"use client"

import { useState, useEffect, useRef } from "react";
import { useRouter, useSearchParams } 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 { toast } from "sonner";
import { Loader2, ArrowRight } from "lucide-react";
import { motion } from "framer-motion";

export default function LoginForm() {
  const [username, setUsername] = useState("");
  const [password, setPassword] = useState("");
  const [isLoading, setIsLoading] = useState(false);
  const [loginSuccess, setLoginSuccess] = useState(false);
  const redirectTimeoutRef = useRef<NodeJS.Timeout | null>(null);
  const router = useRouter();
  const searchParams = useSearchParams();
  const redirectUrl = searchParams.get("redirectUrl") || "/dashboard";

  // Check if already logged in
  useEffect(() => {
    const authToken = document.cookie
      .split("; ")
      .find((row) => row.startsWith("Authorization="))
      ?.split("=")[1];

    if (authToken) {
      router.push("/dashboard");
    }
  }, [router]);

  // Cleanup timeout on unmount
  useEffect(() => {
    return () => {
      if (redirectTimeoutRef.current) {
        clearTimeout(redirectTimeoutRef.current);
      }
    };
  }, []);

  async function handleLogin(e: React.FormEvent) {
    e.preventDefault();
    setIsLoading(true);

    try {
      const response = await fetch("/api/auth/login", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ username, password }),
      });

      let data;
      try {
        data = await response.json();
      } catch (parseError) {
        console.error("Login parse error:", parseError);
        toast.error("Server Error", {
          description: "The server response couldn't be processed. Please try again."
        });
        setIsLoading(false);
        return;
      }

      if (response.ok && data.token) {
        document.cookie = `Authorization=${data.token}; path=/; Secure; SameSite=Strict; max-age=10800`;
        localStorage.setItem("Authorization", data.token);

        toast.success("Welcome back!", { duration: 2000 });
        setLoginSuccess(true);

        router.push(redirectUrl);
        redirectTimeoutRef.current = setTimeout(() => {
          window.location.href = redirectUrl;
        }, 1500);
      } else {
        const errorMessage = data.error || data.message || data.details || "Invalid credentials";
        toast.error("Access Denied", {
          description: errorMessage,
        });
        setIsLoading(false);
      }
    } catch (error) {
      toast.error("Connection Error", {
        description: "Unable to connect to server.",
      });
      setIsLoading(false);
    }
  }

  return (
    <motion.div
      initial={{ opacity: 0, y: 20 }}
      animate={{ opacity: 1, y: 0 }}
      transition={{ duration: 0.5 }}
      className="w-full max-w-md relative z-10"
    >
      <div className={`
        overflow-hidden rounded-2xl border border-white/10 shadow-2xl transition-all duration-300
        bg-black/40 backdrop-blur-xl
        p-8
        ${loginSuccess ? 'scale-[0.98] opacity-80' : 'scale-100 opacity-100'}
      `}>
        <div className="text-center mb-8">
          <h2 className="text-2xl font-bold text-white tracking-tight">Welcome back</h2>
          <p className="mt-2 text-sm text-zinc-400">Enter your credentials to access the dashboard</p>
        </div>

        <form className="space-y-6" onSubmit={handleLogin}>
          <div className="space-y-4">
            <div className="space-y-2">
              <Label htmlFor="username" className="text-zinc-300">Username</Label>
              <Input
                id="username"
                type="text"
                autoComplete="username"
                required
                value={username}
                onChange={(e) => setUsername(e.target.value)}
                className="bg-white/5 border-white/10 text-white placeholder:text-zinc-500 focus:border-indigo-500/50 focus:ring-indigo-500/20 transition-all duration-300"
                placeholder="Enter your username"
                disabled={isLoading || loginSuccess}
              />
            </div>
            <div className="space-y-2">
              <div className="flex items-center justify-between">
                <Label htmlFor="password" className="text-zinc-300">Password</Label>
                <Link href="/auth/reset-password" className="text-xs text-indigo-400 hover:text-indigo-300 transition-colors">
                  Forgot password?
                </Link>
              </div>
              <Input
                id="password"
                type="password"
                autoComplete="current-password"
                required
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                className="bg-white/5 border-white/10 text-white placeholder:text-zinc-500 focus:border-indigo-500/50 focus:ring-indigo-500/20 transition-all duration-300"
                placeholder="Enter your password"
                disabled={isLoading || loginSuccess}
              />
            </div>
          </div>

          <Button
            type="submit"
            className={`
              w-full h-11 font-medium text-sm transition-all duration-300
              ${loginSuccess
                ? 'bg-green-500/90 hover:bg-green-500 text-white'
                : 'bg-gradient-to-r from-indigo-600 to-purple-600 hover:from-indigo-500 hover:to-purple-500 text-white shadow-lg shadow-indigo-500/25'}
            `}
            disabled={isLoading || loginSuccess}
          >
            {isLoading ? (
              <span className="flex items-center justify-center gap-2">
                <Loader2 className="h-4 w-4 animate-spin" />
                Signing in...
              </span>
            ) : loginSuccess ? (
              <span className="flex items-center justify-center gap-2">
                <ArrowRight className="h-4 w-4" />
                Redirecting...
              </span>
            ) : (
              "Sign in"
            )}
          </Button>
        </form>

        <div className="mt-8 pt-6 border-t border-white/10 text-center">
          <p className="text-sm text-zinc-400">
            Don't have an account?{" "}
            <Link
              href="/auth/register"
              className="text-indigo-400 hover:text-indigo-300 font-medium transition-colors inline-flex items-center gap-1"
            >
              Sign up <ArrowRight className="w-3 h-3" />
            </Link>
          </p>
        </div>
      </div>
    </motion.div>
  );
}