import { uniqify } from '@peertube/peertube-core-utils'
import { FileStorage, ThumbnailType, ThumbnailType_Type } from '@peertube/peertube-models'
import { DIRECTORIES, USER_EXPORT_FILE_PREFIX } from '@server/initializers/constants.js'
import { listKeysOfPrefix, removeObjectByFullKey } from '@server/lib/object-storage/object-storage-helpers.js'
import { UserExportModel } from '@server/models/user/user-export.js'
import { VideoFileModel } from '@server/models/video/video-file.js'
import { VideoSourceModel } from '@server/models/video/video-source.js'
import { VideoStreamingPlaylistModel } from '@server/models/video/video-streaming-playlist.js'
import Bluebird from 'bluebird'
import { remove } from 'fs-extra/esm'
import { readdir, stat } from 'fs/promises'
import { basename, dirname, join } from 'path'
import { getUUIDFromFilename } from '../core/helpers/utils.js'
import { CONFIG } from '../core/initializers/config.js'
import { initDatabaseModels } from '../core/initializers/database.js'
import { ActorImageModel } from '../core/models/actor/actor-image.js'
import { VideoRedundancyModel } from '../core/models/redundancy/video-redundancy.js'
import { ThumbnailModel } from '../core/models/video/thumbnail.js'
import { VideoModel } from '../core/models/video/video.js'
import { askConfirmation, displayPeerTubeMustBeStoppedWarning } from './shared/common.js'

run()
  .then(() => process.exit(0))
  .catch(err => {
    console.error(err)
    process.exit(-1)
  })

async function run () {
  await initDatabaseModels(true)

  displayPeerTubeMustBeStoppedWarning()

  await new FSPruner().prune()

  console.log('\n')

  await new ObjectStoragePruner().prune()
}

// ---------------------------------------------------------------------------
// Object storage
// ---------------------------------------------------------------------------

class ObjectStoragePruner {
  private readonly keysToDelete: { bucket: string, key: string }[] = []

  async prune () {
    if (!CONFIG.OBJECT_STORAGE.ENABLED) return

    console.log('Pruning object storage.')

    await this.findFilesToDelete(CONFIG.OBJECT_STORAGE.WEB_VIDEOS, this.doesWebVideoFileExistFactory())
    await this.findFilesToDelete(CONFIG.OBJECT_STORAGE.STREAMING_PLAYLISTS, this.doesStreamingPlaylistFileExistFactory())
    await this.findFilesToDelete(CONFIG.OBJECT_STORAGE.ORIGINAL_VIDEO_FILES, this.doesOriginalFileExistFactory())
    await this.findFilesToDelete(CONFIG.OBJECT_STORAGE.USER_EXPORTS, this.doesUserExportFileExistFactory())

    if (this.keysToDelete.length === 0) {
      console.log('No unknown object storage files to delete.')
      return
    }

    const formattedKeysToDelete = this.keysToDelete.map(({ bucket, key }) => ` In bucket ${bucket}: ${key}`).join('\n')
    console.log(`${this.keysToDelete.length} unknown files from object storage can be deleted:\n${formattedKeysToDelete}\n`)

    const res = await askPruneConfirmation()
    if (res !== true) {
      console.log('Exiting without deleting object storage files.')
      return
    }

    console.log('Deleting object storage files...\n')

    for (const { bucket, key } of this.keysToDelete) {
      await removeObjectByFullKey(key, { BUCKET_NAME: bucket })
    }

    console.log(`${this.keysToDelete.length} object storage files deleted.`)
  }

  private async findFilesToDelete (
    config: { BUCKET_NAME: string, PREFIX?: string },
    existFun: (file: string) => Promise<boolean> | boolean
  ) {
    try {
      const keys = await listKeysOfPrefix('', config)

      await Bluebird.map(keys, async key => {
        if (await existFun(key) !== true) {
          this.keysToDelete.push({ bucket: config.BUCKET_NAME, key })
        }
      }, { concurrency: 20 })
    } catch (err) {
      const prefixMessage = config.PREFIX
        ? ` and prefix ${config.PREFIX}`
        : ''

      console.error('Cannot find files to delete in bucket ' + config.BUCKET_NAME + prefixMessage)
    }
  }

  private doesWebVideoFileExistFactory () {
    return (key: string) => {
      const filename = this.sanitizeKey(key, CONFIG.OBJECT_STORAGE.WEB_VIDEOS)

      return VideoFileModel.doesOwnedFileExist(filename, FileStorage.OBJECT_STORAGE)
    }
  }

  private doesStreamingPlaylistFileExistFactory () {
    return (key: string) => {
      const uuid = basename(dirname(this.sanitizeKey(key, CONFIG.OBJECT_STORAGE.STREAMING_PLAYLISTS)))

      return VideoStreamingPlaylistModel.doesOwnedVideoUUIDExist(uuid, FileStorage.OBJECT_STORAGE)
    }
  }

  private doesOriginalFileExistFactory () {
    return (key: string) => {
      const filename = this.sanitizeKey(key, CONFIG.OBJECT_STORAGE.ORIGINAL_VIDEO_FILES)

      return VideoSourceModel.doesOwnedFileExist(filename, FileStorage.OBJECT_STORAGE)
    }
  }

  private doesUserExportFileExistFactory () {
    return (key: string) => {
      const filename = this.sanitizeKey(key, CONFIG.OBJECT_STORAGE.USER_EXPORTS)

      return UserExportModel.doesOwnedFileExist(filename, FileStorage.OBJECT_STORAGE)
    }
  }

  private sanitizeKey (key: string, config: { PREFIX: string }) {
    return key.replace(new RegExp(`^${config.PREFIX}`), '')
  }
}

// ---------------------------------------------------------------------------
// FS
// ---------------------------------------------------------------------------

class FSPruner {
  private pathsToDelete: string[] = []

  async prune () {
    const dirs = Object.values(CONFIG.STORAGE)

    if (uniqify(dirs).length !== dirs.length) {
      console.error('Cannot prune storage because you put multiple storage keys in the same directory.')
      process.exit(0)
    }

    console.log('Pruning filesystem storage.')

    console.log('Detecting files to remove, it can take a while...')

    await this.findFilesToDelete(DIRECTORIES.WEB_VIDEOS.PUBLIC, this.doesWebVideoFileExistFactory())
    await this.findFilesToDelete(DIRECTORIES.WEB_VIDEOS.PRIVATE, this.doesWebVideoFileExistFactory())

    await this.findFilesToDelete(DIRECTORIES.HLS_STREAMING_PLAYLIST.PRIVATE, this.doesHLSPlaylistExistFactory())
    await this.findFilesToDelete(DIRECTORIES.HLS_STREAMING_PLAYLIST.PUBLIC, this.doesHLSPlaylistExistFactory())

    await this.findFilesToDelete(DIRECTORIES.ORIGINAL_VIDEOS, this.doesOriginalVideoExistFactory())

    await this.findFilesToDelete(CONFIG.STORAGE.TORRENTS_DIR, this.doesTorrentFileExistFactory())

    await this.findFilesToDelete(CONFIG.STORAGE.REDUNDANCY_DIR, this.doesRedundancyExistFactory())

    await this.findFilesToDelete(CONFIG.STORAGE.PREVIEWS_DIR, this.doesThumbnailExistFactory(true, ThumbnailType.PREVIEW))
    await this.findFilesToDelete(CONFIG.STORAGE.THUMBNAILS_DIR, this.doesThumbnailExistFactory(false, ThumbnailType.MINIATURE))

    await this.findFilesToDelete(CONFIG.STORAGE.ACTOR_IMAGES_DIR, this.doesActorImageExistFactory())

    await this.findFilesToDelete(CONFIG.STORAGE.TMP_PERSISTENT_DIR, this.doesUserExportExistFactory())

    const tmpFiles = await readdir(CONFIG.STORAGE.TMP_DIR)
    this.pathsToDelete = [ ...this.pathsToDelete, ...tmpFiles.map(t => join(CONFIG.STORAGE.TMP_DIR, t)) ]

    if (this.pathsToDelete.length === 0) {
      console.log('No unknown filesystem files to delete.')
      return
    }

    const formattedKeysToDelete = this.pathsToDelete.map(p => ` ${p}`).join('\n')
    console.log(`${this.pathsToDelete.length} unknown files from filesystem can be deleted:\n${formattedKeysToDelete}\n`)

    const res = await askPruneConfirmation()
    if (res !== true) {
      console.log('Exiting without deleting filesystem files.')
      return
    }

    console.log('Deleting filesystem files...\n')

    for (const path of this.pathsToDelete) {
      await remove(path)
    }

    console.log(`${this.pathsToDelete.length} filesystem files deleted.`)
  }

  private async findFilesToDelete (directory: string, existFun: (file: string) => Promise<boolean> | boolean) {
    const files = await readdir(directory)

    await Bluebird.map(files, async file => {
      const filePath = join(directory, file)

      if (await existFun(filePath) !== true) {
        this.pathsToDelete.push(filePath)
      }
    }, { concurrency: 20 })
  }

  private doesWebVideoFileExistFactory () {
    return (filePath: string) => {
      // Don't delete private directory
      if (filePath === DIRECTORIES.WEB_VIDEOS.PRIVATE) return true

      return VideoFileModel.doesOwnedFileExist(basename(filePath), FileStorage.FILE_SYSTEM)
    }
  }

  private doesHLSPlaylistExistFactory () {
    return (hlsPath: string) => {
      // Don't delete private directory
      if (hlsPath === DIRECTORIES.HLS_STREAMING_PLAYLIST.PRIVATE) return true

      return VideoStreamingPlaylistModel.doesOwnedVideoUUIDExist(basename(hlsPath), FileStorage.FILE_SYSTEM)
    }
  }

  private doesOriginalVideoExistFactory () {
    return (filePath: string) => {
      return VideoSourceModel.doesOwnedFileExist(basename(filePath), FileStorage.FILE_SYSTEM)
    }
  }

  private doesTorrentFileExistFactory () {
    return (filePath: string) => VideoFileModel.doesOwnedTorrentFileExist(basename(filePath))
  }

  private doesThumbnailExistFactory (keepOnlyOwned: boolean, type: ThumbnailType_Type) {
    return async (filePath: string) => {
      const thumbnail = await ThumbnailModel.loadByFilename(basename(filePath), type)
      if (!thumbnail) return false

      if (keepOnlyOwned) {
        const video = await VideoModel.load(thumbnail.videoId)
        if (video.isOwned() === false) return false
      }

      return true
    }
  }

  private doesActorImageExistFactory () {
    return async (filePath: string) => {
      const image = await ActorImageModel.loadByName(basename(filePath))

      return !!image
    }
  }

  private doesRedundancyExistFactory () {
    return async (filePath: string) => {
      const isPlaylist = (await stat(filePath)).isDirectory()

      if (isPlaylist) {
        // Don't delete HLS redundancy directory
        if (filePath === DIRECTORIES.HLS_REDUNDANCY) return true

        const uuid = getUUIDFromFilename(filePath)
        const video = await VideoModel.loadWithFiles(uuid)
        if (!video) return false

        const p = video.getHLSPlaylist()
        if (!p) return false

        const redundancy = await VideoRedundancyModel.loadLocalByStreamingPlaylistId(p.id)
        return !!redundancy
      }

      const file = await VideoFileModel.loadByFilename(basename(filePath))
      if (!file) return false

      const redundancy = await VideoRedundancyModel.loadLocalByFileId(file.id)
      return !!redundancy
    }
  }

  private doesUserExportExistFactory () {
    return (filePath: string) => {
      const filename = basename(filePath)

      // Only detect non-existing user export
      if (!filename.startsWith(USER_EXPORT_FILE_PREFIX)) return true

      return UserExportModel.doesOwnedFileExist(filename, FileStorage.FILE_SYSTEM)
    }
  }
}

async function askPruneConfirmation () {
  return askConfirmation(
    'These unknown files can be deleted, but please check your backups first (bugs happen). ' +
    'Can we delete these files?'
  )
}