.com'],
  [213,'Arlo Secure','Home Security','other','https://www.arlo.com/','arlo.com'],
  [214,'Wyze Cam Plus','Home Security','other','https://www.wyze.com/','wyze.com'],
  [215,'Abode','Home Security','other','https://goabode.com/','goabode.com'],
  // ── Financial Data & Aggregation ────────────────────────────────────────────
  [216,'SimpleFIN Bridge','Financial Data','software','https://simplefin.org/','simplefin.org'],
  [217,'Tiller Money','Financial Data','software','https://www.tillerhq.com/','tillerhq.com'],
  [218,'Monarch Money','Finance Software','software','https://www.monarchmoney.com/','monarchmoney.com'],
  [219,'Empower','Finance Software','software','https://www.empower.com/','empower.com'],
  // ── Cloud Backup ─────────────────────────────────────────────────────────────
  [220,'Backblaze','Cloud Backup','cloud','https://www.backblaze.com/','backblaze.com'],
  [221,'Carbonite','Cloud Backup','cloud','https://www.carbonite.com/','carbonite.com'],
  [222,'iDrive','Cloud Backup','cloud','https://www.idrive.com/','idrive.com'],
  // ── Email ────────────────────────────────────────────────────────────────────
  [223,'Proton Mail','Email & Privacy','software','https://proton.me/mail','proton.me'],
  [224,'Fastmail','Email','software','https://www.fastmail.com/','fastmail.com'],
  [225,'Superhuman','Email','software','https://superhuman.com/','superhuman.com'],
  [226,'Hey','Email','software','https://www.hey.com/','hey.com'],
  // ── Security / Privacy ───────────────────────────────────────────────────────
  [227,'Bitwarden','Security','security','https://bitwarden.com/','bitwarden.com'],
  [228,'Keeper','Security','security','https://www.keepersecurity.com/','keepersecurity.com'],
  [229,'LastPass','Security','security','https://www.lastpass.com/','lastpass.com'],
  [230,'Proton VPN','Security','security','https://protonvpn.com/','protonvpn.com'],
  [231,'Mullvad VPN','Security','security','https://mullvad.net/','mullvad.net'],
  [232,'Private Internet Access','Security','security','https://www.privateinternetaccess.com/','privateinternetaccess.com'],
  [233,'Proton Pass','Security','security','https://proton.me/pass','proton.me'],
  [234,'SimpleLogin','Email Privacy','software','https://simplelogin.io/','simplelogin.io'],
  // ── Identity Protection ──────────────────────────────────────────────────────
  [235,'LifeLock','Identity Protection','security','https://www.lifelock.com/','lifelock.com'],
  [236,'Aura','Identity Protection','security','https://www.aura.com/','aura.com'],
  [237,'IdentityForce','Identity Protection','security','https://www.identityforce.com/','identityforce.com'],
  // ── Comics ───────────────────────────────────────────────────────────────────
  [238,'Marvel Unlimited','Comics','streaming','https://www.marvel.com/unlimited','marvel.com'],
  [239,'DC Universe Infinite','Comics','streaming','https://www.dcuniverseinfinite.com/','dcuniverseinfinite.com'],
  // ── Genealogy ────────────────────────────────────────────────────────────────
  [240,'Ancestry','Genealogy','other','https://www.ancestry.com/','ancestry.com'],
  [241,'MyHeritage','Genealogy','other','https://www.myheritage.com/','myheritage.com'],
  [242,'Findmypast','Genealogy','other','https://www.findmypast.com/','findmypast.com'],
  // ── Telehealth ───────────────────────────────────────────────────────────────
  [243,'BetterHelp','Telehealth','other','https://www.betterhelp.com/','betterhelp.com'],
  [244,'Talkspace','Telehealth','other','https://www.talkspace.com/','talkspace.com'],
  [245,'Teladoc','Telehealth','other','https://www.teladoc.com/','teladoc.com'],
  [246,'Hims & Hers','Telehealth','other','https://www.forhims.com/','forhims.com'],
  [247,'Cerebral','Telehealth','other','https://cerebral.com/','cerebral.com'],
  // ── Website Builder / Hosting / Domains ─────────────────────────────────────
  [248,'Squarespace','Website Builder','software','https://www.squarespace.com/','squarespace.com'],
  [249,'Wix','Website Builder','software','https://www.wix.com/','wix.com'],
  [250,'Webflow','Website Builder','software','https://webflow.com/','webflow.com'],
  [251,'GoDaddy','Domain & Hosting','software','https://www.godaddy.com/','godaddy.com'],
  [252,'Namecheap','Domain & Hosting','software','https://www.namecheap.com/','namecheap.com'],
  [253,'Netlify','Developer Tools','software','https://www.netlify.com/','netlify.com'],
  [254,'Vercel','Developer Tools','software','https://vercel.com/','vercel.com'],
  // ── Learning ─────────────────────────────────────────────────────────────────
  [255,'LinkedIn Learning','Education','education','https://www.linkedin.com/learning/','linkedin.com'],
  [256,'Pluralsight','Education','education','https://www.pluralsight.com/','pluralsight.com'],
  [257,"O'Reilly",'Education','education','https://www.oreilly.com/','oreilly.com'],
  [258,'CBT Nuggets','Education','education','https://www.cbtnuggets.com/','cbtnuggets.com'],
  [259,'Udacity','Education','education','https://www.udacity.com/','udacity.com'],
  [260,'Frontend Masters','Education','education','https://frontendmasters.com/','frontendmasters.com'],
  // ── Project Management ───────────────────────────────────────────────────────
  [261,'Monday.com','Software & Productivity','software','https://monday.com/','monday.com'],
  [262,'Asana','Software & Productivity','software','https://asana.com/','asana.com'],
  [263,'ClickUp','Software & Productivity','software','https://clickup.com/','clickup.com'],
  [264,'Linear','Developer Tools','software','https://linear.app/','linear.app'],
  [265,'Basecamp','Software & Productivity','software','https://basecamp.com/','basecamp.com'],
  [266,'Jira','Developer Tools','software','https://www.atlassian.com/software/jira','atlassian.com'],
  [267,'Miro','Software & Productivity','software','https://miro.com/','miro.com'],
  [268,'Airtable','Software & Productivity','software','https://airtable.com/','airtable.com'],
  // ── Email Marketing ──────────────────────────────────────────────────────────
  [269,'Mailchimp','Email Marketing','software','https://mailchimp.com/','mailchimp.com'],
  [270,'ConvertKit','Email Marketing','software','https://convertkit.com/','convertkit.com'],
  [271,'Beehiiv','Newsletter Platform','software','https://www.beehiiv.com/','beehiiv.com'],
  [272,'Constant Contact','Email Marketing','software','https://www.constantcontact.com/','constantcontact.com'],
  [273,'ActiveCampaign','Email Marketing','software','https://www.activecampaign.com/','activecampaign.com'],
  // ── Cloud Computing ──────────────────────────────────────────────────────────
  [274,'DigitalOcean','Cloud Computing','cloud','https://www.digitalocean.com/','digitalocean.com'],
  [275,'Linode','Cloud Computing','cloud','https://www.linode.com/','linode.com'],
  [276,'Render','Cloud Computing','cloud','https://render.com/','render.com'],
  [277,'Vultr','Cloud Computing','cloud','https://www.vultr.com/','vultr.com'],
  [278,'Hetzner','Cloud Computing','cloud','https://www.hetzner.com/','hetzner.com'],
  [279,'Cloudflare','Network & Security','cloud','https://www.cloudflare.com/','cloudflare.com'],
  // ── Media Server ─────────────────────────────────────────────────────────────
  [280,'Plex Pass','Media Server','streaming','https://www.plex.tv/plex-pass/','plex.tv'],
  [281,'Emby Premiere','Media Server','streaming','https://emby.media/premiere/','emby.media'],
  // ── Network / Homelab ────────────────────────────────────────────────────────
  [282,'NextDNS','Network & Security','software','https://nextdns.io/','nextdns.io'],
  [283,'Tailscale','Network & Security','software','https://tailscale.com/','tailscale.com'],
  // ── Productivity ─────────────────────────────────────────────────────────────
  [284,'Obsidian Sync','Software & Productivity','software','https://obsidian.md/','obsidian.md'],
  [285,'Readwise','Software & Productivity','software','https://readwise.io/','readwise.io'],
  [286,'Loom','Software & Productivity','software','https://www.loom.com/','loom.com'],
  [287,'Raycast Pro','Software & Productivity','software','https://www.raycast.com/','raycast.com'],
  // ── Developer Tools ──────────────────────────────────────────────────────────
  [288,'JetBrains','Developer Tools','software','https://www.jetbrains.com/','jetbrains.com'],
  [289,'Tabnine','Developer Tools','software','https://www.tabnine.com/','tabnine.com'],
  // ── Communication ────────────────────────────────────────────────────────────
  [290,'Telegram Premium','Messaging','software','https://telegram.org/','telegram.org'],
];

function runSubscriptionCatalogV2Migration(database) {
  // Category fixes for existing rows
  database.prepare(`
    UPDATE subscription_catalog SET subscription_type = 'software'
    WHERE name = 'Discord Nitro' AND subscription_type = 'news'
  `).run();
  database.prepare(`
    UPDATE subscription_catalog SET subscription_type = 'streaming'
    WHERE name = 'Twitch Turbo' AND subscription_type = 'news'
  `).run();
  database.prepare(`
    UPDATE subscription_catalog SET subscription_type = 'software'
    WHERE name = 'X Premium' AND subscription_type = 'news'
  `).run();

  // New entries — skip any name already in the catalog
  const existing = new Set(
    database.prepare('SELECT name FROM subscription_catalog').all().map(r => r.name)
  );
  const toInsert = SUBSCRIPTION_CATALOG_V2_ROWS.filter(r => !existing.has(r[1]));
  if (toInsert.length > 0) {
    const insert = database.prepare(
      'INSERT INTO subscription_catalog (rank, name, category, subscription_type, website, domain) VALUES (?,?,?,?,?,?)'
    );
    const insertMany = database.transaction((rows) => {
      for (const row of rows) insert.run(...row);
    });
    insertMany(toInsert);
    console.log(`[migration] subscription_catalog v2: added ${toInsert.length} new entries`);
  }
}

function runAdvisoryFiltersMigration(database) {
  database.exec(`
    CREATE TABLE IF NOT EXISTS advisory_non_bill_filters (
      id TEXT PRIMARY KEY,
      pattern TEXT NOT NULL,
      confidence TEXT NOT NULL CHECK(confidence IN ('high', 'medium')),
      category TEXT NOT NULL,
      rationale TEXT
    );
    CREATE INDEX IF NOT EXISTS idx_advisory_filters_confidence
      ON advisory_non_bill_filters(confidence);

    CREATE TABLE IF NOT EXISTS advisory_bill_like_overrides (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      term TEXT NOT NULL UNIQUE
    );
  `);

  const filterCount = database.prepare('SELECT COUNT(*) as n FROM advisory_non_bill_filters').get();
  if (filterCount.n === 0) {
    const jsonPath = path.join(__dirname, '..', 'docs', 'advisory_non_bill_transaction_filters_us_ms_5000.json');
    const raw = fs.readFileSync(jsonPath, 'utf8');
    const data = JSON.parse(raw);

    const insertFilter = database.prepare(
      'INSERT INTO advisory_non_bill_filters (id, pattern, confidence, category, rationale) VALUES (?,?,?,?,?)'
    );
    const insertFilters = database.transaction((rows) => {
      for (const row of rows) {
        insertFilter.run(row.id, row.pattern, row.confidence, row.category, row.rationale || null);
      }
    });
    insertFilters(data.patterns || []);
    console.log(`[migration] advisory_non_bill_filters: seeded ${(data.patterns || []).length} rows`);

    const overrideTerms = data.bill_like_override_terms || [];
    if (overrideTerms.length > 0) {
      const insertOverride = database.prepare(
        'INSERT OR IGNORE INTO advisory_bill_like_overrides (term) VALUES (?)'
      );
      const insertOverrides = database.transaction((terms) => {
        for (const term of terms) insertOverride.run(term);
      });
      insertOverrides(overrideTerms);
      console.log(`[migration] advisory_bill_like_overrides: seeded ${overrideTerms.length} rows`);
    }
  }
}

function runSubscriptionCatalogMigration(database) {
  database.exec(`
    CREATE TABLE IF NOT EXISTS subscription_catalog (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      rank INTEGER NOT NULL,
      name TEXT NOT NULL,
      category TEXT NOT NULL,
      subscription_type TEXT NOT NULL,
      website TEXT,
      domain TEXT,
      created_at TEXT NOT NULL DEFAULT (datetime('now'))
    );
    CREATE INDEX IF NOT EXISTS idx_subscription_catalog_rank ON subscription_catalog(rank);
    CREATE INDEX IF NOT EXISTS idx_subscription_catalog_type ON subscription_catalog(subscription_type);
  `);

  const existing = database.prepare('SELECT COUNT(*) as n FROM subscription_catalog').get();
  if (existing.n === 0) {
    const insert = database.prepare(
      'INSERT INTO subscription_catalog (rank, name, category, subscription_type, website, domain) VALUES (?,?,?,?,?,?)'
    );
    const insertMany = database.transaction((rows) => {
      for (const row of rows) insert.run(...row);
    });
    insertMany(SUBSCRIPTION_CATALOG_ROWS);
    console.log(`[migration] subscription_catalog: seeded ${SUBSCRIPTION_CATALOG_ROWS.length} rows`);
  }
}

function seedManualDataSources(database = db) {
  if (!database) return;
  const hasDataSources = database.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='data_sources'").get();
  const hasUsers = database.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='users'").get();
  if (!hasDataSources || !hasUsers) return;

  database.exec(`
    INSERT INTO data_sources (user_id, type, provider, name, status)
    SELECT u.id, 'manual', 'manual', 'Manual Entry', 'active'
    FROM users u
    WHERE NOT EXISTS (
      SELECT 1
      FROM data_sources ds
      WHERE ds.user_id = u.id
        AND ds.type = 'manual'
        AND ds.provider = 'manual'
    )
  `);
}

function ensureTransactionFoundationSchema(database = db) {
  database.exec(`
    CREATE TABLE IF NOT EXISTS data_sources (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
      type TEXT NOT NULL,
      provider TEXT,
      name TEXT NOT NULL,
      status TEXT NOT NULL DEFAULT 'active',
      config_json TEXT,
      encrypted_secret TEXT,
      last_sync_at TEXT,
      last_error TEXT,
      created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
      updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
    );

    CREATE TABLE IF NOT EXISTS financial_accounts (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
      data_source_id INTEGER,
      provider_account_id TEXT,
      name TEXT NOT NULL,
      org_name TEXT,
      account_type TEXT,
      currency TEXT,
      balance INTEGER,
      available_balance INTEGER,
      monitored INTEGER NOT NULL DEFAULT 1,
      raw_data TEXT,
      created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
      updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,

      FOREIGN KEY (data_source_id) REFERENCES data_sources(id) ON DELETE SET NULL,
      UNIQUE(data_source_id, provider_account_id)
    );

    CREATE TABLE IF NOT EXISTS transactions (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
      data_source_id INTEGER,
      account_id INTEGER,
      provider_transaction_id TEXT,
      source_type TEXT NOT NULL,
      transaction_type TEXT,
      posted_date TEXT,
      transacted_at TEXT,
      amount INTEGER NOT NULL,
      currency TEXT,
      description TEXT,
      payee TEXT,
      memo TEXT,
      category TEXT,
      raw_data TEXT,
      matched_bill_id INTEGER,
      match_status TEXT NOT NULL DEFAULT 'unmatched',
      ignored INTEGER NOT NULL DEFAULT 0,
      created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
      updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,

      FOREIGN KEY (data_source_id) REFERENCES data_sources(id) ON DELETE SET NULL,
      FOREIGN KEY (account_id) REFERENCES financial_accounts(id) ON DELETE SET NULL,
      FOREIGN KEY (matched_bill_id) REFERENCES bills(id) ON DELETE SET NULL
    );

    CREATE INDEX IF NOT EXISTS idx_data_sources_user_type ON data_sources(user_id, type, status);
    CREATE UNIQUE INDEX IF NOT EXISTS idx_data_sources_user_manual
      ON data_sources(user_id, type, provider)
      WHERE type = 'manual' AND provider = 'manual';
    CREATE INDEX IF NOT EXISTS idx_financial_accounts_user_source ON financial_accounts(user_id, data_source_id);
    CREATE INDEX IF NOT EXISTS idx_transactions_user_date ON transactions(user_id, posted_date, transacted_at);
    CREATE INDEX IF NOT EXISTS idx_transactions_user_match ON transactions(user_id, match_status, ignored);
    CREATE INDEX IF NOT EXISTS idx_transactions_account ON transactions(account_id);
    CREATE INDEX IF NOT EXISTS idx_transactions_matched_bill ON transactions(matched_bill_id);
    CREATE UNIQUE INDEX IF NOT EXISTS idx_transactions_provider_dedupe
      ON transactions (data_source_id, provider_transaction_id)
      WHERE provider_transaction_id IS NOT NULL;
  `);

  seedManualDataSources(database);
}

fs.mkdirSync(path.dirname(DB_PATH), { recursive: true });

let db = null;
let initializing = false;

function assertWritableDbPath() {
  const dir = path.dirname(DB_PATH);
  const probe = path.join(dir, `.write-test-${process.pid}-${Date.now()}`);

  try {
    fs.mkdirSync(dir, { recursive: true });
    fs.writeFileSync(probe, 'ok');
    fs.unlinkSync(probe);

    if (fs.existsSync(DB_PATH)) {
      fs.accessSync(DB_PATH, fs.constants.R_OK | fs.constants.W_OK);
    }
  } catch (err) {
    const message = [
      `Database path is not writable: ${DB_PATH}`,
      `Ensure the DB directory is writable by the app user. In Docker, rebuild the image and recreate the container so the entrypoint can chown /data.`,
      `Original error: ${err.message}`,
    ].join('\n');
    const wrapped = new Error(message);
    wrapped.code = err.code;
    throw wrapped;
  } finally {
    try {
      if (fs.existsSync(probe)) fs.unlinkSync(probe);
    } catch {}
  }
}

function sleep(ms) {
  Atomics.wait(new Int32Array(new SharedArrayBuffer(4)), 0, 0, ms);
}

function getDb() {
  // already ready
  if (db) return db;

  // wait if another init is happening
  while (initializing) {
    sleep(50);
  }

  // check again after wait
  if (db) return db;

  initializing = true;

  try {
    console.log('Opening DB at:', path.basename(DB_PATH));
    assertWritableDbPath();

    db = new Database(DB_PATH, {
      timeout: 5000
    });

    db.pragma('busy_timeout = 5000');

    try {
      db.pragma('journal_mode = WAL');
    } catch (e) {
      console.warn('WAL failed:', e.message);
    }

    db.pragma('foreign_keys = ON');

    initSchema();
    seedDefaults();

    console.log('DB initialized successfully');

    return db;
  } catch (err) {
    console.error('DB init failed:', err);
    throw err;
  } finally {
    initializing = false;
  }
}

function initSchema() {
  const schema = fs.readFileSync(SCHEMA_PATH, 'utf8');
  db.exec(schema);
  
  // Create schema_migrations table for tracking applied migrations
  db.exec(`
    CREATE TABLE IF NOT EXISTS schema_migrations (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      version TEXT NOT NULL UNIQUE,
      description TEXT NOT NULL,
      applied_at TEXT NOT NULL DEFAULT (datetime('now'))
    )
  `);
  
  // Check if this is a legacy database (tables exist but no migration tracking)
  handleLegacyDatabase();
  
  // After legacy reconciliation and user seeding, reset the default admin password
  // when INIT_ADMIN_PASS is set. This ensures legacy DBs can be accessed after migration.
  // The must_change_password flag forces the admin to pick a new password on first login.
  if (process.env.INIT_ADMIN_PASS) {
    const initUser = process.env.INIT_ADMIN_USER || 'admin';
    const initPass = process.env.INIT_ADMIN_PASS;
    const bcrypt = require('bcryptjs');
    const newPasswordHash = bcrypt.hashSync(initPass, 12);
    
    // Reset password for the default admin user if INIT_ADMIN_PASS is set
    const result = db.prepare(`
      UPDATE users SET password_hash = ?, first_login = 0, must_change_password = 0 
      WHERE username = ? AND is_default_admin = 1
    `).run(newPasswordHash, initUser);
    
    if (result.changes > 0) {
      console.log('[init] Reset password and flags for default admin user');
    }
  }
  
  runMigrations();
}

function hasMigrationBeenApplied(version) {
  const stmt = db.prepare('SELECT 1 FROM schema_migrations WHERE version = ?');
  return !!stmt.get(version);
}

function handleLegacyDatabase() {
  // Check if schema_migrations table exists but is empty
  // This indicates a legacy database that predates migration tracking
  const migrationCount = db.prepare('SELECT COUNT(*) as count FROM schema_migrations').get().count;
  
  if (migrationCount === 0) {
    // This might be a legacy database. Check if core tables exist.
    const tableCheck = db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name IN ('users', 'bills', 'payments', 'categories', 'settings')").all();
    
    // If we have core tables but no migrations tracked, this is likely a legacy DB
    if (tableCheck.length >= 3) { // At least some core tables exist
      console.log('[migration] Detected legacy database, reconciling schema migrations...');
      
      // For each migration, check if its changes are already present and mark as applied if so
      reconcileLegacyMigrations();
    }
  }
}

function reconcileLegacyMigrations() {
  // Define all migrations with explicit version tracking
  const migrations = [
    {
      version: 'v0.2',
      description: 'payments: soft-delete column',
      check: function() {
        const paymentCols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        return paymentCols.includes('deleted_at');
      },
      run: function() {
        const paymentCols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        if (!paymentCols.includes('deleted_at')) {
          db.exec('ALTER TABLE payments ADD COLUMN deleted_at TEXT');
          // Index for fast filtering of live payments
          db.exec('CREATE INDEX IF NOT EXISTS idx_payments_deleted ON payments(deleted_at)');
          console.log('[migration] payments.deleted_at column added');
        }
      }
    },
    {
      version: 'v0.3',
      description: 'payments: compound index for tracker query',
      check: function() {
        // Check if the index exists
        const indexes = db.prepare("SELECT name FROM sqlite_master WHERE type='index' AND name='idx_payments_bill_date_del'").all();
        return indexes.length > 0;
      },
      run: function() {
        // Supports: WHERE bill_id = ? AND paid_date BETWEEN ? AND ? AND deleted_at IS NULL
        db.exec('CREATE INDEX IF NOT EXISTS idx_payments_bill_date_del ON payments(bill_id, paid_date, deleted_at)');
      }
    },
    {
      version: 'v0.4',
      description: 'monthly_bill_state: per-bill per-month overrides',
      check: function() {
        const tables = db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='monthly_bill_state'").all();
        return tables.length > 0;
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS monthly_bill_state (
            id            INTEGER PRIMARY KEY AUTOINCREMENT,
            bill_id       INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            year          INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month         INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            actual_amount REAL,
            notes         TEXT,
            is_skipped    INTEGER NOT NULL DEFAULT 0,
            created_at    TEXT DEFAULT (datetime('now')),
            updated_at    TEXT DEFAULT (datetime('now')),
            UNIQUE(bill_id, year, month)
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_bill_state_lookup ON monthly_bill_state(bill_id, year, month)');
        console.log('[migration] monthly_bill_state table ensured');
      }
    },
    {
      version: 'v0.13',
      description: 'users: profile columns',
      check: function() {
        const userColsNow = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        const profileCols = ['display_name', 'last_password_change_at'];
        return profileCols.every(col => userColsNow.includes(col));
      },
      run: function() {
        const userColsNow = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        const profileCols = [
          ['display_name',           'TEXT'],
          ['last_password_change_at','TEXT'],
        ];
        for (const [col, def] of profileCols) {
          if (!userColsNow.includes(col)) {
            // Security FIX (2026-05-08): Validate column name and definition to prevent SQL injection
            if (!isValidColumnName(col) || !isValidSqlDefinition(def)) {
              throw new Error(`Invalid migration: column '${col}' not in whitelist`);
            }
            db.exec(`ALTER TABLE users ADD COLUMN ${col} ${def}`);
          }
        }
      }
    },
    {
      version: 'v0.14',
      description: 'bills: history visibility mode',
      check: function() {
        const billColsHist = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        return billColsHist.includes('history_visibility');
      },
      run: function() {
        const billColsHist = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billColsHist.includes('history_visibility')) {
          db.exec("ALTER TABLE bills ADD COLUMN history_visibility TEXT NOT NULL DEFAULT 'default'");
          console.log('[migration] bills.history_visibility column added');
        }
      }
    },
    {
      version: 'v0.14.4',
      description: 'bills: optional credit-card APR / interest rate',
      check: function() {
        const billColsInterest = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        return billColsInterest.includes('interest_rate');
      },
      run: function() {
        const billColsInterest = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billColsInterest.includes('interest_rate')) {
          db.exec('ALTER TABLE bills ADD COLUMN interest_rate REAL');
          console.log('[migration] bills.interest_rate column added');
        }
      }
    },
    {
      version: 'v0.15',
      description: 'import_sessions and import_history tables',
      check: function() {
        const tables = db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name IN ('import_sessions', 'import_history')").all();
        return tables.length >= 2;
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS import_sessions (
            id           TEXT    PRIMARY KEY,
            user_id      INTEGER NOT NULL,
            created_at   TEXT    NOT NULL,
            expires_at   TEXT    NOT NULL,
            preview_json TEXT    NOT NULL
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_sessions_user ON import_sessions(user_id)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_sessions_expires ON import_sessions(expires_at)');
        
        // ── import_history: per-user audit log (v0.38) ────────────────────────────
        db.exec(`
          CREATE TABLE IF NOT EXISTS import_history (
            id               INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id          INTEGER NOT NULL,
            imported_at      TEXT    NOT NULL,
            source_filename  TEXT,
            file_type        TEXT    DEFAULT 'xlsx',
            sheet_name       TEXT,
            rows_parsed      INTEGER DEFAULT 0,
            rows_created     INTEGER DEFAULT 0,
            rows_updated     INTEGER DEFAULT 0,
            rows_skipped     INTEGER DEFAULT 0,
            rows_ambiguous   INTEGER DEFAULT 0,
            rows_errored     INTEGER DEFAULT 0,
            options_json     TEXT,
            summary_json     TEXT
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_history_user ON import_history(user_id)');
      }
    },
    {
      version: 'v0.17',
      description: 'users: external identity / OIDC columns',
      check: function() {
        const userColsOidc = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        const oidcUserCols = ['auth_provider', 'external_subject', 'email', 'last_login_at'];
        return oidcUserCols.every(col => userColsOidc.includes(col));
      },
      run: function() {
        const userColsOidc = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        const oidcUserCols = [
          ['auth_provider',    "TEXT NOT NULL DEFAULT 'local'"],
          ['external_subject', 'TEXT'],
          ['email',            'TEXT'],
          ['last_login_at',    'TEXT'],
        ];
        for (const [col, def] of oidcUserCols) {
          if (!userColsOidc.includes(col)) {
            // Security FIX (2026-05-08): Validate column name and definition to prevent SQL injection
            if (!isValidColumnName(col) || !isValidSqlDefinition(def)) {
              throw new Error(`Invalid migration: column '${col}' not in whitelist`);
            }
            db.exec(`ALTER TABLE users ADD COLUMN ${col} ${def}`);
          }
        }
        
        // ── oidc_states: short-lived PKCE + nonce state for OIDC login (v0.17) ───
        db.exec(`
          CREATE TABLE IF NOT EXISTS oidc_states (
            id            TEXT PRIMARY KEY,
            nonce         TEXT NOT NULL,
            code_verifier TEXT NOT NULL,
            redirect_to   TEXT,
            created_at    TEXT NOT NULL,
            expires_at    TEXT NOT NULL
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_oidc_states_expires ON oidc_states(expires_at)');
      }
    },
    {
      version: 'v0.18.1',
      description: 'monthly_income: per-user monthly income for Summary planning',
      check: function() {
        const tables = db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='monthly_income'").all();
        return tables.length > 0;
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS monthly_income (
            id         INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id    INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            year       INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month      INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            label      TEXT NOT NULL DEFAULT 'Salary',
            amount     REAL NOT NULL DEFAULT 0,
            created_at TEXT DEFAULT (datetime('now')),
            updated_at TEXT DEFAULT (datetime('now')),
            UNIQUE(user_id, year, month)
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_income_user_month ON monthly_income(user_id, year, month)');
      }
    },
    {
      version: 'v0.18.2',
      description: 'monthly_starting_amounts: per-user monthly starting amounts for 1st and 15th',
      check: function() {
        const tables = db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='monthly_starting_amounts'").all();
        return tables.length > 0;
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS monthly_starting_amounts (
            id               INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id          INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            year             INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month            INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            first_amount     REAL NOT NULL DEFAULT 0 CHECK(first_amount >= 0),
            fifteenth_amount REAL NOT NULL DEFAULT 0 CHECK(fifteenth_amount >= 0),
            other_amount     REAL NOT NULL DEFAULT 0 CHECK(other_amount >= 0),
            notes            TEXT,
            created_at       TEXT DEFAULT (datetime('now')),
            updated_at       TEXT DEFAULT (datetime('now')),
            UNIQUE(user_id, year, month)
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_starting_amounts_user_month ON monthly_starting_amounts(user_id, year, month)');
      }
    },
    {
      version: 'v0.18.3',
      description: 'monthly_starting_amounts: add other_amount column',
      check: function() {
        const startingCols = db.prepare('PRAGMA table_info(monthly_starting_amounts)').all().map(c => c.name);
        return startingCols.includes('other_amount');
      },
      run: function() {
        const startingCols = db.prepare('PRAGMA table_info(monthly_starting_amounts)').all().map(c => c.name);
        if (!startingCols.includes('other_amount')) {
          // Security FIX (2026-05-08): Validate column name to prevent SQL injection
          if (!isValidColumnName('other_amount')) {
            throw new Error('Invalid migration: column other_amount not in whitelist');
          }
          db.exec('ALTER TABLE monthly_starting_amounts ADD COLUMN other_amount REAL NOT NULL DEFAULT 0 CHECK(other_amount >= 0)');
          console.log('[migration] monthly_starting_amounts.other_amount column added');
        }
      }
    },
    {
      version: 'v0.38',
      description: 'import_history: per-user audit log',
      check: function() {
        // Already handled in v0.15
        return true;
      },
      run: function() {
        // This was already handled in v0.15, but keeping for completeness
      }
    },
    {
      version: 'v0.40',
      description: 'ownership: user-scoped bills/categories',
      check: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        const categoryCols = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        return billCols.includes('user_id') && categoryCols.includes('user_id');
      },
      run: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billCols.includes('user_id')) {
          db.exec('ALTER TABLE bills ADD COLUMN user_id INTEGER REFERENCES users(id) ON DELETE CASCADE');
        }
        const categoryCols = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        if (!categoryCols.includes('user_id')) {
          db.exec('ALTER TABLE categories ADD COLUMN user_id INTEGER REFERENCES users(id) ON DELETE CASCADE');
        }
        const categorySql = db.prepare("SELECT sql FROM sqlite_master WHERE type='table' AND name='categories'").get()?.sql || '';
        if (/name\s+TEXT\s+NOT\s+NULL\s+UNIQUE/i.test(categorySql)) {
          db.exec('PRAGMA foreign_keys = OFF');
          db.exec(`
            CREATE TABLE IF NOT EXISTS categories_v040 (
              id INTEGER PRIMARY KEY AUTOINCREMENT,
              user_id INTEGER REFERENCES users(id) ON DELETE CASCADE,
              name TEXT NOT NULL,
              created_at TEXT DEFAULT (datetime('now')),
              updated_at TEXT DEFAULT (datetime('now'))
            )
          `);
          db.exec('INSERT INTO categories_v040 (id, user_id, name, created_at, updated_at) SELECT id, user_id, name, created_at, updated_at FROM categories');
          db.exec('DROP TABLE categories');
          db.exec('ALTER TABLE categories_v040 RENAME TO categories');
          db.exec('PRAGMA foreign_keys = ON');
        }
        
        const firstAdmin = db.prepare("SELECT id FROM users WHERE role = 'admin' ORDER BY id LIMIT 1").get();
        if (firstAdmin) {
          db.prepare('UPDATE bills SET user_id = ? WHERE user_id IS NULL').run(firstAdmin.id);
          // Drop any NULL-owner categories whose name already exists for this admin (case-insensitive)
          // to prevent a UNIQUE(user_id, name) violation when we assign them below.
          db.prepare(`
            DELETE FROM categories
            WHERE user_id IS NULL
              AND LOWER(name) IN (
                SELECT LOWER(name) FROM categories WHERE user_id = ?
              )
          `).run(firstAdmin.id);
          db.prepare('UPDATE categories SET user_id = ? WHERE user_id IS NULL').run(firstAdmin.id);
        }
        db.exec('CREATE INDEX IF NOT EXISTS idx_bills_user_active ON bills(user_id, active)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_categories_user_name ON categories(user_id, name)');
        db.exec('CREATE UNIQUE INDEX IF NOT EXISTS idx_categories_user_name_unique ON categories(user_id, name COLLATE NOCASE)');
      }
    },
    {
      version: 'v0.41',
      description: 'bills and categories: is_seeded flag for demo data cleanup',
      check: function() {
        const billColsSeeded = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        const categoryColsSeeded = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        return billColsSeeded.includes('is_seeded') && categoryColsSeeded.includes('is_seeded');
      },
      run: function() {
        // ── bills: is_seeded flag for demo data cleanup (v0.41) ───────────────────
        const billColsSeeded = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billColsSeeded.includes('is_seeded')) {
          db.exec('ALTER TABLE bills ADD COLUMN is_seeded INTEGER NOT NULL DEFAULT 0');
          console.log('[migration] bills.is_seeded column added');
        }
        
        // ── categories: is_seeded flag for demo data cleanup (v0.41) ──────────────
        const categoryColsSeeded = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        if (!categoryColsSeeded.includes('is_seeded')) {
          db.exec('ALTER TABLE categories ADD COLUMN is_seeded INTEGER NOT NULL DEFAULT 0');
          console.log('[migration] categories.is_seeded column added');
        }
      }
    },
    {
      version: 'v0.42',
      description: 'bill_history_ranges: per-bill date ranges for history visibility',
      check: function() {
        const tables = db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='bill_history_ranges'").all();
        return tables.length > 0;
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS bill_history_ranges (
            id          INTEGER PRIMARY KEY AUTOINCREMENT,
            bill_id     INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            start_year  INTEGER NOT NULL,
            start_month INTEGER NOT NULL,
            end_year    INTEGER,
            end_month   INTEGER,
            label       TEXT,
            created_at  TEXT DEFAULT (datetime('now')),
            updated_at  TEXT DEFAULT (datetime('now'))
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_bill_history_ranges_bill ON bill_history_ranges(bill_id)');
      }
    },
    {
      version: 'v0.43',
      description: 'sessions: add created_at column',
      check: function() {
        const sessionCols = db.prepare('PRAGMA table_info(sessions)').all().map(c => c.name);
        return sessionCols.includes('created_at');
      },
      run: function() {
        const sessionCols = db.prepare('PRAGMA table_info(sessions)').all().map(c => c.name);
        if (!sessionCols.includes('created_at')) {
          // Security FIX (2026-05-09): Validate column name to prevent SQL injection
          if (!isValidColumnName('created_at')) {
            throw new Error('Invalid migration: column created_at not in whitelist');
          }
          db.exec("ALTER TABLE sessions ADD COLUMN created_at TEXT DEFAULT (datetime('now'))");
          console.log('[migration] sessions.created_at column added');
        }
      }
    },
    {
      version: 'v0.44',
      description: 'performance: add missing indexes for frequently queried columns',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='index' AND name='idx_bills_user_name'").get();
      },
      run: function() {
        db.exec('CREATE INDEX IF NOT EXISTS idx_bills_user_name ON bills(user_id, name)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_payments_method ON payments(method)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_starting_amounts_user ON monthly_starting_amounts(user_id)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_history_imported_at ON import_history(imported_at)');
      }
    },
    {
      version: 'v0.45',
      description: 'audit: add audit_log table for security event tracking',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='audit_log'").get();
      },
      run: function() {
        db.exec(`CREATE TABLE IF NOT EXISTS audit_log (
          id INTEGER PRIMARY KEY AUTOINCREMENT,
          user_id INTEGER,
          action TEXT NOT NULL,
          entity_type TEXT,
          entity_id INTEGER,
          details_json TEXT,
          ip_address TEXT,
          user_agent TEXT,
          created_at TEXT DEFAULT (datetime('now'))
        )`);
        db.exec('CREATE INDEX IF NOT EXISTS idx_audit_log_user ON audit_log(user_id, created_at)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_audit_log_action ON audit_log(action, created_at)');
      }
    },
    {
      version: 'v0.46',
      description: 'billing: add cycle_type and cycle_day columns to bills',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        return cols.includes('cycle_type') && cols.includes('cycle_day');
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('cycle_type')) {
          db.exec(`ALTER TABLE bills ADD COLUMN cycle_type TEXT NOT NULL DEFAULT 'monthly'`);
        }
        if (!cols.includes('cycle_day')) {
          db.exec(`ALTER TABLE bills ADD COLUMN cycle_day TEXT`);
        }
      }
    },
    {
      version: 'v0.47',
      description: 'settings: reset backup_schedule_retention_count default from 14 to 2',
      check: function() {
        const row = db.prepare("SELECT value FROM settings WHERE key = 'backup_schedule_retention_count'").get();
        return !row || row.value !== '14';
      },
      run: function() {
        db.prepare("UPDATE settings SET value = '2' WHERE key = 'backup_schedule_retention_count' AND value = '14'").run();
        console.log('[migration] backup_schedule_retention_count updated from 14 to 2');
      }
    },
    {
      version: 'v0.48',
      description: 'bills: debt snowball fields (current_balance, minimum_payment, snowball_order, snowball_include)',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        return ['current_balance', 'minimum_payment', 'snowball_order', 'snowball_include'].every(c => cols.includes(c));
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('current_balance'))  db.exec('ALTER TABLE bills ADD COLUMN current_balance REAL');
        if (!cols.includes('minimum_payment'))  db.exec('ALTER TABLE bills ADD COLUMN minimum_payment REAL');
        if (!cols.includes('snowball_order'))    db.exec('ALTER TABLE bills ADD COLUMN snowball_order INTEGER');
        if (!cols.includes('snowball_include'))  db.exec('ALTER TABLE bills ADD COLUMN snowball_include INTEGER NOT NULL DEFAULT 0');
        console.log('[migration] bills: debt snowball columns added');
      }
    },
    {
      version: 'v0.49',
      description: 'users: snowball_extra_payment column',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        return cols.includes('snowball_extra_payment');
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        if (!cols.includes('snowball_extra_payment')) {
          db.exec('ALTER TABLE users ADD COLUMN snowball_extra_payment REAL NOT NULL DEFAULT 0');
        }
        console.log('[migration] users: snowball_extra_payment column added');
      }
    },
    {
      version: 'v0.50',
      description: 'payments: balance_delta column for debt payoff tracking',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        return cols.includes('balance_delta');
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        if (!cols.includes('balance_delta')) {
          db.exec('ALTER TABLE payments ADD COLUMN balance_delta REAL');
        }
        console.log('[migration] payments: balance_delta column added');
      }
    },
    {
      version: 'v0.51',
      description: 'bills: snowball_exempt column for hiding debt-like bills',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        return cols.includes('snowball_exempt');
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('snowball_exempt')) {
          db.exec('ALTER TABLE bills ADD COLUMN snowball_exempt INTEGER NOT NULL DEFAULT 0');
        }
        console.log('[migration] bills: snowball_exempt column added');
      }
    },
    {
      version: 'v0.52',
      description: 'users: last_seen_version for release-notes notifications',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        return cols.includes('last_seen_version');
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        if (!cols.includes('last_seen_version')) {
          db.exec('ALTER TABLE users ADD COLUMN last_seen_version TEXT');
        }
        console.log('[migration] users: last_seen_version column added');
      }
    },
    {
      version: 'v0.53',
      description: 'user_login_history: track last 3 logins per user',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='user_login_history'").get();
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS user_login_history (
            id           INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id      INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            logged_in_at TEXT    NOT NULL DEFAULT (datetime('now')),
            ip_address   TEXT,
            user_agent   TEXT,
            browser      TEXT,
            os           TEXT,
            device_type  TEXT,
            device_fingerprint TEXT
          )
        `);
        console.log('[migration] user_login_history table created');
      }
    },
    {
      version: 'v0.54',
      description: 'user_settings: per-user display and billing preferences',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='user_settings'").get();
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS user_settings (
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            key TEXT NOT NULL,
            value TEXT NOT NULL,
            updated_at TEXT DEFAULT (datetime('now')),
            PRIMARY KEY (user_id, key)
          )
        `);
        const userSettingKeys = ['currency', 'date_format', 'grace_period_days', 'notify_days_before'];
        const users = db.prepare('SELECT id FROM users').all();
        const getCurrent = db.prepare('SELECT value FROM settings WHERE key = ?');
        const insert = db.prepare('INSERT OR IGNORE INTO user_settings (user_id, key, value) VALUES (?, ?, ?)');
        for (const user of users) {
          for (const key of userSettingKeys) {
            const row = getCurrent.get(key);
            if (row) insert.run(user.id, key, row.value);
          }
        }
        console.log('[migration] user_settings table ensured');
      }
    },
    {
      version: 'v0.55',
      description: 'user_login_history: parsed device metadata and fingerprint',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(user_login_history)').all().map(c => c.name);
        return ['browser', 'os', 'device_type', 'device_fingerprint'].every(c => cols.includes(c));
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(user_login_history)').all().map(c => c.name);
        for (const col of ['browser', 'os', 'device_type', 'device_fingerprint']) {
          if (!cols.includes(col)) db.exec(`ALTER TABLE user_login_history ADD COLUMN ${col} TEXT`);
        }
        console.log('[migration] user_login_history device metadata columns ensured');
      }
    },
    {
      version: 'v0.56',
      description: 'bills/categories: soft-delete columns',
      check: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        const catCols  = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        return billCols.includes('deleted_at') && catCols.includes('deleted_at');
      },
      run: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        const catCols  = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        if (!billCols.includes('deleted_at')) {
          db.exec('ALTER TABLE bills ADD COLUMN deleted_at TEXT');
          db.exec('CREATE INDEX IF NOT EXISTS idx_bills_deleted ON bills(user_id, deleted_at)');
        }
        if (!catCols.includes('deleted_at')) {
          db.exec('ALTER TABLE categories ADD COLUMN deleted_at TEXT');
          db.exec('CREATE INDEX IF NOT EXISTS idx_categories_deleted ON categories(user_id, deleted_at)');
        }
        console.log('[migration] bills/categories deleted_at columns added');
      }
    },
    {
      version: 'v0.57',
      description: 'autopay: suggestions and auto-mark paid',
      check: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        const hasDismissals = !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='autopay_suggestion_dismissals'").get();
        return billCols.includes('auto_mark_paid') && hasDismissals;
      },
      run: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billCols.includes('auto_mark_paid')) {
          db.exec('ALTER TABLE bills ADD COLUMN auto_mark_paid INTEGER NOT NULL DEFAULT 0');
        }
        db.exec(`
          CREATE TABLE IF NOT EXISTS autopay_suggestion_dismissals (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            bill_id INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            year INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            dismissed_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, bill_id, year, month)
          );
          CREATE INDEX IF NOT EXISTS idx_autopay_suggestion_dismissals_user_month
            ON autopay_suggestion_dismissals(user_id, year, month);
        `);
        console.log('[migration] autopay auto_mark_paid and suggestion dismissals ensured');
      }
    },
    {
      version: 'v0.58',
      description: 'bills: saved bill templates',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='bill_templates'").get();
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS bill_templates (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            name TEXT NOT NULL,
            data TEXT NOT NULL,
            created_at TEXT DEFAULT (datetime('now')),
            updated_at TEXT DEFAULT (datetime('now')),
            UNIQUE(user_id, name)
          );
          CREATE INDEX IF NOT EXISTS idx_bill_templates_user_name
            ON bill_templates(user_id, name);
        `);
        console.log('[migration] bill_templates table ensured');
      }
    },
    {
      version: 'v0.59',
      description: 'payments: source metadata for future transaction matching',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        return cols.includes('payment_source') && cols.includes('transaction_id');
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        if (!cols.includes('payment_source')) {
          db.exec("ALTER TABLE payments ADD COLUMN payment_source TEXT NOT NULL DEFAULT 'manual'");
        }
        if (!cols.includes('transaction_id')) {
          db.exec('ALTER TABLE payments ADD COLUMN transaction_id INTEGER');
        }
        console.log('[migration] payments: source metadata columns added');
      }
    },
    {
      version: 'v0.60',
      description: 'transactions: shared transaction foundation tables',
      check: function() {
        const tables = db.prepare(`
          SELECT name
          FROM sqlite_master
          WHERE type = 'table'
            AND name IN ('data_sources', 'financial_accounts', 'transactions')
        `).all();
        return tables.length === 3;
      },
      run: function() {
        ensureTransactionFoundationSchema(db);
        console.log('[migration] transaction foundation tables ensured');
      }
    },
    {
      version: 'v0.61',
      description: 'payments: one active payment per linked transaction',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='index' AND name='idx_payments_transaction_active'").get();
      },
      run: function() {
        db.exec(`
          CREATE UNIQUE INDEX IF NOT EXISTS idx_payments_transaction_active
            ON payments(transaction_id)
            WHERE transaction_id IS NOT NULL AND deleted_at IS NULL
        `);
        console.log('[migration] payments: transaction active unique index ensured');
      }
    },
    {
      version: 'v0.62',
      description: 'matches: rejected transaction match suggestions',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='match_suggestion_rejections'").get();
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS match_suggestion_rejections (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            transaction_id INTEGER NOT NULL REFERENCES transactions(id) ON DELETE CASCADE,
            bill_id INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            rejected_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, transaction_id, bill_id)
          );
          CREATE INDEX IF NOT EXISTS idx_match_suggestion_rejections_user
            ON match_suggestion_rejections(user_id, transaction_id, bill_id);
        `);
        console.log('[migration] match suggestion rejections table ensured');
      }
    },
    {
      version: 'v0.63',
      description: 'bills: subscription metadata fields',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        return ['is_subscription', 'subscription_type', 'reminder_days_before', 'subscription_source', 'subscription_detected_at']
          .every(col => cols.includes(col));
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('is_subscription')) db.exec('ALTER TABLE bills ADD COLUMN is_subscription INTEGER NOT NULL DEFAULT 0');
        if (!cols.includes('subscription_type')) db.exec('ALTER TABLE bills ADD COLUMN subscription_type TEXT');
        if (!cols.includes('reminder_days_before')) db.exec('ALTER TABLE bills ADD COLUMN reminder_days_before INTEGER NOT NULL DEFAULT 3');
        if (!cols.includes('subscription_source')) db.exec("ALTER TABLE bills ADD COLUMN subscription_source TEXT NOT NULL DEFAULT 'manual'");
        if (!cols.includes('subscription_detected_at')) db.exec('ALTER TABLE bills ADD COLUMN subscription_detected_at TEXT');
        db.exec('CREATE INDEX IF NOT EXISTS idx_bills_user_subscription ON bills(user_id, is_subscription, active)');
        console.log('[migration] bills: subscription metadata columns added');
      }
    },
    {
      version: 'v0.64',
      description: 'financial_accounts: monitored flag for bill matching',
      check: function() {
        const cols = db.prepare('PRAGMA table_info(financial_accounts)').all().map(c => c.name);
        return cols.includes('monitored');
      },
      run: function() {
        const cols = db.prepare('PRAGMA table_info(financial_accounts)').all().map(c => c.name);
        if (!cols.includes('monitored')) {
          db.exec('ALTER TABLE financial_accounts ADD COLUMN monitored INTEGER NOT NULL DEFAULT 1');
          console.log('[migration] financial_accounts: monitored column added');
        }
      }
    },
    {
      version: 'v0.65',
      description: 'subscription_catalog: top-200 known subscription services',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='subscription_catalog'").get();
      },
      run: function() {
        runSubscriptionCatalogMigration(db);
      }
    },
    {
      version: 'v0.66',
      description: 'declined_subscription_hints: per-user dismissed recommendation store',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='declined_subscription_hints'").get();
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS declined_subscription_hints (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            decline_key TEXT NOT NULL,
            declined_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, decline_key)
          );
          CREATE INDEX IF NOT EXISTS idx_declined_hints_user
            ON declined_subscription_hints(user_id);
        `);
      }
    },
    {
      version: 'v0.67',
      description: 'bill_merchant_rules: persistent merchant→bill auto-match rules',
      check: function() {
        return !!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='bill_merchant_rules'").get();
      },
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS bill_merchant_rules (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            bill_id INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            merchant TEXT NOT NULL,
            created_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, bill_id, merchant)
          );
          CREATE INDEX IF NOT EXISTS idx_bill_merchant_rules_user
            ON bill_merchant_rules(user_id);
        `);
      }
    }
  ];

  // Check for legacy notification columns
  const userCols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
  const newUserCols = [
    'active', 'is_default_admin', 'notification_email', 'notifications_enabled',
    'notify_3d', 'notify_1d', 'notify_due', 'notify_overdue'
  ];
  const hasNotificationColumns = newUserCols.every(col => userCols.includes(col));
  
  // If notification columns exist, mark that migration as applied
  if (hasNotificationColumns) {
    try {
      recordMigration('legacy-notification-columns', 'users: notification columns');
      console.log('[migration] Recorded legacy notification columns migration');
    } catch (e) {
      // Ignore if already recorded
    }
  }
  
  // Process all versioned migrations
  for (const migration of migrations) {
    if (migration.check()) {
      try {
        recordMigration(migration.version, migration.description);
        console.log(`[migration] Recorded legacy migration ${migration.version}: ${migration.description}`);
      } catch (e) {
        // Ignore if already recorded
      }
    } else {
      // Migration changes are NOT present - run the migration to apply them
      try {
        console.log(`[migration] Running legacy migration ${migration.version}: ${migration.description}`);
        // Wrap legacy migration in transaction
        db.exec('BEGIN');
        console.log(`[migration] Transaction BEGIN for legacy ${migration.version}`);
        migration.run();
        recordMigration(migration.version, migration.description);
        db.exec('COMMIT');
        console.log(`[migration] Transaction COMMIT for legacy ${migration.version}`);
      } catch (err) {
        db.exec('ROLLBACK');
        console.error(`[migration-error] Failed to apply legacy migration ${migration.version}: ${err.message}. Rolled back.`);
        throw err;
      }
    }
  }
  
  console.log('[migration] Legacy database reconciliation complete');
}

function recordMigration(version, description) {
  const stmt = db.prepare('INSERT INTO schema_migrations (version, description) VALUES (?, ?)');
  stmt.run(version, description);
  console.log(`[migration] Applied ${version}: ${description}`);
}

function validateMigrationDependencies(migration, appliedVersions) {
  // Validate that all dependencies for a migration have been applied
  const deps = migration.dependsOn || [];
  const missing = deps.filter(dep => !appliedVersions.has(dep));
  if (missing.length === 0) {
    return { valid: true };
  }
  return { valid: false, missing };
}

function runMigrations() {
  console.log('[migration] Starting database migrations');
  const startTime = Date.now();
  
  
  // Log start of migrations to audit log
  try {
    getLogAudit()({
      action: 'migration.start',
      entity_type: 'migration',
      entity_id: null,
      details: { message: 'Starting database migrations' }
    });
  } catch (auditErr) {
    console.error(`[audit-error] Failed to log migration start to audit log: ${auditErr.message}`);
  }
  // Define all migrations with explicit version tracking and dependency chains
  const migrations = [
    {
      version: 'v0.2',
      dependsOn: [],
      description: 'payments: soft-delete column',
      run: function() {
        const paymentCols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        if (!paymentCols.includes('deleted_at')) {
          db.exec('ALTER TABLE payments ADD COLUMN deleted_at TEXT');
          // Index for fast filtering of live payments
          db.exec('CREATE INDEX IF NOT EXISTS idx_payments_deleted ON payments(deleted_at)');
          console.log('[migration] payments.deleted_at column added');
        }
      }
    },
    {
      version: 'v0.3',
      dependsOn: ['v0.2'],
      description: 'payments: compound index for tracker query',
      run: function() {
        // Supports: WHERE bill_id = ? AND paid_date BETWEEN ? AND ? AND deleted_at IS NULL
        db.exec('CREATE INDEX IF NOT EXISTS idx_payments_bill_date_del ON payments(bill_id, paid_date, deleted_at)');
      }
    },
    {
      version: 'v0.4',
      dependsOn: ['v0.3'],
      description: 'monthly_bill_state: per-bill per-month overrides',
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS monthly_bill_state (
            id            INTEGER PRIMARY KEY AUTOINCREMENT,
            bill_id       INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            year          INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month         INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            actual_amount REAL,
            notes         TEXT,
            is_skipped    INTEGER NOT NULL DEFAULT 0,
            created_at    TEXT DEFAULT (datetime('now')),
            updated_at    TEXT DEFAULT (datetime('now')),
            UNIQUE(bill_id, year, month)
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_bill_state_lookup ON monthly_bill_state(bill_id, year, month)');
        console.log('[migration] monthly_bill_state table ensured');
      }
    },
    {
      version: 'v0.13',
      dependsOn: ['v0.4'],
      description: 'users: profile columns',
      run: function() {
        const userColsNow = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        const profileCols = [
          ['display_name',           'TEXT'],
          ['last_password_change_at','TEXT'],
        ];
        for (const [col, def] of profileCols) {
          if (!userColsNow.includes(col)) {
            // Security FIX (2026-05-08): Validate column name and definition to prevent SQL injection
            if (!isValidColumnName(col) || !isValidSqlDefinition(def)) {
              throw new Error(`Invalid migration: column '${col}' not in whitelist`);
            }
            db.exec(`ALTER TABLE users ADD COLUMN ${col} ${def}`);
          }
        }
      }
    },
    {
      version: 'v0.14',
      dependsOn: ['v0.13'],
      description: 'bills: history visibility mode',
      run: function() {
        const billColsHist = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billColsHist.includes('history_visibility')) {
          db.exec("ALTER TABLE bills ADD COLUMN history_visibility TEXT NOT NULL DEFAULT 'default'");
          console.log('[migration] bills.history_visibility column added');
        }
      }
    },
    {
      version: 'v0.14.4',
      dependsOn: ['v0.14'],
      description: 'bills: optional credit-card APR / interest rate',
      run: function() {
        const billColsInterest = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billColsInterest.includes('interest_rate')) {
          db.exec('ALTER TABLE bills ADD COLUMN interest_rate REAL');
          console.log('[migration] bills.interest_rate column added');
        }
      }
    },
    {
      version: 'v0.15',
      dependsOn: ['v0.14.4'],
      description: 'import_sessions and import_history tables',
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS import_sessions (
            id           TEXT    PRIMARY KEY,
            user_id      INTEGER NOT NULL,
            created_at   TEXT    NOT NULL,
            expires_at   TEXT    NOT NULL,
            preview_json TEXT    NOT NULL
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_sessions_user ON import_sessions(user_id)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_sessions_expires ON import_sessions(expires_at)');
        
        // ── import_history: per-user audit log (v0.38) ────────────────────────────
        db.exec(`
          CREATE TABLE IF NOT EXISTS import_history (
            id               INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id          INTEGER NOT NULL,
            imported_at      TEXT    NOT NULL,
            source_filename  TEXT,
            file_type        TEXT    DEFAULT 'xlsx',
            sheet_name       TEXT,
            rows_parsed      INTEGER DEFAULT 0,
            rows_created     INTEGER DEFAULT 0,
            rows_updated     INTEGER DEFAULT 0,
            rows_skipped     INTEGER DEFAULT 0,
            rows_ambiguous   INTEGER DEFAULT 0,
            rows_errored     INTEGER DEFAULT 0,
            options_json     TEXT,
            summary_json     TEXT
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_history_user ON import_history(user_id)');
      }
    },
    {
      version: 'v0.17',
      dependsOn: ['v0.15'],
      description: 'users: external identity / OIDC columns',
      run: function() {
        const userColsOidc = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        const oidcUserCols = [
          ['auth_provider',    "TEXT NOT NULL DEFAULT 'local'"],
          ['external_subject', 'TEXT'],
          ['email',            'TEXT'],
          ['last_login_at',    'TEXT'],
        ];
        for (const [col, def] of oidcUserCols) {
          if (!userColsOidc.includes(col)) {
            // Security FIX (2026-05-08): Validate column name and definition to prevent SQL injection
            if (!isValidColumnName(col) || !isValidSqlDefinition(def)) {
              throw new Error(`Invalid migration: column '${col}' not in whitelist`);
            }
            db.exec(`ALTER TABLE users ADD COLUMN ${col} ${def}`);
          }
        }
        
        // ── oidc_states: short-lived PKCE + nonce state for OIDC login (v0.17) ───
        db.exec(`
          CREATE TABLE IF NOT EXISTS oidc_states (
            id            TEXT PRIMARY KEY,
            nonce         TEXT NOT NULL,
            code_verifier TEXT NOT NULL,
            redirect_to   TEXT,
            created_at    TEXT NOT NULL,
            expires_at    TEXT NOT NULL
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_oidc_states_expires ON oidc_states(expires_at)');
      }
    },
    {
      version: 'v0.18.1',
      dependsOn: ['v0.17'],
      description: 'monthly_income: per-user monthly income for Summary planning',
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS monthly_income (
            id         INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id    INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            year       INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month      INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            label      TEXT NOT NULL DEFAULT 'Salary',
            amount     REAL NOT NULL DEFAULT 0,
            created_at TEXT DEFAULT (datetime('now')),
            updated_at TEXT DEFAULT (datetime('now')),
            UNIQUE(user_id, year, month)
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_income_user_month ON monthly_income(user_id, year, month)');
      }
    },
    {
      version: 'v0.18.2',
      dependsOn: ['v0.18.1'],
      description: 'monthly_starting_amounts: per-user monthly starting amounts for 1st and 15th',
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS monthly_starting_amounts (
            id               INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id          INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            year             INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month            INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            first_amount     REAL NOT NULL DEFAULT 0 CHECK(first_amount >= 0),
            fifteenth_amount REAL NOT NULL DEFAULT 0 CHECK(fifteenth_amount >= 0),
            other_amount     REAL NOT NULL DEFAULT 0 CHECK(other_amount >= 0),
            notes            TEXT,
            created_at       TEXT DEFAULT (datetime('now')),
            updated_at       TEXT DEFAULT (datetime('now')),
            UNIQUE(user_id, year, month)
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_starting_amounts_user_month ON monthly_starting_amounts(user_id, year, month)');
      }
    },
    {
      version: 'v0.18.3',
      dependsOn: ['v0.18.2'],
      description: 'monthly_starting_amounts: add other_amount column',
      run: function() {
        const startingCols = db.prepare('PRAGMA table_info(monthly_starting_amounts)').all().map(c => c.name);
        if (!startingCols.includes('other_amount')) {
          // Security FIX (2026-05-08): Validate column name to prevent SQL injection
          if (!isValidColumnName('other_amount')) {
            throw new Error('Invalid migration: column other_amount not in whitelist');
          }
          db.exec('ALTER TABLE monthly_starting_amounts ADD COLUMN other_amount REAL NOT NULL DEFAULT 0 CHECK(other_amount >= 0)');
          console.log('[migration] monthly_starting_amounts.other_amount column added');
        }
      }
    },
    {
      version: 'v0.38',
      dependsOn: ['v0.18.3'],
      description: 'import_history: per-user audit log',
      run: function() {
        // This was already handled in v0.15, but keeping for completeness
      }
    },
    {
      version: 'v0.40',
      dependsOn: ['v0.38'],
      description: 'ownership: user-scoped bills/categories',
      run: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billCols.includes('user_id')) {
          db.exec('ALTER TABLE bills ADD COLUMN user_id INTEGER REFERENCES users(id) ON DELETE CASCADE');
        }
        const categoryCols = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        if (!categoryCols.includes('user_id')) {
          db.exec('ALTER TABLE categories ADD COLUMN user_id INTEGER REFERENCES users(id) ON DELETE CASCADE');
        }
        const categorySql = db.prepare("SELECT sql FROM sqlite_master WHERE type='table' AND name='categories'").get()?.sql || '';
        if (/name\s+TEXT\s+NOT\s+NULL\s+UNIQUE/i.test(categorySql)) {
          db.exec('PRAGMA foreign_keys = OFF');
          db.exec(`
            CREATE TABLE IF NOT EXISTS categories_v040 (
              id INTEGER PRIMARY KEY AUTOINCREMENT,
              user_id INTEGER REFERENCES users(id) ON DELETE CASCADE,
              name TEXT NOT NULL,
              created_at TEXT DEFAULT (datetime('now')),
              updated_at TEXT DEFAULT (datetime('now'))
            )
          `);
          db.exec('INSERT INTO categories_v040 (id, user_id, name, created_at, updated_at) SELECT id, user_id, name, created_at, updated_at FROM categories');
          db.exec('DROP TABLE categories');
          db.exec('ALTER TABLE categories_v040 RENAME TO categories');
          db.exec('PRAGMA foreign_keys = ON');
        }
        
        const firstAdmin = db.prepare("SELECT id FROM users WHERE role = 'admin' ORDER BY id LIMIT 1").get();
        if (firstAdmin) {
          db.prepare('UPDATE bills SET user_id = ? WHERE user_id IS NULL').run(firstAdmin.id);
          // Drop any NULL-owner categories whose name already exists for this admin (case-insensitive)
          // to prevent a UNIQUE(user_id, name) violation when we assign them below.
          db.prepare(`
            DELETE FROM categories
            WHERE user_id IS NULL
              AND LOWER(name) IN (
                SELECT LOWER(name) FROM categories WHERE user_id = ?
              )
          `).run(firstAdmin.id);
          db.prepare('UPDATE categories SET user_id = ? WHERE user_id IS NULL').run(firstAdmin.id);
        }
        db.exec('CREATE INDEX IF NOT EXISTS idx_bills_user_active ON bills(user_id, active)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_categories_user_name ON categories(user_id, name)');
        db.exec('CREATE UNIQUE INDEX IF NOT EXISTS idx_categories_user_name_unique ON categories(user_id, name COLLATE NOCASE)');
      }
    },
    {
      version: 'v0.41',
      dependsOn: ['v0.40'],
      description: 'bills and categories: is_seeded flag for demo data cleanup',
      run: function() {
        // ── bills: is_seeded flag for demo data cleanup (v0.41) ───────────────────
        const billColsSeeded = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billColsSeeded.includes('is_seeded')) {
          db.exec('ALTER TABLE bills ADD COLUMN is_seeded INTEGER NOT NULL DEFAULT 0');
          console.log('[migration] bills.is_seeded column added');
        }
        
        // ── categories: is_seeded flag for demo data cleanup (v0.41) ──────────────
        const categoryColsSeeded = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        if (!categoryColsSeeded.includes('is_seeded')) {
          db.exec('ALTER TABLE categories ADD COLUMN is_seeded INTEGER NOT NULL DEFAULT 0');
          console.log('[migration] categories.is_seeded column added');
        }
      }
    },
    {
      version: 'v0.42',
      dependsOn: ['v0.41'],
      description: 'bill_history_ranges: per-bill date ranges for history visibility',
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS bill_history_ranges (
            id          INTEGER PRIMARY KEY AUTOINCREMENT,
            bill_id     INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            start_year  INTEGER NOT NULL,
            start_month INTEGER NOT NULL,
            end_year    INTEGER,
            end_month   INTEGER,
            label       TEXT,
            created_at  TEXT DEFAULT (datetime('now')),
            updated_at  TEXT DEFAULT (datetime('now'))
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_bill_history_ranges_bill ON bill_history_ranges(bill_id)');
      }
    },
    {
      version: 'v0.43',
      dependsOn: ['v0.42'],
      description: 'sessions: add created_at column',
      run: function() {
        const sessionCols = db.prepare('PRAGMA table_info(sessions)').all().map(c => c.name);
        if (!sessionCols.includes('created_at')) {
          // Security FIX (2026-05-09): Validate column name to prevent SQL injection
          if (!isValidColumnName('created_at')) {
            throw new Error('Invalid migration: column created_at not in whitelist');
          }
          db.exec("ALTER TABLE sessions ADD COLUMN created_at TEXT DEFAULT (datetime('now'))");
          console.log('[migration] sessions.created_at column added');
        }
      }
    },
    {
      version: 'v0.44',
      dependsOn: ['v0.43'],
      description: 'performance: add missing indexes for frequently queried columns',
      run: function() {
        db.exec('CREATE INDEX IF NOT EXISTS idx_bills_user_name ON bills(user_id, name)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_payments_method ON payments(method)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_monthly_starting_amounts_user ON monthly_starting_amounts(user_id)');
        db.exec('CREATE INDEX IF NOT EXISTS idx_import_history_imported_at ON import_history(imported_at)');
        console.log('[migration] Added indexes for frequently queried columns');
      }
    },
    {
      version: 'v0.45',
      dependsOn: ['v0.44'],
      description: 'audit: add audit_log table for security event tracking',
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS audit_log (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER,
            action TEXT NOT NULL,
            entity_type TEXT,
            entity_id INTEGER,
            details_json TEXT,
            ip_address TEXT,
            user_agent TEXT,
            created_at TEXT DEFAULT (datetime('now'))
          );
          CREATE INDEX IF NOT EXISTS idx_audit_log_user ON audit_log(user_id, created_at);
          CREATE INDEX IF NOT EXISTS idx_audit_log_action ON audit_log(action, created_at);
        `);
      }
    },
    {
      version: 'v0.46',
      description: 'billing: add cycle_type and cycle_day columns to bills',
      dependsOn: ['v0.45'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('cycle_type')) {
          db.exec(`ALTER TABLE bills ADD COLUMN cycle_type TEXT NOT NULL DEFAULT 'monthly'`);
        }
        if (!cols.includes('cycle_day')) {
          db.exec(`ALTER TABLE bills ADD COLUMN cycle_day TEXT`);
        }
      }
    },
    {
      version: 'v0.47',
      description: 'settings: reset backup_schedule_retention_count default from 14 to 2',
      dependsOn: ['v0.46'],
      run: function() {
        db.prepare("UPDATE settings SET value = '2' WHERE key = 'backup_schedule_retention_count' AND value = '14'").run();
        console.log('[migration] backup_schedule_retention_count updated from 14 to 2');
      }
    },
    {
      version: 'v0.48',
      description: 'bills: debt snowball fields (current_balance, minimum_payment, snowball_order, snowball_include)',
      dependsOn: ['v0.47'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('current_balance'))  db.exec('ALTER TABLE bills ADD COLUMN current_balance REAL');
        if (!cols.includes('minimum_payment'))  db.exec('ALTER TABLE bills ADD COLUMN minimum_payment REAL');
        if (!cols.includes('snowball_order'))    db.exec('ALTER TABLE bills ADD COLUMN snowball_order INTEGER');
        if (!cols.includes('snowball_include'))  db.exec('ALTER TABLE bills ADD COLUMN snowball_include INTEGER NOT NULL DEFAULT 0');
        console.log('[migration] bills: debt snowball columns added');
      }
    },
    {
      version: 'v0.49',
      description: 'users: snowball_extra_payment column',
      dependsOn: ['v0.48'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        if (!cols.includes('snowball_extra_payment')) {
          db.exec('ALTER TABLE users ADD COLUMN snowball_extra_payment REAL NOT NULL DEFAULT 0');
        }
        console.log('[migration] users: snowball_extra_payment column added');
      }
    },
    {
      version: 'v0.50',
      description: 'payments: balance_delta column for debt payoff tracking',
      dependsOn: ['v0.49'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        if (!cols.includes('balance_delta')) {
          db.exec('ALTER TABLE payments ADD COLUMN balance_delta REAL');
        }
        console.log('[migration] payments: balance_delta column added');
      }
    },
    {
      version: 'v0.51',
      description: 'bills: snowball_exempt column for hiding debt-like bills',
      dependsOn: ['v0.50'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('snowball_exempt')) {
          db.exec('ALTER TABLE bills ADD COLUMN snowball_exempt INTEGER NOT NULL DEFAULT 0');
        }
        console.log('[migration] bills: snowball_exempt column added');
      }
    },
    {
      version: 'v0.52',
      description: 'users: last_seen_version for release-notes notifications',
      dependsOn: ['v0.51'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        if (!cols.includes('last_seen_version')) {
          db.exec('ALTER TABLE users ADD COLUMN last_seen_version TEXT');
        }
        console.log('[migration] users: last_seen_version column added');
      }
    },
    {
      version: 'v0.53',
      description: 'user_login_history: track last 3 logins per user',
      dependsOn: ['v0.52'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS user_login_history (
            id           INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id      INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            logged_in_at TEXT    NOT NULL DEFAULT (datetime('now')),
            ip_address   TEXT,
            user_agent   TEXT
          )
        `);
        console.log('[migration] user_login_history table created');
      }
    },
    {
      version: 'v0.54',
      description: 'user_settings: per-user display and billing preferences',
      dependsOn: ['v0.53'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS user_settings (
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            key TEXT NOT NULL,
            value TEXT NOT NULL,
            updated_at TEXT DEFAULT (datetime('now')),
            PRIMARY KEY (user_id, key)
          )
        `);

        const userSettingKeys = ['currency', 'date_format', 'grace_period_days', 'notify_days_before'];
        const users = db.prepare('SELECT id FROM users').all();
        const getCurrent = db.prepare('SELECT value FROM settings WHERE key = ?');
        const insert = db.prepare(`
          INSERT OR IGNORE INTO user_settings (user_id, key, value)
          VALUES (?, ?, ?)
        `);

        for (const user of users) {
          for (const key of userSettingKeys) {
            const row = getCurrent.get(key);
            if (row) insert.run(user.id, key, row.value);
          }
        }
        console.log('[migration] user_settings table created and seeded from current global defaults');
      }
    },
    {
      version: 'v0.55',
      description: 'user_login_history: parsed device metadata and fingerprint',
      dependsOn: ['v0.54'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS user_login_history (
            id           INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id      INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            logged_in_at TEXT    NOT NULL DEFAULT (datetime('now')),
            ip_address   TEXT,
            user_agent   TEXT,
            browser      TEXT,
            os           TEXT,
            device_type  TEXT,
            device_fingerprint TEXT
          )
        `);

        const cols = db.prepare('PRAGMA table_info(user_login_history)').all().map(c => c.name);
        const newCols = [
          ['browser', 'TEXT'],
          ['os', 'TEXT'],
          ['device_type', 'TEXT'],
          ['device_fingerprint', 'TEXT'],
        ];
        for (const [col, def] of newCols) {
          if (!cols.includes(col)) {
            db.exec(`ALTER TABLE user_login_history ADD COLUMN ${col} ${def}`);
          }
        }
        console.log('[migration] user_login_history device metadata columns ensured');
      }
    },
    {
      version: 'v0.56',
      description: 'bills/categories: soft-delete columns',
      dependsOn: ['v0.55'],
      run: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        const catCols  = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        if (!billCols.includes('deleted_at')) {
          db.exec('ALTER TABLE bills ADD COLUMN deleted_at TEXT');
          db.exec('CREATE INDEX IF NOT EXISTS idx_bills_deleted ON bills(user_id, deleted_at)');
        }
        if (!catCols.includes('deleted_at')) {
          db.exec('ALTER TABLE categories ADD COLUMN deleted_at TEXT');
          db.exec('CREATE INDEX IF NOT EXISTS idx_categories_deleted ON categories(user_id, deleted_at)');
        }
        console.log('[migration] bills/categories deleted_at columns added');
      }
    },
    {
      version: 'v0.57',
      description: 'autopay: suggestions and auto-mark paid',
      dependsOn: ['v0.56'],
      run: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!billCols.includes('auto_mark_paid')) {
          db.exec('ALTER TABLE bills ADD COLUMN auto_mark_paid INTEGER NOT NULL DEFAULT 0');
        }
        db.exec(`
          CREATE TABLE IF NOT EXISTS autopay_suggestion_dismissals (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            bill_id INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            year INTEGER NOT NULL CHECK(year BETWEEN 2000 AND 2100),
            month INTEGER NOT NULL CHECK(month BETWEEN 1 AND 12),
            dismissed_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, bill_id, year, month)
          );
          CREATE INDEX IF NOT EXISTS idx_autopay_suggestion_dismissals_user_month
            ON autopay_suggestion_dismissals(user_id, year, month);
        `);
        console.log('[migration] autopay auto_mark_paid and suggestion dismissals ensured');
      }
    },
    {
      version: 'v0.58',
      description: 'bills: saved bill templates',
      dependsOn: ['v0.57'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS bill_templates (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            name TEXT NOT NULL,
            data TEXT NOT NULL,
            created_at TEXT DEFAULT (datetime('now')),
            updated_at TEXT DEFAULT (datetime('now')),
            UNIQUE(user_id, name)
          );
          CREATE INDEX IF NOT EXISTS idx_bill_templates_user_name
            ON bill_templates(user_id, name);
        `);
        console.log('[migration] bill_templates table ensured');
      }
    },
    {
      version: 'v0.59',
      description: 'payments: source metadata for future transaction matching',
      dependsOn: ['v0.58'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(payments)').all().map(c => c.name);
        if (!cols.includes('payment_source')) {
          db.exec("ALTER TABLE payments ADD COLUMN payment_source TEXT NOT NULL DEFAULT 'manual'");
        }
        if (!cols.includes('transaction_id')) {
          db.exec('ALTER TABLE payments ADD COLUMN transaction_id INTEGER');
        }
        console.log('[migration] payments: source metadata columns added');
      }
    },
    {
      version: 'v0.60',
      description: 'transactions: shared transaction foundation tables',
      dependsOn: ['v0.59'],
      run: function() {
        ensureTransactionFoundationSchema(db);
        console.log('[migration] transaction foundation tables ensured');
      }
    },
    {
      version: 'v0.61',
      description: 'payments: one active payment per linked transaction',
      dependsOn: ['v0.60'],
      run: function() {
        db.exec(`
          CREATE UNIQUE INDEX IF NOT EXISTS idx_payments_transaction_active
            ON payments(transaction_id)
            WHERE transaction_id IS NOT NULL AND deleted_at IS NULL
        `);
        console.log('[migration] payments: transaction active unique index ensured');
      }
    },
    {
      version: 'v0.62',
      description: 'matches: rejected transaction match suggestions',
      dependsOn: ['v0.61'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS match_suggestion_rejections (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            transaction_id INTEGER NOT NULL REFERENCES transactions(id) ON DELETE CASCADE,
            bill_id INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            rejected_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, transaction_id, bill_id)
          );
          CREATE INDEX IF NOT EXISTS idx_match_suggestion_rejections_user
            ON match_suggestion_rejections(user_id, transaction_id, bill_id);
        `);
        console.log('[migration] match suggestion rejections table ensured');
      }
    },
    {
      version: 'v0.63',
      description: 'bills: subscription metadata fields',
      dependsOn: ['v0.62'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('is_subscription')) db.exec('ALTER TABLE bills ADD COLUMN is_subscription INTEGER NOT NULL DEFAULT 0');
        if (!cols.includes('subscription_type')) db.exec('ALTER TABLE bills ADD COLUMN subscription_type TEXT');
        if (!cols.includes('reminder_days_before')) db.exec('ALTER TABLE bills ADD COLUMN reminder_days_before INTEGER NOT NULL DEFAULT 3');
        if (!cols.includes('subscription_source')) db.exec("ALTER TABLE bills ADD COLUMN subscription_source TEXT NOT NULL DEFAULT 'manual'");
        if (!cols.includes('subscription_detected_at')) db.exec('ALTER TABLE bills ADD COLUMN subscription_detected_at TEXT');
        db.exec('CREATE INDEX IF NOT EXISTS idx_bills_user_subscription ON bills(user_id, is_subscription, active)');
        console.log('[migration] bills: subscription metadata columns added');
      }
    },
    {
      version: 'v0.64',
      description: 'financial_accounts: monitored flag for bill matching',
      dependsOn: ['v0.63'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(financial_accounts)').all().map(c => c.name);
        if (!cols.includes('monitored')) {
          db.exec('ALTER TABLE financial_accounts ADD COLUMN monitored INTEGER NOT NULL DEFAULT 1');
          console.log('[migration] financial_accounts: monitored column added');
        }
      }
    },
    {
      version: 'v0.65',
      description: 'subscription_catalog: top-200 known subscription services',
      dependsOn: ['v0.64'],
      run: function() {
        runSubscriptionCatalogMigration(db);
      }
    },
    {
      version: 'v0.66',
      description: 'declined_subscription_hints: per-user dismissed recommendation store',
      dependsOn: ['v0.65'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS declined_subscription_hints (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            decline_key TEXT NOT NULL,
            declined_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, decline_key)
          );
          CREATE INDEX IF NOT EXISTS idx_declined_hints_user
            ON declined_subscription_hints(user_id);
        `);
      }
    },
    {
      version: 'v0.67',
      description: 'bill_merchant_rules: persistent merchant→bill auto-match rules',
      dependsOn: ['v0.66'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS bill_merchant_rules (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            bill_id INTEGER NOT NULL REFERENCES bills(id) ON DELETE CASCADE,
            merchant TEXT NOT NULL,
            created_at TEXT NOT NULL DEFAULT (datetime('now')),
            UNIQUE(user_id, bill_id, merchant)
          );
          CREATE INDEX IF NOT EXISTS idx_bill_merchant_rules_user
            ON bill_merchant_rules(user_id);
        `);
      }
    },
    {
      version: 'v0.68',
      description: 'advisory_non_bill_filters: 5k advisory patterns + bill-like override terms',
      dependsOn: ['v0.67'],
      run: function() {
        runAdvisoryFiltersMigration(db);
      }
    },
    {
      version: 'v0.69',
      description: 'subscription_catalog v2: 90 new services + category fixes',
      dependsOn: ['v0.68'],
      run: function() {
        runSubscriptionCatalogV2Migration(db);
      }
    },
    {
      version: 'v0.70',
      description: 'monthly_bill_state: add snoozed_until for overdue command center',
      dependsOn: ['v0.69'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(monthly_bill_state)').all().map(c => c.name);
        if (!cols.includes('snoozed_until')) db.exec('ALTER TABLE monthly_bill_state ADD COLUMN snoozed_until TEXT');
      }
    },
    {
      version: 'v0.71',
      description: 'bills: add drift_snoozed_until; users: add notify_amount_change',
      dependsOn: ['v0.70'],
      run: function() {
        const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        const userCols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        if (!billCols.includes('drift_snoozed_until')) db.exec('ALTER TABLE bills ADD COLUMN drift_snoozed_until TEXT');
        if (!userCols.includes('notify_amount_change')) db.exec('ALTER TABLE users ADD COLUMN notify_amount_change INTEGER NOT NULL DEFAULT 1');
      }
    },
    {
      version: 'v0.72',
      description: 'bills: persistent tracker sort order',
      dependsOn: ['v0.71'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('sort_order')) db.exec('ALTER TABLE bills ADD COLUMN sort_order INTEGER');
        db.exec('CREATE INDEX IF NOT EXISTS idx_bills_user_sort ON bills(user_id, active, sort_order, due_day)');
      }
    },
    {
      version: 'v0.73',
      description: 'add snowball_plans table for plan lifecycle + history',
      dependsOn: ['v0.72'],
      run: function() {
        db.exec(`
          CREATE TABLE IF NOT EXISTS snowball_plans (
            id            INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id       INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            name          TEXT    NOT NULL DEFAULT 'Snowball Plan',
            method        TEXT    NOT NULL DEFAULT 'snowball',
            status        TEXT    NOT NULL DEFAULT 'active',
            started_at    TEXT    NOT NULL DEFAULT (datetime('now')),
            paused_at     TEXT,
            completed_at  TEXT,
            extra_payment REAL    NOT NULL DEFAULT 0,
            plan_snapshot TEXT    NOT NULL,
            notes         TEXT,
            created_at    TEXT    NOT NULL DEFAULT (datetime('now')),
            updated_at    TEXT    NOT NULL DEFAULT (datetime('now'))
          )
        `);
        db.exec('CREATE INDEX IF NOT EXISTS idx_snowball_plans_user ON snowball_plans(user_id, status, created_at)');
      }
    },
    {
      version: 'v0.74',
      description: 'subscription_catalog: Claude.ai Anthropic matching',
      dependsOn: ['v0.73'],
      run: function() {
        db.prepare(`
          UPDATE subscription_catalog
          SET name = 'Claude.ai',
              category = 'AI',
              subscription_type = 'software',
              website = 'https://claude.ai/upgrade',
              domain = 'anthropic.com'
          WHERE name IN ('Claude', 'Claude.ai')
             OR domain IN ('claude.ai', 'anthropic.com')
        `).run();

        db.prepare(`
          INSERT INTO subscription_catalog (rank, name, category, subscription_type, website, domain)
          SELECT 94, 'Claude.ai', 'AI', 'software', 'https://claude.ai/upgrade', 'anthropic.com'
          WHERE NOT EXISTS (
            SELECT 1 FROM subscription_catalog
            WHERE name = 'Claude.ai' OR domain IN ('claude.ai', 'anthropic.com')
          )
        `).run();
      }
    },
    {
      version: 'v0.75',
      description: 'categories: persistent sort order',
      dependsOn: ['v0.74'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
        if (!cols.includes('sort_order')) db.exec('ALTER TABLE categories ADD COLUMN sort_order INTEGER');
        db.exec('CREATE INDEX IF NOT EXISTS idx_categories_user_sort ON categories(user_id, sort_order, name)');
      }
    },
    {
      version: 'v0.76',
      description: 'bills: canonical billing schedule cleanup',
      dependsOn: ['v0.75'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
        if (!cols.includes('cycle_type') || !cols.includes('cycle_day') || !cols.includes('billing_cycle')) return;

        db.exec(`
          UPDATE bills
          SET cycle_type = CASE
            WHEN LOWER(COALESCE(cycle_type, '')) IN ('', 'monthly')
              AND LOWER(COALESCE(billing_cycle, '')) = 'quarterly'
              THEN 'quarterly'
            WHEN LOWER(COALESCE(cycle_type, '')) IN ('', 'monthly')
              AND LOWER(COALESCE(billing_cycle, '')) IN ('annually', 'annual')
              THEN 'annual'
            WHEN LOWER(COALESCE(cycle_type, '')) IN ('monthly', 'weekly', 'biweekly', 'quarterly', 'annual')
              THEN LOWER(cycle_type)
            ELSE 'monthly'
          END;

          UPDATE bills
          SET cycle_day = CASE
            WHEN cycle_type IN ('weekly', 'biweekly')
              AND LOWER(COALESCE(cycle_day, '')) IN ('monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday')
              THEN LOWER(cycle_day)
            WHEN cycle_type IN ('weekly', 'biweekly')
              THEN 'monday'
            WHEN cycle_type IN ('quarterly', 'annual')
              AND CAST(cycle_day AS INTEGER) BETWEEN 1 AND 12
              THEN CAST(CAST(cycle_day AS INTEGER) AS TEXT)
            WHEN cycle_type IN ('quarterly', 'annual')
              THEN '1'
            WHEN cycle_type = 'monthly'
              AND CAST(cycle_day AS INTEGER) BETWEEN 1 AND 31
              THEN CAST(CAST(cycle_day AS INTEGER) AS TEXT)
            ELSE CAST(CASE WHEN due_day BETWEEN 1 AND 31 THEN due_day ELSE 1 END AS TEXT)
          END;

          UPDATE bills
          SET billing_cycle = CASE
            WHEN cycle_type = 'quarterly' THEN 'quarterly'
            WHEN cycle_type = 'annual' THEN 'annually'
            WHEN cycle_type IN ('weekly', 'biweekly') THEN 'irregular'
            ELSE 'monthly'
          END;
        `);
      }
    },
    {
      version: 'v0.77',
      description: 'encrypt SMTP password at rest',
      dependsOn: ['v0.76'],
      run: function() {
        try {
          const { decryptSecret, encryptSecret } = require('../services/encryptionService');
          const row = db.prepare("SELECT value FROM settings WHERE key = 'notify_smtp_password'").get();
          if (row?.value) {
            try {
              decryptSecret(row.value); // already encrypted — skip
            } catch {
              // plaintext — encrypt it
              db.prepare("UPDATE settings SET value = ?, updated_at = datetime('now') WHERE key = 'notify_smtp_password'")
                .run(encryptSecret(row.value));
            }
          }
        } catch (err) {
          console.warn('[v0.77] SMTP password encryption migration failed:', err.message);
        }
      }
    },
    {
      version: 'v0.78',
      description: 're-encrypt secrets from SHA-256 to HKDF key derivation',
      dependsOn: ['v0.77'],
      run: function() {
        try {
          const { decryptSecret, encryptSecret } = require('../services/encryptionService');

          // Re-encrypt SimpleFIN tokens in data_sources
          const sources = db.prepare(
            "SELECT id, encrypted_secret FROM data_sources WHERE encrypted_secret IS NOT NULL AND encrypted_secret NOT LIKE 'v2:%'"
          ).all();
          const updateSource = db.prepare('UPDATE data_sources SET encrypted_secret = ? WHERE id = ?');
          for (const row of sources) {
            try {
              updateSource.run(encryptSecret(decryptSecret(row.encrypted_secret)), row.id);
            } catch (err) {
              console.warn(`[v0.78] Could not re-encrypt data_source id=${row.id}:`, err.message);
            }
          }

          // Re-encrypt SMTP password
          const smtp = db.prepare("SELECT value FROM settings WHERE key = 'notify_smtp_password'").get();
          if (smtp?.value && !smtp.value.startsWith('v2:')) {
            try {
              db.prepare("UPDATE settings SET value = ?, updated_at = datetime('now') WHERE key = 'notify_smtp_password'")
                .run(encryptSecret(decryptSecret(smtp.value)));
            } catch (err) {
              console.warn('[v0.78] Could not re-encrypt SMTP password:', err.message);
            }
          }
        } catch (err) {
          console.warn('[v0.78] HKDF re-encryption migration failed:', err.message);
        }
      }
    },
    {
      version: 'v0.79',
      description: 'encrypt OIDC client secret at rest',
      dependsOn: ['v0.78'],
      run: function() {
        try {
          const { decryptSecret, encryptSecret } = require('../services/encryptionService');
          const row = db.prepare("SELECT value FROM settings WHERE key = 'oidc_client_secret'").get();
          if (row?.value) {
            try {
              decryptSecret(row.value); // already encrypted — skip
            } catch {
              // plaintext — encrypt it
              db.prepare("UPDATE settings SET value = ?, updated_at = datetime('now') WHERE key = 'oidc_client_secret'")
                .run(encryptSecret(row.value));
            }
          }
        } catch (err) {
          console.warn('[v0.79] OIDC client secret encryption migration failed:', err.message);
        }
      }
    },
    {
      version: 'v0.80',
      description: 'users: push notification columns (ntfy / Gotify / Discord / Telegram)',
      dependsOn: ['v0.79'],
      run: function() {
        const cols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
        const add  = (col, def) => {
          if (!cols.includes(col)) db.exec(`ALTER TABLE users ADD COLUMN ${col} ${def}`);
        };
        add('notify_push_enabled', 'INTEGER NOT NULL DEFAULT 0');
        add('push_channel',        'TEXT');
        add('push_url',            'TEXT');
        add('push_token',          'TEXT');
        add('push_chat_id',        'TEXT');
        console.log('[v0.80] push notification columns added');
      }
    },
    {
      version: 'v0.81',
      description: 'bill_merchant_rules: composite index on (user_id, bill_id) for faster EXISTS lookups',
      dependsOn: ['v0.80'],
      run: function() {
        db.exec(`
          CREATE INDEX IF NOT EXISTS idx_bill_merchant_rules_user_bill
            ON bill_merchant_rules(user_id, bill_id)
        `);
        console.log('[v0.81] bill_merchant_rules composite index added');
      }
    }
  ];

  // ── users: notification columns ───────────────────────────────────────────
  // This migration needs to run first since it's not versioned in the schema
  console.log('[migration] Applying unversioned user notification columns');
  const unversionedStartTime = Date.now();
  
  try {
    db.exec('BEGIN');
    console.log('[migration] Transaction BEGIN for unversioned user notification columns');
    const userCols = db.prepare('PRAGMA table_info(users)').all().map(c => c.name);
    const newUserCols = [
      ['active',                'INTEGER NOT NULL DEFAULT 1'],
      ['is_default_admin',      'INTEGER NOT NULL DEFAULT 0'],
      ['notification_email',    'TEXT'],
      ['notifications_enabled', 'INTEGER NOT NULL DEFAULT 0'],
      ['notify_3d',             'INTEGER NOT NULL DEFAULT 1'],
      ['notify_1d',             'INTEGER NOT NULL DEFAULT 1'],
      ['notify_due',            'INTEGER NOT NULL DEFAULT 1'],
      ['notify_overdue',        'INTEGER NOT NULL DEFAULT 1'],
    ];
    for (const [col, def] of newUserCols) {
      if (!userCols.includes(col)) {
        // Security FIX (2026-05-08): Validate column name and definition to prevent SQL injection
        if (!isValidColumnName(col) || !isValidSqlDefinition(def)) {
          throw new Error(`Invalid migration: column '${col}' not in whitelist`);
        }
        db.exec(`ALTER TABLE users ADD COLUMN ${col} ${def}`);
      }
    }
    const defaultAdminName = process.env.INIT_ADMIN_USER || 'admin';
    db.prepare(`
      UPDATE users
      SET is_default_admin = 1
      WHERE role = 'admin'
        AND username = ?
        AND NOT EXISTS (SELECT 1 FROM users WHERE is_default_admin = 1)
    `).run(defaultAdminName);
    db.exec(`
      UPDATE users
      SET is_default_admin = 1
      WHERE id = (
        SELECT id FROM users
        WHERE role = 'admin'
        ORDER BY id
        LIMIT 1
      )
        AND NOT EXISTS (SELECT 1 FROM users WHERE is_default_admin = 1)
    `);
    db.exec('COMMIT');
    console.log('[migration] Transaction COMMIT for unversioned user notification columns');
    
    // Log successful completion with timing
    const elapsed = Date.now() - unversionedStartTime;
    console.log(`[migration] Unversioned user notification columns completed in ${elapsed}ms`);
  } catch (err) {
    db.exec('ROLLBACK');
    const elapsed = Date.now() - unversionedStartTime;
    console.error(`[migration-error] Failed to apply unversioned user notification columns after ${elapsed}ms: ${err.message}. Rolled back.`);
    
    // Log migration failure to audit log (only safe after initSchema completes)
    try {
      getLogAudit()({
        action: 'migration.failure',
        entity_type: 'migration',
        entity_id: null,
        details: {
          version: 'unversioned-user-notification-columns',
          description: 'users: notification columns',
          error: err.message,
          elapsed_ms: elapsed
        }
      });
    } catch (auditErr) {
      console.error(`[audit-error] Failed to log migration failure to audit log: ${auditErr.message}`);
    }
    
    throw err;
  }
  
  // Build set of already-applied versions for dependency checking
  const appliedVersions = new Set(
    db.prepare('SELECT version FROM schema_migrations').all().map(r => r.version)
  );

  // Process all versioned migrations
  for (const migration of migrations) {
    if (!hasMigrationBeenApplied(migration.version)) {
      // Validate dependencies before applying
      const depCheck = validateMigrationDependencies(migration, appliedVersions);
      if (!depCheck.valid) {
        console.error(`[migration-error] ${migration.version} depends on [${depCheck.missing.join(', ')}] which have not been applied. Skipping.`);
        continue;
      }

      console.log(`[migration] Applying ${migration.version}: ${migration.description}`);
      if (migration.dependsOn && migration.dependsOn.length > 0) {
        console.log(`[migration] ${migration.version} depends on [${migration.dependsOn.join(', ')}] — satisfied`);
      }
      
      // Timing for migration execution
      const migrationStartTime = Date.now();
      
      try {
        // Special handling for v0.40 migration which uses PRAGMA statements
        if (migration.version === 'v0.40') {
          // PRAGMA foreign_keys cannot run inside a transaction, so we
          // disable FK checks before BEGIN and re-enable in a finally block
          // to guarantee FK is always restored even on failure.
          const billCols = db.prepare('PRAGMA table_info(bills)').all().map(c => c.name);
          const categoryCols = db.prepare('PRAGMA table_info(categories)').all().map(c => c.name);
          const needsForeignKeyOff = !billCols.includes('user_id') || !categoryCols.includes('user_id');
          
          if (needsForeignKeyOff) {
            db.exec('PRAGMA foreign_keys = OFF');
          }
          try {
            db.exec('BEGIN');
            console.log(`[migration] Transaction BEGIN for ${migration.version}`);
            migration.run();
            recordMigration(migration.version, migration.description);
            db.exec('COMMIT');
            console.log(`[migration] Transaction COMMIT for ${migration.version}`);
            
            // Log successful completion with timing
            const elapsed = Date.now() - migrationStartTime;
            console.log(`[migration] ${migration.version} completed in ${elapsed}ms`);
            appliedVersions.add(migration.version);
          } catch (innerErr) {
            db.exec('ROLLBACK');
            const elapsed = Date.now() - migrationStartTime;
            console.error(`[migration-error] ${migration.version} failed after ${elapsed}ms: ${innerErr.message}. Rolled back.`);
            
            // Log migration failure to audit log (only safe after initSchema completes)
            try {
              getLogAudit()({
                action: 'migration.failure',
                entity_type: 'migration',
                entity_id: null,
                details: {
                  version: migration.version,
                  description: migration.description,
                  error: innerErr.message,
                  elapsed_ms: elapsed
                }
              });
            } catch (auditErr) {
              console.error(`[audit-error] Failed to log migration failure to audit log: ${auditErr.message}`);
            }
            
            throw innerErr;
          } finally {
            // Always restore FK checks — even on failure path
            if (needsForeignKeyOff) {
              db.exec('PRAGMA foreign_keys = ON');
            }
          }
        } else {
          // Standard transaction wrapping for other migrations
          db.exec('BEGIN');
          console.log(`[migration] Transaction BEGIN for ${migration.version}`);
          migration.run();
          recordMigration(migration.version, migration.description);
          db.exec('COMMIT');
          console.log(`[migration] Transaction COMMIT for ${migration.version}`);
          
          // Log successful completion with timing
          const elapsed = Date.now() - migrationStartTime;
          console.log(`[migration] ${migration.version} completed in ${elapsed}ms`);
          appliedVersions.add(migration.version);
        }
      } catch (err) {
        db.exec('ROLLBACK');
        const elapsed = Date.now() - migrationStartTime;
        console.error(`[migration-error] Failed to apply ${migration.version} after ${elapsed}ms: ${err.message}. Rolled back.`);
        
        // Log migration failure to audit log (only safe after initSchema completes)
        try {
          getLogAudit()({
            action: 'migration.failure',
            entity_type: 'migration',
            entity_id: null,
            details: {
              version: migration.version,
              description: migration.description,
              error: err.message,
              elapsed_ms: elapsed
            }
          });
        } catch (auditErr) {
          console.error(`[audit-error] Failed to log migration failure to audit log: ${auditErr.message}`);
        }
        
        throw err;
      }
    } else {
      console.log(`[migration] Skipping already applied ${migration.version}: ${migration.description}`);
    }
  }
  
  // Log total migration time
  
  // Log completion of all migrations to audit log
  try {
    getLogAudit()({
      action: 'migration.complete',
      entity_type: 'migration',
      entity_id: null,
      details: {
        total_time_ms: Date.now() - startTime,
        message: 'All migrations completed successfully'
      }
    });
  } catch (auditErr) {
    console.error(`[audit-error] Failed to log migration completion to audit log: ${auditErr.message}`);
  }
  const totalTime = Date.now() - startTime;
  console.log(`[migration] All migrations completed in ${totalTime}ms`);
  
  // All migrations are now versioned
}

function seedDefaults() {
  const defaults = [
    ['currency', 'USD'],
    ['date_format', 'MM/DD/YYYY'],
    ['grace_period_days', '5'],
    ['notify_days_before', '3'],
    ['backup_enabled', 'false'],
    ['backup_frequency_days', '1'],
    ['backup_keep_count', '14'],
    ['backup_path', process.env.BACKUP_PATH || path.join(__dirname, '..', 'backups')],
    ['backup_schedule_enabled', 'false'],
    ['backup_schedule_frequency', 'daily'],
    ['backup_schedule_time', '02:00'],
    ['backup_schedule_retention_count', '2'],
    ['backup_schedule_last_run_at', ''],
    ['backup_schedule_last_error', ''],
    ['auth_mode', 'multi'],
    ['default_user_id', ''],
    ['notify_smtp_enabled', 'false'],
    ['notify_sender_name', 'Bill Tracker'],
    ['notify_sender_address', ''],
    ['notify_smtp_host', ''],
    ['notify_smtp_port', '587'],
    ['notify_smtp_encryption', 'starttls'],
    ['notify_smtp_self_signed', 'false'],
    ['notify_smtp_username', ''],
    ['notify_smtp_password', ''],
    ['notify_allow_user_config', 'false'],
    ['notify_global_recipient', ''],
    // Cleanup worker settings (v0.15)
    ['cleanup_import_sessions_enabled',     'true'],
    ['cleanup_temp_exports_enabled',        'true'],
    ['cleanup_temp_export_max_age_hours',   '2'],
    ['cleanup_backup_partials_enabled',     'true'],
    ['cleanup_import_history_enabled',      'false'],
    ['cleanup_import_history_max_age_days', '365'],
    ['cleanup_last_run_at',  ''],
    ['cleanup_last_result',  ''],
    // Auth method settings (v0.18)
    ['local_login_enabled',  'true'],
    ['oidc_login_enabled',   'false'],
    ['oidc_provider_name',   'authentik'],
    ['oidc_issuer_url',      ''],
    ['oidc_client_id',       ''],
    ['oidc_client_secret',   ''],
    ['oidc_token_auth_method', 'client_secret_basic'],
    ['oidc_redirect_uri',    ''],
    ['oidc_scopes',          'openid email profile groups'],
    ['oidc_auto_provision',  'true'],
    ['oidc_admin_group',     ''],
    ['oidc_default_role',    'user'],
  ];

  const insert = db.prepare(
    'INSERT OR IGNORE INTO settings (key, value) VALUES (?, ?)'
  );

  for (const [key, value] of defaults) {
    insert.run(key, value);
  }

  // Category defaults are user-scoped. They are applied by
  // ensureUserDefaultCategories(userId) when user-owned category/bill data is read.

  // ── Create initial admin user if none exists ─────────────────────────────
  const userCount = db.prepare('SELECT COUNT(*) as cnt FROM users').get().cnt;
  if (userCount === 0) {
    const initUser = process.env.INIT_ADMIN_USER || 'admin';
    const initPass = process.env.INIT_ADMIN_PASS || 'admin123';
    // Use bcryptjs sync for database init (safe, runs once at startup)
    const bcrypt = require('bcryptjs');
    const password_hash = bcrypt.hashSync(initPass, 12);
    db.prepare(`
      INSERT INTO users (username, password_hash, role, is_default_admin, active, email, created_at, updated_at)
      VALUES (?, ?, 'admin', 1, 1, ?, datetime('now'), datetime('now'))
    `).run(initUser, password_hash, initUser + '@local');
    console.log(`[seed] Created initial admin user: ${initUser}`);
  }

  seedManualDataSources(db);
}

function ensureUserDefaultCategories(userId) {
  const db = getDb();
  const insert = db.prepare('INSERT INTO categories (user_id, name) VALUES (?, ?)');
  for (const name of DEFAULT_CATEGORIES) {
    const existing = db.prepare('SELECT id FROM categories WHERE user_id = ? AND name = ? COLLATE NOCASE')
      .get(userId, name);
    if (!existing) insert.run(userId, name);
  }
}

function getSetting(key) {
  const db = getDb();
  const row = db.prepare('SELECT value FROM settings WHERE key = ?').get(key);
  return row ? row.value : null;
}

function setSetting(key, value) {
  const db = getDb();
  db.prepare(
    "INSERT OR REPLACE INTO settings (key, value, updated_at) VALUES (?, ?, datetime('now'))"
  ).run(key, String(value));
}

function closeDb() {
  if (!db) return;
  db.close();
  db = null;
}

function getDbPath() {
  return DB_PATH;
}

// Rollback SQL definitions
const ROLLBACK_SQL_MAP = {
  'v0.44': {
    description: 'performance: add missing indexes for frequently queried columns',
    sql: [
      'DROP INDEX IF EXISTS idx_bills_user_name',
      'DROP INDEX IF EXISTS idx_payments_method',
      'DROP INDEX IF EXISTS idx_monthly_starting_amounts_user',
      'DROP INDEX IF EXISTS idx_import_history_imported_at'
    ]
  },
  'v0.45': {
    description: 'audit: add audit_log table for security event tracking',
    sql: [
      'DROP INDEX IF EXISTS idx_audit_log_user',
      'DROP INDEX IF EXISTS idx_audit_log_action',
      'DROP TABLE IF EXISTS audit_log'
    ]
  },
  'v0.46': {
    description: 'billing: add cycle_type and cycle_day columns to bills',
    sql: [
      'ALTER TABLE bills DROP COLUMN cycle_day',
      'ALTER TABLE bills DROP COLUMN cycle_type'
    ]
  },
  'v0.47': {
    description: 'settings: reset backup_schedule_retention_count default from 14 to 2',
    sql: [
      "UPDATE settings SET value = '14' WHERE key = 'backup_schedule_retention_count' AND value = '2'"
    ]
  },
  'v0.48': {
    description: 'bills: debt snowball fields',
    sql: [
      'ALTER TABLE bills DROP COLUMN snowball_include',
      'ALTER TABLE bills DROP COLUMN snowball_order',
      'ALTER TABLE bills DROP COLUMN minimum_payment',
      'ALTER TABLE bills DROP COLUMN current_balance',
    ]
  },
  'v0.49': {
    description: 'users: snowball extra payment field',
    sql: ['ALTER TABLE users DROP COLUMN snowball_extra_payment']
  },
  'v0.50': {
    description: 'payments: balance_delta column',
    sql: ['ALTER TABLE payments DROP COLUMN balance_delta']
  },
  'v0.59': {
    description: 'payments: source metadata columns',
    sql: [
      'ALTER TABLE payments DROP COLUMN transaction_id',
      'ALTER TABLE payments DROP COLUMN payment_source',
    ]
  },
  'v0.60': {
    description: 'transactions: shared transaction foundation tables',
    sql: [
      'DROP INDEX IF EXISTS idx_transactions_provider_dedupe',
      'DROP INDEX IF EXISTS idx_transactions_matched_bill',
      'DROP INDEX IF EXISTS idx_transactions_account',
      'DROP INDEX IF EXISTS idx_transactions_user_match',
      'DROP INDEX IF EXISTS idx_transactions_user_date',
      'DROP INDEX IF EXISTS idx_financial_accounts_user_source',
      'DROP INDEX IF EXISTS idx_data_sources_user_manual',
      'DROP INDEX IF EXISTS idx_data_sources_user_type',
      'DROP TABLE IF EXISTS transactions',
      'DROP TABLE IF EXISTS financial_accounts',
      'DROP TABLE IF EXISTS data_sources',
    ]
  },
  'v0.61': {
    description: 'payments: one active payment per linked transaction',
    sql: ['DROP INDEX IF EXISTS idx_payments_transaction_active']
  },
  'v0.62': {
    description: 'matches: rejected transaction match suggestions',
    sql: [
      'DROP INDEX IF EXISTS idx_match_suggestion_rejections_user',
      'DROP TABLE IF EXISTS match_suggestion_rejections',
    ]
  },
  'v0.63': {
    description: 'bills: subscription metadata fields',
    sql: [
      'DROP INDEX IF EXISTS idx_bills_user_subscription',
      'ALTER TABLE bills DROP COLUMN subscription_detected_at',
      'ALTER TABLE bills DROP COLUMN subscription_source',
      'ALTER TABLE bills DROP COLUMN reminder_days_before',
      'ALTER TABLE bills DROP COLUMN subscription_type',
      'ALTER TABLE bills DROP COLUMN is_subscription',
    ]
  },
  'v0.72': {
    description: 'bills: persistent tracker sort order',
    sql: [
      'DROP INDEX IF EXISTS idx_bills_user_sort',
      'ALTER TABLE bills DROP COLUMN sort_order',
    ]
  },
  'v0.75': {
    description: 'categories: persistent sort order',
    sql: [
      'DROP INDEX IF EXISTS idx_categories_user_sort',
      'ALTER TABLE categories DROP COLUMN sort_order',
    ]
  },
  'v0.76': {
    description: 'bills: canonical billing schedule cleanup',
    sql: [
      `UPDATE bills
       SET billing_cycle = CASE
         WHEN cycle_type = 'quarterly' THEN 'quarterly'
         WHEN cycle_type = 'annual' THEN 'annually'
         WHEN cycle_type IN ('weekly', 'biweekly') THEN 'irregular'
         ELSE 'monthly'
       END`,
    ]
  },
  'v0.51': {
    description: 'bills: snowball_exempt column',
    sql: ['ALTER TABLE bills DROP COLUMN snowball_exempt']
  },
  'v0.52': {
    description: 'users: last_seen_version column',
    sql: ['ALTER TABLE users DROP COLUMN last_seen_version']
  },
  'v0.53': {
    description: 'user_login_history table',
    sql: ['DROP TABLE IF EXISTS user_login_history']
  },
  'v0.54': {
    description: 'user_settings table',
    sql: ['DROP TABLE IF EXISTS user_settings']
  },
  'v0.55': {
    description: 'user_login_history device metadata columns',
    sql: [
      'ALTER TABLE user_login_history DROP COLUMN device_fingerprint',
      'ALTER TABLE user_login_history DROP COLUMN device_type',
      'ALTER TABLE user_login_history DROP COLUMN os',
      'ALTER TABLE user_login_history DROP COLUMN browser',
    ]
  },
  'v0.56': {
    description: 'bills/categories soft-delete columns',
    sql: [
      'DROP INDEX IF EXISTS idx_categories_deleted',
      'DROP INDEX IF EXISTS idx_bills_deleted',
      'ALTER TABLE categories DROP COLUMN deleted_at',
      'ALTER TABLE bills DROP COLUMN deleted_at',
    ]
  },
  'v0.57': {
    description: 'autopay suggestions and auto-mark paid',
    sql: [
      'DROP INDEX IF EXISTS idx_autopay_suggestion_dismissals_user_month',
      'DROP TABLE IF EXISTS autopay_suggestion_dismissals',
      'ALTER TABLE bills DROP COLUMN auto_mark_paid',
    ]
  },
  'v0.58': {
    description: 'saved bill templates',
    sql: [
      'DROP INDEX IF EXISTS idx_bill_templates_user_name',
      'DROP TABLE IF EXISTS bill_templates',
    ]
  }
};

function rollbackMigration(version) {
  if (!db) throw new Error('Database not initialized');

  // Check the migration was actually applied
  const applied = db.prepare('SELECT 1 FROM schema_migrations WHERE version = ?').get(version);
  if (!applied) {
    const err = new Error(`Migration ${version} has not been applied — cannot rollback`);
    err.code = 'NOT_APPLIED';
    throw err;
  }

  const rollback = ROLLBACK_SQL_MAP[version];
  if (!rollback) {
    const err = new Error(`Migration ${version} does not support rollback`);
    err.code = 'ROLLBACK_NOT_SUPPORTED';
    throw err;
  }

  console.log(`[rollback] Rolling back ${version}: ${rollback.description}`);
  const startTime = Date.now();

  try {
    db.exec('BEGIN');
    console.log(`[rollback] Transaction BEGIN for ${version}`);

    for (const stmt of rollback.sql) {
      console.log(`[rollback] Executing: ${stmt}`);
      db.exec(stmt);
    }

    // Remove migration record
    db.prepare('DELETE FROM schema_migrations WHERE version = ?').run(version);
    console.log(`[rollback] Removed ${version} from schema_migrations`);

    db.exec('COMMIT');
    console.log(`[rollback] Transaction COMMIT for ${version}`);

    const elapsed = Date.now() - startTime;
    console.log(`[rollback] ${version} rolled back in ${elapsed}ms`);

    // Audit log
    try {
      getLogAudit()({
        action: 'migration.rollback',
        entity_type: 'migration',
        entity_id: null,
        details: { version, description: rollback.description, elapsed_ms: elapsed }
      });
    } catch (auditErr) {
      console.error(`[audit-error] Failed to log rollback to audit log: ${auditErr.message}`);
    }

    return { success: true, version, description: rollback.description, elapsed_ms: elapsed };
  } catch (err) {
    db.exec('ROLLBACK');
    const elapsed = Date.now() - startTime;
    console.error(`[rollback-error] ${version} failed after ${elapsed}ms: ${err.message}`);

    // Audit log
    try {
      getLogAudit()({
        action: 'migration.rollback.failure',
        entity_type: 'migration',
        entity_id: null,
        details: { version, description: rollback.description, error: err.message, elapsed_ms: elapsed }
      });
    } catch (auditErr) {
      console.error(`[audit-error] Failed to log rollback failure to audit log: ${auditErr.message}`);
    }

    throw err;
  }
}

/**
 * Cleanup expired sessions from the database
 * @returns {Object} Result object with changes count
 */
function cleanupExpiredSessions() {
  const result = db.prepare("DELETE FROM sessions WHERE expires_at < datetime('now')").run();
  console.log(`[cleanup] Purged ${result.changes} expired sessions`);
  return result;
}

module.exports = { getDb, getSetting, setSetting, closeDb, getDbPath, ensureUserDefaultCategories, cleanupExpiredSessions, rollbackMigration };