"use client";

import { useState } from "react";
import { useRouter } from "next/navigation";
import { login, AuthError } from "@duoc-thu/api-client";

export default function AdminLoginPage() {
  const router = useRouter();
  const [username, setUsername] = useState("");
  const [password, setPassword] = useState("");
  const [error, setError] = useState<string | null>(null);
  const [pending, setPending] = useState(false);

  async function onSubmit(event: React.FormEvent) {
    event.preventDefault();
    setError(null);
    setPending(true);
    try {
      const user = await login({ username, password });
      if (user.role !== "admin") {
        setError("Tài khoản này không có quyền quản trị.");
        return;
      }
      router.push("/admin");
      router.refresh();
    } catch (err) {
      setError(
        err instanceof AuthError && err.status === 401
          ? "Sai tên đăng nhập hoặc mật khẩu."
          : "Không thể đăng nhập lúc này. Vui lòng thử lại."
      );
    } finally {
      setPending(false);
    }
  }

  return (
    <div className="flex flex-1 items-center justify-center p-6">
      <form
        onSubmit={onSubmit}
        className="w-full max-w-sm space-y-4 rounded-2xl border border-border-subtle bg-surface p-6 shadow-sm"
      >
        <h1 className="text-lg font-bold text-txt-primary">Đăng nhập quản trị</h1>
        <div className="space-y-1">
          <label className="text-xs font-semibold text-txt-secondary" htmlFor="username">
            Tên đăng nhập
          </label>
          <input
            id="username"
            className="w-full rounded-lg border border-border-subtle bg-app px-3 py-2 text-sm text-txt-primary"
            value={username}
            onChange={(e) => setUsername(e.target.value)}
            autoComplete="username"
            required
          />
        </div>
        <div className="space-y-1">
          <label className="text-xs font-semibold text-txt-secondary" htmlFor="password">
            Mật khẩu
          </label>
          <input
            id="password"
            type="password"
            className="w-full rounded-lg border border-border-subtle bg-app px-3 py-2 text-sm text-txt-primary"
            value={password}
            onChange={(e) => setPassword(e.target.value)}
            autoComplete="current-password"
            required
          />
        </div>
        {error && <p className="text-xs font-medium text-status-danger">{error}</p>}
        <button
          type="submit"
          disabled={pending}
          className="w-full rounded-lg bg-accent-primary py-2 text-sm font-semibold text-txt-inverse disabled:opacity-60"
        >
          {pending ? "Đang đăng nhập..." : "Đăng nhập"}
        </button>
      </form>
    </div>
  );
}