addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request))
})

// Base58 编码函数（Cloudflare Workers 兼容）
const BASE58_ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
function base58Encode(obj) {
  const str = JSON.stringify(obj)
  const bytes = new TextEncoder().encode(str) // Uint8Array

  // 转 BigInt
  let intVal = 0n
  for (let b of bytes) {
    intVal = (intVal << 8n) + BigInt(b)
  }

  // 编码为 Base58
  let result = ''
  while (intVal > 0n) {
    const mod = intVal % 58n
    result = BASE58_ALPHABET[Number(mod)] + result
    intVal = intVal / 58n
  }

  // 保留前导零
  for (let b of bytes) {
    if (b === 0) result = BASE58_ALPHABET[0] + result
    else break
  }

  return result
}

// JSON api 字段前缀替换
function addOrReplacePrefix(obj, newPrefix) {
  if (typeof obj !== 'object' || obj === null) return obj
  if (Array.isArray(obj)) return obj.map(item => addOrReplacePrefix(item, newPrefix))
  const newObj = {}
  for (const key in obj) {
    if (key === 'api' && typeof obj[key] === 'string') {
      let apiUrl = obj[key]
      const urlIndex = apiUrl.indexOf('?url=')
      if (urlIndex !== -1) apiUrl = apiUrl.slice(urlIndex + 5)
      if (!apiUrl.startsWith(newPrefix)) apiUrl = newPrefix + apiUrl
      newObj[key] = apiUrl
    } else {
      newObj[key] = addOrReplacePrefix(obj[key], newPrefix)
    }
  }
  return newObj
}

async function handleRequest(request) {
  const corsHeaders = {
    'Access-Control-Allow-Origin': '*',
    'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, OPTIONS',
    'Access-Control-Allow-Headers': 'Content-Type, Authorization',
    'Access-Control-Max-Age': '86400',
  }

  if (request.method === 'OPTIONS') return new Response(null, { status: 204, headers: corsHeaders })

  const reqUrl = new URL(request.url)
  const targetUrlParam = reqUrl.searchParams.get('url')
  const configParam = reqUrl.searchParams.get('config')
  const prefixParam = reqUrl.searchParams.get('prefix')
  const encodeParam = reqUrl.searchParams.get('encode')

  const currentOrigin = reqUrl.origin
  const defaultPrefix = currentOrigin + '/?url='

  // -------------------- 通用 API 中转代理 --------------------
  if (targetUrlParam) {
    let fullTargetUrl = targetUrlParam
    const urlMatch = request.url.match(/[?&]url=([^&]+(?:&.*)?)/)
    if (urlMatch) fullTargetUrl = decodeURIComponent(urlMatch[1])

    let targetURL
    try {
      targetURL = new URL(fullTargetUrl)
    } catch (e) {
      return new Response(JSON.stringify({ error: 'Invalid URL', url: fullTargetUrl }, null, 2), {
        status: 400,
        headers: { 'Content-Type': 'application/json; charset=utf-8', ...corsHeaders }
      })
    }

    try {
      const proxyRequest = new Request(targetURL.toString(), {
        method: request.method,
        headers: request.headers,
        body: request.method !== 'GET' && request.method !== 'HEAD' ? await request.arrayBuffer() : undefined,
      })

      const controller = new AbortController()
      const timeoutId = setTimeout(() => controller.abort(), 30000)
      const response = await fetch(proxyRequest, { signal: controller.signal })
      clearTimeout(timeoutId)

      const responseHeaders = new Headers(corsHeaders)
      const excludeHeaders = [
        'content-encoding', 'content-length', 'transfer-encoding',
        'connection', 'keep-alive', 'set-cookie', 'set-cookie2'
      ]
      for (const [key, value] of response.headers) {
        if (!excludeHeaders.includes(key.toLowerCase())) responseHeaders.set(key, value)
      }

      return new Response(response.body, {
        status: response.status,
        statusText: response.statusText,
        headers: responseHeaders
      })
    } catch (err) {
      return new Response(JSON.stringify({
        error: 'Proxy Error',
        message: err.message || '代理请求失败',
        target: fullTargetUrl,
        timestamp: new Date().toISOString()
      }, null, 2), {
        status: 502,
        headers: { 'Content-Type': 'application/json; charset=utf-8', ...corsHeaders }
      })
    }
  }

// -------------------- JSON 配置 + API 前缀替换 + Base58 --------------------
if (configParam === '1') {
  try {
    const jsonUrl = 'https://raw.githubusercontent.com/hafrey1/LunaTV-config/main/LunaTV-config.json'
    const response = await fetch(jsonUrl)
    const data = await response.json()
    const newData = addOrReplacePrefix(data, prefixParam || defaultPrefix)

    if (encodeParam === 'base58') {
      const encoded = base58Encode(newData)
      return new Response(encoded, {
        headers: { 'Content-Type': 'text/plain;charset=UTF-8', ...corsHeaders },
      })
    } else {
      return new Response(JSON.stringify(newData), {
        headers: { 'Content-Type': 'application/json;charset=UTF-8', ...corsHeaders },
      })
    }
  } catch (err) {
    return new Response(JSON.stringify({ error: err.message }), {
      status: 500,
      headers: { 'Content-Type': 'application/json;charset=UTF-8', ...corsHeaders },
    })
  }
}

// -------------------- JSON 配置（原始，不加前缀） config=0 --------------------
if (configParam === '0') {
  try {
    const jsonUrl = 'https://raw.githubusercontent.com/hafrey1/LunaTV-config/main/LunaTV-config.json'
    const response = await fetch(jsonUrl)
    const data = await response.json()

    if (encodeParam === 'base58') {
      const encoded = base58Encode(data)
      return new Response(encoded, {
        headers: { 'Content-Type': 'text/plain;charset=UTF-8', ...corsHeaders },
      })
    } else {
      return new Response(JSON.stringify(data), {
        headers: { 'Content-Type': 'application/json;charset=UTF-8', ...corsHeaders },
      })
    }
  } catch (err) {
    return new Response(JSON.stringify({ error: err.message }), {
      status: 500,
      headers: { 'Content-Type': 'application/json;charset=UTF-8', ...corsHeaders },
    })
  }
}


  // -------------------- 根目录或其他情况返回说明页面 --------------------
  const html = `
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>API 中转代理服务</title>
<style>
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif; max-width: 800px; margin: 50px auto; padding: 20px; line-height: 1.6; }
h1 { color: #333; }
code { background: #f4f4f4; padding: 2px 6px; border-radius: 3px; font-size: 14px; }
pre { background: #f4f4f4; padding: 15px; border-radius: 5px; overflow-x: auto; }
.example { background: #e8f5e9; padding: 15px; border-left: 4px solid #4caf50; margin: 20px 0; }
</style>
</head>
<body>
<h1>🔄 API 中转代理服务</h1>
<p>通用 API 中转代理，用于访问被墙或限制的接口。</p>

<h2>使用方法</h2>
<p>中转任意 API：在请求 URL 后添加 <code>?url=目标地址</code> 参数</p>
<pre>${defaultPrefix}https://example.com/api</pre>

<div class="example">
<strong>示例：</strong><br>
<a href="${defaultPrefix}https://caiji.kuaichezy.org/api.php/provide/vod" target="_blank">
${defaultPrefix}https://caiji.kuaichezy.org/api.php/provide/vod
</a>
</div>
<h2>订阅链接</h2>
<p>
  原始JSON 配置：
  <code class="copyable">${currentOrigin}?config=0</code>
  <button class="copy-btn">复制</button>
</p>
<p>
  JSON 配置：
  <code class="copyable">${currentOrigin}?config=1</code>
  <button class="copy-btn">复制</button>
</p>
<p>
  Base58 编码订阅：
  <code class="copyable">${currentOrigin}?config=1&encode=base58</code>
  <button class="copy-btn">复制</button>
</p>
<p>
  JSON 配置 + 自定义中转API：
  <code class="copyable">${currentOrigin}?config=1&prefix=自定义中转API</code>
  <button class="copy-btn">复制</button>
</p>

<script>
  document.querySelectorAll('.copy-btn').forEach((btn, idx) => {
    btn.addEventListener('click', () => {
      const text = document.querySelectorAll('.copyable')[idx].innerText;
      navigator.clipboard.writeText(text).then(() => {
        btn.innerText = '已复制！';
        setTimeout(() => (btn.innerText = '复制'), 1500);
      });
    });
  });
</script>

<h2>支持的功能</h2>
<ul>
<li>✅ 支持 GET、POST、PUT、DELETE 等所有 HTTP 方法</li>
<li>✅ 自动转发请求头和请求体</li>
<li>✅ 保留原始响应头（除敏感信息）</li>
<li>✅ 完整的 CORS 支持</li>
<li>✅ 超时保护（30 秒）</li>
</ul>
</body>
</html>
`
  return new Response(html, { status: 200, headers: { 'Content-Type': 'text/html; charset=utf-8', ...corsHeaders } })
}