'use strict'
const zlib = require('zlib')
const debug = require('debug')
const appRoot = require('app-root-path')
const cors = require('cors')

const { matomoMiddleware } = require(`${appRoot}/logging/matomoHelper`)
const {
  contextMiddleware,
} = require(`${appRoot}/modules/shared`)
const { validatePermissionsReadStream } = require('./authUtils')
const { SpeckleObjectsStream } = require('./speckleObjectsStream')
const { getObjectsStream } = require('../services/objects')

const { pipeline, PassThrough } = require('stream')

module.exports = (app) => {
  app.options('/api/getobjects/:streamId', cors())

  app.post(
    '/api/getobjects/:streamId',
    cors(),
    contextMiddleware,
    matomoMiddleware,
    async (req, res) => {
      let hasStreamAccess = await validatePermissionsReadStream(
        req.params.streamId,
        req
      )
      if (!hasStreamAccess.result) {
        return res.status(hasStreamAccess.status).end()
      }

      let childrenList = JSON.parse(req.body.objects)

      let simpleText = req.headers.accept === 'text/plain'

      res.writeHead(200, {
        'Content-Encoding': 'gzip',
        'Content-Type': simpleText ? 'text/plain; charset=UTF-8' : 'application/json'
      })

      let dbStream = await getObjectsStream({
        streamId: req.params.streamId,
        objectIds: childrenList
      })
      let speckleObjStream = new SpeckleObjectsStream(simpleText)
      let gzipStream = zlib.createGzip()

      pipeline(
        dbStream,
        speckleObjStream,
        gzipStream,
        new PassThrough({ highWaterMark: 16384 * 31 }),
        res,
        (err) => {
          if (err) {
            debug('speckle:error')(
              `[User ${
                req.context.userId || '-'
              }] Error streaming objects from stream ${req.params.streamId}: ${err}`
            )
          } else {
            debug('speckle:info')(
              `[User ${req.context.userId || '-'}] Streamed ${
                childrenList.length
              } objects from stream ${req.params.streamId} (size: ${
                gzipStream.bytesWritten / 1000000
              } MB)`
            )
          }
        }
      )
    }
  )
}