"use client";

import React, { useState } from "react";
import { signInWithEmailAndPassword } from "firebase/auth";
import { auth } from "@/lib/firebase";
import { useRouter } from "next/navigation";
import { motion } from "framer-motion";
import { Lock, User, ArrowRight, ShieldCheck } from "lucide-react";

import Link from "next/link";

export default function LoginPage() {
  const [email, setEmail] = useState("admin@erp.com");
  const [password, setPassword] = useState("admin123");
  const [error, setError] = useState("");
  const [loading, setLoading] = useState(false);
  const router = useRouter();

  const handleLogin = async (e: React.FormEvent) => {
    e.preventDefault();
    setLoading(true);
    setError("");
    try {
      await signInWithEmailAndPassword(auth, email, password);
      router.push("/");
    } catch (err: any) {
      // Auto-create admin if it doesn't exist
      if (err.code === "auth/user-not-found" && email === "admin@erp.com") {
        try {
          const { createUserWithEmailAndPassword } = await import("firebase/auth");
          await createUserWithEmailAndPassword(auth, email, password);
          router.push("/");
          return;
        } catch (regErr: any) {
          setError("Error al crear cuenta administrativa automática.");
        }
      } else if (err.code === "auth/invalid-credential" || err.code === "auth/wrong-password") {
         setError("Credenciales inválidas. Intente de nuevo.");
      } else {
         setError("Error de conexión. Intente de nuevo.");
      }
      setLoading(false);
    }
  };

  return (
    <div className="fixed inset-0 bg-[#020617] flex items-center justify-center p-6 z-[100]">
      {/* Background Decorative Elements */}
      <div className="absolute top-[-10%] left-[-10%] w-[40%] h-[40%] bg-blue-600/20 rounded-full blur-[120px] animate-pulse"></div>
      <div className="absolute bottom-[-10%] right-[-10%] w-[40%] h-[40%] bg-indigo-600/20 rounded-full blur-[120px] animate-pulse delay-1000"></div>

      <motion.div 
        initial={{ opacity: 0, y: 20 }}
        animate={{ opacity: 1, y: 0 }}
        className="w-full max-w-md bg-white/5 border border-white/10 rounded-[2.5rem] p-10 backdrop-blur-3xl shadow-2xl relative overflow-hidden"
      >
        <div className="absolute top-0 left-0 w-full h-1 bg-gradient-to-r from-blue-500 via-indigo-500 to-purple-500"></div>
        
        <div className="flex flex-col items-center mb-10">
          <div className="w-16 h-16 bg-gradient-to-br from-blue-600 to-indigo-600 rounded-[1.5rem] flex items-center justify-center shadow-2xl shadow-blue-500/20 mb-6">
            <ShieldCheck size={32} className="text-white" />
          </div>
          <h1 className="text-3xl font-black tracking-tighter italic uppercase text-white">
            NEXUS <span className="text-blue-500 italic">ERP</span>
          </h1>
          <p className="text-gray-500 font-bold mt-2 uppercase text-[10px] tracking-[0.3em]">Acceso Seguro al Panel de Control</p>
        </div>

        <form onSubmit={handleLogin} className="space-y-6">
          <div className="space-y-2">
            <label className="text-[10px] font-black uppercase tracking-widest text-gray-400 ml-4">Usuario / Email</label>
            <div className="relative group">
              <User className="absolute left-4 top-1/2 -translate-y-1/2 text-gray-500 group-focus-within:text-blue-400 transition-colors" size={18} />
              <input 
                type="email" 
                value={email}
                onChange={(e) => setEmail(e.target.value)}
                className="w-full bg-white/5 border border-white/10 rounded-2xl py-4 pl-12 pr-4 text-sm font-medium focus:ring-2 focus:ring-blue-500/50 outline-none transition-all focus:bg-white/10"
                placeholder="usuario@empresa.com"
                required
              />
            </div>
          </div>

          <div className="space-y-2">
            <label className="text-[10px] font-black uppercase tracking-widest text-gray-400 ml-4">Contraseña</label>
            <div className="relative group">
              <Lock className="absolute left-4 top-1/2 -translate-y-1/2 text-gray-500 group-focus-within:text-blue-400 transition-colors" size={18} />
              <input 
                type="password" 
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                className="w-full bg-white/5 border border-white/10 rounded-2xl py-4 pl-12 pr-4 text-sm font-medium focus:ring-2 focus:ring-blue-500/50 outline-none transition-all focus:bg-white/10"
                placeholder="••••••••"
                required
              />
            </div>
          </div>

          {error && (
            <motion.p 
              initial={{ opacity: 0, x: -10 }}
              animate={{ opacity: 1, x: 0 }}
              className="text-red-400 text-xs font-bold text-center bg-red-500/10 py-3 rounded-xl border border-red-500/20"
            >
              {error}
            </motion.p>
          )}

          <button 
            type="submit" 
            disabled={loading}
            className="w-full bg-gradient-to-r from-blue-600 to-indigo-600 hover:from-blue-500 hover:to-indigo-500 text-white font-black py-4 rounded-2xl shadow-xl shadow-blue-900/40 flex items-center justify-center gap-2 group transition-all active:scale-[0.98] disabled:opacity-50"
          >
            {loading ? "Iniciando Sesión..." : (
              <>
                Entrar al Sistema
                <ArrowRight size={18} className="group-hover:translate-x-1 transition-transform" />
              </>
            )}
          </button>
        </form>

        <div className="mt-8 pt-8 border-t border-white/5 flex flex-col gap-4">
           <div className="bg-blue-500/5 border border-blue-500/10 rounded-2xl p-4 flex items-center gap-4">
              <div className="w-8 h-8 rounded-full bg-blue-500/10 flex items-center justify-center">
                 <ShieldCheck size={14} className="text-blue-400" />
              </div>
              <div>
                <p className="text-[9px] font-black uppercase text-blue-400 tracking-wider">Modo Demo Activado</p>
                <p className="text-[10px] text-gray-500 font-medium">Haga clic en 'Entrar' para acceder rápidamente.</p>
              </div>
           </div>

           <p className="text-center text-xs text-gray-500 font-medium">
             ¿No tienes una cuenta? {" "}
             <Link href="/register" className="text-blue-400 font-black hover:text-blue-300 transition-colors">
               Regístrate aquí
             </Link>
           </p>
        </div>
      </motion.div>
    </div>
  );
}