"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 } from "lucide-react";

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 {
      // Using fetch directly with the proxy path
      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) {
        // Store the token in both cookie and localStorage for redundancy
        document.cookie = `Authorization=${data.token}; path=/; Secure; SameSite=Strict; max-age=10800`;
        localStorage.setItem("Authorization", data.token);
        
        // Show success notification
        toast.success("Login successful");
        
        // Set success state for animation
        setLoginSuccess(true);
        
        // Try Next.js router navigation
        router.push(redirectUrl);
        
        // Set up a fallback manual redirect if Next.js navigation doesn't work
        redirectTimeoutRef.current = setTimeout(() => {
          window.location.href = redirectUrl;
        }, 1500); // Wait 1.5 seconds before trying manual redirect
      } else {
        // Handle HTTP error responses
        const errorMessage = data.error || data.message || data.details || "Invalid credentials";
        toast.error("Login Failed", {
          description: errorMessage,
        });
        console.error("Login error response:", { status: response.status, data });
        setIsLoading(false);
      }
    } catch (error) {
      toast.error("Connection Error", {
        description: "Unable to connect to the server. Please check your internet connection and try again.",
      });
      console.error("Login network error:", error);
      setIsLoading(false);
    }
  }

  return (
    <div className={`flex items-center justify-center min-h-screen bg-gray-100 dark:bg-[#0F0F12] transition-opacity duration-300 ${loginSuccess ? 'opacity-0' : 'opacity-100'}`}>
      <div className={`w-full max-w-md p-8 space-y-8 bg-white dark:bg-[#1F1F23] rounded-xl shadow-lg transition-all duration-300 ${loginSuccess ? 'scale-95 opacity-0' : 'scale-100 opacity-100'} ${isLoading && !loginSuccess ? 'animate-pulse' : ''}`}>
        <div className="text-center">
          <h2 className="mt-6 text-3xl font-bold text-gray-900 dark:text-white">Welcome back</h2>
          <p className="mt-2 text-sm text-gray-600 dark:text-gray-400">Please sign in to your account</p>
        </div>

        <form className="mt-8 space-y-6" onSubmit={handleLogin}>
          <div className="space-y-4">
            <div className="animate-in fade-in duration-500">
              <Label htmlFor="username">Username</Label>
              <Input
                id="username"
                name="username"
                type="text"
                autoComplete="username"
                required
                value={username}
                onChange={(e) => setUsername(e.target.value)}
                className="mt-1"
                disabled={isLoading || loginSuccess}
              />
            </div>
            <div className="animate-in fade-in duration-500 delay-150">
              <Label htmlFor="password">Password</Label>
              <Input
                id="password"
                name="password"
                type="password"
                autoComplete="current-password"
                required
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                className="mt-1"
                disabled={isLoading || loginSuccess}
              />
            </div>
          </div>

          <Button 
            type="submit" 
            className={`w-full animate-in fade-in-50 duration-500 delay-300 ${loginSuccess ? 'bg-green-600 hover:bg-green-700' : ''}`} 
            disabled={isLoading || loginSuccess}
          >
            {isLoading ? (
              <span className="flex items-center justify-center">
                <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                Signing in...
              </span>
            ) : loginSuccess ? (
              <span className="flex items-center justify-center">
                Redirecting...
              </span>
            ) : (
              "Sign in"
            )}
          </Button>
        </form>

        <p className="mt-10 text-sm text-center text-gray-600 dark:text-gray-400 animate-in fade-in duration-500 delay-500">
          Don't have an account?{" "}
          <Link href="/auth/register" className="text-blue-600 hover:underline dark:text-blue-400">
            Sign up
          </Link>
        </p>
      </div>
    </div>
  );
}