import * as express from 'express'
import * as Bluebird from 'bluebird'
import * as Sequelize from 'sequelize'

import { database as db } from '../../../initializers/database'
import {
  REQUEST_ENDPOINT_ACTIONS,
  REQUEST_ENDPOINTS,
  REQUEST_VIDEO_EVENT_TYPES,
  REQUEST_VIDEO_QADU_TYPES
} from '../../../initializers'
import {
  checkSignature,
  signatureValidator,
  remoteVideosValidator,
  remoteQaduVideosValidator,
  remoteEventsVideosValidator
} from '../../../middlewares'
import { logger, retryTransactionWrapper, resetSequelizeInstance } from '../../../helpers'
import { quickAndDirtyUpdatesVideoToFriends, fetchVideoChannelByHostAndUUID } from '../../../lib'
import { PodInstance, VideoFileInstance } from '../../../models'
import {
  RemoteVideoRequest,
  RemoteVideoCreateData,
  RemoteVideoUpdateData,
  RemoteVideoRemoveData,
  RemoteVideoReportAbuseData,
  RemoteQaduVideoRequest,
  RemoteQaduVideoData,
  RemoteVideoEventRequest,
  RemoteVideoEventData,
  RemoteVideoChannelCreateData,
  RemoteVideoChannelUpdateData,
  RemoteVideoChannelRemoveData,
  RemoteVideoAuthorRemoveData,
  RemoteVideoAuthorCreateData
} from '../../../../shared'
import { VideoInstance } from '../../../models/video/video-interface'

const ENDPOINT_ACTIONS = REQUEST_ENDPOINT_ACTIONS[REQUEST_ENDPOINTS.VIDEOS]

// Functions to call when processing a remote request
// FIXME: use RemoteVideoRequestType as id type
const functionsHash: { [ id: string ]: (...args) => Promise<any> } = {}
functionsHash[ENDPOINT_ACTIONS.ADD_VIDEO] = addRemoteVideoRetryWrapper
functionsHash[ENDPOINT_ACTIONS.UPDATE_VIDEO] = updateRemoteVideoRetryWrapper
functionsHash[ENDPOINT_ACTIONS.REMOVE_VIDEO] = removeRemoteVideoRetryWrapper
functionsHash[ENDPOINT_ACTIONS.ADD_CHANNEL] = addRemoteVideoChannelRetryWrapper
functionsHash[ENDPOINT_ACTIONS.UPDATE_CHANNEL] = updateRemoteVideoChannelRetryWrapper
functionsHash[ENDPOINT_ACTIONS.REMOVE_CHANNEL] = removeRemoteVideoChannelRetryWrapper
functionsHash[ENDPOINT_ACTIONS.REPORT_ABUSE] = reportAbuseRemoteVideoRetryWrapper
functionsHash[ENDPOINT_ACTIONS.ADD_AUTHOR] = addRemoteVideoAuthorRetryWrapper
functionsHash[ENDPOINT_ACTIONS.REMOVE_AUTHOR] = removeRemoteVideoAuthorRetryWrapper

const remoteVideosRouter = express.Router()

remoteVideosRouter.post('/',
  signatureValidator,
  checkSignature,
  remoteVideosValidator,
  remoteVideos
)

remoteVideosRouter.post('/qadu',
  signatureValidator,
  checkSignature,
  remoteQaduVideosValidator,
  remoteVideosQadu
)

remoteVideosRouter.post('/events',
  signatureValidator,
  checkSignature,
  remoteEventsVideosValidator,
  remoteVideosEvents
)

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

export {
  remoteVideosRouter
}

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

function remoteVideos (req: express.Request, res: express.Response, next: express.NextFunction) {
  const requests: RemoteVideoRequest[] = req.body.data
  const fromPod = res.locals.secure.pod

  // We need to process in the same order to keep consistency
  Bluebird.each(requests, request => {
    const data = request.data

    // Get the function we need to call in order to process the request
    const fun = functionsHash[request.type]
    if (fun === undefined) {
      logger.error('Unknown remote request type %s.', request.type)
      return
    }

    return fun.call(this, data, fromPod)
  })
  .catch(err => logger.error('Error managing remote videos.', err))

  // Don't block the other pod
  return res.type('json').status(204).end()
}

function remoteVideosQadu (req: express.Request, res: express.Response, next: express.NextFunction) {
  const requests: RemoteQaduVideoRequest[] = req.body.data
  const fromPod = res.locals.secure.pod

  Bluebird.each(requests, request => {
    const videoData = request.data

    return quickAndDirtyUpdateVideoRetryWrapper(videoData, fromPod)
  })
  .catch(err => logger.error('Error managing remote videos.', err))

  return res.type('json').status(204).end()
}

function remoteVideosEvents (req: express.Request, res: express.Response, next: express.NextFunction) {
  const requests: RemoteVideoEventRequest[] = req.body.data
  const fromPod = res.locals.secure.pod

  Bluebird.each(requests, request => {
    const eventData = request.data

    return processVideosEventsRetryWrapper(eventData, fromPod)
  })
  .catch(err => logger.error('Error managing remote videos.', err))

  return res.type('json').status(204).end()
}

async function processVideosEventsRetryWrapper (eventData: RemoteVideoEventData, fromPod: PodInstance) {
  const options = {
    arguments: [ eventData, fromPod ],
    errorMessage: 'Cannot process videos events with many retries.'
  }

  await retryTransactionWrapper(processVideosEvents, options)
}

async function processVideosEvents (eventData: RemoteVideoEventData, fromPod: PodInstance) {
  await db.sequelize.transaction(async t => {
    const sequelizeOptions = { transaction: t }
    const videoInstance = await fetchLocalVideoByUUID(eventData.uuid, t)

    let columnToUpdate
    let qaduType

    switch (eventData.eventType) {
    case REQUEST_VIDEO_EVENT_TYPES.VIEWS:
      columnToUpdate = 'views'
      qaduType = REQUEST_VIDEO_QADU_TYPES.VIEWS
      break

    case REQUEST_VIDEO_EVENT_TYPES.LIKES:
      columnToUpdate = 'likes'
      qaduType = REQUEST_VIDEO_QADU_TYPES.LIKES
      break

    case REQUEST_VIDEO_EVENT_TYPES.DISLIKES:
      columnToUpdate = 'dislikes'
      qaduType = REQUEST_VIDEO_QADU_TYPES.DISLIKES
      break

    default:
      throw new Error('Unknown video event type.')
    }

    const query = {}
    query[columnToUpdate] = eventData.count

    await videoInstance.increment(query, sequelizeOptions)

    const qadusParams = [
      {
        videoId: videoInstance.id,
        type: qaduType
      }
    ]
    await quickAndDirtyUpdatesVideoToFriends(qadusParams, t)
  })

  logger.info('Remote video event processed for video with uuid %s.', eventData.uuid)
}

async function quickAndDirtyUpdateVideoRetryWrapper (videoData: RemoteQaduVideoData, fromPod: PodInstance) {
  const options = {
    arguments: [ videoData, fromPod ],
    errorMessage: 'Cannot update quick and dirty the remote video with many retries.'
  }

  await retryTransactionWrapper(quickAndDirtyUpdateVideo, options)
}

async function quickAndDirtyUpdateVideo (videoData: RemoteQaduVideoData, fromPod: PodInstance) {
  let videoUUID = ''

  await db.sequelize.transaction(async t => {
    const videoInstance = await fetchVideoByHostAndUUID(fromPod.host, videoData.uuid, t)
    const sequelizeOptions = { transaction: t }

    videoUUID = videoInstance.uuid

    if (videoData.views) {
      videoInstance.set('views', videoData.views)
    }

    if (videoData.likes) {
      videoInstance.set('likes', videoData.likes)
    }

    if (videoData.dislikes) {
      videoInstance.set('dislikes', videoData.dislikes)
    }

    await videoInstance.save(sequelizeOptions)
  })

  logger.info('Remote video with uuid %s quick and dirty updated', videoUUID)
}

// Handle retries on fail
async function addRemoteVideoRetryWrapper (videoToCreateData: RemoteVideoCreateData, fromPod: PodInstance) {
  const options = {
    arguments: [ videoToCreateData, fromPod ],
    errorMessage: 'Cannot insert the remote video with many retries.'
  }

  await retryTransactionWrapper(addRemoteVideo, options)
}

async function addRemoteVideo (videoToCreateData: RemoteVideoCreateData, fromPod: PodInstance) {
  logger.debug('Adding remote video "%s".', videoToCreateData.uuid)

  await db.sequelize.transaction(async t => {
    const sequelizeOptions = {
      transaction: t
    }

    const videoFromDatabase = await db.Video.loadByUUID(videoToCreateData.uuid)
    if (videoFromDatabase) throw new Error('UUID already exists.')

    const videoChannel = await db.VideoChannel.loadByHostAndUUID(fromPod.host, videoToCreateData.channelUUID, t)
    if (!videoChannel) throw new Error('Video channel ' + videoToCreateData.channelUUID + ' not found.')

    const tags = videoToCreateData.tags
    const tagInstances = await db.Tag.findOrCreateTags(tags, t)

    const videoData = {
      name: videoToCreateData.name,
      uuid: videoToCreateData.uuid,
      category: videoToCreateData.category,
      licence: videoToCreateData.licence,
      language: videoToCreateData.language,
      nsfw: videoToCreateData.nsfw,
      description: videoToCreateData.truncatedDescription,
      channelId: videoChannel.id,
      duration: videoToCreateData.duration,
      createdAt: videoToCreateData.createdAt,
      // FIXME: updatedAt does not seems to be considered by Sequelize
      updatedAt: videoToCreateData.updatedAt,
      views: videoToCreateData.views,
      likes: videoToCreateData.likes,
      dislikes: videoToCreateData.dislikes,
      remote: true
    }

    const video = db.Video.build(videoData)
    await db.Video.generateThumbnailFromData(video, videoToCreateData.thumbnailData)
    const videoCreated = await video.save(sequelizeOptions)

    const tasks = []
    for (const fileData of videoToCreateData.files) {
      const videoFileInstance = db.VideoFile.build({
        extname: fileData.extname,
        infoHash: fileData.infoHash,
        resolution: fileData.resolution,
        size: fileData.size,
        videoId: videoCreated.id
      })

      tasks.push(videoFileInstance.save(sequelizeOptions))
    }

    await Promise.all(tasks)

    await videoCreated.setTags(tagInstances, sequelizeOptions)
  })

  logger.info('Remote video with uuid %s inserted.', videoToCreateData.uuid)
}

// Handle retries on fail
async function updateRemoteVideoRetryWrapper (videoAttributesToUpdate: RemoteVideoUpdateData, fromPod: PodInstance) {
  const options = {
    arguments: [ videoAttributesToUpdate, fromPod ],
    errorMessage: 'Cannot update the remote video with many retries'
  }

  await retryTransactionWrapper(updateRemoteVideo, options)
}

async function updateRemoteVideo (videoAttributesToUpdate: RemoteVideoUpdateData, fromPod: PodInstance) {
  logger.debug('Updating remote video "%s".', videoAttributesToUpdate.uuid)
  let videoInstance: VideoInstance
  let videoFieldsSave: object

  try {
    await db.sequelize.transaction(async t => {
      const sequelizeOptions = {
        transaction: t
      }

      const videoInstance = await fetchVideoByHostAndUUID(fromPod.host, videoAttributesToUpdate.uuid, t)
      videoFieldsSave = videoInstance.toJSON()
      const tags = videoAttributesToUpdate.tags

      const tagInstances = await db.Tag.findOrCreateTags(tags, t)

      videoInstance.set('name', videoAttributesToUpdate.name)
      videoInstance.set('category', videoAttributesToUpdate.category)
      videoInstance.set('licence', videoAttributesToUpdate.licence)
      videoInstance.set('language', videoAttributesToUpdate.language)
      videoInstance.set('nsfw', videoAttributesToUpdate.nsfw)
      videoInstance.set('description', videoAttributesToUpdate.truncatedDescription)
      videoInstance.set('duration', videoAttributesToUpdate.duration)
      videoInstance.set('createdAt', videoAttributesToUpdate.createdAt)
      videoInstance.set('updatedAt', videoAttributesToUpdate.updatedAt)
      videoInstance.set('views', videoAttributesToUpdate.views)
      videoInstance.set('likes', videoAttributesToUpdate.likes)
      videoInstance.set('dislikes', videoAttributesToUpdate.dislikes)

      await videoInstance.save(sequelizeOptions)

      // Remove old video files
      const videoFileDestroyTasks: Bluebird<void>[] = []
      for (const videoFile of videoInstance.VideoFiles) {
        videoFileDestroyTasks.push(videoFile.destroy(sequelizeOptions))
      }
      await Promise.all(videoFileDestroyTasks)

      const videoFileCreateTasks: Bluebird<VideoFileInstance>[] = []
      for (const fileData of videoAttributesToUpdate.files) {
        const videoFileInstance = db.VideoFile.build({
          extname: fileData.extname,
          infoHash: fileData.infoHash,
          resolution: fileData.resolution,
          size: fileData.size,
          videoId: videoInstance.id
        })

        videoFileCreateTasks.push(videoFileInstance.save(sequelizeOptions))
      }

      await Promise.all(videoFileCreateTasks)

      await videoInstance.setTags(tagInstances, sequelizeOptions)
    })

    logger.info('Remote video with uuid %s updated', videoAttributesToUpdate.uuid)
  } catch (err) {
    if (videoInstance !== undefined && videoFieldsSave !== undefined) {
      resetSequelizeInstance(videoInstance, videoFieldsSave)
    }

    // This is just a debug because we will retry the insert
    logger.debug('Cannot update the remote video.', err)
    throw err
  }
}

async function removeRemoteVideoRetryWrapper (videoToRemoveData: RemoteVideoRemoveData, fromPod: PodInstance) {
  const options = {
    arguments: [ videoToRemoveData, fromPod ],
    errorMessage: 'Cannot remove the remote video channel with many retries.'
  }

  await retryTransactionWrapper(removeRemoteVideo, options)
}

async function removeRemoteVideo (videoToRemoveData: RemoteVideoRemoveData, fromPod: PodInstance) {
  logger.debug('Removing remote video "%s".', videoToRemoveData.uuid)

  await db.sequelize.transaction(async t => {
    // We need the instance because we have to remove some other stuffs (thumbnail etc)
    const videoInstance = await fetchVideoByHostAndUUID(fromPod.host, videoToRemoveData.uuid, t)
    await videoInstance.destroy({ transaction: t })
  })

  logger.info('Remote video with uuid %s removed.', videoToRemoveData.uuid)
}

async function addRemoteVideoAuthorRetryWrapper (authorToCreateData: RemoteVideoAuthorCreateData, fromPod: PodInstance) {
  const options = {
    arguments: [ authorToCreateData, fromPod ],
    errorMessage: 'Cannot insert the remote video author with many retries.'
  }

  await retryTransactionWrapper(addRemoteVideoAuthor, options)
}

async function addRemoteVideoAuthor (authorToCreateData: RemoteVideoAuthorCreateData, fromPod: PodInstance) {
  logger.debug('Adding remote video author "%s".', authorToCreateData.uuid)

  await db.sequelize.transaction(async t => {
    const authorInDatabase = await db.Author.loadAuthorByPodAndUUID(authorToCreateData.uuid, fromPod.id, t)
    if (authorInDatabase) throw new Error('Author with UUID ' + authorToCreateData.uuid + ' already exists.')

    const videoAuthorData = {
      name: authorToCreateData.name,
      uuid: authorToCreateData.uuid,
      userId: null, // Not on our pod
      podId: fromPod.id
    }

    const author = db.Author.build(videoAuthorData)
    await author.save({ transaction: t })
  })

  logger.info('Remote video author with uuid %s inserted.', authorToCreateData.uuid)
}

async function removeRemoteVideoAuthorRetryWrapper (authorAttributesToRemove: RemoteVideoAuthorRemoveData, fromPod: PodInstance) {
  const options = {
    arguments: [ authorAttributesToRemove, fromPod ],
    errorMessage: 'Cannot remove the remote video author with many retries.'
  }

  await retryTransactionWrapper(removeRemoteVideoAuthor, options)
}

async function removeRemoteVideoAuthor (authorAttributesToRemove: RemoteVideoAuthorRemoveData, fromPod: PodInstance) {
  logger.debug('Removing remote video author "%s".', authorAttributesToRemove.uuid)

  await db.sequelize.transaction(async t => {
    const videoAuthor = await db.Author.loadAuthorByPodAndUUID(authorAttributesToRemove.uuid, fromPod.id, t)
    await videoAuthor.destroy({ transaction: t })
  })

  logger.info('Remote video author with uuid %s removed.', authorAttributesToRemove.uuid)
}

async function addRemoteVideoChannelRetryWrapper (videoChannelToCreateData: RemoteVideoChannelCreateData, fromPod: PodInstance) {
  const options = {
    arguments: [ videoChannelToCreateData, fromPod ],
    errorMessage: 'Cannot insert the remote video channel with many retries.'
  }

  await retryTransactionWrapper(addRemoteVideoChannel, options)
}

async function addRemoteVideoChannel (videoChannelToCreateData: RemoteVideoChannelCreateData, fromPod: PodInstance) {
  logger.debug('Adding remote video channel "%s".', videoChannelToCreateData.uuid)

  await db.sequelize.transaction(async t => {
    const videoChannelInDatabase = await db.VideoChannel.loadByUUID(videoChannelToCreateData.uuid)
    if (videoChannelInDatabase) {
      throw new Error('Video channel with UUID ' + videoChannelToCreateData.uuid + ' already exists.')
    }

    const authorUUID = videoChannelToCreateData.ownerUUID
    const podId = fromPod.id

    const author = await db.Author.loadAuthorByPodAndUUID(authorUUID, podId, t)
    if (!author) throw new Error('Unknown author UUID' + authorUUID + '.')

    const videoChannelData = {
      name: videoChannelToCreateData.name,
      description: videoChannelToCreateData.description,
      uuid: videoChannelToCreateData.uuid,
      createdAt: videoChannelToCreateData.createdAt,
      updatedAt: videoChannelToCreateData.updatedAt,
      remote: true,
      authorId: author.id
    }

    const videoChannel = db.VideoChannel.build(videoChannelData)
    await videoChannel.save({ transaction: t })
  })

  logger.info('Remote video channel with uuid %s inserted.', videoChannelToCreateData.uuid)
}

async function updateRemoteVideoChannelRetryWrapper (videoChannelAttributesToUpdate: RemoteVideoChannelUpdateData, fromPod: PodInstance) {
  const options = {
    arguments: [ videoChannelAttributesToUpdate, fromPod ],
    errorMessage: 'Cannot update the remote video channel with many retries.'
  }

  await retryTransactionWrapper(updateRemoteVideoChannel, options)
}

async function updateRemoteVideoChannel (videoChannelAttributesToUpdate: RemoteVideoChannelUpdateData, fromPod: PodInstance) {
  logger.debug('Updating remote video channel "%s".', videoChannelAttributesToUpdate.uuid)

  await db.sequelize.transaction(async t => {
    const sequelizeOptions = { transaction: t }

    const videoChannelInstance = await fetchVideoChannelByHostAndUUID(fromPod.host, videoChannelAttributesToUpdate.uuid, t)
    videoChannelInstance.set('name', videoChannelAttributesToUpdate.name)
    videoChannelInstance.set('description', videoChannelAttributesToUpdate.description)
    videoChannelInstance.set('createdAt', videoChannelAttributesToUpdate.createdAt)
    videoChannelInstance.set('updatedAt', videoChannelAttributesToUpdate.updatedAt)

    await videoChannelInstance.save(sequelizeOptions)
  })

  logger.info('Remote video channel with uuid %s updated', videoChannelAttributesToUpdate.uuid)
}

async function removeRemoteVideoChannelRetryWrapper (videoChannelAttributesToRemove: RemoteVideoChannelRemoveData, fromPod: PodInstance) {
  const options = {
    arguments: [ videoChannelAttributesToRemove, fromPod ],
    errorMessage: 'Cannot remove the remote video channel with many retries.'
  }

  await retryTransactionWrapper(removeRemoteVideoChannel, options)
}

async function removeRemoteVideoChannel (videoChannelAttributesToRemove: RemoteVideoChannelRemoveData, fromPod: PodInstance) {
  logger.debug('Removing remote video channel "%s".', videoChannelAttributesToRemove.uuid)

  await db.sequelize.transaction(async t => {
    const videoChannel = await fetchVideoChannelByHostAndUUID(fromPod.host, videoChannelAttributesToRemove.uuid, t)
    await videoChannel.destroy({ transaction: t })
  })

  logger.info('Remote video channel with uuid %s removed.', videoChannelAttributesToRemove.uuid)
}

async function reportAbuseRemoteVideoRetryWrapper (reportData: RemoteVideoReportAbuseData, fromPod: PodInstance) {
  const options = {
    arguments: [ reportData, fromPod ],
    errorMessage: 'Cannot create remote abuse video with many retries.'
  }

  await retryTransactionWrapper(reportAbuseRemoteVideo, options)
}

async function reportAbuseRemoteVideo (reportData: RemoteVideoReportAbuseData, fromPod: PodInstance) {
  logger.debug('Reporting remote abuse for video %s.', reportData.videoUUID)

  await db.sequelize.transaction(async t => {
    const videoInstance = await fetchLocalVideoByUUID(reportData.videoUUID, t)
    const videoAbuseData = {
      reporterUsername: reportData.reporterUsername,
      reason: reportData.reportReason,
      reporterPodId: fromPod.id,
      videoId: videoInstance.id
    }

    await db.VideoAbuse.create(videoAbuseData)

  })

  logger.info('Remote abuse for video uuid %s created', reportData.videoUUID)
}

async function fetchLocalVideoByUUID (id: string, t: Sequelize.Transaction) {
  try {
    const video = await db.Video.loadLocalVideoByUUID(id, t)

    if (!video) throw new Error('Video ' + id + ' not found')

    return video
  } catch (err) {
    logger.error('Cannot load owned video from id.', { error: err.stack, id })
    throw err
  }
}

async function fetchVideoByHostAndUUID (podHost: string, uuid: string, t: Sequelize.Transaction) {
  try {
    const video = await db.Video.loadByHostAndUUID(podHost, uuid, t)
    if (!video) throw new Error('Video not found')

    return video
  } catch (err) {
    logger.error('Cannot load video from host and uuid.', { error: err.stack, podHost, uuid })
    throw err
  }
}