"use client";

import { useState, FormEvent } from "react";
import { useRouter } from "next/navigation";
import { useAuth } from "@/lib/auth";
import { MessageSquare } from "lucide-react";

export default function LoginPage() {
  const { login } = useAuth();
  const router = useRouter();
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [error, setError] = useState("");
  const [isLoading, setIsLoading] = useState(false);

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    setError("");
    setIsLoading(true);
    try {
      await login(email, password);
      router.push("/chat");
    } catch (err: any) {
      const rawMsg =
        err.response?.data?.error ||
        err.response?.data?.message ||
        err.message ||
        "Login failed";
      // Only show safe, generic error messages to avoid leaking backend internals
      const safeMsg = typeof rawMsg === "string" ? rawMsg : "Login failed";
      const status = err.response?.status;
      if (status === 401 || status === 403) {
        setError("Invalid email or password.");
      } else if (status === 429) {
        setError("Too many attempts. Please try again later.");
      } else if (status >= 500) {
        setError("Server error. Please try again later.");
      } else {
        setError(safeMsg);
      }
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <div className="min-h-screen flex flex-col bg-white">
      {/* Header */}
      <header className="flex items-center justify-center py-8 bg-slack-purple">
        <div className="flex items-center gap-2 text-white">
          <MessageSquare size={28} />
          <span className="text-xl font-bold">ChatApp</span>
        </div>
      </header>

      {/* Form */}
      <div className="flex-1 flex items-center justify-center px-4 py-12 bg-[#f9f9f9]">
        <div className="w-full max-w-md bg-white rounded-lg shadow-sm border border-gray-200 p-8">
          <h1 className="text-2xl font-bold text-gray-900 mb-2">Sign in to ChatApp</h1>
          <p className="text-sm text-gray-500 mb-6">
            Enter your email and password to continue.
          </p>

          {error && (
            <div className="mb-4 p-3 rounded-md bg-red-50 border border-red-200 text-red-700 text-sm">
              {error}
            </div>
          )}

          <form onSubmit={handleSubmit} className="space-y-4">
            <div>
              <label htmlFor="email" className="block text-sm font-semibold text-gray-700 mb-1">
                Email address
              </label>
              <input
                id="email"
                type="email"
                value={email}
                onChange={(e) => setEmail(e.target.value)}
                required
                placeholder="you@example.com"
                className="w-full px-3 py-2 rounded-md border border-gray-300 focus:outline-none focus:ring-2 focus:ring-slack-purple focus:border-transparent"
                autoComplete="email"
              />
            </div>

            <div>
              <label htmlFor="password" className="block text-sm font-semibold text-gray-700 mb-1">
                Password
              </label>
              <input
                id="password"
                type="password"
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                required
                placeholder="••••••••"
                className="w-full px-3 py-2 rounded-md border border-gray-300 focus:outline-none focus:ring-2 focus:ring-slack-purple focus:border-transparent"
                autoComplete="current-password"
              />
            </div>

            <button
              type="submit"
              disabled={isLoading}
              className="w-full py-2.5 px-4 rounded-md bg-slack-purple text-white font-semibold hover:bg-slack-darkpurple transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
            >
              {isLoading ? "Signing in..." : "Sign in"}
            </button>
          </form>

          <div className="mt-6 pt-4 border-t border-gray-100 text-center text-sm text-gray-500">
            Don&apos;t have an account?{" "}
            <a href="/register" className="text-slack-purple font-semibold hover:underline">
              Create one
            </a>
          </div>

          <div className="mt-4 pt-4 border-t border-gray-100 text-center text-xs text-gray-400">
            <p className="font-semibold text-gray-500">Demo credentials</p>
            <p className="mt-1">Contact your administrator for access.</p>
          </div>
        </div>
      </div>

      <footer className="py-4 text-center text-xs text-gray-400">
        &copy; {new Date().getFullYear()} ChatApp. A Slack-like team communication app.
      </footer>
    </div>
  );
}