'use client';

import { useState } from 'react';
import { DashboardShell } from '@/components/layouts/dashboard-shell';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { useEventos, useUpdateEvento } from '@/lib/hooks/use-calendario';
import { Calendar, ChevronLeft, ChevronRight, Check, Clock, FileText, CreditCard } from 'lucide-react';
import { cn } from '@/lib/utils';

const meses = ['Enero', 'Febrero', 'Marzo', 'Abril', 'Mayo', 'Junio', 'Julio', 'Agosto', 'Septiembre', 'Octubre', 'Noviembre', 'Diciembre'];

const tipoIcons = {
  declaracion: FileText,
  pago: CreditCard,
  obligacion: Clock,
  custom: Calendar,
};

const tipoColors = {
  declaracion: 'bg-blue-100 text-blue-800 dark:bg-blue-900 dark:text-blue-200',
  pago: 'bg-green-100 text-green-800 dark:bg-green-900 dark:text-green-200',
  obligacion: 'bg-orange-100 text-orange-800 dark:bg-orange-900 dark:text-orange-200',
  custom: 'bg-gray-100 text-gray-800 dark:bg-gray-800 dark:text-gray-200',
};

export default function CalendarioPage() {
  const [año, setAño] = useState(new Date().getFullYear());
  const [mes, setMes] = useState(new Date().getMonth() + 1);
  const { data: eventos, isLoading } = useEventos(año, mes);
  const updateEvento = useUpdateEvento();

  const handlePrevMonth = () => {
    if (mes === 1) {
      setMes(12);
      setAño(año - 1);
    } else {
      setMes(mes - 1);
    }
  };

  const handleNextMonth = () => {
    if (mes === 12) {
      setMes(1);
      setAño(año + 1);
    } else {
      setMes(mes + 1);
    }
  };

  const handleToggleComplete = (id: number, completado: boolean) => {
    updateEvento.mutate({ id, data: { completado: !completado } });
  };

  // Generate calendar days
  const firstDay = new Date(año, mes - 1, 1).getDay();
  const daysInMonth = new Date(año, mes, 0).getDate();
  const days = Array.from({ length: 42 }, (_, i) => {
    const day = i - firstDay + 1;
    if (day < 1 || day > daysInMonth) return null;
    return day;
  });

  const getEventosForDay = (day: number) => {
    return eventos?.filter(e => {
      const fecha = new Date(e.fechaLimite);
      return fecha.getDate() === day;
    }) || [];
  };

  return (
    <DashboardShell
      title="Calendario Fiscal"
      description="Obligaciones fiscales y eventos importantes"
    >
      <div className="grid gap-4 lg:grid-cols-3">
        {/* Calendar */}
        <Card className="lg:col-span-2">
          <CardHeader className="flex flex-row items-center justify-between">
            <CardTitle className="flex items-center gap-2">
              <Calendar className="h-5 w-5" />
              {meses[mes - 1]} {año}
            </CardTitle>
            <div className="flex gap-1">
              <Button variant="outline" size="icon" onClick={handlePrevMonth}>
                <ChevronLeft className="h-4 w-4" />
              </Button>
              <Button variant="outline" size="icon" onClick={handleNextMonth}>
                <ChevronRight className="h-4 w-4" />
              </Button>
            </div>
          </CardHeader>
          <CardContent>
            <div className="grid grid-cols-7 gap-1">
              {['Dom', 'Lun', 'Mar', 'Mié', 'Jue', 'Vie', 'Sáb'].map(d => (
                <div key={d} className="text-center text-sm font-medium text-muted-foreground py-2">
                  {d}
                </div>
              ))}
              {days.map((day, i) => {
                const dayEventos = day ? getEventosForDay(day) : [];
                const isToday = day === new Date().getDate() && mes === new Date().getMonth() + 1 && año === new Date().getFullYear();
                return (
                  <div
                    key={i}
                    className={cn(
                      'min-h-[80px] p-1 border rounded-md',
                      day ? 'bg-background' : 'bg-muted/30',
                      isToday && 'ring-2 ring-primary'
                    )}
                  >
                    {day && (
                      <>
                        <div className={cn('text-sm font-medium', isToday && 'text-primary')}>{day}</div>
                        <div className="space-y-1 mt-1">
                          {dayEventos.slice(0, 2).map(e => {
                            const Icon = tipoIcons[e.tipo];
                            return (
                              <div
                                key={e.id}
                                className={cn(
                                  'text-xs px-1 py-0.5 rounded truncate flex items-center gap-1',
                                  tipoColors[e.tipo],
                                  e.completado && 'opacity-50 line-through'
                                )}
                                title={e.titulo}
                              >
                                <Icon className="h-3 w-3 flex-shrink-0" />
                                <span className="truncate">{e.titulo}</span>
                              </div>
                            );
                          })}
                          {dayEventos.length > 2 && (
                            <div className="text-xs text-muted-foreground">+{dayEventos.length - 2} más</div>
                          )}
                        </div>
                      </>
                    )}
                  </div>
                );
              })}
            </div>
          </CardContent>
        </Card>

        {/* Event List */}
        <Card>
          <CardHeader>
            <CardTitle>Eventos del Mes</CardTitle>
          </CardHeader>
          <CardContent>
            {isLoading ? (
              <div className="text-center py-4 text-muted-foreground">Cargando...</div>
            ) : eventos?.length === 0 ? (
              <div className="text-center py-4 text-muted-foreground">No hay eventos este mes</div>
            ) : (
              <div className="space-y-3">
                {eventos?.map(evento => {
                  const Icon = tipoIcons[evento.tipo];
                  return (
                    <div
                      key={evento.id}
                      className={cn(
                        'p-3 rounded-lg border',
                        evento.completado && 'opacity-50'
                      )}
                    >
                      <div className="flex items-start justify-between">
                        <div className="flex items-start gap-2">
                          <div className={cn('p-1.5 rounded', tipoColors[evento.tipo])}>
                            <Icon className="h-4 w-4" />
                          </div>
                          <div>
                            <h4 className={cn('font-medium text-sm', evento.completado && 'line-through')}>
                              {evento.titulo}
                            </h4>
                            <p className="text-xs text-muted-foreground mt-0.5">{evento.descripcion}</p>
                            <p className="text-xs text-muted-foreground mt-1">
                              {new Date(evento.fechaLimite).toLocaleDateString('es-MX', {
                                day: 'numeric',
                                month: 'short',
                              })}
                            </p>
                          </div>
                        </div>
                        <Button
                          variant="ghost"
                          size="icon"
                          className="h-8 w-8"
                          onClick={() => handleToggleComplete(evento.id, evento.completado)}
                        >
                          <Check className={cn('h-4 w-4', evento.completado && 'text-success')} />
                        </Button>
                      </div>
                    </div>
                  );
                })}
              </div>
            )}
          </CardContent>
        </Card>
      </div>
    </DashboardShell>
  );
}