"use client";

import React, { useState, useTransition, Suspense } from "react";
import { useRouter, useSearchParams } from "next/navigation";
import { ShieldCheck, Lock, Mail, Eye, EyeOff, ArrowRight, Loader2, AlertCircle } from "lucide-react";
import toast from "react-hot-toast";
import { loginAdminAction } from "@/app/actions/auth";

function LoginForm() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const from = searchParams.get("from") || "/dashboard";

  const [identifier, setIdentifier] = useState("");
  const [password, setPassword] = useState("");
  const [showPassword, setShowPassword] = useState(false);
  const [rememberMe, setRememberMe] = useState(true);
  const [errorMessage, setErrorMessage] = useState<string | null>(null);
  const [isPending, startTransition] = useTransition();

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    setErrorMessage(null);

    if (!identifier.trim() || !password) {
      setErrorMessage("Veuillez remplir tous les champs.");
      return;
    }

    startTransition(async () => {
      try {
        const res = await loginAdminAction({
          identifier: identifier.trim(),
          password,
          rememberMe,
        });

        if (!res.success) {
          setErrorMessage(res.error || "Échec de l'authentification.");
          toast.error(res.error || "Erreur lors de la connexion");
          return;
        }

        toast.success(`Bienvenue, ${res.user?.name || "Administrateur"} !`);
        // Full page redirect ensures middleware & server cookies are freshly synchronized
        window.location.href = from.startsWith("/") && !from.startsWith("//") && !from.startsWith("/\\") ? from : "/dashboard";
      } catch (err) {
        console.error("Login client error:", err);
        setErrorMessage("Une erreur imprévue est survenue. Veuillez réessayer.");
        toast.error("Erreur serveur");
      }
    });
  };

  return (
    <div className="min-h-screen flex items-center justify-center p-4 sm:p-6 bg-[#0b0f19] relative overflow-hidden">
      {/* Background ambient lighting */}
      <div className="absolute top-1/4 left-1/2 -translate-x-1/2 -translate-y-1/2 w-[500px] h-[500px] bg-indigo-600/15 rounded-full blur-[120px] pointer-events-none" />
      <div className="absolute bottom-10 right-10 w-80 h-80 bg-violet-600/10 rounded-full blur-[100px] pointer-events-none" />

      <div className="w-full max-w-md relative z-10">
        {/* Card Header & Brand */}
        <div className="text-center mb-8">
          <div className="inline-flex items-center justify-center w-16 h-16 rounded-2xl bg-gradient-to-tr from-indigo-600 to-violet-500 shadow-xl shadow-indigo-500/25 mb-4 ring-4 ring-indigo-500/20">
            <ShieldCheck className="w-9 h-9 text-white" />
          </div>
          <h1 className="text-3xl font-extrabold text-white tracking-tight">AfroAdmin</h1>
          <p className="text-sm text-slate-400 mt-2">
            Portail d'administration sécurisé Afrohub
          </p>
        </div>

        {/* Card Form */}
        <div className="bg-slate-900/80 backdrop-blur-xl border border-slate-800/80 rounded-2xl shadow-2xl p-6 sm:p-8">
          {errorMessage && (
            <div className="mb-6 p-4 rounded-xl bg-red-950/40 border border-red-800/60 flex items-start gap-3 text-red-200 text-sm animate-shake">
              <AlertCircle className="w-5 h-5 text-red-400 shrink-0 mt-0.5" />
              <div className="flex-1">{errorMessage}</div>
            </div>
          )}

          <form onSubmit={handleSubmit} className="space-y-5">
            {/* Identifier (Email / Username) */}
            <div>
              <label className="block text-xs font-semibold text-slate-300 uppercase tracking-wider mb-2">
                Email ou Identifiant
              </label>
              <div className="relative">
                <div className="absolute inset-y-0 left-0 pl-3.5 flex items-center pointer-events-none text-slate-400">
                  <Mail className="w-5 h-5" />
                </div>
                <input
                  id="admin-identifier"
                  type="text"
                  autoComplete="username"
                  required
                  placeholder="admin@afrohub.com"
                  value={identifier}
                  onChange={(e) => setIdentifier(e.target.value)}
                  disabled={isPending}
                  className="w-full pl-11 pr-4 py-3 bg-slate-800/80 border border-slate-700/80 rounded-xl text-white placeholder-slate-500 text-sm focus:outline-none focus:border-indigo-500 focus:ring-2 focus:ring-indigo-500/20 transition-all disabled:opacity-50"
                />
              </div>
            </div>

            {/* Password */}
            <div>
              <div className="flex items-center justify-between mb-2">
                <label className="block text-xs font-semibold text-slate-300 uppercase tracking-wider">
                  Mot de passe
                </label>
              </div>
              <div className="relative">
                <div className="absolute inset-y-0 left-0 pl-3.5 flex items-center pointer-events-none text-slate-400">
                  <Lock className="w-5 h-5" />
                </div>
                <input
                  id="admin-password"
                  type={showPassword ? "text" : "password"}
                  autoComplete="current-password"
                  required
                  placeholder="••••••••••••"
                  value={password}
                  onChange={(e) => setPassword(e.target.value)}
                  disabled={isPending}
                  className="w-full pl-11 pr-11 py-3 bg-slate-800/80 border border-slate-700/80 rounded-xl text-white placeholder-slate-500 text-sm focus:outline-none focus:border-indigo-500 focus:ring-2 focus:ring-indigo-500/20 transition-all disabled:opacity-50"
                />
                <button
                  type="button"
                  onClick={() => setShowPassword(!showPassword)}
                  className="absolute inset-y-0 right-0 pr-3.5 flex items-center text-slate-400 hover:text-slate-200 focus:outline-none transition-colors"
                  aria-label={showPassword ? "Masquer le mot de passe" : "Afficher le mot de passe"}
                >
                  {showPassword ? <EyeOff className="w-5 h-5" /> : <Eye className="w-5 h-5" />}
                </button>
              </div>
            </div>

            {/* Remember Me */}
            <div className="flex items-center justify-between text-sm">
              <label className="flex items-center gap-2 cursor-pointer select-none text-slate-400 hover:text-slate-300">
                <input
                  type="checkbox"
                  checked={rememberMe}
                  onChange={(e) => setRememberMe(e.target.checked)}
                  disabled={isPending}
                  className="w-4 h-4 rounded border-slate-700 bg-slate-800 text-indigo-600 focus:ring-indigo-500/30 focus:ring-offset-0"
                />
                <span>Mémoriser ma session (30 jours)</span>
              </label>
            </div>

            {/* Submit Button */}
            <button
              type="submit"
              disabled={isPending}
              className="w-full mt-2 py-3.5 px-4 bg-gradient-to-r from-indigo-600 to-indigo-500 hover:from-indigo-500 hover:to-indigo-400 text-white font-medium rounded-xl shadow-lg shadow-indigo-600/30 hover:shadow-indigo-600/40 focus:outline-none focus:ring-2 focus:ring-indigo-500/50 transition-all flex items-center justify-center gap-2 disabled:opacity-60 disabled:cursor-not-allowed cursor-pointer"
            >
              {isPending ? (
                <>
                  <Loader2 className="w-5 h-5 animate-spin" />
                  <span>Vérification en cours...</span>
                </>
              ) : (
                <>
                  <span>Connexion à l'espace Admin</span>
                  <ArrowRight className="w-4 h-4 ml-1" />
                </>
              )}
            </button>
          </form>

          {/* Security footnote */}
          <div className="mt-8 pt-6 border-t border-slate-800 text-center">
            <div className="flex items-center justify-center gap-1.5 text-xs text-slate-500">
              <Lock className="w-3.5 h-3.5 text-emerald-400" />
              <span>Chiffrement SHA-256 de session &bull; Accès strictement restreint</span>
            </div>
          </div>
        </div>

        {/* Brand copyright */}
        <p className="text-center text-xs text-slate-600 mt-6">
          &copy; {new Date().getFullYear()} Afrohub. Tous droits réservés.
        </p>
      </div>
    </div>
  );
}

export default function LoginPage() {
  return (
    <Suspense
      fallback={
        <div className="min-h-screen flex items-center justify-center bg-[#0b0f19] text-white">
          <Loader2 className="w-8 h-8 animate-spin text-indigo-500" />
        </div>
      }
    >
      <LoginForm />
    </Suspense>
  );
}