import * as express from 'express'
import { body, param } from 'express-validator/check'
import { UserRight } from '../../../shared'
import { isIdValid } from '../../helpers/custom-validators/misc'
import {
  isVideoChannelDescriptionValid,
  isVideoChannelExist,
  isVideoChannelNameValid
} from '../../helpers/custom-validators/video-channels'
import { isIdOrUUIDValid } from '../../helpers/index'
import { logger } from '../../helpers/logger'
import { database as db } from '../../initializers'
import { UserInstance } from '../../models'
import { areValidationErrors } from './utils'
import { isAccountIdExist } from '../../helpers/custom-validators/accounts'
import { VideoChannelInstance } from '../../models/video/video-channel-interface'

const listVideoAccountChannelsValidator = [
  param('accountId').custom(isIdOrUUIDValid).withMessage('Should have a valid account id'),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    logger.debug('Checking listVideoAccountChannelsValidator parameters', { parameters: req.body })

    if (areValidationErrors(req, res)) return
    if (!await isAccountIdExist(req.params.accountId, res)) return

    return next()
  }
]

const videoChannelsAddValidator = [
  body('name').custom(isVideoChannelNameValid).withMessage('Should have a valid name'),
  body('description').custom(isVideoChannelDescriptionValid).withMessage('Should have a valid description'),

  (req: express.Request, res: express.Response, next: express.NextFunction) => {
    logger.debug('Checking videoChannelsAdd parameters', { parameters: req.body })

    if (areValidationErrors(req, res)) return

    return next()
  }
]

const videoChannelsUpdateValidator = [
  param('id').custom(isIdOrUUIDValid).not().isEmpty().withMessage('Should have a valid id'),
  body('name').optional().custom(isVideoChannelNameValid).withMessage('Should have a valid name'),
  body('description').optional().custom(isVideoChannelDescriptionValid).withMessage('Should have a valid description'),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    logger.debug('Checking videoChannelsUpdate parameters', { parameters: req.body })

    if (areValidationErrors(req, res)) return
    if (!await isVideoChannelExist(req.params.id, res)) return

    // We need to make additional checks
    if (res.locals.videoChannel.isOwned() === false) {
      return res.status(403)
        .json({ error: 'Cannot update video channel of another server' })
        .end()
    }

    if (res.locals.videoChannel.Account.userId !== res.locals.oauth.token.User.id) {
      return res.status(403)
        .json({ error: 'Cannot update video channel of another user' })
        .end()
    }

    return next()
  }
]

const videoChannelsRemoveValidator = [
  param('id').custom(isIdOrUUIDValid).not().isEmpty().withMessage('Should have a valid id'),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    logger.debug('Checking videoChannelsRemove parameters', { parameters: req.params })

    if (areValidationErrors(req, res)) return
    if (!await isVideoChannelExist(req.params.id, res)) return

    // Check if the user who did the request is able to delete the video
    if (!checkUserCanDeleteVideoChannel(res.locals.user, res.locals.videoChannel, res)) return
    if (!await checkVideoChannelIsNotTheLastOne(res)) return

    return next()
  }
]

const videoChannelsGetValidator = [
  param('id').custom(isIdOrUUIDValid).not().isEmpty().withMessage('Should have a valid id'),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    logger.debug('Checking videoChannelsGet parameters', { parameters: req.params })

    if (areValidationErrors(req, res)) return
    if (!await isVideoChannelExist(req.params.id, res)) return

    return next()
  }
]

const videoChannelsShareValidator = [
  param('id').custom(isIdOrUUIDValid).not().isEmpty().withMessage('Should have a valid id'),
  param('accountId').custom(isIdValid).not().isEmpty().withMessage('Should have a valid account id'),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    logger.debug('Checking videoChannelShare parameters', { parameters: req.params })

    if (areValidationErrors(req, res)) return
    if (!await isVideoChannelExist(req.params.id, res)) return

    const share = await db.VideoChannelShare.load(res.locals.video.id, req.params.accountId)
    if (!share) {
      return res.status(404)
        .end()
    }

    res.locals.videoChannelShare = share

    return next()
  }
]

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

export {
  listVideoAccountChannelsValidator,
  videoChannelsAddValidator,
  videoChannelsUpdateValidator,
  videoChannelsRemoveValidator,
  videoChannelsGetValidator,
  videoChannelsShareValidator
}

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

function checkUserCanDeleteVideoChannel (user: UserInstance, videoChannel: VideoChannelInstance, res: express.Response) {
  // Retrieve the user who did the request
  if (videoChannel.isOwned() === false) {
    res.status(403)
              .json({ error: 'Cannot remove video channel of another server.' })
              .end()

    return false
  }

  // Check if the user can delete the video channel
  // The user can delete it if s/he is an admin
  // Or if s/he is the video channel's account
  if (user.hasRight(UserRight.REMOVE_ANY_VIDEO_CHANNEL) === false && videoChannel.Account.userId !== user.id) {
    res.status(403)
              .json({ error: 'Cannot remove video channel of another user' })
              .end()

    return false
  }

  return true
}

async function checkVideoChannelIsNotTheLastOne (res: express.Response) {
  const count = await db.VideoChannel.countByAccount(res.locals.oauth.token.User.Account.id)

  if (count <= 1) {
    res.status(409)
      .json({ error: 'Cannot remove the last channel of this user' })
      .end()

    return false
  }

  return true
}