import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import { Link } from 'react-router-dom';
import { toast } from 'sonner';
import {
  Bell,
  CalendarDays,
  CheckCircle2,
  CheckCircle,
  Cloud,
  ArrowDown,
  ArrowUp,
  GripVertical,
  AlertTriangle,
  Info,
  Link2,
  Loader2,
  Pause,
  Plus,
  RefreshCw,
  Repeat,
  Search,
  Sparkles,
  X,
} from 'lucide-react';
import { api } from '@/api';
import { cn, fmt, fmtDate } from '@/lib/utils';
import { scheduleLabel } from '@/lib/billingSchedule';
import { Button } from '@/components/ui/button';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Badge } from '@/components/ui/badge';
import { Input } from '@/components/ui/input';
import {
  Dialog, DialogContent, DialogFooter, DialogHeader, DialogTitle,
} from '@/components/ui/dialog';
import BillModal from '@/components/BillModal';
import { moveInArray, movedItemId, reorderPayload } from '@/lib/reorder';

const TYPE_LABELS = {
  streaming: 'Streaming',
  software: 'Software',
  cloud: 'Cloud',
  music: 'Music',
  news: 'News',
  fitness: 'Fitness',
  gaming: 'Gaming',
  utilities: 'Utilities',
  insurance: 'Insurance',
  food: 'Food',
  education: 'Education',
  shopping: 'Shopping',
  security: 'Security',
  other: 'Other',
};

function cycleLabel(item) {
  return scheduleLabel(item);
}

function StatCard({ icon: Icon, label, value, hint }) {
  return (
    <div className="min-w-0 rounded-lg border border-border/70 bg-card/80 p-4">
      <div className="flex items-center gap-2 text-xs font-semibold uppercase tracking-wide text-foreground/70">
        <Icon className="h-4 w-4 text-primary" />
        <span className="truncate">{label}</span>
      </div>
      <p className="tracker-number mt-2 truncate text-2xl font-bold tracking-tight text-foreground">{value}</p>
      {hint && <p className="mt-1 text-xs font-medium text-muted-foreground">{hint}</p>}
    </div>
  );
}

function SubscriptionRow({ item, onEdit, onToggle, moveControls, dragProps }) {
  return (
    <div
      draggable={dragProps?.draggable}
      onDragStart={dragProps?.onDragStart}
      onDragEnter={dragProps?.onDragEnter}
      onDragOver={dragProps?.onDragOver}
      onDragEnd={dragProps?.onDragEnd}
      onDrop={dragProps?.onDrop}
      className={cn(
      'group',
      'grid min-w-0 gap-3 border-b border-border/40 px-4 py-4 last:border-b-0',
      'md:grid-cols-[auto_minmax(0,1fr)_14rem_auto] md:items-center',
      !item.active && 'opacity-60',
      dragProps?.isDragging && 'opacity-45',
      dragProps?.isDropTarget && 'ring-2 ring-inset ring-primary/35',
    )}>
      <div className="flex shrink-0 items-center gap-0.5 self-start md:self-center">
        <GripVertical
          className={cn(
            'h-4 w-4 text-muted-foreground/55',
            moveControls?.enabled && 'cursor-grab group-active:cursor-grabbing',
            !moveControls?.enabled && 'opacity-30',
          )}
          aria-hidden="true"
        />
        <div className="flex flex-col">
          <button
            type="button"
            onClick={moveControls?.onMoveUp}
            disabled={!moveControls?.enabled || !moveControls?.canMoveUp || moveControls?.moving}
            className="rounded text-muted-foreground transition-colors hover:bg-accent hover:text-foreground disabled:pointer-events-none disabled:opacity-25"
            title="Move subscription up"
            aria-label={`Move ${item.name} up`}
          >
            <ArrowUp className="h-3 w-3" />
          </button>
          <button
            type="button"
            onClick={moveControls?.onMoveDown}
            disabled={!moveControls?.enabled || !moveControls?.canMoveDown || moveControls?.moving}
            className="rounded text-muted-foreground transition-colors hover:bg-accent hover:text-foreground disabled:pointer-events-none disabled:opacity-25"
            title="Move subscription down"
            aria-label={`Move ${item.name} down`}
          >
            <ArrowDown className="h-3 w-3" />
          </button>
        </div>
      </div>
      <div className="min-w-0 flex-1">
        <div className="flex flex-wrap items-center gap-2">
          <button
            type="button"
            onClick={() => onEdit(item)}
            className="min-w-0 max-w-full truncate text-left text-[15px] font-semibold text-foreground hover:text-primary"
          >
            {item.name}
          </button>
          <Badge variant="outline" className="capitalize border-primary/25 bg-primary/10 text-primary">
            {TYPE_LABELS[item.subscription_type] || 'Other'}
          </Badge>
          {!item.active && (
            <Badge variant="outline" className="border-amber-500/25 bg-amber-500/10 text-amber-300">
              Paused
            </Badge>
          )}
        </div>
        <div className="mt-1 flex flex-wrap items-center gap-x-3 gap-y-1 text-xs font-medium text-muted-foreground">
          <span>{item.category_name || 'Uncategorized'}</span>
          <span>Due {fmtDate(item.next_due_date)}</span>
          <span className="capitalize">{cycleLabel(item)}</span>
          <span>{item.reminder_days_before ?? 3}d reminder</span>
        </div>
      </div>

      <div className="grid grid-cols-2 gap-3 md:w-56">
        <div>
          <p className="text-xs text-muted-foreground">Per cycle</p>
          <p className="tracker-number text-sm font-semibold text-foreground">{fmt(item.expected_amount)}</p>
        </div>
        <div>
          <p className="text-xs text-muted-foreground">Monthly</p>
          <p className="tracker-number text-sm font-semibold text-emerald-600 dark:text-emerald-300">{fmt(item.monthly_equivalent)}</p>
        </div>
      </div>

      <div className="flex gap-2 md:justify-end">
        <Button type="button" variant="outline" size="sm" className="flex-1 md:flex-none" onClick={() => onEdit(item)}>
          Edit
        </Button>
        <Button
          type="button"
          variant="ghost"
          size="sm"
          className={cn(
            'flex-1 md:flex-none',
            item.active ? 'text-amber-300 hover:bg-amber-500/10 hover:text-amber-200' : 'text-emerald-300 hover:bg-emerald-500/10 hover:text-emerald-200',
          )}
          onClick={() => onToggle(item)}
        >
          {item.active ? 'Pause' : 'Resume'}
        </Button>
      </div>
    </div>
  );
}

function BillPickerDialog({ open, onClose, recommendation, bills, onConfirm, busy }) {
  const [search, setSearch] = useState('');
  const [selectedId, setSelectedId] = useState(null);

  useEffect(() => { if (open) { setSearch(''); setSelectedId(null); } }, [open]);

  const filtered = useMemo(() => {
    const q = search.toLowerCase();
    return (bills || []).filter(b => !q || b.name.toLowerCase().includes(q));
  }, [bills, search]);

  return (
    <Dialog open={open} onOpenChange={v => { if (!v) onClose(); }}>
      <DialogContent className="max-w-md">
        <DialogHeader>
          <DialogTitle>Link to existing bill</DialogTitle>
          <p className="text-sm text-muted-foreground mt-1">
            <span className="font-medium text-foreground">{recommendation?.name}</span>
            {recommendation && (
              <span className="ml-2 text-xs">{recommendation.occurrence_count} charge{recommendation.occurrence_count !== 1 ? 's' : ''} · {fmt(recommendation.expected_amount)}</span>
            )}
          </p>
          <p className="text-xs text-muted-foreground">
            The matching transactions will be marked as paid under the selected bill.
          </p>
        </DialogHeader>

        <Input
          autoFocus
          placeholder="Search bills…"
          value={search}
          onChange={e => setSearch(e.target.value)}
          className="text-sm"
        />

        <div className="max-h-56 overflow-y-auto rounded-lg border border-border/60 divide-y divide-border/40">
          {filtered.length === 0 ? (
            <p className="px-3 py-4 text-sm text-muted-foreground text-center">No bills found.</p>
          ) : filtered.map(bill => (
            <button
              key={bill.id}
              type="button"
              onClick={() => setSelectedId(bill.id)}
              className={cn(
                'w-full flex items-center justify-between px-3 py-2.5 text-left text-sm transition-colors hover:bg-muted/40',
                selectedId === bill.id && 'bg-primary/10 text-primary',
              )}
            >
              <span className="truncate font-medium">{bill.name}</span>
              <span className="shrink-0 ml-3 text-xs text-muted-foreground tabular-nums">
                ${(bill.expected_amount ?? 0).toFixed(2)}/mo
              </span>
            </button>
          ))}
        </div>

        <DialogFooter>
          <Button variant="ghost" onClick={onClose} disabled={busy}>Cancel</Button>
          <Button onClick={() => onConfirm(selectedId)} disabled={!selectedId || busy}>
            {busy ? <><Loader2 className="h-3.5 w-3.5 animate-spin mr-1.5" />Linking…</> : 'Link to bill'}
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}

function TxResultRow({ tx, onTrack }) {
  const dollars = (Math.abs(tx.amount) / 100).toFixed(2);
  const label   = tx.payee || tx.description || tx.memo || '—';
  const account = tx.account_name || tx.data_source_name || null;
  const isMatched = tx.match_status === 'matched';
  const catalogMatch = tx.catalog_match;

  return (
    <div className="flex items-center gap-3 px-4 py-2.5 border-b border-border/30 last:border-0 hover:bg-muted/20 transition-colors">
      <div className="flex-1 min-w-0">
        <div className="flex flex-wrap items-center gap-1.5">
          <span className="text-sm font-medium truncate max-w-[200px]">{label}</span>
          {isMatched ? (
            <Badge className="shrink-0 border-emerald-400/25 bg-emerald-500/10 text-emerald-600 dark:text-emerald-400 gap-1 text-[10px]">
              <CheckCircle className="h-3 w-3" />
              {tx.matched_bill_name || 'Matched'}
            </Badge>
          ) : (
            <Badge variant="outline" className="shrink-0 text-[10px] text-muted-foreground">Unmatched</Badge>
          )}
          {catalogMatch && (
            <Badge variant="outline" className="shrink-0 border-primary/25 bg-primary/10 text-primary text-[10px]">
              Known: {catalogMatch.name}
            </Badge>
          )}
        </div>
        <p className="text-[11px] text-muted-foreground mt-0.5">
          {tx.posted_date}{account ? ` · ${account}` : ''}
          {catalogMatch ? ` · ${TYPE_LABELS[catalogMatch.subscription_type] || 'Other'}` : ''}
        </p>
      </div>
      <span className="font-mono text-sm font-semibold tabular-nums shrink-0">${dollars}</span>
      {!isMatched && (
        <Button size="sm" variant="outline" onClick={() => onTrack(tx)}
          className="shrink-0 h-7 px-2 text-xs gap-1">
          <Plus className="h-3 w-3" /> Track
        </Button>
      )}
    </div>
  );
}

function RecommendationCard({ recommendation, categoryId, onAccept, onDecline, onMatch, onDetails, busy }) {
  const identity = recommendation.evidence?.identity;
  const amount = recommendation.evidence?.amount;
  const cadence = recommendation.evidence?.cadence;
  const amountRange = recommendation.evidence?.amount_range;
  const ambiguity = recommendation.evidence?.ambiguity;

  return (
    <div className="rounded-lg border border-primary/20 bg-primary/[0.05] p-4">
      <div className="space-y-3">
        <div className="flex min-w-0 items-start justify-between gap-3">
          <div className="min-w-0 flex-1">
            <p className="truncate text-sm font-semibold text-foreground">{recommendation.name}</p>
            <p className="mt-1 text-xs font-medium text-muted-foreground">
              {TYPE_LABELS[recommendation.subscription_type] || 'Other'} · {recommendation.occurrence_count} charges · last seen {fmtDate(recommendation.last_seen_date)}
            </p>
            {recommendation.catalog_match?.starting_monthly_usd && (
              <p className="mt-1 text-xs font-medium text-muted-foreground">
                Catalog starts at {fmt(recommendation.catalog_match.starting_monthly_usd)} / mo
                {recommendation.catalog_match.starting_annual_usd
                  ? ` or ${fmt(recommendation.catalog_match.starting_annual_usd)} / yr`
                  : ''}
              </p>
            )}
            {recommendation.accounts?.length > 0 && (
              <p className="mt-1 truncate text-xs font-medium text-muted-foreground">
                {recommendation.accounts.length > 1 ? 'Accounts' : 'Account'}: {recommendation.accounts.join(', ')}
              </p>
            )}
          </div>
          <div className="shrink-0 text-right">
            <p className="tracker-number text-base font-semibold text-foreground">{fmt(recommendation.expected_amount)}</p>
            <p className="tracker-number text-xs font-semibold text-emerald-600 dark:text-emerald-300">
              {fmt(recommendation.monthly_equivalent)} / mo
            </p>
          </div>
        </div>

        <div className="flex min-w-0 flex-wrap items-center gap-2">
          <Badge variant="outline" className="border-primary/25 bg-primary/10 text-primary">
            {recommendation.confidence}% match
          </Badge>
          {identity?.label && (
            <Badge variant="outline" className="border-emerald-500/25 bg-emerald-500/10 text-emerald-600 dark:text-emerald-300">
              {identity.label}
            </Badge>
          )}
          {amount?.label && (
            <Badge
              variant="outline"
              className={cn(
                'text-[11px]',
                amount.match === 'unusual'
                  ? 'border-amber-500/25 bg-amber-500/10 text-amber-500'
                  : 'border-sky-500/25 bg-sky-500/10 text-sky-600 dark:text-sky-300',
              )}
            >
              {amount.match === 'unusual' ? 'Unusual amount' : 'Price checked'}
            </Badge>
          )}
          {cadence?.recurring && (
            <Badge variant="outline" className="border-violet-500/25 bg-violet-500/10 text-violet-600 dark:text-violet-300">
              Recurring
            </Badge>
          )}
          {ambiguity?.ambiguous && (
            <Badge variant="outline" className="gap-1 border-amber-500/25 bg-amber-500/10 text-amber-600 dark:text-amber-300">
              <AlertTriangle className="h-3 w-3" />
              Review
            </Badge>
          )}
          {amountRange && amountRange.min !== amountRange.max && (
            <span className="rounded-md border border-border/60 bg-background/60 px-2 py-1 text-[11px] font-medium text-muted-foreground">
              Range {fmt(amountRange.min)}-{fmt(amountRange.max)}
            </span>
          )}
          {recommendation.reasons?.map(reason => (
            <span key={reason} className="max-w-full rounded-md border border-border/60 bg-background/60 px-2 py-1 text-[11px] font-medium text-muted-foreground">
              {reason}
            </span>
          ))}
        </div>

        <div className="grid grid-cols-2 gap-2 min-[520px]:grid-cols-4">
          <Button
            type="button"
            size="sm"
            variant="outline"
            className="gap-1.5"
            disabled={busy}
            onClick={() => onDetails(recommendation)}
          >
            <Info className="h-3.5 w-3.5" />
            Details
          </Button>
          <Button
            type="button"
            size="sm"
            variant="ghost"
            className="gap-1.5 text-muted-foreground hover:text-destructive"
            disabled={busy}
            onClick={() => onDecline(recommendation)}
          >
            {busy ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <X className="h-3.5 w-3.5" />}
            Decline
          </Button>
          <Button
            type="button"
            size="sm"
            variant="outline"
            className="gap-1.5"
            disabled={busy}
            onClick={() => onMatch(recommendation)}
          >
            <Link2 className="h-3.5 w-3.5" />
            Link to bill
          </Button>
          <Button
            type="button"
            size="sm"
            className="gap-2"
            disabled={busy}
            onClick={() => onAccept({ ...recommendation, category_id: categoryId })}
          >
            {busy ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <CheckCircle2 className="h-3.5 w-3.5" />}
            Track
          </Button>
        </div>
      </div>
    </div>
  );
}

function EvidenceItem({ label, value, tone = 'default' }) {
  if (!value) return null;
  return (
    <div className={cn(
      'rounded-lg border px-3 py-2',
      tone === 'warn'
        ? 'border-amber-500/25 bg-amber-500/10'
        : 'border-border/60 bg-muted/20',
    )}>
      <p className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">{label}</p>
      <p className="mt-1 text-sm font-medium text-foreground">{value}</p>
    </div>
  );
}

function RecommendationDetailsDialog({ open, recommendation, categoryId, onClose, onAccept, onDecline, onMatch, busy }) {
  if (!recommendation) return null;

  const identity = recommendation.evidence?.identity;
  const amount = recommendation.evidence?.amount;
  const cadence = recommendation.evidence?.cadence;
  const amountRange = recommendation.evidence?.amount_range;
  const ambiguity = recommendation.evidence?.ambiguity;
  const transactions = recommendation.transactions || [];
  const handleAccept = async () => {
    await onAccept({ ...recommendation, category_id: categoryId });
    onClose();
  };
  const handleDecline = async () => {
    await onDecline(recommendation);
    onClose();
  };
  const handleMatch = () => {
    onMatch(recommendation);
    onClose();
  };

  return (
    <Dialog open={open} onOpenChange={value => { if (!value) onClose(); }}>
      <DialogContent className="max-h-[90vh] overflow-y-auto sm:max-w-2xl">
        <DialogHeader>
          <DialogTitle className="flex flex-wrap items-center gap-2">
            <span>{recommendation.name}</span>
            <Badge variant="outline" className="border-primary/25 bg-primary/10 text-primary">
              {recommendation.confidence}% match
            </Badge>
            {ambiguity?.ambiguous && (
              <Badge variant="outline" className="gap-1 border-amber-500/25 bg-amber-500/10 text-amber-600 dark:text-amber-300">
                <AlertTriangle className="h-3 w-3" />
                Review
              </Badge>
            )}
          </DialogTitle>
          <p className="text-sm text-muted-foreground">
            {TYPE_LABELS[recommendation.subscription_type] || 'Other'} · {recommendation.occurrence_count} charge{recommendation.occurrence_count !== 1 ? 's' : ''} · last seen {fmtDate(recommendation.last_seen_date)}
          </p>
        </DialogHeader>

        <div className="grid gap-3 sm:grid-cols-2">
          <EvidenceItem label="Expected" value={`${fmt(recommendation.expected_amount)} ${recommendation.cycle_type || 'monthly'}`} />
          <EvidenceItem label="Monthly" value={`${fmt(recommendation.monthly_equivalent)} / mo`} />
          <EvidenceItem label="Identity" value={identity?.label} />
          <EvidenceItem label="Price" value={amount?.label} tone={amount?.match === 'unusual' ? 'warn' : 'default'} />
          <EvidenceItem label="Cadence" value={cadence?.label} />
          <EvidenceItem
            label="Catalog"
            value={recommendation.catalog_match
              ? [
                  recommendation.catalog_match.name,
                  recommendation.catalog_match.starting_monthly_usd ? `from ${fmt(recommendation.catalog_match.starting_monthly_usd)} / mo` : null,
                ].filter(Boolean).join(' · ')
              : null}
          />
        </div>

        {amountRange && (
          <div className="rounded-lg border border-border/60 bg-muted/20 px-3 py-2">
            <p className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">Amount Range</p>
            <p className="mt-1 text-sm font-medium text-foreground">
              {fmt(amountRange.min)}-{fmt(amountRange.max)} across matching transactions
            </p>
          </div>
        )}

        {ambiguity?.ambiguous && (
          <div className="rounded-lg border border-amber-500/25 bg-amber-500/10 px-3 py-2">
            <p className="flex items-center gap-1.5 text-sm font-semibold text-amber-700 dark:text-amber-300">
              <AlertTriangle className="h-4 w-4" />
              {ambiguity.label || 'Review before tracking'}
            </p>
            {ambiguity.reasons?.length > 0 && (
              <div className="mt-2 space-y-1 text-sm text-muted-foreground">
                {ambiguity.reasons.map(reason => (
                  <p key={reason}>{reason}</p>
                ))}
              </div>
            )}
          </div>
        )}

        {recommendation.reasons?.length > 0 && (
          <div className="flex flex-wrap gap-2">
            {recommendation.reasons.map(reason => (
              <span key={reason} className="rounded-md border border-border/60 bg-background/60 px-2 py-1 text-[11px] font-medium text-muted-foreground">
                {reason}
              </span>
            ))}
          </div>
        )}

        {transactions.length > 0 && (
          <div className="overflow-hidden rounded-lg border border-border/60">
            <div className="border-b border-border/50 bg-muted/20 px-3 py-2">
              <p className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">
                Bank Transactions
              </p>
            </div>
            <div className="divide-y divide-border/40">
              {transactions.map(tx => (
                <div key={tx.id} className="grid gap-1 px-3 py-2.5 sm:grid-cols-[1fr_auto] sm:items-center">
                  <div className="min-w-0">
                    <p className="truncate text-sm font-medium text-foreground">
                      {tx.payee || tx.description || tx.memo || 'Transaction'}
                    </p>
                    <p className="truncate text-xs text-muted-foreground">
                      {fmtDate(tx.date)}{tx.account ? ` · ${tx.account}` : ''}
                    </p>
                  </div>
                  <p className="tracker-number text-sm font-semibold text-foreground">{fmt(tx.amount)}</p>
                </div>
              ))}
            </div>
          </div>
        )}

        <DialogFooter className="gap-2 sm:gap-0">
          <Button variant="ghost" onClick={handleDecline} disabled={busy} className="gap-1.5 text-muted-foreground hover:text-destructive">
            {busy ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <X className="h-3.5 w-3.5" />}
            Decline
          </Button>
          <Button variant="outline" onClick={handleMatch} disabled={busy} className="gap-1.5">
            <Link2 className="h-3.5 w-3.5" />
            Link to bill
          </Button>
          <Button onClick={handleAccept} disabled={busy} className="gap-2">
            {busy ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <CheckCircle2 className="h-3.5 w-3.5" />}
            Track
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}

export default function SubscriptionsPage() {
  const [data, setData] = useState({ summary: {}, subscriptions: [] });
  const [recommendations, setRecommendations] = useState([]);
  const [categories, setCategories] = useState([]);
  const [bills, setBills] = useState([]);
  const [loading, setLoading] = useState(true);
  const [recommendationsLoading, setRecommendationsLoading] = useState(true);
  const [busyId, setBusyId] = useState(null);
  const [modal, setModal] = useState(null);
  const [matchTarget, setMatchTarget] = useState(null);
  const [detailsTarget, setDetailsTarget] = useState(null);
  const [recSearch, setRecSearch] = useState('');
  const [draggingId, setDraggingId] = useState(null);
  const [dropTargetId, setDropTargetId] = useState(null);
  const [movingBillId, setMovingBillId] = useState(null);

  const [txQuery, setTxQuery]         = useState('');
  const [txResults, setTxResults]     = useState([]);
  const [txSearching, setTxSearching] = useState(false);
  const txDebounce = useRef(null);

  const subscriptionCategoryId = useMemo(() => {
    const match = categories.find(category => /subscrip/i.test(category.name));
    return match?.id || null;
  }, [categories]);

  const load = useCallback(async () => {
    setLoading(true);
    try {
      const [subscriptionData, categoryData] = await Promise.all([
        api.subscriptions(),
        api.categories(),
      ]);
      setData(subscriptionData);
      setCategories(categoryData || []);
    } catch (err) {
      toast.error(err.message || 'Failed to load subscriptions.');
    } finally {
      setLoading(false);
    }
  }, []);

  const loadRecommendations = useCallback(async () => {
    setRecommendationsLoading(true);
    try {
      const result = await api.subscriptionRecommendations();
      setRecommendations(result.recommendations || []);
    } catch (err) {
      toast.error(err.message || 'Failed to scan subscription recommendations.');
    } finally {
      setRecommendationsLoading(false);
    }
  }, []);

  useEffect(() => {
    load();
    loadRecommendations();
    api.allBills()
      .then(b => setBills(Array.isArray(b) ? b : []))
      .catch(err => {
        console.error('[SubscriptionsPage] failed to load bills', err);
        toast.error(err.message || 'Bills could not be loaded for subscription linking.');
      });
  }, [load, loadRecommendations]);

  useEffect(() => {
    clearTimeout(txDebounce.current);
    const q = txQuery.trim();
    if (!q) { setTxResults([]); return; }
    txDebounce.current = setTimeout(async () => {
      setTxSearching(true);
      try {
        const result = await api.subscriptionTransactionMatches({ q, limit: 50 });
        setTxResults(Array.isArray(result) ? result : (result?.transactions ?? []));
      } catch (err) {
        setTxResults([]);
        toast.error(err.message || 'Transaction search failed.');
      }
      finally { setTxSearching(false); }
    }, 300);
    return () => clearTimeout(txDebounce.current);
  }, [txQuery]);

  async function refreshAll() {
    await Promise.all([load(), loadRecommendations()]);
  }

  async function toggleSubscription(item) {
    setBusyId(`toggle-${item.id}`);
    try {
      await api.updateSubscription(item.id, { active: !item.active });
      toast.success(item.active ? 'Subscription paused' : 'Subscription resumed');
      await load();
    } catch (err) {
      toast.error(err.message || 'Subscription could not be updated.');
    } finally {
      setBusyId(null);
    }
  }

  async function acceptRecommendation(recommendation) {
    setBusyId(`rec-${recommendation.id}`);
    try {
      await api.createSubscriptionFromRecommendation(recommendation);
      toast.success(`${recommendation.name} is now tracked.`);
      await refreshAll();
    } catch (err) {
      toast.error(err.message || 'Could not create subscription.');
    } finally {
      setBusyId(null);
    }
  }

  async function declineRecommendation(recommendation) {
    if (!recommendation.decline_key) return;
    setBusyId(`dec-${recommendation.id}`);
    try {
      await api.declineRecommendation(recommendation.decline_key);
      setRecommendations(prev => prev.filter(r => r.id !== recommendation.id));
    } catch (err) {
      toast.error(err.message || 'Could not dismiss recommendation.');
    } finally {
      setBusyId(null);
    }
  }

  async function matchRecommendationToBill(billId) {
    if (!matchTarget || !billId) return;
    setBusyId(`match-${matchTarget.id}`);
    try {
      const result = await api.matchRecommendationToBill(matchTarget.transaction_ids, billId, matchTarget.merchant);
      toast.success(`Linked ${result.matched_count} transaction${result.matched_count !== 1 ? 's' : ''} to "${result.bill_name}".`);
      setMatchTarget(null);
      setRecommendations(prev => prev.filter(r => r.id !== matchTarget.id));
    } catch (err) {
      toast.error(err.message || 'Could not link recommendation to bill.');
    } finally {
      setBusyId(null);
    }
  }

  function openManualSubscription() {
    setModal({
      bill: null,
      initialBill: {
        name: '',
        category_id: subscriptionCategoryId,
        due_day: new Date().getDate(),
        expected_amount: '',
        billing_cycle: 'monthly',
        cycle_type: 'monthly',
        cycle_day: String(new Date().getDate()),
        is_subscription: 1,
        subscription_type: 'other',
        reminder_days_before: 3,
      },
    });
  }

  function openFromTransaction(tx) {
    const catalogMatch = tx.catalog_match;
    const label   = catalogMatch?.name || tx.payee || tx.description || tx.memo || '';
    const dollars = Math.abs(tx.amount ?? 0) / 100;
    const rawDay  = tx.posted_date ? new Date(tx.posted_date + 'T12:00:00').getDate() : NaN;
    const dueDay  = Number.isInteger(rawDay) && rawDay >= 1 && rawDay <= 31 ? rawDay : new Date().getDate();
    setModal({
      bill: null,
      initialBill: {
        name: label,
        category_id: subscriptionCategoryId,
        due_day: dueDay,
        expected_amount: dollars > 0 ? dollars.toFixed(2) : '',
        cycle_type: 'monthly',
        is_subscription: 1,
        subscription_type: catalogMatch?.subscription_type || 'other',
        website: catalogMatch?.website || undefined,
        notes: catalogMatch
          ? `Matched known subscription catalog entry: ${catalogMatch.name}`
          : undefined,
        reminder_days_before: 3,
      },
    });
  }

  const summary = data.summary || {};
  const subscriptions = data.subscriptions || [];
  const active = subscriptions.filter(item => item.active);
  const paused = subscriptions.filter(item => !item.active);
  const reorderEnabled = !loading && bills.length > 0;

  async function persistSubscriptionOrder(nextSubscriptions, nextBills, movedId) {
    setData(prev => ({ ...prev, subscriptions: nextSubscriptions }));
    setBills(nextBills);
    setMovingBillId(movedId);
    try {
      await api.reorderBills(reorderPayload(nextBills));
      toast.success('Subscription order saved');
      await load();
      api.allBills().then(b => setBills(Array.isArray(b) ? b : [])).catch(err => console.error('[SubscriptionsPage] failed to refresh bills after reorder', err));
    } catch (err) {
      toast.error(err.message || 'Failed to save subscription order');
      await load();
    } finally {
      setMovingBillId(null);
    }
  }

  function reorderSubscriptionGroup(activeState, orderedGroup) {
    const sourceGroup = subscriptions.filter(item => !!item.active === activeState);
    const replacements = [...orderedGroup];
    const nextSubscriptions = subscriptions.map(item => (
      !!item.active === activeState ? replacements.shift() : item
    ));

    const sourceBills = bills.length ? bills : subscriptions;
    const affectedIds = new Set(sourceGroup.map(item => item.id));
    const billById = new Map(sourceBills.map(item => [item.id, item]));
    const orderedBills = orderedGroup.map(item => ({ ...(billById.get(item.id) || item), ...item }));
    const nextBills = sourceBills.map(bill => (
      affectedIds.has(bill.id) ? orderedBills.shift() : bill
    ));
    persistSubscriptionOrder(nextSubscriptions, nextBills, movedItemId(sourceGroup, orderedGroup));
  }

  function moveControlsForGroup(group, activeState) {
    return (item, index) => ({
      enabled: reorderEnabled,
      moving: movingBillId === item.id,
      canMoveUp: index > 0,
      canMoveDown: index < group.length - 1,
      onMoveUp: () => reorderSubscriptionGroup(activeState, moveInArray(group, index, index - 1)),
      onMoveDown: () => reorderSubscriptionGroup(activeState, moveInArray(group, index, index + 1)),
    });
  }

  function dragPropsForGroup(group, activeState) {
    return (item, index) => {
      if (!reorderEnabled) return { draggable: false };
      return {
        draggable: true,
        isDragging: draggingId === item.id,
        isDropTarget: dropTargetId === item.id && draggingId !== item.id,
        onDragStart: (event) => {
          setDraggingId(item.id);
          event.dataTransfer.effectAllowed = 'move';
          event.dataTransfer.setData('text/plain', String(item.id));
        },
        onDragEnter: () => {
          if (draggingId && draggingId !== item.id) setDropTargetId(item.id);
        },
        onDragOver: (event) => {
          event.preventDefault();
          event.dataTransfer.dropEffect = 'move';
          if (draggingId && draggingId !== item.id) setDropTargetId(item.id);
        },
        onDrop: (event) => {
          event.preventDefault();
          const sourceId = Number(event.dataTransfer.getData('text/plain') || draggingId);
          const fromIndex = group.findIndex(row => row.id === sourceId);
          if (fromIndex >= 0) reorderSubscriptionGroup(activeState, moveInArray(group, fromIndex, index));
          setDraggingId(null);
          setDropTargetId(null);
        },
        onDragEnd: () => {
          setDraggingId(null);
          setDropTargetId(null);
        },
      };
    };
  }

  const MIN_CONFIDENCE = 90;
  const highConfidenceRecs = useMemo(
    () => recommendations.filter(r => r.catalog_match && (r.confidence ?? 0) >= MIN_CONFIDENCE),
    [recommendations],
  );
  const filteredRecs = useMemo(() => {
    const q = recSearch.trim().toLowerCase();
    return q ? highConfidenceRecs.filter(r => r.name?.toLowerCase().includes(q)) : highConfidenceRecs;
  }, [highConfidenceRecs, recSearch]);

  return (
    <div className="mx-auto w-full max-w-6xl space-y-6">
      <div className="flex flex-col gap-4 lg:flex-row lg:items-end lg:justify-between">
        <div className="min-w-0">
          <p className="mb-1 text-[11px] font-semibold uppercase tracking-[0.15em] text-muted-foreground">
            Recurring Services
          </p>
          <h1 className="text-3xl font-semibold tracking-tight">Subscriptions</h1>
          <p className="mt-1 text-sm text-muted-foreground">
            Track manual subscriptions and review recurring SimpleFIN charges.
          </p>
        </div>
        <div className="grid grid-cols-2 gap-2 sm:flex sm:flex-wrap">
          <Button type="button" variant="outline" className="gap-2" onClick={refreshAll} disabled={loading || recommendationsLoading}>
            <RefreshCw className={cn('h-4 w-4', (loading || recommendationsLoading) && 'animate-spin')} />
            Refresh
          </Button>
          <Button type="button" className="gap-2" onClick={openManualSubscription}>
            <Plus className="h-4 w-4" />
            Add Subscription
          </Button>
        </div>
      </div>

      <div className="grid gap-3 sm:grid-cols-2 xl:grid-cols-4">
        <StatCard icon={Repeat} label="Monthly" value={fmt(summary.monthly_total)} hint={`${summary.active_count || 0} active subscriptions`} />
        <StatCard icon={CalendarDays} label="Yearly" value={fmt(summary.yearly_total)} hint="Normalized yearly impact" />
        <StatCard icon={Pause} label="Paused" value={summary.paused_count || 0} hint="Kept but not active" />
        <StatCard icon={Cloud} label="Top Type" value={summary.top_type ? TYPE_LABELS[summary.top_type.type] || summary.top_type.type : '—'} hint={summary.top_type ? `${fmt(summary.top_type.monthly_total)} / mo` : 'No active subscriptions'} />
      </div>

      <div className="grid min-w-0 gap-5 2xl:grid-cols-[minmax(0,1fr)_minmax(360px,420px)]">
        <Card className="overflow-hidden">
          <CardHeader className="px-4 pb-3 sm:px-6">
            <CardTitle className="text-base">Tracked Subscriptions</CardTitle>
            <CardDescription>Subscriptions are bills with recurring-service metadata.</CardDescription>
          </CardHeader>
          <CardContent className="p-0">
            {loading ? (
              <div className="p-4">
                {Array.from({ length: 4 }).map((_, index) => (
                  <div key={index} className="mb-2 h-20 animate-pulse rounded-lg bg-muted/40" />
                ))}
              </div>
            ) : subscriptions.length === 0 ? (
              <div className="px-4 py-14 text-center">
                <Repeat className="mx-auto h-8 w-8 text-muted-foreground" />
                <p className="mt-3 text-sm font-medium">No subscriptions tracked yet.</p>
                <p className="mt-1 text-sm text-muted-foreground">Add one manually or accept a SimpleFIN recommendation.</p>
              </div>
            ) : (
              <>
                {active.map((item, index) => (
                  <SubscriptionRow
                    key={item.id}
                    item={item}
                    onEdit={bill => setModal({ bill })}
                    onToggle={toggleSubscription}
                    moveControls={moveControlsForGroup(active, true)(item, index)}
                    dragProps={dragPropsForGroup(active, true)(item, index)}
                  />
                ))}
                {paused.map((item, index) => (
                  <SubscriptionRow
                    key={item.id}
                    item={item}
                    onEdit={bill => setModal({ bill })}
                    onToggle={toggleSubscription}
                    moveControls={moveControlsForGroup(paused, false)(item, index)}
                    dragProps={dragPropsForGroup(paused, false)(item, index)}
                  />
                ))}
              </>
            )}
          </CardContent>
        </Card>

        <Card className="overflow-hidden">
          <CardHeader className="px-4 pb-3 sm:px-6">
            <div className="flex items-center gap-2">
              <Sparkles className="h-4 w-4 text-primary" />
              <CardTitle className="text-base">Recommendations</CardTitle>
              {!recommendationsLoading && highConfidenceRecs.length > 0 && (
                <span className="ml-auto text-[11px] font-medium text-muted-foreground tabular-nums">
                  {filteredRecs.length} of {highConfidenceRecs.length}
                </span>
              )}
            </div>
            <CardDescription>Known subscription services found in your bank transactions with 90%+ confidence.</CardDescription>
            {!recommendationsLoading && highConfidenceRecs.length > 0 && (
              <div className="relative mt-2">
                <Search className="absolute left-2.5 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground pointer-events-none" />
                <Input
                  type="search"
                  placeholder="Search recommendations…"
                  value={recSearch}
                  onChange={e => setRecSearch(e.target.value)}
                  className="pl-8 h-8 text-sm"
                />
              </div>
            )}
          </CardHeader>
          <CardContent className="space-y-3">
            {recommendationsLoading ? (
              <div className="rounded-lg border border-border/60 bg-muted/20 px-4 py-10 text-center text-sm text-muted-foreground">
                Scanning transactions…
              </div>
            ) : highConfidenceRecs.length === 0 ? (
              <div className="rounded-lg border border-dashed border-border/70 px-4 py-10 text-center">
                <Bell className="mx-auto h-7 w-7 text-muted-foreground" />
                <p className="mt-3 text-sm font-medium">No high-confidence recommendations.</p>
                <p className="mt-1 text-sm text-muted-foreground">
                  {recommendations.length > 0
                    ? 'More account activity or stronger descriptors will improve accuracy.'
                    : 'Sync your accounts after charges from known subscription services appear.'}
                </p>
              </div>
            ) : filteredRecs.length === 0 ? (
              <div className="rounded-lg border border-dashed border-border/70 px-4 py-8 text-center">
                <Search className="mx-auto h-6 w-6 text-muted-foreground" />
                <p className="mt-3 text-sm font-medium">No matches for "{recSearch}"</p>
                <button
                  type="button"
                  className="mt-1 text-xs text-primary hover:underline"
                  onClick={() => setRecSearch('')}
                >
                  Clear search
                </button>
              </div>
            ) : (
              filteredRecs.map(recommendation => (
                <RecommendationCard
                  key={recommendation.id}
                  recommendation={recommendation}
                  categoryId={subscriptionCategoryId}
                  busy={busyId === `rec-${recommendation.id}` || busyId === `dec-${recommendation.id}` || busyId === `match-${recommendation.id}`}
                  onAccept={acceptRecommendation}
                  onDecline={declineRecommendation}
                  onMatch={rec => setMatchTarget(rec)}
                  onDetails={setDetailsTarget}
                />
              ))
            )}
          </CardContent>
        </Card>
      </div>

      {/* Transaction search */}
      <Card className="overflow-hidden">
        <CardHeader className="px-4 pb-3 sm:px-6">
          <div className="flex items-center gap-2">
            <Search className="h-4 w-4 text-primary" />
            <CardTitle className="text-base">Search Bank Transactions</CardTitle>
          </div>
          <CardDescription>
            Search all account charges — matched and unmatched — to find subscriptions the algorithm may have missed.
          </CardDescription>
          <div className="relative mt-2">
            <Search className="absolute left-2.5 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground pointer-events-none" />
            <Input
              type="search"
              placeholder="Search by merchant, description, or payee…"
              value={txQuery}
              onChange={e => setTxQuery(e.target.value)}
              className="pl-8 h-9 text-sm"
              autoComplete="off"
            />
          </div>
        </CardHeader>

        {(txQuery.trim() || txSearching) && (
          <CardContent className="p-0">
            {txSearching ? (
              <div className="flex items-center justify-center gap-2 py-8 text-sm text-muted-foreground">
                <Loader2 className="h-4 w-4 animate-spin" />
                Searching transactions…
              </div>
            ) : txResults.length === 0 ? (
              <div className="px-4 py-8 text-center">
                <Search className="mx-auto h-7 w-7 text-muted-foreground" />
                <p className="mt-3 text-sm font-medium">No transactions found for "{txQuery}"</p>
                <p className="mt-1 text-xs text-muted-foreground">Try a different merchant name or description.</p>
              </div>
            ) : (
              <div>
                <div className="px-4 py-2 border-b border-border/40 bg-muted/20">
                  <p className="text-[11px] font-semibold uppercase tracking-wider text-muted-foreground">
                    {txResults.length} result{txResults.length !== 1 ? 's' : ''}
                    {txResults.length === 50 ? ' (showing first 50)' : ''}
                  </p>
                </div>
                {txResults.map(tx => (
                  <TxResultRow key={tx.id} tx={tx} onTrack={openFromTransaction} />
                ))}
              </div>
            )}
          </CardContent>
        )}
      </Card>

      <Card className="overflow-hidden">
        <CardHeader className="px-4 pb-3 sm:px-6">
          <div className="flex items-center gap-2">
            <Link2 className="h-4 w-4 text-primary" />
            <CardTitle className="text-base">Improve Matching</CardTitle>
          </div>
          <CardDescription>
            Manage known services, catalog links, and custom bank descriptors on a dedicated page.
          </CardDescription>
        </CardHeader>
        <CardContent className="flex flex-col gap-3 px-4 pb-4 sm:flex-row sm:items-center sm:justify-between sm:px-6">
          <p className="text-sm text-muted-foreground">
            Use the service catalog when a recommendation names the wrong service, a bill needs a catalog link, or your bank uses a custom descriptor.
          </p>
          <Button asChild type="button" variant="outline" className="shrink-0 gap-2">
            <Link to="/subscriptions/catalog">
              <Link2 className="h-4 w-4" />
              Service Catalog
            </Link>
          </Button>
        </CardContent>
      </Card>

      {modal && (
        <BillModal
          key={modal.bill?.id ? `subscription-edit-${modal.bill.id}` : 'subscription-new'}
          bill={modal.bill}
          initialBill={modal.initialBill}
          categories={categories}
          onClose={() => setModal(null)}
          onSave={async () => {
            setModal(null);
            await refreshAll();
          }}
        />
      )}

      <RecommendationDetailsDialog
        open={!!detailsTarget}
        recommendation={detailsTarget}
        categoryId={subscriptionCategoryId}
        onClose={() => setDetailsTarget(null)}
        onAccept={acceptRecommendation}
        onDecline={declineRecommendation}
        onMatch={rec => setMatchTarget(rec)}
        busy={detailsTarget ? (
          busyId === `rec-${detailsTarget.id}`
          || busyId === `dec-${detailsTarget.id}`
          || busyId === `match-${detailsTarget.id}`
        ) : false}
      />

      <BillPickerDialog
        open={!!matchTarget}
        onClose={() => setMatchTarget(null)}
        recommendation={matchTarget}
        bills={bills}
        onConfirm={matchRecommendationToBill}
        busy={!!busyId?.startsWith('match-')}
      />
    </div>
  );
}