// _worker.js

// Docker镜像仓库主机地址
let hub_host = 'registry-1.docker.io';
// Docker认证服务器地址
const auth_url = 'https://auth.docker.io';
// 自定义的工作服务器地址
let workers_url = '';

let 屏蔽爬虫UA = ['netcraft'];

// 根据主机名选择对应的上游地址
function routeByHosts(host) {
	// 定义路由表
	const routes = {
		// 生产环境
		"quay": "quay.io",
		"gcr": "gcr.io",
		"k8s-gcr": "k8s.gcr.io",
		"k8s": "registry.k8s.io",
		"ghcr": "ghcr.io",
		"cloudsmith": "docker.cloudsmith.io",
		"nvcr": "nvcr.io",
		
		// 测试环境
		"test": "registry-1.docker.io",
	};

	if (host in routes) return [ routes[host], false ];
	else return [ hub_host, true ];
}

/** @type {RequestInit} */
const PREFLIGHT_INIT = {
	// 预检请求配置
	headers: new Headers({
		'access-control-allow-origin': '*', // 允许所有来源
		'access-control-allow-methods': 'GET,POST,PUT,PATCH,TRACE,DELETE,HEAD,OPTIONS', // 允许的HTTP方法
		'access-control-max-age': '1728000', // 预检请求的缓存时间
	}),
}

/**
 * 构造响应
 * @param {any} body 响应体
 * @param {number} status 响应状态码
 * @param {Object<string, string>} headers 响应头
 */
function makeRes(body, status = 200, headers = {}) {
	headers['access-control-allow-origin'] = '*' // 允许所有来源
	return new Response(body, { status, headers }) // 返回新构造的响应
}

/**
 * 构造新的URL对象
 * @param {string} urlStr URL字符串
 */
function newUrl(urlStr) {
	try {
		return new URL(urlStr) // 尝试构造新的URL对象
	} catch (err) {
		return null // 构造失败返回null
	}
}

function isUUID(uuid) {
	// 定义一个正则表达式来匹配 UUID 格式
	const uuidRegex = /^[0-9a-f]{8}-[0-9a-f]{4}-[4][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
	
	// 使用正则表达式测试 UUID 字符串
	return uuidRegex.test(uuid);
}

async function nginx() {
	const text = `
	<!DOCTYPE html>
	<html>
	<head>
	<title>Welcome to nginx!</title>
	<style>
		body {
			width: 35em;
			margin: 0 auto;
			font-family: Tahoma, Verdana, Arial, sans-serif;
		}
	</style>
	</head>
	<body>
	<h1>Welcome to nginx!</h1>
	<p>If you see this page, the nginx web server is successfully installed and
	working. Further configuration is required.</p>
	
	<p>For online documentation and support please refer to
	<a href="http://nginx.org/">nginx.org</a>.<br/>
	Commercial support is available at
	<a href="http://nginx.com/">nginx.com</a>.</p>
	
	<p><em>Thank you for using nginx.</em></p>
	</body>
	</html>
	`
	return text;
}

async function searchInterface() {
	const text = `
	<!DOCTYPE html>
	<html>
	<head>
		<title>Docker Hub Search</title>
		<style>
		body {
			font-family: Arial, sans-serif;
			display: flex;
			flex-direction: column;
			align-items: center;
			justify-content: center;
			height: 100vh;
			margin: 0;
			background: linear-gradient(to right, rgb(28, 143, 237), rgb(29, 99, 237));
		}
		.logo {
			margin-bottom: 20px;
		}
		.search-container {
			display: flex;
			align-items: center;
		}
		#search-input {
			padding: 10px;
			font-size: 16px;
			border: 1px solid #ddd;
			border-radius: 4px;
			width: 300px;
			margin-right: 10px;
		}
		#search-button {
			padding: 10px;
			background-color: rgba(255, 255, 255, 0.2); /* 设置白色，透明度为10% */
			border: none;
			border-radius: 4px;
			cursor: pointer;
			width: 44px;
			height: 44px;
			display: flex;
			align-items: center;
			justify-content: center;
		}			
		#search-button svg {
			width: 24px;
			height: 24px;
		}
		</style>
	</head>
	<body>
		<div class="logo">
		<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 18" fill="#ffffff" width="100" height="75">
			<path d="M23.763 6.886c-.065-.053-.673-.512-1.954-.512-.32 0-.659.03-1.01.087-.248-1.703-1.651-2.533-1.716-2.57l-.345-.2-.227.328a4.596 4.596 0 0 0-.611 1.433c-.23.972-.09 1.884.403 2.666-.596.331-1.546.418-1.744.42H.752a.753.753 0 0 0-.75.749c-.007 1.456.233 2.864.692 4.07.545 1.43 1.355 2.483 2.409 3.13 1.181.725 3.104 1.14 5.276 1.14 1.016 0 2.03-.092 2.93-.266 1.417-.273 2.705-.742 3.826-1.391a10.497 10.497 0 0 0 2.61-2.14c1.252-1.42 1.998-3.005 2.553-4.408.075.003.148.005.221.005 1.371 0 2.215-.55 2.68-1.01.505-.5.685-.998.704-1.053L24 7.076l-.237-.19Z"></path>
			<path d="M2.216 8.075h2.119a.186.186 0 0 0 .185-.186V6a.186.186 0 0 0-.185-.186H2.216A.186.186 0 0 0 2.031 6v1.89c0 .103.083.186.185.186Zm2.92 0h2.118a.185.185 0 0 0 .185-.186V6a.185.185 0 0 0-.185-.186H5.136A.185.185 0 0 0 4.95 6v1.89c0 .103.083.186.186.186Zm2.964 0h2.118a.186.186 0 0 0 .185-.186V6a.186.186 0 0 0-.185-.186H8.1A.185.185 0 0 0 7.914 6v1.89c0 .103.083.186.186.186Zm2.928 0h2.119a.185.185 0 0 0 .185-.186V6a.185.185 0 0 0-.185-.186h-2.119a.186.186 0 0 0-.185.186v1.89c0 .103.083.186.185.186Zm-5.892-2.72h2.118a.185.185 0 0 0 .185-.186V3.28a.186.186 0 0 0-.185-.186H5.136a.186.186 0 0 0-.186.186v1.89c0 .103.083.186.186.186Zm2.964 0h2.118a.186.186 0 0 0 .185-.186V3.28a.186.186 0 0 0-.185-.186H8.1a.186.186 0 0 0-.186.186v1.89c0 .103.083.186.186.186Zm2.928 0h2.119a.185.185 0 0 0 .185-.186V3.28a.186.186 0 0 0-.185-.186h-2.119a.186.186 0 0 0-.185.186v1.89c0 .103.083.186.185.186Zm0-2.72h2.119a.186.186 0 0 0 .185-.186V.56a.185.185 0 0 0-.185-.186h-2.119a.186.186 0 0 0-.185.186v1.89c0 .103.083.186.185.186Zm2.955 5.44h2.118a.185.185 0 0 0 .186-.186V6a.185.185 0 0 0-.186-.186h-2.118a.185.185 0 0 0-.185.186v1.89c0 .103.083.186.185.186Z"></path>
		</svg>
		</div>
		<div class="search-container">
		<input type="text" id="search-input" placeholder="Search Docker Hub">
		<button id="search-button">
			<svg focusable="false" aria-hidden="true" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
			<path d="M21 21L16.65 16.65M19 11C19 15.4183 15.4183 19 11 19C6.58172 19 3 15.4183 3 11C3 6.58172 6.58172 3 11 3C15.4183 3 19 6.58172 19 11Z" stroke="white" fill="none" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path>
			</svg>
		</button>
		</div>
		<script>
		function performSearch() {
			const query = document.getElementById('search-input').value;
			if (query) {
			window.location.href = '/search?q=' + encodeURIComponent(query);
			}
		}
	
		document.getElementById('search-button').addEventListener('click', performSearch);
		document.getElementById('search-input').addEventListener('keypress', function(event) {
			if (event.key === 'Enter') {
			performSearch();
			}
		});
		</script>
	</body>
	</html>
	`;
	return text;
}

export default {
	async fetch(request, env, ctx) {
		const getReqHeader = (key) => request.headers.get(key); // 获取请求头

		let url = new URL(request.url); // 解析请求URL
		const userAgentHeader = request.headers.get('User-Agent');
		const userAgent = userAgentHeader ? userAgentHeader.toLowerCase() : "null";
		if (env.UA) 屏蔽爬虫UA = 屏蔽爬虫UA.concat(await ADD(env.UA));
		workers_url = `https://${url.hostname}`;
		const pathname = url.pathname;

		// 获取请求参数中的 ns
		const ns = url.searchParams.get('ns'); 
		const hostname = url.searchParams.get('hubhost') || url.hostname;
		const hostTop = hostname.split('.')[0]; // 获取主机名的第一部分

		let checkHost; // 在这里定义 checkHost 变量
		// 如果存在 ns 参数，优先使用它来确定 hub_host
		if (ns) {
			if (ns === 'docker.io') {
				hub_host = 'registry-1.docker.io'; // 设置上游地址为 registry-1.docker.io
			} else {
				hub_host = ns; // 直接使用 ns 作为 hub_host
			}
		} else {
			checkHost = routeByHosts(hostTop);
			hub_host = checkHost[0]; // 获取上游地址
		}

		const fakePage = checkHost ? checkHost[1] : false; // 确保 fakePage 不为 undefined
		console.log(`域名头部: ${hostTop}\n反代地址: ${hub_host}\n伪装首页: ${fakePage}`);
		const isUuid = isUUID(pathname.split('/')[1].split('/')[0]);

		if (屏蔽爬虫UA.some(fxxk => userAgent.includes(fxxk)) && 屏蔽爬虫UA.length > 0) {
			// 首页改成一个nginx伪装页
			return new Response(await nginx(), {
				headers: {
					'Content-Type': 'text/html; charset=UTF-8',
				},
			});
		}

		const conditions = [
			isUuid,
			pathname.includes('/_'),
			pathname.includes('/r/'),
			pathname.includes('/v2/repositories'),
			pathname.includes('/v2/user'),
			pathname.includes('/v2/orgs'),
			pathname.includes('/v2/_catalog'),
			pathname.includes('/v2/categories'),
			pathname.includes('/v2/feature-flags'),
			pathname.includes('search'),
			pathname.includes('source'),
			pathname == '/',
			pathname == '/favicon.ico',
			pathname == '/auth/profile',
		];

		if (conditions.some(condition => condition) && (fakePage === true || hostTop == 'docker')) {
			if (env.URL302) {
				return Response.redirect(env.URL302, 302);
			} else if (env.URL) {
				if (env.URL.toLowerCase() == 'nginx') {
					//首页改成一个nginx伪装页
					return new Response(await nginx(), {
						headers: {
							'Content-Type': 'text/html; charset=UTF-8',
						},
					});
				} else return fetch(new Request(env.URL, request));
			} else if (url.pathname == '/'){
				return new Response(await searchInterface(), {
					headers: {
					  'Content-Type': 'text/html; charset=UTF-8',
					},
				});
			}
			
			const newUrl = new URL("https://registry.hub.docker.com" + pathname + url.search);

			// 复制原始请求的标头
			const headers = new Headers(request.headers);

			// 确保 Host 头部被替换为 hub.docker.com
			headers.set('Host', 'registry.hub.docker.com');

			const newRequest = new Request(newUrl, {
					method: request.method,
					headers: headers,
					body: request.method !== 'GET' && request.method !== 'HEAD' ? await request.blob() : null,
					redirect: 'follow'
			});

			return fetch(newRequest);
		}

		// 修改包含 %2F 和 %3A 的请求
		if (!/%2F/.test(url.search) && /%3A/.test(url.toString())) {
			let modifiedUrl = url.toString().replace(/%3A(?=.*?&)/, '%3Alibrary%2F');
			url = new URL(modifiedUrl);
			console.log(`handle_url: ${url}`);
		}

		// 处理token请求
		if (url.pathname.includes('/token')) {
			let token_parameter = {
				headers: {
					'Host': 'auth.docker.io',
					'User-Agent': getReqHeader("User-Agent"),
					'Accept': getReqHeader("Accept"),
					'Accept-Language': getReqHeader("Accept-Language"),
					'Accept-Encoding': getReqHeader("Accept-Encoding"),
					'Connection': 'keep-alive',
					'Cache-Control': 'max-age=0'
				}
			};
			let token_url = auth_url + url.pathname + url.search;
			return fetch(new Request(token_url, request), token_parameter);
		}

		// 修改 /v2/ 请求路径
		if ( hub_host == 'registry-1.docker.io' && /^\/v2\/[^/]+\/[^/]+\/[^/]+$/.test(url.pathname) && !/^\/v2\/library/.test(url.pathname)) {
			//url.pathname = url.pathname.replace(/\/v2\//, '/v2/library/');
			url.pathname = '/v2/library/' + url.pathname.split('/v2/')[1];
			console.log(`modified_url: ${url.pathname}`);
		}

		// 更改请求的主机名
		url.hostname = hub_host;

		// 构造请求参数
		let parameter = {
			headers: {
				'Host': hub_host,
				'User-Agent': getReqHeader("User-Agent"),
				'Accept': getReqHeader("Accept"),
				'Accept-Language': getReqHeader("Accept-Language"),
				'Accept-Encoding': getReqHeader("Accept-Encoding"),
				'Connection': 'keep-alive',
				'Cache-Control': 'max-age=0'
			},
			cacheTtl: 3600 // 缓存时间
		};

		// 添加Authorization头
		if (request.headers.has("Authorization")) {
			parameter.headers.Authorization = getReqHeader("Authorization");
		}

		// 发起请求并处理响应
		let original_response = await fetch(new Request(url, request), parameter);
		let original_response_clone = original_response.clone();
		let original_text = original_response_clone.body;
		let response_headers = original_response.headers;
		let new_response_headers = new Headers(response_headers);
		let status = original_response.status;

		// 修改 Www-Authenticate 头
		if (new_response_headers.get("Www-Authenticate")) {
			let auth = new_response_headers.get("Www-Authenticate");
			let re = new RegExp(auth_url, 'g');
			new_response_headers.set("Www-Authenticate", response_headers.get("Www-Authenticate").replace(re, workers_url));
		}

		// 处理重定向
		if (new_response_headers.get("Location")) {
			return httpHandler(request, new_response_headers.get("Location"));
		}

		// 返回修改后的响应
		let response = new Response(original_text, {
			status,
			headers: new_response_headers
		});
		return response;
	}
};

/**
 * 处理HTTP请求
 * @param {Request} req 请求对象
 * @param {string} pathname 请求路径
 */
function httpHandler(req, pathname) {
	const reqHdrRaw = req.headers;

	// 处理预检请求
	if (req.method === 'OPTIONS' &&
		reqHdrRaw.has('access-control-request-headers')
	) {
		return new Response(null, PREFLIGHT_INIT);
	}

	let rawLen = '';

	const reqHdrNew = new Headers(reqHdrRaw);

	const refer = reqHdrNew.get('referer');

	let urlStr = pathname;

	const urlObj = newUrl(urlStr);

	/** @type {RequestInit} */
	const reqInit = {
		method: req.method,
		headers: reqHdrNew,
		redirect: 'follow',
		body: req.body
	};
	return proxy(urlObj, reqInit, rawLen);
}

/**
 * 代理请求
 * @param {URL} urlObj URL对象
 * @param {RequestInit} reqInit 请求初始化对象
 * @param {string} rawLen 原始长度
 */
async function proxy(urlObj, reqInit, rawLen) {
	const res = await fetch(urlObj.href, reqInit);
	const resHdrOld = res.headers;
	const resHdrNew = new Headers(resHdrOld);

	// 验证长度
	if (rawLen) {
		const newLen = resHdrOld.get('content-length') || '';
		const badLen = (rawLen !== newLen);

		if (badLen) {
			return makeRes(res.body, 400, {
				'--error': `bad len: ${newLen}, except: ${rawLen}`,
				'access-control-expose-headers': '--error',
			});
		}
	}
	const status = res.status;
	resHdrNew.set('access-control-expose-headers', '*');
	resHdrNew.set('access-control-allow-origin', '*');
	resHdrNew.set('Cache-Control', 'max-age=1500');

	// 删除不必要的头
	resHdrNew.delete('content-security-policy');
	resHdrNew.delete('content-security-policy-report-only');
	resHdrNew.delete('clear-site-data');

	return new Response(res.body, {
		status,
		headers: resHdrNew
	});
}

async function ADD(envadd) {
	var addtext = envadd.replace(/[	 |"'\r\n]+/g, ',').replace(/,+/g, ',');	// 将空格、双引号、单引号和换行符替换为逗号
	if (addtext.charAt(0) == ',') addtext = addtext.slice(1);
	if (addtext.charAt(addtext.length - 1) == ',') addtext = addtext.slice(0, addtext.length - 1);
	const add = addtext.split(',');
	return add;
}
