'use client';

import { useEffect, useState } from 'react';
import { useSearchParams, useRouter } from 'next/navigation';
import { userManager } from '@/lib/oidc-config';
import { Loader2, CheckCircle, XCircle } from 'lucide-react';
import { Card, CardContent, CardHeader, CardTitle } from '@repo/ui/components/card';
import { Alert, AlertDescription } from '@repo/ui/components/alert';

export default function CallbackPage() {
	const searchParams = useSearchParams();
	const router = useRouter();
	const [status, setStatus] = useState<'loading' | 'success' | 'error'>('loading');
	const [error, setError] = useState<string | null>(null);

	useEffect(() => {
		const handleCallback = async () => {
			try {
				if (!userManager) {
					throw new Error('用户管理器未初始化');
				}

				// 处理OIDC回调
				const user = await userManager.signinRedirectCallback();

				if (user) {
					setStatus('success');
					// 延迟跳转到首页
					setTimeout(() => {
						router.push('/');
					}, 2000);
				} else {
					throw new Error('未收到用户信息');
				}
			} catch (err) {
				console.error('回调处理失败:', err);
				setError(err instanceof Error ? err.message : '未知错误');
				setStatus('error');
			}
		};

		// 检查是否有授权码或错误参数
		const code = searchParams.get('code');
		const error = searchParams.get('error');
		const errorDescription = searchParams.get('error_description');

		if (error) {
			setError(`${error}: ${errorDescription || '授权失败'}`);
			setStatus('error');
			return;
		}

		if (code) {
			handleCallback();
		} else {
			setError('缺少授权码');
			setStatus('error');
		}
	}, [searchParams, router]);

	const getStatusIcon = () => {
		switch (status) {
			case 'loading':
				return <Loader2 className="h-8 w-8 animate-spin text-blue-500" />;
			case 'success':
				return <CheckCircle className="h-8 w-8 text-green-500" />;
			case 'error':
				return <XCircle className="h-8 w-8 text-red-500" />;
		}
	};

	const getStatusMessage = () => {
		switch (status) {
			case 'loading':
				return '正在处理登录回调...';
			case 'success':
				return '登录成功！正在跳转...';
			case 'error':
				return '登录失败';
		}
	};

	return (
		<div className="min-h-screen flex items-center justify-center bg-gray-50 dark:bg-gray-900">
			<Card className="w-full max-w-md">
				<CardHeader className="text-center">
					<div className="flex justify-center mb-4">{getStatusIcon()}</div>
					<CardTitle className="text-xl">{getStatusMessage()}</CardTitle>
				</CardHeader>
				<CardContent>
					{status === 'error' && error && (
						<Alert variant="destructive">
							<AlertDescription>{error}</AlertDescription>
						</Alert>
					)}

					{status === 'loading' && (
						<div className="text-center text-sm text-gray-600 dark:text-gray-400">
							<p>请等待，正在验证您的登录信息...</p>
						</div>
					)}

					{status === 'success' && (
						<div className="text-center text-sm text-gray-600 dark:text-gray-400">
							<p>登录成功！即将跳转到首页...</p>
						</div>
					)}

					{status === 'error' && (
						<div className="text-center mt-4">
							<button onClick={() => router.push('/')} className="text-blue-600 hover:text-blue-800 text-sm">
								返回首页
							</button>
						</div>
					)}
				</CardContent>
			</Card>
		</div>
	);
}