'use strict'

const Router = require('express').Router
const formidable = require('formidable')
const path = require('path')
const FileType = require('file-type')
const fs = require('fs')
const os = require('os')
const rimraf = require('rimraf')

const config = require('../../config')
const logger = require('../../logger')
const errors = require('../../errors')

const imageRouter = module.exports = Router()

async function checkUploadType (filePath) {
  const typeFromMagic = await FileType.fromFile(filePath)
  if (typeFromMagic === undefined) {
    logger.error(`Image upload error: Could not determine MIME-type`)
    return false
  }
  if (path.extname(filePath) !== '.' + typeFromMagic.ext) {
    logger.error(`Image upload error: Provided file extension does not match MIME-type`)
    return false
  }
  if (!config.allowedUploadMimeTypes.includes(typeFromMagic.mime)) {
    logger.error(`Image upload error: MIME-type "${typeFromMagic.mime}" of uploaded file not allowed, only "${config.allowedUploadMimeTypes.join(', ')}" are allowed`)
    return false
  }
  return true
}

// upload image
imageRouter.post('/uploadimage', function (req, res) {
  if (!req.isAuthenticated() && !config.allowAnonymous && !config.allowAnonymousEdits) {
    logger.error(`Image upload error: Anonymous edits and therefore uploads are not allowed)`)
    return errors.errorForbidden(res)
  }

  var form = new formidable.IncomingForm()
  form.keepExtensions = true
  const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'hedgedoc-'))
  form.uploadDir = tmpDir

  form.parse(req, async function (err, fields, files) {
    if (err) {
      logger.error(`Image upload error: formidable error: ${err}`)
      rimraf(tmpDir)
      return errors.errorForbidden(res)
    } else if (!files.image || !files.image.path) {
      logger.error(`Image upload error: Upload didn't contain file)`)
      rimraf.sync(tmpDir)
      return errors.errorBadRequest(res)
    } else if (!await checkUploadType(files.image.path)) {
      rimraf.sync(tmpDir)
      return errors.errorBadRequest(res)
    } else {
      logger.debug(`SERVER received uploadimage: ${JSON.stringify(files.image)}`)

      const uploadProvider = require('./' + config.imageUploadType)
      logger.debug(`imageRouter: Uploading ${files.image.path} using ${config.imageUploadType}`)
      uploadProvider.uploadImage(files.image.path, function (err, url) {
        rimraf.sync(tmpDir)
        if (err !== null) {
          logger.error(err)
          return res.status(500).end('upload image error')
        }
        logger.debug(`SERVER sending ${url} to client`)
        res.send({
          link: url
        })
      })
    }
  })
})