// 边缘函数入口
const { serveNcmApi } = require('../../server')

// 默认配置
const defaultEnv = {
  ENABLE_GENERAL_UNBLOCK: 'true',
  ENABLE_FLAC: 'true',
  SELECT_MAX_BR: 'true',
  UNBLOCK_SOURCE: 'pyncmd,qq,kuwo,migu,kugou',
  FOLLOW_SOURCE_ORDER: 'true',
  CORS_ALLOW_ORIGIN: '*',
  ENABLE_PROXY: 'false',
  PROXY_URL: '',
  NETEASE_COOKIE: '',
  JOOX_COOKIE: '',
  MIGU_COOKIE: '',
  QQ_COOKIE: '',
  YOUTUBE_KEY: ''
}

let app = null

export async function onRequest(context) {
  const { request, env } = context

  // 合并默认配置和环境变量
  Object.keys(defaultEnv).forEach(key => {
    process.env[key] = env[key] || defaultEnv[key]
  })

  if (!app) {
    app = await serveNcmApi({
      checkVersion: false // 禁用版本检查，避免在边缘函数环境中发起不必要的网络请求
    })
  }

  // 解析请求体
  let body = []
  if (request.method !== 'GET' && request.method !== 'HEAD') {
    const buffer = await request.arrayBuffer()
    if (buffer.byteLength > 0) {
      body = Buffer.from(buffer)
    }
  }

  // 构造 Express 兼容的请求对象
  const req = new Proxy(request, {
    get: (target, prop) => {
      switch(prop) {
        case 'body':
          return body
        case 'query':
          return Object.fromEntries(new URL(request.url).searchParams)
        case 'cookies':
          const cookieHeader = request.headers.get('cookie') || ''
          return Object.fromEntries(
            cookieHeader.split(';')
              .map(cookie => cookie.trim().split('='))
              .filter(([key]) => key)
              .map(([key, value]) => [key, decodeURIComponent(value || '')])
          )
        case 'ip':
          return request.headers.get('cf-connecting-ip') || 
                 request.headers.get('x-real-ip') || 
                 request.headers.get('x-forwarded-for')?.split(',')[0] || 
                 '127.0.0.1'
        case 'path':
          return new URL(request.url).pathname
        case 'method':
          return request.method
        case 'headers':
          return Object.fromEntries([...request.headers])
        default:
          return target[prop]
      }
    }
  })

  // 构造 Express 兼容的响应对象
  return new Promise((resolve) => {
    const res = {
      status: (code) => {
        res.statusCode = code
        return res
      },
      set: (headers) => {
        Object.entries(headers).forEach(([key, value]) => {
          if (Array.isArray(value)) {
            value.forEach(v => res.headers[key] = v)
          } else {
            res.headers[key] = value
          }
        })
        return res
      },
      send: (body) => {
        const response = new Response(
          typeof body === 'string' ? body : JSON.stringify(body),
          {
            status: res.statusCode || 200,
            headers: {
              'Content-Type': 'application/json;charset=utf-8',
              ...res.headers
            }
          }
        )
        resolve(response)
      },
      append: (key, value) => {
        if (Array.isArray(value)) {
          value.forEach(v => {
            const current = res.headers[key]
            res.headers[key] = current ? `${current}, ${v}` : v
          })
        } else {
          const current = res.headers[key]
          res.headers[key] = current ? `${current}, ${value}` : value
        }
        return res
      },
      statusCode: 200,
      headers: {}
    }

    // 处理请求
    app.handle(req, res)
  })
}