"use client";
import { fetchData } from "@/lib/data-service";

import { useState, useEffect } from "react";
import { useRouter } from "next/navigation";
import Image from "next/image";
import Link from "next/link";
import { Button } from "@/components/ui/button";
import { Checkbox } from "@/components/ui/checkbox";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { toast } from "sonner";

export default function LoginPage() {
  const [username, setUsername] = useState(""); 
  const [password, setPassword] = useState("");
  const [isLoading, setIsLoading] = useState(false);
  const [isRedirecting, setIsRedirecting] = useState(false);
  const router = useRouter();

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

  async function handleLogin(e: React.FormEvent) {
    e.preventDefault();
    
    if (isLoading || isRedirecting) return;
    
    setIsLoading(true);

    try {
      const response = await fetch(`${process.env.NEXT_PUBLIC_API_URL}/auth/login`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ username, password }),
        credentials: "include",
      });
      
      const data = await response.json();
      
      if (response.ok && data.token) {
        // Set redirecting state to prevent multiple redirect attempts
        setIsRedirecting(true);
        
        // Store the token in both cookie and localStorage for redundancy
        document.cookie = `Authorization=${data.token}; path=/; Secure; SameSite=Strict; max-age=604800`;
        localStorage.setItem("Authorization", data.token);
        
        // Show toast before redirect
        toast.success("Login successful");
        
        // Use a small timeout to ensure the cookie is set before navigation
        setTimeout(() => {
          try {
            router.push("/dashboard");
            // Force a hard redirect if router.push doesn't work
            setTimeout(() => {
              window.location.href = "/dashboard";
            }, 1000);
          } catch (navError) {
            console.error("Navigation error:", navError);
            window.location.href = "/dashboard";
          }
        }, 300);
      } else {
        // Handle HTTP error responses (including 401)
        const errorMessage = data.error || "Invalid credentials";
        toast.error("Login Failed", {
          description: errorMessage,
        });
      }
    } catch (error) {
      // This will now only catch network errors or JSON parsing errors
      toast.error("Connection Error", {
        description: "Unable to connect to the server. Please check your internet connection and try again.",
      });
      console.error("Login error:", error);
    } finally {
      setIsLoading(false);
    }
  }

  // If already redirecting, show loading state
  if (isRedirecting) {
    return (
      <div className="flex items-center justify-center min-h-screen bg-gray-100 dark:bg-[#0F0F12]">
        <div className="w-full max-w-md p-8 space-y-8 bg-white dark:bg-[#1F1F23] rounded-xl shadow-lg text-center">
          <h2 className="mt-6 text-3xl font-bold text-gray-900 dark:text-white">Logging in</h2>
          <p className="mt-2 text-sm text-gray-600 dark:text-gray-400">Redirecting to dashboard...</p>
          <div className="mt-6 flex justify-center">
            <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-primary"></div>
          </div>
        </div>
      </div>
    );
  }

  return (
    <div className="flex items-center justify-center min-h-screen bg-gray-100 dark:bg-[#0F0F12]">
      <div className="w-full max-w-md p-8 space-y-8 bg-white dark:bg-[#1F1F23] rounded-xl shadow-lg">
        <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>
              <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"
              />
            </div>
            <div>
              <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"
              />
            </div>
          </div>

          <Button type="submit" className="w-full" disabled={isLoading || isRedirecting}>
            {isLoading ? "Signing in..." : "Sign in"}
          </Button>
        </form>

        <p className="mt-10 text-sm text-center text-gray-600 dark:text-gray-400">
          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>
  );
}