let querystring = require('querystring')
let stream_buffers = require('stream-buffers')
let XDate = require('xdate')

return async env => {
  let globals = await env.site.get_json('/_config/globals.json')

  let message
  if (env.request.method === 'POST') {
    let write_stream = new stream_buffers.WritableStreamBuffer()
    let data = new Promise(
      (resolve, reject) => {
        write_stream.
        on('finish', () => {resolve(write_stream.getContents())}).
        on('error', () => {reject()})
      }
    )
    env.request.pipe(write_stream)
    let query = querystring.parse((await data).toString())
    console.log('received feedback form:', query.page)

    // save the form contents in a dated logfile, so that we can
    // recover manually if the email doesn't send for some reason
    date = new XDate()
    query.date = date.toUTCString()

    let transaction = await env.site.database.Transaction()
    ;(
      await (
        await (
          await (
            await transaction.get({})
          ).get('logs', {})
        ).get(date.toUTCString('yyyyMMdd'), {})
      ).get('feedback', [])
    ).push(transaction.json_to_logjson(query))
    transaction.commit()

    // send email (asynchronously)
    let emailjs_feedback = await env.site.get_emailjs(
      '/_config/email_feedback.json'
    )
    emailjs_feedback.send(
      {
        from: globals.feedback_from,
        to: globals.feedback_to,
        subject: 'Page: ' + query.page,
        text: query.message,
      },
      (err, message) => {
        if (err)
          console.error(err.stack || err.message)
        else
          console.log('sent feedback email:', query.page)
      }
    )

    message = 'Thanks!'
  }
  else
    message = 'Please POST.'

  env.site.serve(env, 200, Buffer.from(message), 'feedback.html.jst')
}