import { useEffect, useState } from 'react';
import { ChevronDown, Copy, Link2, Link2Off, Pencil, Plus, Trash2 } from 'lucide-react';
import { toast } from 'sonner';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import {
  Dialog, DialogContent, DialogHeader, DialogTitle, DialogFooter,
} from '@/components/ui/dialog';
import {
  AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent,
  AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle,
} from '@/components/ui/alert-dialog';
import {
  Select, SelectTrigger, SelectValue, SelectContent, SelectItem,
} from '@/components/ui/select';
import { api } from '@/api';
import { cn, fmt, fmtDate, todayStr } from '@/lib/utils';

function getOrdinalSuffix(day) {
  if (day > 3 && day < 21) return 'th';
  switch (day % 10) {
    case 1: return 'st';
    case 2: return 'nd';
    case 3: return 'rd';
    default: return 'th';
  }
}

function defaultCycleDayFor(type) {
  return type === 'weekly' || type === 'biweekly' ? 'monday' : '1';
}

// Radix Select crashes on empty string value
const CAT_NONE = 'none';
const PAYMENT_METHODS = [
  ['manual', 'Manual'],
  ['bank', 'Bank Transfer'],
  ['card', 'Card'],
  ['autopay', 'Autopay'],
  ['check', 'Check'],
  ['cash', 'Cash'],
];

const DEBT_KEYWORDS = ['credit', 'loan', 'mortgage', 'housing', 'debt'];
const SNOWBALL_KEYWORDS = ['credit', 'loan', 'debt'];
const SUBSCRIPTION_TYPES = [
  ['streaming', 'Streaming'],
  ['software', 'Software'],
  ['cloud', 'Cloud'],
  ['music', 'Music'],
  ['news', 'News'],
  ['fitness', 'Fitness'],
  ['gaming', 'Gaming'],
  ['utilities', 'Utilities'],
  ['insurance', 'Insurance'],
  ['other', 'Other'],
];

function fmtTransactionAmount(amount, currency = 'USD') {
  const cents = Number(amount || 0);
  const value = Math.abs(cents) / 100;
  const sign = cents < 0 ? '-' : '+';
  return `${sign}${new Intl.NumberFormat(undefined, {
    style: 'currency',
    currency: currency || 'USD',
  }).format(value)}`;
}

function transactionDate(tx) {
  return tx?.posted_date || String(tx?.transacted_at || '').slice(0, 10) || null;
}

function transactionTitle(tx) {
  return tx?.payee || tx?.description || tx?.memo || 'Transaction';
}

function isTransactionLinkedPayment(payment) {
  return payment?.payment_source === 'transaction_match' || payment?.transaction_id != null;
}

function paymentSourceLabel(source) {
  const labels = {
    manual: 'Manual',
    file_import: 'File import',
    provider_sync: 'Sync',
    transaction_match: 'Transaction',
  };
  return labels[source] || source || 'Manual';
}

function paymentSourceTone(source) {
  const tones = {
    manual: 'border-emerald-500/25 bg-emerald-500/10 text-emerald-600 dark:text-emerald-400',
    file_import: 'border-sky-500/25 bg-sky-500/10 text-sky-600 dark:text-sky-400',
    provider_sync: 'border-violet-500/25 bg-violet-500/10 text-violet-600 dark:text-violet-400',
    transaction_match: 'border-primary/25 bg-primary/10 text-primary',
  };
  return tones[source] || tones.manual;
}

function isDebtCat(categories, catId) {
  if (!catId || catId === CAT_NONE) return false;
  const cat = categories.find(c => String(c.id) === catId);
  return cat ? DEBT_KEYWORDS.some(kw => cat.name.toLowerCase().includes(kw)) : false;
}
function isSnowballCat(categories, catId) {
  if (!catId || catId === CAT_NONE) return false;
  const cat = categories.find(c => String(c.id) === catId);
  return cat ? SNOWBALL_KEYWORDS.some(kw => cat.name.toLowerCase().includes(kw)) : false;
}

export default function BillModal({ bill, initialBill, categories, onClose, onSave, onDuplicate }) {
  const isNew = !bill;
  const sourceBill = bill || initialBill || null;

  const [name,           setName]         = useState(sourceBill?.name            || '');
  const [categoryId,     setCategoryId]   = useState(sourceBill?.category_id ? String(sourceBill.category_id) : CAT_NONE);
  const [dueDay,         setDueDay]       = useState(String(sourceBill?.due_day   || ''));
  const [expectedAmount, setExpected]     = useState(String(sourceBill?.expected_amount || ''));
  const [interestRate,   setInterestRate] = useState(sourceBill?.interest_rate == null ? '' : String(sourceBill.interest_rate));
  const [billingCycle,   setCycle]        = useState(sourceBill?.billing_cycle    || 'monthly');
  const [cycleType,      setCycleType]    = useState(sourceBill?.cycle_type      || 'monthly');
  const [cycleDay,       setCycleDay]     = useState(sourceBill?.cycle_day       || '1');
  const [autopay,        setAutopay]      = useState(!!sourceBill?.autopay_enabled);
  const [autodraftStatus, setAutodraftStatus] = useState(sourceBill?.autodraft_status || (sourceBill?.autopay_enabled ? 'assumed_paid' : 'none'));
  const [autoMarkPaid,   setAutoMarkPaid] = useState(!!sourceBill?.auto_mark_paid);
  const [isSubscription, setIsSubscription] = useState(!!sourceBill?.is_subscription);
  const [subscriptionType, setSubscriptionType] = useState(sourceBill?.subscription_type || 'other');
  const [reminderDaysBefore, setReminderDaysBefore] = useState(String(sourceBill?.reminder_days_before ?? 3));
  const [has2fa,         setHas2fa]       = useState(!!sourceBill?.has_2fa);
  const [website,        setWebsite]      = useState(sourceBill?.website          || '');
  const [username,       setUsername]     = useState(sourceBill?.username          || '');
  const [accountInfo,    setAccountInfo]  = useState(sourceBill?.account_info     || '');
  const [notes,          setNotes]        = useState(sourceBill?.notes            || '');
  const [currentBalance, setCurrentBalance] = useState(sourceBill?.current_balance == null ? '' : String(sourceBill.current_balance));
  const [minimumPayment, setMinimumPayment] = useState(sourceBill?.minimum_payment == null ? '' : String(sourceBill.minimum_payment));
  const [snowballInclude, setSnowballInclude] = useState(!!sourceBill?.snowball_include);
  const [snowballExempt, setSnowballExempt] = useState(!!sourceBill?.snowball_exempt);
  const [showDebtSection, setShowDebtSection] = useState(
    () => isDebtCat(categories, sourceBill?.category_id ? String(sourceBill.category_id) : CAT_NONE)
      || !!sourceBill?.snowball_include
      || !!sourceBill?.snowball_exempt
      || sourceBill?.current_balance != null
      || sourceBill?.minimum_payment != null
  );
  const [saveTemplate, setSaveTemplate] = useState(false);
  const [templateName, setTemplateName] = useState('');
  const [busy,           setBusy]         = useState(false);
  const [errors,         setErrors]       = useState({});
  const [payments,       setPayments]     = useState([]);
  const [paymentsLoading, setPaymentsLoading] = useState(false);
  const [linkedTransactions, setLinkedTransactions] = useState([]);
  const [linkedTransactionsLoading, setLinkedTransactionsLoading] = useState(false);
  const [transactionBusyId, setTransactionBusyId] = useState(null);
  const [paymentBusy,    setPaymentBusy]  = useState(false);
  const [paymentFormOpen, setPaymentFormOpen] = useState(false);
  const [editingPayment, setEditingPayment] = useState(null);
  const [deletePaymentTarget, setDeletePaymentTarget] = useState(null);
  const [paymentAmount,  setPaymentAmount] = useState('');
  const [paymentDate,    setPaymentDate]   = useState(todayStr());
  const [paymentMethod,  setPaymentMethod] = useState('manual');
  const [paymentNotes,   setPaymentNotes]  = useState('');

  const isDebtCategory = isDebtCat(categories, categoryId);
  const isSnowballCategory = isSnowballCat(categories, categoryId);
  const showOnSnowball = snowballInclude || (isSnowballCategory && !snowballExempt);
  const canAutoMarkPaid = autopay && autodraftStatus === 'assumed_paid';

  async function loadPayments() {
    if (isNew || !bill?.id) return;
    setPaymentsLoading(true);
    try {
      const data = await api.billPayments(bill.id, 1, 100);
      setPayments(data.payments || []);
    } catch (err) {
      toast.error(err.message || 'Failed to load payment history.');
    } finally {
      setPaymentsLoading(false);
    }
  }

  async function loadLinkedTransactions() {
    if (isNew || !bill?.id) return;
    setLinkedTransactionsLoading(true);
    try {
      const data = await api.billTransactions(bill.id);
      setLinkedTransactions(data.transactions || []);
    } catch (err) {
      toast.error(err.message || 'Failed to load linked transactions.');
    } finally {
      setLinkedTransactionsLoading(false);
    }
  }

  useEffect(() => {
    loadPayments();
    loadLinkedTransactions();
  }, [bill?.id]);

  const validateName = (val) => {
    if (!val || val.trim() === '') return 'Name is required';
    if (val.trim().length < 2) return 'Name must be at least 2 characters';
    return '';
  };

  const validateDueDay = (val) => {
    if (!val || val.trim() === '') return 'Due day is required';
    const num = parseInt(val, 10);
    if (isNaN(num) || num < 1 || num > 31) return 'Due day must be between 1 and 31';
    return '';
  };

  const validateExpectedAmount = (val) => {
    if (val === '' || val === null) return '';
    const num = parseFloat(val);
    if (isNaN(num) || num < 0) return 'Amount must be a positive number';
    return '';
  };

  const validateInterestRate = (val) => {
    if (val === '' || val === null) return '';
    const num = parseFloat(val);
    if (isNaN(num)) return 'Invalid number';
    if (num < 0 || num > 100) return 'Interest rate must be between 0 and 100';
    return '';
  };

  const validateCurrentBalance = (val) => {
    if (val === '' || val === null) return '';
    const num = parseFloat(val);
    if (isNaN(num) || num < 0) return 'Balance must be a non-negative number';
    return '';
  };

  const validateMinimumPayment = (val) => {
    if (val === '' || val === null) return '';
    const num = parseFloat(val);
    if (isNaN(num) || num < 0) return 'Min payment must be a non-negative number';
    return '';
  };

  const validateForm = () => {
    const newErrors = {
      name: validateName(name),
      dueDay: validateDueDay(dueDay),
      expectedAmount: validateExpectedAmount(expectedAmount),
      interestRate: validateInterestRate(interestRate),
      currentBalance: validateCurrentBalance(currentBalance),
      minimumPayment: validateMinimumPayment(minimumPayment),
    };
    setErrors(newErrors);
    return Object.values(newErrors).every(err => err === '');
  };

  const handleBlur = (field, validator) => {
    setErrors(prev => ({ ...prev, [field]: validator(
      field === 'name' ? name :
      field === 'dueDay' ? dueDay :
      field === 'expectedAmount' ? expectedAmount :
      interestRate
    )}));
  };

  const handleCategoryChange = (val) => {
    setCategoryId(val);
    if (isDebtCat(categories, val)) {
      setShowDebtSection(true);
    } else {
      setSnowballExempt(false);
    }
  };

  const handleSnowballVisibilityChange = (checked) => {
    if (checked) {
      setSnowballExempt(false);
      setSnowballInclude(!isSnowballCategory);
    } else {
      setSnowballInclude(false);
      setSnowballExempt(isSnowballCategory);
    }
  };

  const handleAutopayChange = (checked) => {
    setAutopay(checked);
    if (checked) {
      setAutodraftStatus(prev => (prev && prev !== 'none' ? prev : 'assumed_paid'));
    } else {
      setAutodraftStatus('none');
      setAutoMarkPaid(false);
    }
  };

  const handleCycleTypeChange = (value) => {
    setCycleType(value);
    setCycleDay(defaultCycleDayFor(value));
  };

  function resetPaymentForm() {
    setPaymentAmount('');
    setPaymentDate(todayStr());
    setPaymentMethod('manual');
    setPaymentNotes('');
    setEditingPayment(null);
  }

  function startAddPayment() {
    resetPaymentForm();
    setPaymentFormOpen(true);
  }

  function startEditPayment(payment) {
    setEditingPayment(payment);
    setPaymentAmount(String(payment.amount ?? ''));
    setPaymentDate(payment.paid_date || todayStr());
    setPaymentMethod(payment.method || 'manual');
    setPaymentNotes(payment.notes || '');
    setPaymentFormOpen(true);
  }

  async function handlePaymentSubmit(e) {
    e.preventDefault();
    const parsedAmount = parseFloat(paymentAmount);
    if (!Number.isFinite(parsedAmount) || parsedAmount <= 0) {
      toast.error('Enter a positive payment amount.');
      return;
    }
    if (!paymentDate) {
      toast.error('Choose a paid date.');
      return;
    }

    setPaymentBusy(true);
    try {
      const payload = {
        amount: parsedAmount,
        paid_date: paymentDate,
        method: paymentMethod,
        notes: paymentNotes || null,
        payment_source: 'manual',
      };
      if (editingPayment) {
        await api.updatePayment(editingPayment.id, payload);
        toast.success('Payment updated');
      } else {
        await api.createPayment({ ...payload, bill_id: bill.id });
        toast.success('Payment added');
      }
      resetPaymentForm();
      setPaymentFormOpen(false);
      await loadPayments();
      onSave?.();
    } catch (err) {
      toast.error(err.message || 'Payment could not be saved.');
    } finally {
      setPaymentBusy(false);
    }
  }

  async function handleDeletePayment() {
    if (!deletePaymentTarget) return;
    const payment = deletePaymentTarget;
    setPaymentBusy(true);
    try {
      await api.deletePayment(payment.id);
      setDeletePaymentTarget(null);
      toast.success('Payment moved to recovery.', {
        action: {
          label: 'Undo',
          onClick: async () => {
            try {
              await api.restorePayment(payment.id);
              toast.success('Payment restored');
              await loadPayments();
              onSave?.();
            } catch (err) {
              toast.error(err.message || 'Failed to restore payment.');
            }
          },
        },
      });
      if (editingPayment?.id === payment.id) {
        resetPaymentForm();
        setPaymentFormOpen(false);
      }
      await loadPayments();
      onSave?.();
    } catch (err) {
      toast.error(err.message || 'Payment could not be removed.');
    } finally {
      setPaymentBusy(false);
    }
  }

  async function handleUnmatchTransaction(transaction) {
    if (!transaction?.id) return;
    setTransactionBusyId(transaction.id);
    try {
      await api.unmatchTransaction(transaction.id);
      toast.success('Transaction unmatched');
      await Promise.all([loadPayments(), loadLinkedTransactions()]);
      onSave?.();
    } catch (err) {
      toast.error(err.message || 'Transaction could not be unmatched.');
    } finally {
      setTransactionBusyId(null);
    }
  }

  async function handleSubmit(e) {
    e.preventDefault();

    if (!validateForm()) {
      toast.error('Please fix the form errors before saving.');
      return;
    }

    const parsedDueDay = Number(dueDay);
    if (!Number.isInteger(parsedDueDay) || parsedDueDay < 1 || parsedDueDay > 31) {
      toast.error('Due day must be a whole number from 1 to 31.');
      return;
    }

    const trimmedInterestRate = interestRate.trim();
    const parsedInterestRate = trimmedInterestRate === '' ? null : Number(trimmedInterestRate);
    if (parsedInterestRate !== null && (!Number.isFinite(parsedInterestRate) || parsedInterestRate < 0 || parsedInterestRate > 100)) {
      toast.error('Interest rate must be blank or a number from 0 to 100.');
      return;
    }

    const data = {
      source_bill_id:    sourceBill?.source_bill_id,
      name:              name.trim(),
      category_id:       categoryId === CAT_NONE ? null : parseInt(categoryId, 10),
      due_day:           parsedDueDay,
      override_due_date: sourceBill?.override_due_date,
      expected_amount:   parseFloat(expectedAmount) || 0,
      interest_rate:     parsedInterestRate,
      billing_cycle:     billingCycle,
      cycle_type:        cycleType,
      cycle_day:         cycleDay,
      autopay_enabled:   autopay,
      autodraft_status:  autopay ? autodraftStatus : 'none',
      auto_mark_paid:    canAutoMarkPaid && autoMarkPaid,
      is_subscription:   isSubscription,
      subscription_type: isSubscription ? subscriptionType : null,
      reminder_days_before: isSubscription ? parseInt(reminderDaysBefore || '3', 10) : 3,
      subscription_source: sourceBill?.subscription_source || 'manual',
      subscription_detected_at: sourceBill?.subscription_detected_at,
      has_2fa:           has2fa,
      website:           website     || null,
      username:          username    || null,
      account_info:      accountInfo || null,
      notes:             notes       || null,
      history_visibility: sourceBill?.history_visibility,
      current_balance:   currentBalance === '' ? null : parseFloat(currentBalance),
      minimum_payment:   minimumPayment === '' ? null : parseFloat(minimumPayment),
      snowball_order:    sourceBill?.snowball_order,
      snowball_include:  snowballInclude,
      snowball_exempt:   snowballExempt,
    };
    setBusy(true);
    try {
      if (isNew) {
        if (data.source_bill_id) {
          await api.duplicateBill(data.source_bill_id, data);
        } else {
          await api.createBill(data);
        }
        toast.success('Bill added');
      } else {
        await api.updateBill(bill.id, data);
        toast.success('Bill updated');
      }
      if (saveTemplate) {
        const safeTemplateName = templateName.trim() || data.name;
        await api.saveBillTemplate({ name: safeTemplateName, data });
        toast.success('Template saved');
      }
      onSave();
      onClose();
    } catch (err) {
      toast.error(err.message);
    } finally {
      setBusy(false);
    }
  }

  const inp = 'bg-background/50 border-border/60 h-9 text-sm w-full';

  return (
    <Dialog open onOpenChange={v => { if (!v) onClose(); }}>
      <DialogContent className="max-h-[92svh] overflow-y-auto border-border/60 bg-card/95 backdrop-blur-xl sm:max-w-2xl">
        <DialogHeader>
          <DialogTitle className="text-base font-semibold tracking-tight">
            {isNew ? 'Add Bill' : 'Edit Bill'}
          </DialogTitle>
        </DialogHeader>

        <form id="bill-modal-form" onSubmit={handleSubmit}>
          <div className="grid gap-x-5 gap-y-4 py-2 sm:grid-cols-2">

            {/* Name */}
            <div className="col-span-2 space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Name *</Label>
              <Input
                className={cn(inp, errors.name && 'border-red-500 focus-visible:ring-red-500')}
                placeholder="e.g. Electricity"
                value={name}
                onChange={e => {
                  setName(e.target.value);
                  setTimeout(() => setErrors(prev => ({ ...prev, name: validateName(e.target.value) })), 300);
                }}
                onBlur={() => handleBlur('name', validateName)}
                required
              />
              {errors.name && (
                <span className="text-[10px] text-red-500 font-medium">{errors.name}</span>
              )}
            </div>

            {/* Category */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Category</Label>
              <Select value={categoryId} onValueChange={handleCategoryChange}>
                <SelectTrigger className={cn(inp, 'w-full')}>
                  <SelectValue placeholder="— none —" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value={CAT_NONE}>— none —</SelectItem>
                  {categories.map(c => (
                    <SelectItem key={c.id} value={String(c.id)}>{c.name}</SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>

            {/* Due Day */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Due day of month *</Label>
              <Input
                className={cn(inp, errors.dueDay && 'border-red-500 focus-visible:ring-red-500')}
                type="number" min="1" max="31" required
                value={dueDay}
                onChange={e => {
                  setDueDay(e.target.value);
                  setTimeout(() => setErrors(prev => ({ ...prev, dueDay: validateDueDay(e.target.value) })), 300);
                }}
                onBlur={() => handleBlur('dueDay', validateDueDay)}
              />
              {errors.dueDay && (
                <span className="text-[10px] text-red-500 font-medium">{errors.dueDay}</span>
              )}
              <p className="text-[10px] text-muted-foreground/70">
                Enter the day of the month this bill is due.
              </p>
            </div>

            {/* Expected Amount */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Expected Amount ($)</Label>
              <Input
                className={cn(inp, 'font-mono', errors.expectedAmount && 'border-red-500 focus-visible:ring-red-500')}
                type="number" min="0" step="0.01" placeholder="0.00"
                value={expectedAmount}
                onChange={e => {
                  setExpected(e.target.value);
                  setTimeout(() => setErrors(prev => ({ ...prev, expectedAmount: validateExpectedAmount(e.target.value) })), 300);
                }}
                onBlur={() => handleBlur('expectedAmount', validateExpectedAmount)}
              />
              {errors.expectedAmount && (
                <span className="text-[10px] text-red-500 font-medium">{errors.expectedAmount}</span>
              )}
            </div>

            {/* Billing Cycle */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Billing Cycle</Label>
              <Select value={billingCycle} onValueChange={setCycle}>
                <SelectTrigger className={cn(inp, 'w-full')}>
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="monthly">Monthly</SelectItem>
                  <SelectItem value="quarterly">Quarterly</SelectItem>
                  <SelectItem value="annually">Annually</SelectItem>
                  <SelectItem value="irregular">Irregular</SelectItem>
                </SelectContent>
              </Select>
            </div>

            {/* Cycle Type */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Cycle Type</Label>
              <Select value={cycleType} onValueChange={handleCycleTypeChange}>
                <SelectTrigger className={cn(inp, 'w-full')}>
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="monthly">Monthly</SelectItem>
                  <SelectItem value="weekly">Weekly</SelectItem>
                  <SelectItem value="biweekly">Biweekly</SelectItem>
                  <SelectItem value="quarterly">Quarterly</SelectItem>
                  <SelectItem value="annual">Annual</SelectItem>
                </SelectContent>
              </Select>
            </div>

            {/* Cycle Day */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Cycle Day</Label>
              {cycleType === 'monthly' ? (
                <Select value={cycleDay} onValueChange={setCycleDay}>
                  <SelectTrigger className={cn(inp, 'w-full')}>
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    {[...Array(31)].map((_, i) => (
                      <SelectItem key={i+1} value={String(i+1)}>{i+1}{getOrdinalSuffix(i+1)}</SelectItem>
                    ))}
                  </SelectContent>
                </Select>
              ) : cycleType === 'weekly' || cycleType === 'biweekly' ? (
                <Select value={cycleDay} onValueChange={setCycleDay}>
                  <SelectTrigger className={cn(inp, 'w-full')}>
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectItem value="monday">Monday</SelectItem>
                    <SelectItem value="tuesday">Tuesday</SelectItem>
                    <SelectItem value="wednesday">Wednesday</SelectItem>
                    <SelectItem value="thursday">Thursday</SelectItem>
                    <SelectItem value="friday">Friday</SelectItem>
                    <SelectItem value="saturday">Saturday</SelectItem>
                    <SelectItem value="sunday">Sunday</SelectItem>
                  </SelectContent>
                </Select>
              ) : (
                <Select value={cycleDay} onValueChange={setCycleDay}>
                  <SelectTrigger className={cn(inp, 'w-full')}>
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    {[
                      'January', 'February', 'March', 'April', 'May', 'June',
                      'July', 'August', 'September', 'October', 'November', 'December',
                    ].map((label, index) => (
                      <SelectItem key={label} value={String(index + 1)}>{label}</SelectItem>
                    ))}
                  </SelectContent>
                </Select>
              )}
              <p className="text-[10px] text-muted-foreground/70">
                {cycleType === 'monthly' ? 'Day of the month' :
                 cycleType === 'weekly' || cycleType === 'biweekly' ? 'Day of the week' :
                 cycleType === 'quarterly' ? 'First month of the quarterly cycle' :
                 'Month due each year'}
              </p>
            </div>

            {/* Subscription Details */}
            <div className="col-span-2 rounded-lg border border-border/60 bg-muted/20 p-3">
              <label className="flex items-start gap-2.5 cursor-pointer group">
                <input
                  type="checkbox"
                  checked={isSubscription}
                  onChange={e => setIsSubscription(e.target.checked)}
                  className="mt-0.5 h-4 w-4 rounded border-border accent-primary"
                />
                <span>
                  <span className="block text-sm font-medium text-muted-foreground group-hover:text-foreground transition-colors">
                    Track as subscription
                  </span>
                  <span className="mt-0.5 block text-[10px] text-muted-foreground/70">
                    Adds this bill to the subscription view with monthly equivalent cost and SimpleFIN recommendation matching.
                  </span>
                </span>
              </label>

              {isSubscription && (
                <div className="mt-3 grid gap-3 border-t border-border/40 pt-3 sm:grid-cols-2">
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Subscription Type</Label>
                    <Select value={subscriptionType} onValueChange={setSubscriptionType}>
                      <SelectTrigger className={cn(inp, 'w-full')}>
                        <SelectValue />
                      </SelectTrigger>
                      <SelectContent>
                        {SUBSCRIPTION_TYPES.map(([value, label]) => (
                          <SelectItem key={value} value={value}>{label}</SelectItem>
                        ))}
                      </SelectContent>
                    </Select>
                  </div>
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Reminder Days</Label>
                    <Input
                      className={cn(inp, 'tracker-number')}
                      type="number"
                      min="0"
                      max="30"
                      value={reminderDaysBefore}
                      onChange={e => setReminderDaysBefore(e.target.value)}
                    />
                    <p className="text-[10px] text-muted-foreground/70">0-30 days before renewal.</p>
                  </div>
                </div>
              )}
            </div>

            {/* Debt / Snowball Details — collapsible */}
            <div className="col-span-2">
              <button
                type="button"
                onClick={() => setShowDebtSection(s => !s)}
                className="flex items-center gap-2 text-xs uppercase tracking-wider text-muted-foreground hover:text-foreground transition-colors w-full text-left py-1"
              >
                <ChevronDown
                  className={cn('h-3.5 w-3.5 transition-transform duration-150', !showDebtSection && '-rotate-90')}
                />
                Debt / Snowball Details
                {isSnowballCategory && (
                  <span className="ml-1 text-[9px] text-emerald-400 font-semibold tracking-normal normal-case">
                    · snowball auto-detected
                  </span>
                )}
                {!showOnSnowball && isSnowballCategory && (
                  <span className="ml-1 text-[9px] text-amber-400 font-semibold tracking-normal normal-case">
                    · exempt
                  </span>
                )}
              </button>

              {showDebtSection && (
                <div className="grid sm:grid-cols-2 gap-x-5 gap-y-4 mt-3 pt-3 border-t border-border/40">

                  {/* Interest Rate */}
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Interest rate (APR %)</Label>
                    <Input
                      className={cn(inp, 'font-mono', errors.interestRate && 'border-red-500 focus-visible:ring-red-500')}
                      type="number" min="0" max="100" step="0.01" placeholder="Optional"
                      value={interestRate}
                      onChange={e => {
                        setInterestRate(e.target.value);
                        setTimeout(() => setErrors(prev => ({ ...prev, interestRate: validateInterestRate(e.target.value) })), 300);
                      }}
                      onBlur={() => handleBlur('interestRate', validateInterestRate)}
                    />
                    {errors.interestRate && (
                      <span className="text-[10px] text-red-500 font-medium">{errors.interestRate}</span>
                    )}
                    <p className="text-[10px] text-muted-foreground/70">Enter 29.99 for 29.99%.</p>
                  </div>

                  {/* Current Balance */}
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Current Balance ($)</Label>
                    <Input
                      className={cn(inp, 'font-mono', errors.currentBalance && 'border-red-500 focus-visible:ring-red-500')}
                      type="number" min="0" step="0.01" placeholder="Optional"
                      value={currentBalance}
                      onChange={e => {
                        setCurrentBalance(e.target.value);
                        setTimeout(() => setErrors(prev => ({ ...prev, currentBalance: validateCurrentBalance(e.target.value) })), 300);
                      }}
                      onBlur={() => setErrors(prev => ({ ...prev, currentBalance: validateCurrentBalance(currentBalance) }))}
                    />
                    {errors.currentBalance && (
                      <span className="text-[10px] text-red-500 font-medium">{errors.currentBalance}</span>
                    )}
                    <p className="text-[10px] text-muted-foreground/70">Outstanding debt balance.</p>
                  </div>

                  {/* Minimum Payment */}
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Minimum Payment ($)</Label>
                    <Input
                      className={cn(inp, 'font-mono', errors.minimumPayment && 'border-red-500 focus-visible:ring-red-500')}
                      type="number" min="0" step="0.01" placeholder="Optional"
                      value={minimumPayment}
                      onChange={e => {
                        setMinimumPayment(e.target.value);
                        setTimeout(() => setErrors(prev => ({ ...prev, minimumPayment: validateMinimumPayment(e.target.value) })), 300);
                      }}
                      onBlur={() => setErrors(prev => ({ ...prev, minimumPayment: validateMinimumPayment(minimumPayment) }))}
                    />
                    {errors.minimumPayment && (
                      <span className="text-[10px] text-red-500 font-medium">{errors.minimumPayment}</span>
                    )}
                    <p className="text-[10px] text-muted-foreground/70">Required minimum monthly payment.</p>
                  </div>

                  {/* Include in Snowball */}
                  <div className="flex flex-col justify-end pb-1 space-y-1">
                    <label className="flex items-center gap-2.5 cursor-pointer group">
                      <input
                        type="checkbox"
                        checked={showOnSnowball}
                        onChange={e => handleSnowballVisibilityChange(e.target.checked)}
                        className="h-4 w-4 rounded border-border accent-emerald-500"
                      />
                      <span className="text-sm text-muted-foreground group-hover:text-foreground transition-colors">
                        Show on Debt Snowball
                      </span>
                    </label>
                    <p className="text-[10px] text-muted-foreground/70 pl-6">
                      Uncheck to exempt an auto-detected snowball bill, or check to include this bill manually.
                    </p>
                  </div>

                </div>
              )}
            </div>

            {/* Website */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Website</Label>
              <Input
                className={inp}
                placeholder="https://…"
                value={website}
                onChange={e => setWebsite(e.target.value)}
              />
            </div>

            {/* Username */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Username / Email</Label>
              <Input
                className={inp}
                value={username}
                onChange={e => setUsername(e.target.value)}
              />
            </div>

            {/* Account Info */}
            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Account Info</Label>
              <Input
                className={inp}
                placeholder="Last 4 digits, account #…"
                value={accountInfo}
                onChange={e => setAccountInfo(e.target.value)}
              />
            </div>

            {/* Checkboxes */}
            <div className="space-y-2.5 flex flex-col justify-end">
              <label className="flex items-center gap-2.5 cursor-pointer group">
                <input
                  type="checkbox"
                  checked={autopay}
                  onChange={e => handleAutopayChange(e.target.checked)}
                  className="h-4 w-4 rounded border-border accent-emerald-500"
                />
                <span className="text-sm text-muted-foreground group-hover:text-foreground transition-colors">
                  Autopay / Autodraft
                </span>
              </label>
              <label
                className={cn('flex items-center gap-2.5 group', canAutoMarkPaid ? 'cursor-pointer' : 'cursor-not-allowed opacity-50')}
                title={canAutoMarkPaid ? undefined : 'Auto-mark requires Autodraft Status set to Assumed paid'}
              >
                <input
                  type="checkbox"
                  checked={canAutoMarkPaid && autoMarkPaid}
                  onChange={e => setAutoMarkPaid(e.target.checked)}
                  disabled={!canAutoMarkPaid}
                  className="h-4 w-4 rounded border-border accent-sky-500"
                />
                <span className="text-sm text-muted-foreground group-hover:text-foreground transition-colors">
                  Auto-mark paid on due date
                </span>
              </label>
              <label className="flex items-center gap-2.5 cursor-pointer group">
                <input
                  type="checkbox"
                  checked={has2fa}
                  onChange={e => setHas2fa(e.target.checked)}
                  className="h-4 w-4 rounded border-border accent-violet-500"
                />
                <span className="text-sm text-muted-foreground group-hover:text-foreground transition-colors">
                  Has 2FA
                </span>
              </label>
            </div>

            <div className="space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Autodraft Status</Label>
              <Select value={autodraftStatus} onValueChange={setAutodraftStatus} disabled={!autopay}>
                <SelectTrigger className={cn(inp, !autopay && 'opacity-60')}>
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="none">None</SelectItem>
                  <SelectItem value="pending">Pending</SelectItem>
                  <SelectItem value="assumed_paid">Assumed paid</SelectItem>
                  <SelectItem value="confirmed">Confirmed</SelectItem>
                </SelectContent>
              </Select>
            </div>

            {/* Notes */}
            <div className="col-span-2 space-y-1.5">
              <Label className="text-xs uppercase tracking-wider text-muted-foreground">Notes</Label>
              <textarea
                rows={2}
                value={notes}
                onChange={e => setNotes(e.target.value)}
                className={cn(
                  'w-full rounded-md border border-border/60 bg-background/50 px-3 py-2',
                  'text-sm text-foreground placeholder:text-muted-foreground/50',
                  'resize-none outline-none focus:ring-1 focus:ring-ring transition-shadow',
                )}
                placeholder="Any additional notes…"
              />
            </div>

            <div className="col-span-2 rounded-lg border border-border/60 bg-muted/20 p-3">
              <label className="flex items-center gap-2.5 cursor-pointer group">
                <input
                  type="checkbox"
                  checked={saveTemplate}
                  onChange={e => setSaveTemplate(e.target.checked)}
                  className="h-4 w-4 rounded border-border accent-primary"
                />
                <span className="text-sm text-muted-foreground group-hover:text-foreground transition-colors">
                  Save this setup as a reusable template
                </span>
              </label>
              {saveTemplate && (
                <div className="mt-2 space-y-1.5">
                  <Label className="text-xs uppercase tracking-wider text-muted-foreground">Template Name</Label>
                  <Input
                    className={inp}
                    value={templateName}
                    onChange={e => setTemplateName(e.target.value)}
                    placeholder={name || 'My bill template'}
                  />
                </div>
              )}
            </div>

          </div>
        </form>

        {!isNew && (
          <div className="mt-4 border-t border-border/50 pt-4">
            <div className="mb-3 flex items-center justify-between gap-3">
              <div>
                <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Payment history</p>
                <p className="text-[11px] text-muted-foreground/75">{payments.length} recorded</p>
              </div>
              <Button type="button" size="sm" variant="outline" disabled={paymentBusy} onClick={startAddPayment} className="h-8 gap-2 text-xs">
                <Plus className="h-3.5 w-3.5" />
                Add Payment
              </Button>
            </div>

            {paymentsLoading ? (
              <div className="rounded-lg border border-border/60 bg-muted/20 px-3 py-8 text-center text-sm text-muted-foreground">
                Loading payment history...
              </div>
            ) : payments.length === 0 ? (
              <div className="rounded-lg border border-dashed border-border/70 px-3 py-8 text-center text-sm text-muted-foreground">
                No payments recorded for this bill.
              </div>
            ) : (
              <div className="max-h-52 space-y-2 overflow-y-auto pr-1">
                {payments.map(payment => {
                  const linkedPayment = isTransactionLinkedPayment(payment);
                  return (
                    <div key={payment.id} className="flex items-start justify-between gap-3 rounded-lg border border-border/60 bg-background/35 px-3 py-2.5">
                      <div className="min-w-0">
                        <div className="flex flex-wrap items-center gap-2">
                          <p className="font-mono text-sm font-semibold text-foreground">{fmt(payment.amount)}</p>
                          <span className={cn(
                            'rounded-md border px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide',
                            paymentSourceTone(payment.payment_source),
                          )}>
                            {paymentSourceLabel(payment.payment_source)}
                          </span>
                        </div>
                        <p className="mt-0.5 truncate text-xs text-muted-foreground">
                          {fmtDate(payment.paid_date)} · {payment.method || 'manual'}
                        </p>
                        {payment.notes && (
                          <p className="mt-0.5 truncate text-xs text-muted-foreground/80">{payment.notes}</p>
                        )}
                      </div>
                      <div className="flex shrink-0 gap-1">
                        {linkedPayment ? (
                          <span className="inline-flex h-8 items-center gap-1.5 rounded-md border border-primary/20 bg-primary/5 px-2 text-[11px] font-medium text-primary">
                            <Link2 className="h-3.5 w-3.5" />
                            Matched
                          </span>
                        ) : (
                          <>
                            <Button type="button" size="icon" variant="ghost" disabled={paymentBusy} onClick={() => startEditPayment(payment)} className="h-8 w-8" aria-label="Edit payment">
                              <Pencil className="h-3.5 w-3.5" />
                            </Button>
                            <Button type="button" size="icon" variant="ghost" disabled={paymentBusy} onClick={() => setDeletePaymentTarget(payment)} className="h-8 w-8 text-destructive hover:bg-destructive/10 hover:text-destructive" aria-label="Remove payment">
                              <Trash2 className="h-3.5 w-3.5" />
                            </Button>
                          </>
                        )}
                      </div>
                    </div>
                  );
                })}
              </div>
            )}

            <div className="mt-4 rounded-lg border border-border/60 bg-background/35">
              <div className="flex items-center justify-between gap-3 border-b border-border/50 px-3 py-2.5">
                <div className="min-w-0">
                  <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Linked transactions</p>
                  <p className="text-[11px] text-muted-foreground/75">{linkedTransactions.length} confirmed matches</p>
                </div>
                <span className={cn(
                  'inline-flex h-7 items-center gap-1.5 rounded-md border px-2 text-[11px] font-medium',
                  linkedTransactions.length > 0
                    ? 'border-primary/20 bg-primary/5 text-primary'
                    : 'border-border/60 bg-muted/30 text-muted-foreground',
                )}>
                  <Link2 className="h-3.5 w-3.5" />
                  {linkedTransactions.length}
                </span>
              </div>

              {linkedTransactionsLoading ? (
                <div className="px-3 py-8 text-center text-sm text-muted-foreground">
                  Loading linked transactions...
                </div>
              ) : linkedTransactions.length === 0 ? (
                <div className="flex items-center justify-center gap-2 px-3 py-8 text-sm text-muted-foreground">
                  <Link2Off className="h-4 w-4" />
                  No transactions linked to this bill yet.
                </div>
              ) : (
                <div className="max-h-56 divide-y divide-border/40 overflow-y-auto">
                  {linkedTransactions.map(transaction => (
                    <div key={transaction.id} className="flex items-start justify-between gap-3 px-3 py-3">
                      <div className="min-w-0">
                        <div className="flex flex-wrap items-center gap-2">
                          <p className="truncate text-sm font-medium text-foreground">{transactionTitle(transaction)}</p>
                          <span className="rounded-md border border-border/60 bg-muted/40 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
                            {transaction.source_label || transaction.source_type_label || 'Transaction'}
                          </span>
                        </div>
                        <p className="mt-0.5 truncate text-xs text-muted-foreground">
                          {transactionDate(transaction) ? fmtDate(transactionDate(transaction)) : 'No date'} · {transaction.description || transaction.memo || 'No description'}
                        </p>
                        {transaction.account_name && (
                          <p className="mt-0.5 truncate text-[11px] text-muted-foreground/75">{transaction.account_name}</p>
                        )}
                      </div>
                      <div className="flex shrink-0 flex-col items-end gap-2 sm:flex-row sm:items-center">
                        <p className={cn(
                          'font-mono text-sm font-semibold tabular-nums',
                          Number(transaction.amount) < 0 ? 'text-destructive' : 'text-emerald-600',
                        )}>
                          {fmtTransactionAmount(transaction.amount, transaction.currency)}
                        </p>
                        <Button
                          type="button"
                          size="sm"
                          variant="outline"
                          disabled={transactionBusyId === transaction.id}
                          onClick={() => handleUnmatchTransaction(transaction)}
                          className="h-8 gap-1.5 text-xs"
                        >
                          <Link2Off className="h-3.5 w-3.5" />
                          {transactionBusyId === transaction.id ? 'Unmatching...' : 'Unmatch'}
                        </Button>
                      </div>
                    </div>
                  ))}
                </div>
              )}
            </div>

            {paymentFormOpen && (
              <form onSubmit={handlePaymentSubmit} className="mt-3 rounded-lg border border-border/60 bg-muted/20 p-3">
                <div className="mb-3 flex items-center justify-between gap-3">
                  <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">
                    {editingPayment ? 'Edit payment' : 'Add payment'}
                  </p>
                  <span className="rounded-md border border-emerald-500/25 bg-emerald-500/10 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-emerald-600 dark:text-emerald-400">
                    manual
                  </span>
                </div>
                <div className="grid gap-3 sm:grid-cols-2">
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Amount ($)</Label>
                    <Input
                      type="number"
                      min="0"
                      step="0.01"
                      value={paymentAmount}
                      onChange={e => setPaymentAmount(e.target.value)}
                      className={cn(inp, 'font-mono')}
                      required
                    />
                  </div>
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Paid Date</Label>
                    <Input
                      type="date"
                      value={paymentDate}
                      onChange={e => setPaymentDate(e.target.value)}
                      className={cn(inp, 'font-mono')}
                      required
                    />
                  </div>
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Method</Label>
                    <Select value={paymentMethod} onValueChange={setPaymentMethod}>
                      <SelectTrigger className={cn(inp, 'w-full')}>
                        <SelectValue />
                      </SelectTrigger>
                      <SelectContent>
                        {PAYMENT_METHODS.map(([value, label]) => (
                          <SelectItem key={value} value={value}>{label}</SelectItem>
                        ))}
                      </SelectContent>
                    </Select>
                  </div>
                  <div className="space-y-1.5">
                    <Label className="text-xs uppercase tracking-wider text-muted-foreground">Notes</Label>
                    <Input
                      value={paymentNotes}
                      onChange={e => setPaymentNotes(e.target.value)}
                      className={inp}
                      placeholder="Paid from checking"
                    />
                  </div>
                </div>
                <div className="mt-3 flex justify-end gap-2">
                  <Button
                    type="button"
                    variant="ghost"
                    disabled={paymentBusy}
                    onClick={() => {
                      resetPaymentForm();
                      setPaymentFormOpen(false);
                    }}
                    className="text-xs"
                  >
                    Cancel
                  </Button>
                  <Button type="submit" disabled={paymentBusy} className="text-xs">
                    {paymentBusy ? 'Saving...' : editingPayment ? 'Save Payment' : 'Add Payment'}
                  </Button>
                </div>
              </form>
            )}
          </div>
        )}

        <DialogFooter className="mt-2 gap-2 sm:justify-between">
          {!isNew && onDuplicate && (
            <Button
              type="button"
              variant="outline"
              disabled={busy}
              onClick={() => onDuplicate(bill)}
              className="gap-2 text-xs"
            >
              <Copy className="h-3.5 w-3.5" />
              Duplicate
            </Button>
          )}
          <div className="flex gap-2">
          <Button type="button" variant="ghost" disabled={busy} onClick={onClose} className="text-xs">
            Cancel
          </Button>
          <Button type="submit" form="bill-modal-form" disabled={busy} className="text-xs">
            {isNew ? 'Add Bill' : 'Save Changes'}
          </Button>
          </div>
        </DialogFooter>

        <AlertDialog
          open={!!deletePaymentTarget}
          onOpenChange={open => {
            if (!open && !paymentBusy) setDeletePaymentTarget(null);
          }}
        >
          <AlertDialogContent>
            <AlertDialogHeader>
              <AlertDialogTitle>Remove this payment?</AlertDialogTitle>
              <AlertDialogDescription>
                This moves the payment to recovery and removes it from bill status calculations.
              </AlertDialogDescription>
            </AlertDialogHeader>
            <AlertDialogFooter>
              <AlertDialogCancel disabled={paymentBusy}>Cancel</AlertDialogCancel>
              <AlertDialogAction
                disabled={paymentBusy}
                onClick={handleDeletePayment}
                className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
              >
                {paymentBusy ? 'Removing...' : 'Remove Payment'}
              </AlertDialogAction>
            </AlertDialogFooter>
          </AlertDialogContent>
        </AlertDialog>
      </DialogContent>
    </Dialog>
  );
}