'use client';

import { useState, useEffect } from 'react';
import { useCfdisConConciliacion, useConciliar, useDesconciliar } from '@/lib/hooks/use-conciliacion';
import { useBancos } from '@/lib/hooks/use-bancos';
import { useRegimenesDelPeriodo } from '@/lib/hooks/use-dashboard';
import { PeriodSelector, RegimenSelector } from '@horux/shared-ui';
import { CfdiViewerModal } from '@/components/cfdi/cfdi-viewer-modal';
import { Header } from '@/components/layouts/header';
import { Card, CardContent, Button, Select, SelectContent, SelectItem, SelectTrigger, SelectValue, Input } from '@horux/shared-ui';
import { useAuthStore } from '@/stores/auth-store';
import { formatCurrency } from '@/lib/utils';
import { exportToExcel } from '@/lib/export-excel';
import { Eye, Download, X, CheckCircle } from 'lucide-react';

function getMonthRange(year: number, month: number) {
  const start = `${year}-${String(month).padStart(2, '0')}-01`;
  const lastDay = new Date(year, month, 0).getDate();
  const end = `${year}-${String(month).padStart(2, '0')}-${String(lastDay).padStart(2, '0')}`;
  return { start, end };
}

export default function ConciliacionPage() {
  const now = new Date();
  const defaultRange = getMonthRange(now.getFullYear(), now.getMonth() + 1);

  const [fechaInicio, setFechaInicio] = useState(defaultRange.start);
  const [fechaFin, setFechaFin] = useState(defaultRange.end);
  const [regimenSeleccionado, setRegimenSeleccionado] = useState<string | null>(null);
  const [activeTab, setActiveTab] = useState<'EMITIDO' | 'RECIBIDO'>('EMITIDO');
  const [selected, setSelected] = useState<Set<number>>(new Set());
  const [fechaPago, setFechaPago] = useState('');
  const [bancoId, setBancoId] = useState<string>('');
  const [selectedCfdi, setSelectedCfdi] = useState<any>(null);

  const { user } = useAuthStore();
  const isVisor = user?.role === 'visor';

  // Data
  const { data: regimenes, isLoading: regimenesLoading } = useRegimenesDelPeriodo(fechaInicio, fechaFin);
  const { data: cfdis, isLoading } = useCfdisConConciliacion({
    tipo: activeTab,
    fechaInicio,
    fechaFin,
    ...(regimenSeleccionado && { regimen: regimenSeleccionado }),
  });
  const { data: bancos } = useBancos();
  const conciliarMut = useConciliar();
  const desconciliarMut = useDesconciliar();

  // Split data
  const pendientes = cfdis?.filter((c) => c.conciliado !== 'true') || [];
  const conciliadas = cfdis?.filter((c) => c.conciliado === 'true') || [];

  // Score cards — tipo P usa monto_pago_mxn, otros usan total_mxn
  const getMonto = (c: any) => Number(c.montoMxn || c.totalMxn || 0);
  const montoConciliado = conciliadas.reduce((s, c) => s + getMonto(c), 0);
  const montoPendiente = pendientes.reduce((s, c) => s + getMonto(c), 0);

  // Reset selection on tab/filter change
  useEffect(() => {
    setSelected(new Set());
  }, [activeTab, fechaInicio, fechaFin, regimenSeleccionado]);

  // Handlers
  const toggleSelect = (id: number) => {
    setSelected((prev) => {
      const next = new Set(prev);
      if (next.has(id)) {
        next.delete(id);
      } else {
        next.add(id);
      }
      return next;
    });
  };

  const toggleSelectAll = () => {
    if (selected.size === pendientes.length && pendientes.length > 0) {
      setSelected(new Set());
    } else {
      setSelected(new Set(pendientes.map((c) => c.id)));
    }
  };

  const handleConciliar = async () => {
    if (selected.size === 0 || !fechaPago || !bancoId) return;
    try {
      await conciliarMut.mutateAsync({
        cfdiIds: Array.from(selected),
        fechaDePago: fechaPago,
        idBanco: parseInt(bancoId),
      });
      setSelected(new Set());
      setFechaPago('');
      setBancoId('');
    } catch (err: any) {
      alert(err.response?.data?.message || 'Error al conciliar');
    }
  };

  const handleDesconciliar = async (conciliacionId: number) => {
    if (!confirm('¿Desconciliar este CFDI?')) return;
    try {
      await desconciliarMut.mutateAsync(conciliacionId);
    } catch (err: any) {
      alert(err.response?.data?.message || 'Error al desconciliar');
    }
  };

  const handleExport = () => {
    if (!cfdis?.length) return;
    exportToExcel(
      cfdis.map((c) => ({
        ...c,
        _fecha: new Date(c.fechaEmision).toLocaleDateString('es-MX'),
        _totalMxn: getMonto(c),
        _estado: c.conciliado === 'true' ? 'Conciliado' : 'Pendiente',
        _fechaPago: c.conciliacion?.fechaDePago || '',
        _banco: c.conciliacion
          ? `${c.conciliacion.banco} ****${c.conciliacion.terminacionCuenta}`
          : '',
      })),
      [
        { header: 'UUID', key: 'uuid', width: 40 },
        { header: 'Fecha Emisión', key: '_fecha', width: 15 },
        { header: 'RFC Emisor', key: 'rfcEmisor', width: 15 },
        { header: 'Nombre Emisor', key: 'nombreEmisor', width: 30 },
        { header: 'RFC Receptor', key: 'rfcReceptor', width: 15 },
        { header: 'Total MXN', key: '_totalMxn', width: 15 },
        { header: 'Estado', key: '_estado', width: 12 },
        { header: 'Fecha Pago', key: '_fechaPago', width: 15 },
        { header: 'Banco', key: '_banco', width: 20 },
      ],
      `conciliacion-${activeTab.toLowerCase()}`,
    );
  };

  return (
    <>
      <Header title="Conciliación">
        <PeriodSelector
          fechaInicio={fechaInicio}
          fechaFin={fechaFin}
          onChange={(i, f) => {
            setFechaInicio(i);
            setFechaFin(f);
          }}
        />
      </Header>
      <main className="p-6 space-y-6">
        {/* Regimen selector + Export button */}
        <div className="flex items-center justify-between">
          <RegimenSelector
            regimenes={regimenes || []}
            selected={regimenSeleccionado}
            onChange={setRegimenSeleccionado}
            isLoading={regimenesLoading}
          />
          <Button variant="outline" size="sm" onClick={handleExport} disabled={!cfdis?.length}>
            <Download className="h-4 w-4 mr-1" /> Excel
          </Button>
        </div>

        {/* Score cards */}
        <div className="grid gap-4 md:grid-cols-2">
          <Card>
            <CardContent className="p-4">
              <p className="text-sm text-muted-foreground">Monto Conciliado</p>
              <p className="text-2xl font-bold text-success">{formatCurrency(montoConciliado)}</p>
              <p className="text-xs text-muted-foreground mt-1">{conciliadas.length} CFDIs</p>
            </CardContent>
          </Card>
          <Card>
            <CardContent className="p-4">
              <p className="text-sm text-muted-foreground">Monto Pendiente de Conciliar</p>
              <p className="text-2xl font-bold text-destructive">{formatCurrency(montoPendiente)}</p>
              <p className="text-xs text-muted-foreground mt-1">{pendientes.length} CFDIs</p>
            </CardContent>
          </Card>
        </div>

        {/* Tabs */}
        <div className="flex gap-2">
          {(['EMITIDO', 'RECIBIDO'] as const).map((tab) => (
            <Button
              key={tab}
              variant={activeTab === tab ? 'default' : 'outline'}
              onClick={() => {
                setActiveTab(tab);
                setSelected(new Set());
              }}
            >
              {tab === 'EMITIDO' ? 'Emitidas' : 'Recibidas'}
            </Button>
          ))}
        </div>

        {isLoading ? (
          <div className="text-sm text-muted-foreground">Cargando...</div>
        ) : (
          <>
            {/* Por conciliar */}
            <Card>
              <CardContent className="pt-6">
                <h3 className="font-medium mb-4">Por conciliar ({pendientes.length})</h3>
                {pendientes.length === 0 ? (
                  <p className="text-sm text-muted-foreground">
                    No hay CFDIs pendientes de conciliar
                  </p>
                ) : (
                  <div className="overflow-x-auto">
                    <table className="w-full text-sm">
                      <thead>
                        <tr className="border-b text-left text-muted-foreground">
                          {!isVisor && (
                            <th className="pb-3 w-8">
                              <input
                                type="checkbox"
                                checked={
                                  selected.size === pendientes.length && pendientes.length > 0
                                }
                                onChange={toggleSelectAll}
                              />
                            </th>
                          )}
                          <th className="pb-3 font-medium">UUID</th>
                          <th className="pb-3 font-medium">Fecha</th>
                          <th className="pb-3 font-medium">RFC Emisor</th>
                          <th className="pb-3 font-medium">Nombre Emisor</th>
                          <th className="pb-3 font-medium">RFC Receptor</th>
                          <th className="pb-3 font-medium">Nombre Receptor</th>
                          <th className="pb-3 font-medium text-right">Total MXN</th>
                          <th className="pb-3 font-medium">M. Pago</th>
                          <th className="pb-3"></th>
                        </tr>
                      </thead>
                      <tbody>
                        {pendientes.map((cfdi) => (
                          <tr key={cfdi.id} className="border-b hover:bg-muted/50">
                            {!isVisor && (
                              <td className="py-2">
                                <input
                                  type="checkbox"
                                  checked={selected.has(cfdi.id)}
                                  onChange={() => toggleSelect(cfdi.id)}
                                />
                              </td>
                            )}
                            <td className="py-2 font-mono text-xs" title={cfdi.uuid}>
                              {cfdi.uuid?.substring(0, 8)}
                            </td>
                            <td className="py-2 text-xs">
                              {new Date(cfdi.fechaEmision).toLocaleDateString('es-MX')}
                            </td>
                            <td className="py-2 font-mono text-xs">{cfdi.rfcEmisor}</td>
                            <td className="py-2 text-xs truncate max-w-[120px]">
                              {cfdi.nombreEmisor}
                            </td>
                            <td className="py-2 font-mono text-xs">{cfdi.rfcReceptor}</td>
                            <td className="py-2 text-xs truncate max-w-[120px]">
                              {cfdi.nombreReceptor}
                            </td>
                            <td className="py-2 text-right text-xs font-medium">
                              {formatCurrency(getMonto(cfdi))}
                            </td>
                            <td className="py-2 text-xs">{cfdi.metodoPago || '-'}</td>
                            <td className="py-2">
                              <Button
                                variant="ghost"
                                size="sm"
                                onClick={() => setSelectedCfdi(cfdi)}
                                title="Ver factura"
                              >
                                <Eye className="h-4 w-4" />
                              </Button>
                            </td>
                          </tr>
                        ))}
                      </tbody>
                    </table>
                  </div>
                )}
              </CardContent>
            </Card>

            {/* Action bar - only when items selected */}
            {!isVisor && selected.size > 0 && (
              <div className="sticky bottom-4 z-10 bg-card border rounded-lg shadow-lg p-4 flex items-center gap-4">
                <span className="text-sm font-medium">{selected.size} seleccionados</span>
                <Select value={bancoId} onValueChange={setBancoId}>
                  <SelectTrigger className="w-48">
                    <SelectValue placeholder="Seleccionar banco" />
                  </SelectTrigger>
                  <SelectContent>
                    {bancos?.map((b) => (
                      <SelectItem key={b.id} value={String(b.id)}>
                        {b.banco} ****{b.terminacionCuenta}
                      </SelectItem>
                    ))}
                  </SelectContent>
                </Select>
                <Input
                  type="date"
                  value={fechaPago}
                  onChange={(e) => setFechaPago(e.target.value)}
                  className="w-44"
                />
                <Button
                  onClick={handleConciliar}
                  disabled={!fechaPago || !bancoId || conciliarMut.isPending}
                >
                  <CheckCircle className="h-4 w-4 mr-1" />
                  Conciliar {selected.size} facturas
                </Button>
                <Button variant="ghost" size="sm" onClick={() => setSelected(new Set())}>
                  <X className="h-4 w-4" />
                </Button>
              </div>
            )}

            {/* Conciliadas */}
            <Card>
              <CardContent className="pt-6">
                <h3 className="font-medium mb-4">Conciliadas ({conciliadas.length})</h3>
                {conciliadas.length === 0 ? (
                  <p className="text-sm text-muted-foreground">No hay CFDIs conciliados</p>
                ) : (
                  <div className="overflow-x-auto">
                    <table className="w-full text-sm">
                      <thead>
                        <tr className="border-b text-left text-muted-foreground">
                          <th className="pb-3 font-medium">UUID</th>
                          <th className="pb-3 font-medium">Fecha Emisión</th>
                          <th className="pb-3 font-medium">RFC Emisor</th>
                          <th className="pb-3 font-medium">Nombre Emisor</th>
                          <th className="pb-3 font-medium text-right">Total MXN</th>
                          <th className="pb-3 font-medium">Fecha Pago</th>
                          <th className="pb-3 font-medium">Banco</th>
                          <th className="pb-3"></th>
                        </tr>
                      </thead>
                      <tbody>
                        {conciliadas.map((cfdi) => (
                          <tr key={cfdi.id} className="border-b hover:bg-muted/50">
                            <td className="py-2 font-mono text-xs" title={cfdi.uuid}>
                              {cfdi.uuid?.substring(0, 8)}
                            </td>
                            <td className="py-2 text-xs">
                              {new Date(cfdi.fechaEmision).toLocaleDateString('es-MX')}
                            </td>
                            <td className="py-2 font-mono text-xs">{cfdi.rfcEmisor}</td>
                            <td className="py-2 text-xs truncate max-w-[120px]">
                              {cfdi.nombreEmisor}
                            </td>
                            <td className="py-2 text-right text-xs font-medium">
                              {formatCurrency(getMonto(cfdi))}
                            </td>
                            <td className="py-2 text-xs">
                              {cfdi.conciliacion?.fechaDePago
                                ? new Date(
                                    cfdi.conciliacion.fechaDePago + 'T12:00:00',
                                  ).toLocaleDateString('es-MX')
                                : '-'}
                            </td>
                            <td className="py-2 text-xs">
                              {cfdi.conciliacion
                                ? `${cfdi.conciliacion.banco} ****${cfdi.conciliacion.terminacionCuenta}`
                                : '-'}
                            </td>
                            <td className="py-2 flex gap-1">
                              <Button
                                variant="ghost"
                                size="sm"
                                onClick={() => setSelectedCfdi(cfdi)}
                                title="Ver factura"
                              >
                                <Eye className="h-4 w-4" />
                              </Button>
                              {!isVisor && cfdi.conciliacion && (
                                <Button
                                  variant="ghost"
                                  size="sm"
                                  onClick={() => handleDesconciliar(cfdi.conciliacion!.id)}
                                  title="Desconciliar"
                                  className="text-destructive hover:text-destructive"
                                >
                                  <X className="h-4 w-4" />
                                </Button>
                              )}
                            </td>
                          </tr>
                        ))}
                      </tbody>
                    </table>
                  </div>
                )}
              </CardContent>
            </Card>
          </>
        )}
      </main>

      <CfdiViewerModal
        cfdi={selectedCfdi}
        open={!!selectedCfdi}
        onClose={() => setSelectedCfdi(null)}
      />
    </>
  );
}