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

async function handleRequest(request) {
  const url = new URL(request.url)
  const path = url.pathname

  if (path.startsWith('/static/tobs/')) {
    const targetUrl = 'https://storage-b.picacomic.com/static/' + path.substring('/static/tobs/'.length)
    return fetch(targetUrl, request)
  }

  if (path.startsWith('/static/tobeimg/')) {
    const targetUrl = 'https://img.picacomic.com/' + path.substring('/static/tobeimg/'.length)
    return fetch(targetUrl, request)
  }

  const targetUrl = 'https://s3.picacomic.com' + path
  const modifiedHeaders = new Headers(request.headers)
  modifiedHeaders.set('Host', 's3.picacomic.com')
  modifiedHeaders.set('X-Real-IP', request.headers.get('CF-Connecting-IP'))
  modifiedHeaders.set('X-Forwarded-For', request.headers.get('CF-Connecting-IP'))
  modifiedHeaders.set('REMOTE-HOST', request.headers.get('CF-Connecting-IP'))
  modifiedHeaders.set('Upgrade', request.headers.get('Upgrade'))
  modifiedHeaders.set('Connection', request.headers.get('Connection'))
  modifiedHeaders.set('Accept-Encoding', '')
  modifiedHeaders.delete('Cookie')
  modifiedHeaders.delete('Cache-Control')
  modifiedHeaders.delete('expires')

  const modifiedRequest = new Request(targetUrl, {
    method: request.method,
    headers: modifiedHeaders,
    body: request.body,
    redirect: 'manual'
  })

  const response = await fetch(modifiedRequest)
  const modifiedResponse = new Response(response.body, response)
  modifiedResponse.headers.set('X-Cache', response.headers.get('CF-Cache-Status'))

  if (path.match(/\.(gif|png|jpg|css|js|woff|woff2)$/i)) {
    modifiedResponse.headers.set('Expires', new Date(Date.now() + 86400000).toUTCString())
  }

  return modifiedResponse
}