path: root/server/helpers/youtube-dl/youtube-dl-wrapper.ts

import { move, pathExists, readdir, remove } from 'fs-extra'
import { dirname, join } from 'path'
import { CONFIG } from '@server/initializers/config'
import { isVideoFileExtnameValid } from '../custom-validators/videos'
import { logger, loggerTagsFactory } from '../logger'
import { generateVideoImportTmpPath } from '../utils'
import { YoutubeDLCLI } from './youtube-dl-cli'
import { YoutubeDLInfo, YoutubeDLInfoBuilder } from './youtube-dl-info-builder'

const lTags = loggerTagsFactory('youtube-dl')

export type YoutubeDLSubs = {
  language: string
  filename: string
  path: string
}[]

const processOptions = {
  maxBuffer: 1024 * 1024 * 10 // 10MB
}

class YoutubeDLWrapper {

  constructor (private readonly url: string = '', private readonly enabledResolutions: number[] = []) {

  }

  async getInfoForDownload (youtubeDLArgs: string[] = []): Promise<YoutubeDLInfo> {
    const youtubeDL = await YoutubeDLCLI.safeGet()

    const info = await youtubeDL.getInfo({
      url: this.url,
      format: YoutubeDLCLI.getYoutubeDLVideoFormat(this.enabledResolutions),
      additionalYoutubeDLArgs: youtubeDLArgs,
      processOptions
    })

    if (info.is_live === true) throw new Error('Cannot download a live streaming.')

    const infoBuilder = new YoutubeDLInfoBuilder(info)

    return infoBuilder.getInfo()
  }

  async getSubtitles (): Promise<YoutubeDLSubs> {
    const cwd = CONFIG.STORAGE.TMP_DIR

    const youtubeDL = await YoutubeDLCLI.safeGet()

    const files = await youtubeDL.getSubs({ url: this.url, format: 'vtt', processOptions: { cwd } })
    if (!files) return []

    logger.debug('Get subtitles from youtube dl.', { url: this.url, files, ...lTags() })

    const subtitles = files.reduce((acc, filename) => {
      const matched = filename.match(/\.([a-z]{2})(-[a-z]+)?\.(vtt|ttml)/i)
      if (!matched || !matched[1]) return acc

      return [
        ...acc,
        {
          language: matched[1],
          path: join(cwd, filename),
          filename
        }
      ]
    }, [])

    return subtitles
  }

  async downloadVideo (fileExt: string, timeout: number): Promise<string> {
    // Leave empty the extension, youtube-dl will add it
    const pathWithoutExtension = generateVideoImportTmpPath(this.url, '')

    let timer: NodeJS.Timeout

    logger.info('Importing youtubeDL video %s to %s', this.url, pathWithoutExtension, lTags())

    const youtubeDL = await YoutubeDLCLI.safeGet()

    const timeoutPromise = new Promise<string>((_, rej) => {
      timer = setTimeout(() => rej(new Error('YoutubeDL download timeout.')), timeout)
    })

    const downloadPromise = youtubeDL.download({
      url: this.url,
      format: YoutubeDLCLI.getYoutubeDLVideoFormat(this.enabledResolutions),
      output: pathWithoutExtension,
      processOptions
    }).then(() => clearTimeout(timer))
      .then(async () => {
        // If youtube-dl did not guess an extension for our file, just use .mp4 as default
        if (await pathExists(pathWithoutExtension)) {
          await move(pathWithoutExtension, pathWithoutExtension + '.mp4')
        }

        return this.guessVideoPathWithExtension(pathWithoutExtension, fileExt)
      })

    return Promise.race([ downloadPromise, timeoutPromise ])
      .catch(async err => {
        const path = await this.guessVideoPathWithExtension(pathWithoutExtension, fileExt)

        remove(path)
          .catch(err => logger.error('Cannot remove file in youtubeDL timeout.', { err, ...lTags() }))

        throw err
      })
  }

  private async guessVideoPathWithExtension (tmpPath: string, sourceExt: string) {
    if (!isVideoFileExtnameValid(sourceExt)) {
      throw new Error('Invalid video extension ' + sourceExt)
    }

    const extensions = [ sourceExt, '.mp4', '.mkv', '.webm' ]

    for (const extension of extensions) {
      const path = tmpPath + extension

      if (await pathExists(path)) return path
    }

    const directoryContent = await readdir(dirname(tmpPath))

    throw new Error(`Cannot guess path of ${tmpPath}. Directory content: ${directoryContent.join(', ')}`)
  }
}

// ---------------------------------------------------------------------------

export {
  YoutubeDLWrapper
}