import type { FC } from 'react';
import { useCallback, useEffect, useMemo, useState } from 'react';
import { Link } from 'react-router-dom';
import { Search, Ticket, XCircle, RefreshCw, AlertTriangle, Printer, Receipt, User, Pencil } from 'lucide-react';
import Layout from '../components/Layout';
import { Card, Button, Input, Select, Modal, TextArea, Badge, EmptyState, Skeleton, PageHeader, toast } from '../components/ui';
import TicketPrint from '../components/TicketPrint';
import TicketEditor from '../components/TicketEditor';
import { odooApi, type Sale } from '../services/odoo';
import { useAuth } from '../lib/auth';
import { readDateFilterPrefs, writeDateFilterPrefs, DATE_PRESETS, rangeForPreset, type DatePreset } from '../lib/dateRange';

const PREF_KEY = 'skeen_tickets_filtros';

const METODO_LABELS: Record<string, string> = {
  cash: 'Efectivo', card: 'Tarjeta', transfer: 'Transferencia',
  stripe: 'Stripe', mercadopago: 'MercadoPago', points: 'Saldo a favor',
  mixed: 'Mixto', '': '—',
};

const money = (v: number) =>
  '$' + (v ?? 0).toLocaleString('es-MX', { minimumFractionDigits: 2, maximumFractionDigits: 2 });

const ESTADOS = [
  { value: '', label: 'Todos los estados' },
  { value: 'paid', label: 'Pagados' },
  { value: 'partial', label: 'Parciales' },
  { value: 'confirmed', label: 'Confirmados' },
  { value: 'cancelled', label: 'Cancelados' },
];

const METODOS_FILTRO = [
  { value: '', label: 'Todos los métodos' },
  { value: 'cash', label: 'Efectivo' },
  { value: 'card', label: 'Tarjeta' },
  { value: 'transfer', label: 'Transferencia' },
  { value: 'points', label: 'Saldo a favor' },
  { value: 'mixed', label: 'Mixto' },
  { value: 'stripe', label: 'Stripe' },
  { value: 'mercadopago', label: 'MercadoPago' },
];

const PAGE_SIZE = 50;

/**
 * Tickets: encontrar un cobro del POS y cancelarlo sin navegar el módulo de
 * Ventas. Permiso de cancelación: admin y gerencia (el API lo valida).
 */
const Tickets: FC = () => {
  const { user } = useAuth();
  const puedeCorregir = user?.role === 'admin' || user?.role === 'gerencia';
  const prefs = readDateFilterPrefs(PREF_KEY);
  const [preset, setPreset] = useState<DatePreset>(prefs?.preset || 'hoy');
  const [desde, setDesde] = useState(prefs?.start || rangeForPreset('hoy').start);
  const [hasta, setHasta] = useState(prefs?.end || rangeForPreset('hoy').end);
  const [estado, setEstado] = useState('');
  const [metodo, setMetodo] = useState('');
  const [usuario, setUsuario] = useState('');
  const [busqueda, setBusqueda] = useState('');
  const [page, setPage] = useState(1);

  const [sales, setSales] = useState<Sale[]>([]);
  const [total, setTotal] = useState(0);
  const [totalPages, setTotalPages] = useState(1);
  const [loading, setLoading] = useState(true);
  const [detalle, setDetalle] = useState<Sale | null>(null);
  const [cancelando, setCancelando] = useState<Sale | null>(null);
  const [motivo, setMotivo] = useState('');
  const [enviando, setEnviando] = useState(false);
  const [reimprimir, setReimprimir] = useState<Sale | null>(null);
  const [editando, setEditando] = useState<Sale | null>(null);
  const [catalogo, setCatalogo] = useState<{
    servicios: { id: number; name: string; price: number }[];
    items: { id: number; name: string; price: number; qty: number }[];
  }>({ servicios: [], items: [] });
  const [doctores, setDoctores] = useState<{ id: number; name: string }[]>([]);

  // El catálogo y los doctores solo hacen falta para corregir un ticket: se
  // cargan perezosamente la primera vez que se abre el editor.
  const cargarCatalogos = useCallback(async () => {
    if (catalogo.servicios.length) return;
    try {
      const [sv, iv, dc] = await Promise.all([
        odooApi.getServices({ page_size: 200 }),
        odooApi.getInventory(),
        odooApi.getDoctors(),
      ]);
      setCatalogo({
        servicios: (sv.services || []).map((x) => ({ id: x.id, name: x.name, price: x.price })),
        items: (iv.items || []).map((x) => ({ id: x.id, name: x.name, price: x.price ?? 0, qty: x.qty })),
      });
      setDoctores((dc.doctors || []).map((x) => ({ id: x.id, name: x.name })));
    } catch {
      toast.error('No se pudo cargar el catálogo para corregir el ticket');
    }
  }, [catalogo.servicios.length]);

  const aplicarPreset = (p: DatePreset) => {
    setPreset(p);
    if (p !== 'custom') {
      const r = rangeForPreset(p);
      setDesde(r.start);
      setHasta(r.end);
      writeDateFilterPrefs(PREF_KEY, { preset: p, start: r.start, end: r.end });
    }
  };

  const load = useCallback(async () => {
    try {
      setLoading(true);
      const res = await odooApi.getSales({
        date_from: desde,
        date_to: hasta,
        ...(estado ? { state: estado } : {}),
        ...(metodo ? { payment_method: metodo } : {}),
        ...(usuario ? { user: usuario } : {}),
        ...(busqueda ? { search: busqueda } : {}),
        page,
        page_size: PAGE_SIZE,
      });
      if (res.status === 'success') {
        setSales(res.sales || []);
        setTotal(res.total ?? 0);
        setTotalPages(res.total_pages ?? 1);
      }
    } catch {
      toast.error('No se pudieron cargar los tickets');
    } finally {
      setLoading(false);
    }
  }, [desde, hasta, estado, metodo, usuario, busqueda, page]);

  useEffect(() => {
    const t = setTimeout(load, 250);
    return () => clearTimeout(t);
  }, [load]);

  useEffect(() => {
    setPage(1);
  }, [desde, hasta, estado, metodo, usuario, busqueda]);

  const totalPeriodo = useMemo(
    () => sales.filter((s) => s.state !== 'cancelled').reduce((a, s) => a + s.total, 0),
    [sales],
  );
  const canceladosPeriodo = useMemo(
    () => sales.filter((s) => s.state === 'cancelled').length,
    [sales],
  );

  const abrirCancelar = (s: Sale) => {
    setCancelando(s);
    setMotivo('');
  };

  const submitCancelar = async () => {
    if (!cancelando) return;
    if (!motivo.trim()) {
      toast.error('El motivo de cancelación es obligatorio');
      return;
    }
    try {
      setEnviando(true);
      const res = await odooApi.cancelSale(cancelando.id, { reason: motivo.trim() });
      const r = res.result;
      const partes = [
        r?.points_reversed ? `${r.points_reversed} pts revertidos` : '',
        r?.points_restored ? `${r.points_restored} pts devueltos al saldo` : '',
        r?.stock_moves ? `${r.stock_moves} artículos devueltos a inventario` : '',
      ].filter(Boolean);
      toast.success(`Ticket ${cancelando.name} cancelado${partes.length ? ` · ${partes.join(' · ')}` : ''}`);
      setCancelando(null);
      setDetalle(res.sale);
      await load();
    } catch (err) {
      const msg = (err as { response?: { data?: { message?: string } } })?.response?.data?.message;
      toast.error(msg || 'No se pudo cancelar el ticket');
    } finally {
      setEnviando(false);
    }
  };

  return (
    <Layout title="Tickets" subtitle="Cobros del día y cancelaciones">
      <PageHeader title="Tickets" subtitle="Busca un cobro, revísalo y cancélalo con nota de crédito">
        <Button variant="outline" onClick={load} loading={loading}>
          <RefreshCw size={15} className="mr-2" /> Actualizar
        </Button>
      </PageHeader>

      <Card className="mb-4">
        <Card.Body className="space-y-3">
          <div className="flex flex-wrap gap-1.5">
            {DATE_PRESETS.map((p) => (
              <button
                key={p.value}
                type="button"
                onClick={() => aplicarPreset(p.value)}
                className={`px-3 py-1.5 rounded-full text-xs font-medium border transition ${
                  preset === p.value ? 'bg-theme-accent text-theme-inverse border-theme-accent' : 'bg-theme-bg text-theme-muted border-theme-border'
                }`}
              >
                {p.label}
              </button>
            ))}
          </div>
          <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-5 gap-3">
            <Input label="Desde" type="date" value={desde} onChange={(e) => { setDesde(e.target.value); setPreset('custom'); }} />
            <Input label="Hasta" type="date" value={hasta} onChange={(e) => { setHasta(e.target.value); setPreset('custom'); }} />
            <Select label="Estado" options={ESTADOS} value={estado} onChange={(e) => setEstado(e.target.value)} />
            <Select label="Método de pago" options={METODOS_FILTRO} value={metodo} onChange={(e) => setMetodo(e.target.value)} />
            <Input label="Cobró (usuario)" placeholder="ej. recepcion" value={usuario} onChange={(e) => setUsuario(e.target.value)} />
          </div>
          <div className="relative">
            <Search size={16} className="absolute left-3 top-1/2 -translate-y-1/2 text-theme-muted" />
            <Input
              placeholder="Buscar por folio (VENTA-…) o paciente..."
              value={busqueda}
              onChange={(e) => setBusqueda(e.target.value)}
              className="pl-10"
            />
          </div>
        </Card.Body>
      </Card>

      <div className="grid grid-cols-2 lg:grid-cols-4 gap-3 mb-4">
        <Card className="p-4 bg-theme-bg border-0">
          <p className="text-xs text-theme-muted">Tickets en el filtro</p>
          <p className="text-xl font-heading font-semibold text-theme-heading">{total}</p>
        </Card>
        <Card className="p-4 bg-theme-bg border-0">
          <p className="text-xs text-theme-muted">Importe (página)</p>
          <p className="text-xl font-heading font-semibold text-theme-heading">{money(totalPeriodo)}</p>
        </Card>
        <Card className="p-4 bg-theme-bg border-0">
          <p className="text-xs text-theme-muted">Cancelados (página)</p>
          <p className={`text-xl font-heading font-semibold ${canceladosPeriodo > 0 ? 'text-rose-600' : 'text-theme-heading'}`}>
            {canceladosPeriodo}
          </p>
        </Card>
        <Card className="p-4 bg-theme-bg border-0">
          <p className="text-xs text-theme-muted">Página</p>
          <p className="text-xl font-heading font-semibold text-theme-heading">{page} / {totalPages || 1}</p>
        </Card>
      </div>

      <Card>
        <Card.Body>
          {loading ? (
            <Skeleton count={8} className="h-12 w-full" />
          ) : sales.length === 0 ? (
            <EmptyState
              title="Sin tickets"
              subtitle="No hay cobros con estos filtros. Prueba otro rango de fechas."
              icon={<Ticket size={28} />}
            />
          ) : (
            <div className="overflow-x-auto">
              <table className="w-full text-sm">
                <thead className="bg-theme-bg text-theme-muted text-xs uppercase">
                  <tr>
                    <th className="text-left px-3 py-2">Folio</th>
                    <th className="text-left px-3 py-2">Fecha</th>
                    <th className="text-left px-3 py-2">Paciente</th>
                    <th className="text-right px-3 py-2">Total</th>
                    <th className="text-left px-3 py-2 hidden md:table-cell">Método</th>
                    <th className="text-left px-3 py-2 hidden lg:table-cell">Cobró</th>
                    <th className="text-left px-3 py-2">Estado</th>
                    <th className="text-right px-3 py-2">Acciones</th>
                  </tr>
                </thead>
                <tbody className="divide-y divide-theme-border">
                  {sales.map((s) => (
                    <tr key={s.id} className="hover:bg-theme-bg">
                      <td className="px-3 py-2 font-mono text-[12px] text-theme-heading">{s.name}</td>
                      <td className="px-3 py-2 text-theme-muted whitespace-nowrap">{(s.date || '').slice(0, 10)}</td>
                      <td className="px-3 py-2">
                        <Link to={`/pacientes?q=${encodeURIComponent(s.patient || '')}`} className="text-theme-heading hover:underline">
                          {s.patient}
                        </Link>
                      </td>
                      <td className="px-3 py-2 text-right font-semibold text-theme-heading">{money(s.total)}</td>
                      <td className="px-3 py-2 text-theme-muted hidden md:table-cell">
                        {METODO_LABELS[s.payment_method || ''] || s.payment_method || '—'}
                      </td>
                      <td className="px-3 py-2 text-theme-muted hidden lg:table-cell">{s.user_login || '—'}</td>
                      <td className="px-3 py-2">
                        <Badge variant={s.state === 'cancelled' ? 'danger' : s.state === 'paid' ? 'success' : 'pending'}>
                          {s.state === 'cancelled' ? 'Cancelado' : s.state === 'paid' ? 'Pagado' : s.state === 'partial' ? 'Parcial' : 'Confirmado'}
                        </Badge>
                      </td>
                      <td className="px-3 py-2">
                        <div className="flex items-center justify-end gap-1">
                          <Button size="sm" variant="ghost" onClick={() => setDetalle(s)} title="Ver detalle del ticket">
                            <Receipt size={14} />
                          </Button>
                          {s.state !== 'cancelled' && puedeCorregir && (
                            <Button
                              size="sm"
                              variant="ghost"
                              title="Corregir ticket"
                              onClick={async () => { await cargarCatalogos(); setEditando(s); }}
                            >
                              <Pencil size={14} />
                            </Button>
                          )}
                          {s.state !== 'cancelled' && (
                            <Button size="sm" variant="ghost" onClick={() => abrirCancelar(s)} title="Cancelar ticket (nota de crédito)">
                              <XCircle size={14} className="text-rose-600" />
                            </Button>
                          )}
                        </div>
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          )}

          {totalPages > 1 && (
            <div className="flex items-center justify-end gap-2 mt-4 pt-3 border-t border-theme-border">
              <Button variant="outline" size="sm" disabled={page <= 1} onClick={() => setPage((p) => Math.max(1, p - 1))}>
                Anterior
              </Button>
              <Button variant="outline" size="sm" disabled={page >= totalPages} onClick={() => setPage((p) => p + 1)}>
                Siguiente
              </Button>
            </div>
          )}
        </Card.Body>
      </Card>

      {/* Detalle del ticket */}
      <Modal
        isOpen={!!detalle}
        onClose={() => setDetalle(null)}
        title={detalle ? `Ticket ${detalle.name}` : 'Ticket'}
        maxWidth="lg"
        footer={
          <>
            {detalle && detalle.state === 'cancelled' && (
              <Button variant="outline" onClick={() => setReimprimir(detalle)}>
                <Printer size={14} className="mr-1.5" /> Imprimir
              </Button>
            )}
            <Button variant="outline" onClick={() => setDetalle(null)}>Cerrar</Button>
            {detalle && detalle.state !== 'cancelled' && puedeCorregir && (
              <Button variant="secondary" onClick={async () => { const d = detalle; setDetalle(null); await cargarCatalogos(); setEditando(d); }}>
                <Pencil size={14} className="mr-1.5" /> Corregir
              </Button>
            )}
            {detalle && detalle.state !== 'cancelled' && (
              <Button variant="danger" onClick={() => { const d = detalle; setDetalle(null); abrirCancelar(d); }}>
                <XCircle size={14} className="mr-1.5" /> Cancelar ticket
              </Button>
            )}
          </>
        }
      >
        {detalle && (
          <div className="space-y-4">
            <div className="grid grid-cols-2 sm:grid-cols-4 gap-3">
              <div className="p-3 bg-theme-bg rounded-xl">
                <p className="text-xs text-theme-muted">Paciente</p>
                <p className="text-sm font-medium text-theme-heading">{detalle.patient}</p>
              </div>
              <div className="p-3 bg-theme-bg rounded-xl">
                <p className="text-xs text-theme-muted">Total</p>
                <p className="text-sm font-semibold text-theme-heading">{money(detalle.total)}</p>
              </div>
              <div className="p-3 bg-theme-bg rounded-xl">
                <p className="text-xs text-theme-muted">Método</p>
                <p className="text-sm text-theme-heading">{METODO_LABELS[detalle.payment_method || ''] || '—'}</p>
              </div>
              <div className="p-3 bg-theme-bg rounded-xl">
                <p className="text-xs text-theme-muted">Cobró</p>
                <p className="text-sm text-theme-heading inline-flex items-center gap-1">
                  <User size={12} /> {detalle.user_login || '—'}
                </p>
              </div>
            </div>

            <div>
              <p className="text-xs font-medium text-theme-muted uppercase mb-2">Conceptos</p>
              <table className="w-full text-sm">
                <tbody className="divide-y divide-theme-border">
                  {detalle.lines.map((l) => (
                    <tr key={l.id}>
                      <td className="py-1.5 text-theme-heading">{l.description || l.service || l.item || '—'}</td>
                      <td className="py-1.5 text-right text-theme-muted">{l.quantity} × {money(l.price_unit)}</td>
                      <td className="py-1.5 text-right font-medium text-theme-heading">{money(l.subtotal)}</td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>

            <div>
              <p className="text-xs font-medium text-theme-muted uppercase mb-2">Pagos registrados</p>
              {(detalle.pagos || []).length === 0 ? (
                <p className="text-sm text-theme-muted">
                  Sin pagos ligados a este ticket (los cobros anteriores al vínculo de pagos no se pueden asociar).
                </p>
              ) : (
                <table className="w-full text-sm">
                  <tbody className="divide-y divide-theme-border">
                    {(detalle.pagos || []).map((p) => (
                      <tr key={p.id}>
                        <td className="py-1.5 font-mono text-[12px] text-theme-heading">{p.name}</td>
                        <td className="py-1.5 text-theme-muted">{METODO_LABELS[p.payment_method] || p.payment_method}</td>
                        <td className="py-1.5 text-theme-muted">{p.create_date || '—'}</td>
                        <td className="py-1.5 text-right font-medium text-theme-heading">{money(p.amount)}</td>
                      </tr>
                    ))}
                  </tbody>
                </table>
              )}
            </div>

            {detalle.state === 'cancelled' && (
              <div className="rounded-lg bg-rose-50 border border-rose-200 px-3 py-2 text-xs text-rose-800 space-y-1">
                <p className="font-medium">Ticket cancelado</p>
                <p>Motivo: {detalle.cancel_reason || '—'}</p>
                <p>Canceló: {detalle.cancelled_by || '—'} · {detalle.cancelled_at || '—'}</p>
                <p>
                  Puntos revertidos: {detalle.cancel_points_reversed || 0} ·
                  Saldo devuelto al paciente: {detalle.cancel_points_restored || 0}
                </p>
              </div>
            )}
          </div>
        )}
      </Modal>

      {/* Diálogo de cancelación (nota de crédito) */}
      <Modal
        isOpen={!!cancelando}
        onClose={() => setCancelando(null)}
        title={`Cancelar ticket ${cancelando?.name || ''}`}
        maxWidth="sm"
        footer={
          <>
            <Button variant="outline" onClick={() => setCancelando(null)}>Volver</Button>
            <Button variant="danger" onClick={submitCancelar} loading={enviando}>Cancelar ticket</Button>
          </>
        }
      >
        {cancelando && (
          <div className="space-y-4">
            <div className="flex items-start gap-2">
              <AlertTriangle size={16} className="text-amber-600 shrink-0 mt-0.5" />
              <p className="text-sm text-theme-muted">
                Paciente: <span className="font-medium text-theme-heading">{cancelando.patient}</span>
                {' · '}Total: <span className="font-medium text-theme-heading">{money(cancelando.total)}</span>
                {cancelando.user_login ? ` · Cobró: ${cancelando.user_login}` : ''}
              </p>
            </div>

            <div className="rounded-lg bg-rose-50 border border-rose-200 px-3 py-2 text-xs text-rose-800 space-y-1.5">
              <p className="font-medium">Se emitirá la nota de crédito:</p>
              <p>La venta queda cancelada y deja de contar en ingresos, comisiones y reportes.</p>
              <p>Se revierten los puntos otorgados y se devuelve al saldo a favor lo que el paciente canjeó.</p>
              <p>Los artículos vendidos vuelven al inventario.</p>
            </div>

            <div className="rounded-lg bg-amber-50 border border-amber-200 px-3 py-2 text-xs text-amber-900 space-y-1.5">
              <p className="font-medium">Importante: el pago NO se revierte automáticamente</p>
              <p>
                El cobro queda registrado en caja y en el historial de pagos del paciente
                ({(cancelando.pagos || []).length > 0
                  ? `${(cancelando.pagos || []).length} pago(s) por ${money((cancelando.pagos || []).reduce((a, p) => a + p.amount, 0))}`
                  : 'sin pagos ligados a este ticket'}).
              </p>
              <p>Si corresponde devolver el dinero, hay que ajustar la caja por separado.</p>
            </div>

            <TextArea
              label="Motivo de cancelación *"
              placeholder="Ej. recepción cobró el servicio equivocado, cobro duplicado..."
              value={motivo}
              onChange={(e) => setMotivo(e.target.value)}
            />
          </div>
        )}
      </Modal>

      {editando && (
        <TicketEditor
          ticket={editando}
          catalogo={{ servicios: catalogo.servicios, items: catalogo.items }}
          doctores={doctores}
          onClose={() => setEditando(null)}
          onGuardado={(sale) => { setDetalle(sale); load(); }}
        />
      )}

      <TicketPrint
        isOpen={!!reimprimir}
        onClose={() => setReimprimir(null)}
        ticket={reimprimir && {
          folio: reimprimir.name,
          fecha: reimprimir.date,
          paciente: reimprimir.patient,
          lines: reimprimir.lines.map((l) => ({
            name: l.service || l.item || l.description,
            qty: l.quantity,
            price: l.price_unit,
            subtotal: l.subtotal,
          })),
          subtotal: reimprimir.subtotal,
          discount: reimprimir.discount,
          total: reimprimir.total,
          amount_paid: reimprimir.amount_paid,
          amount_due: reimprimir.amount_due,
          metodo: METODO_LABELS[reimprimir.payment_method || ''] || null,
          cajero: reimprimir.user_login,
          doctor: reimprimir.doctor,
          telefono_paciente: reimprimir.patient_phone,
          notas: reimprimir.notes,
        }}
      />
    </Layout>
  );
};

export default Tickets;