"use client";

import { 
  Target, 
  Clock, 
  Calendar,
  TrendingUp,
  FileText,
  AlertTriangle,
  CheckCircle2
} from "lucide-react";

import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Progress } from "@/components/ui/progress";
import { Task } from "@/types/task";

interface TaskStatsProps {
  task: Task;
}

// Formatear fecha completa
function formatDate(dateString: string | null): string {
  if (!dateString) return 'No definida';
  return new Date(dateString).toLocaleDateString('es-ES', {
    day: '2-digit',
    month: 'long',
    year: 'numeric',
  });
}

// Obtener clase de color según progreso
function getProgressColorClass(value: number): string {
  if (value >= 100) return '[&>div]:bg-green-500';
  if (value >= 75) return '[&>div]:bg-blue-500';
  if (value >= 50) return '[&>div]:bg-yellow-500';
  if (value >= 25) return '[&>div]:bg-orange-500';
  return '[&>div]:bg-gray-400';
}

// Calcular si está vencida
function isOverdue(task: Task): boolean {
  const endDate = task.endDate || task.plannedEndDate;
  if (!endDate) return false;
  return new Date(endDate) < new Date() && task.status !== '2';
}

// Calcular días restantes
function getDaysRemaining(task: Task): { days: number; label: string } | null {
  const endDate = task.endDate || task.plannedEndDate;
  if (!endDate) return null;
  
  const end = new Date(endDate);
  const today = new Date();
  today.setHours(0, 0, 0, 0);
  end.setHours(0, 0, 0, 0);
  
  const diffTime = end.getTime() - today.getTime();
  const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24));
  
  if (diffDays < 0) {
    return { days: Math.abs(diffDays), label: `${Math.abs(diffDays)} días de retraso` };
  } else if (diffDays === 0) {
    return { days: 0, label: 'Vence hoy' };
  } else if (diffDays === 1) {
    return { days: 1, label: 'Vence mañana' };
  } else {
    return { days: diffDays, label: `${diffDays} días restantes` };
  }
}

export function TaskStats({ task }: TaskStatsProps) {
  const overdue = isOverdue(task);
  const daysInfo = getDaysRemaining(task);
  const efficiency = task.plannedHours > 0 
    ? Math.round((task.workedHours / task.plannedHours) * 100) 
    : 0;

  return (
    <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-4">
      {/* Progreso */}
      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">Progreso</CardTitle>
          <Target className="h-4 w-4 text-muted-foreground" />
        </CardHeader>
        <CardContent>
          <div className="text-2xl font-bold">{task.progress}%</div>
          <Progress 
            value={task.progress} 
            className={`mt-2 h-2 ${getProgressColorClass(task.progress)}`} 
          />
          <p className="text-xs text-muted-foreground mt-2">
            {task.progress >= 100 ? (
              <span className="flex items-center gap-1 text-green-600">
                <CheckCircle2 className="h-3 w-3" />
                Tarea completada
              </span>
            ) : task.progress > 0 ? (
              'En progreso'
            ) : (
              'Sin iniciar'
            )}
          </p>
        </CardContent>
      </Card>

      {/* Tiempo */}
      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">Tiempo</CardTitle>
          <Clock className="h-4 w-4 text-muted-foreground" />
        </CardHeader>
        <CardContent>
          <div className="text-2xl font-bold">
            {task.workedHours > 0 ? `${task.workedHours}h` : '-'}
          </div>
          {task.plannedHours > 0 && (
            <Progress 
              value={Math.min(efficiency, 100)} 
              className={`mt-2 h-2 ${efficiency > 100 ? '[&>div]:bg-red-500' : '[&>div]:bg-blue-500'}`} 
            />
          )}
          <p className="text-xs text-muted-foreground mt-2">
            {task.plannedHours > 0 ? (
              <>
                de {task.plannedHours}h planificadas
                {efficiency > 100 && (
                  <span className="text-red-500 ml-1">({efficiency}%)</span>
                )}
              </>
            ) : (
              'Sin estimación'
            )}
          </p>
        </CardContent>
      </Card>

      {/* Fecha límite */}
      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">Fecha límite</CardTitle>
          <Calendar className={`h-4 w-4 ${overdue ? 'text-red-500' : 'text-muted-foreground'}`} />
        </CardHeader>
        <CardContent>
          <div className={`text-2xl font-bold ${overdue ? 'text-red-500' : ''}`}>
            {formatDate(task.endDate || task.plannedEndDate).split(' de ')[0] || '-'}
          </div>
          <p className={`text-xs mt-2 ${overdue ? 'text-red-500' : 'text-muted-foreground'}`}>
            {daysInfo ? (
              <span className="flex items-center gap-1">
                {overdue && <AlertTriangle className="h-3 w-3" />}
                {daysInfo.label}
              </span>
            ) : (
              'Sin fecha límite'
            )}
          </p>
        </CardContent>
      </Card>

      {/* Eficiencia / Estado */}
      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">Rendimiento</CardTitle>
          <TrendingUp className="h-4 w-4 text-muted-foreground" />
        </CardHeader>
        <CardContent>
          <div className="text-2xl font-bold">
            {task.plannedHours > 0 && task.workedHours > 0 ? (
              `${Math.round((task.progress / efficiency) * 100)}%`
            ) : task.progress > 0 ? (
              'Activa'
            ) : (
              '-'
            )}
          </div>
          <p className="text-xs text-muted-foreground mt-2">
            {task.plannedHours > 0 && task.workedHours > 0 ? (
              'Progreso vs tiempo invertido'
            ) : (
              <span className="flex items-center gap-1">
                <FileText className="h-3 w-3" />
                {task.description ? 'Con descripción' : 'Sin descripción'}
              </span>
            )}
          </p>
        </CardContent>
      </Card>
    </div>
  );
}