"use client"

import { useState, useEffect } from "react"
import { signIn, useSession } from "next-auth/react"
import { useRouter } from "next/navigation"
import Link from "next/link"
import { Button } from "@/components/ui/button"
import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card"
import { User, Lock, AlertCircle } from "lucide-react"
import { notifications } from "@/lib/notifications"

export default function LoginPage() {
  const [username, setUsername] = useState("")
  const [password, setPassword] = useState("")
  const [loading, setLoading] = useState(false)
  const router = useRouter()
  const { data: session, status } = useSession()

  // Redirigir si ya está autenticado
  useEffect(() => {
    if (session) {
      router.push("/dashboard")
    }
  }, [session, router])

  // Mostrar loading mientras se verifica la sesión
  if (status === "loading") {
    return (
      <div className="min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100 flex items-center justify-center p-4">
        <div className="w-8 h-8 border-4 border-blue-600 border-t-transparent rounded-full animate-spin"></div>
      </div>
    )
  }

  // Si ya está autenticado, mostrar loading mientras redirige
  if (session) {
    return (
      <div className="min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100 flex items-center justify-center p-4">
        <div className="text-center">
          <div className="w-8 h-8 border-4 border-blue-600 border-t-transparent rounded-full animate-spin mx-auto mb-4"></div>
          <p className="text-gray-600">Redirigiendo...</p>
        </div>
      </div>
    )
  }

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    setLoading(true)

    try {
      const result = await signIn("credentials", {
        username,
        password,
        redirect: false,
      })

      if (result?.error) {
        notifications.auth.loginError()
      } else {
        notifications.auth.loginSuccess()
        router.push("/dashboard")
      }
    } catch (error) {
      console.error("Error en login:", error)
      notifications.auth.loginGeneralError()
    } finally {
      setLoading(false)
    }
  }

  return (
    <div className="min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100 flex items-center justify-center p-4">
      <Card className="w-full max-w-md">
        <CardHeader className="text-center">
          <div className="flex items-center justify-center mb-4">
            <div className="w-12 h-12 bg-blue-600 rounded-lg flex items-center justify-center mr-3">
              <User className="w-6 h-6 text-white" />
            </div>
            <CardTitle className="text-2xl">Ani Assistant</CardTitle>
          </div>
          <p className="text-gray-600">Inicia sesión en tu cuenta</p>
        </CardHeader>
        <CardContent>
          <form onSubmit={handleSubmit} className="space-y-4">
            <div className="space-y-2">
              <Label htmlFor="username">Usuario</Label>
              <Input
                id="username"
                type="text"
                placeholder="1206706838-EST"
                value={username}
                onChange={(e) => setUsername(e.target.value)}
                required
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="password">Contraseña</Label>
              <Input
                id="password"
                type="password"
                placeholder="••••••••"
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                required
              />
            </div>
            <div className="space-y-2">
              <Button 
                type="submit" 
                className="w-full" 
                disabled={loading}
              >
                {loading ? (
                  <div className="w-4 h-4 border-2 border-white border-t-transparent rounded-full animate-spin mr-2"></div>
                ) : (
                  <Lock className="w-4 h-4 mr-2" />
                )}
                Iniciar Sesión
              </Button>
              <Button 
                type="button" 
                variant="outline"
                className="w-full" 
                onClick={() => router.push("/")}
                disabled={loading}
              >
                Cancelar
              </Button>
            </div>
          </form>

          <div className="mt-6 p-4 bg-blue-50 rounded-lg">
            <div className="flex items-center">
              <AlertCircle className="w-4 h-4 text-blue-600 mr-2" />
              <p className="text-sm text-blue-800">
                <strong>Acceso UTB:</strong> Usa tus credenciales institucionales 
                (ejemplo: 1206706838-EST)
              </p>
            </div>
          </div>
        </CardContent>
      </Card>
    </div>
  )
}