import * as express from 'express'
import * as multer from 'multer'
import { extname } from 'path'
import { HttpStatusCode } from '../../shared/core-utils/miscs/http-error-codes'
import { CONFIG } from '../initializers/config'
import { REMOTE_SCHEME } from '../initializers/constants'
import { isArray } from './custom-validators/misc'
import { logger } from './logger'
import { deleteFileAndCatch, generateRandomString } from './utils'
import { getExtFromMimetype } from './video'
import { ProblemDocument, ProblemDocumentExtension } from 'http-problem-details'

function buildNSFWFilter (res?: express.Response, paramNSFW?: string) {
  if (paramNSFW === 'true') return true
  if (paramNSFW === 'false') return false
  if (paramNSFW === 'both') return undefined

  if (res?.locals.oauth) {
    const user = res.locals.oauth.token.User

    // User does not want NSFW videos
    if (user.nsfwPolicy === 'do_not_list') return false

    // Both
    return undefined
  }

  if (CONFIG.INSTANCE.DEFAULT_NSFW_POLICY === 'do_not_list') return false

  // Display all
  return null
}

function cleanUpReqFiles (
  req: { files: { [fieldname: string]: Express.Multer.File[] } | Express.Multer.File[] }
) {
  const filesObject = req.files
  if (!filesObject) return

  if (isArray(filesObject)) {
    filesObject.forEach(f => deleteFileAndCatch(f.path))
    return
  }

  for (const key of Object.keys(filesObject)) {
    const files = filesObject[key]

    files.forEach(f => deleteFileAndCatch(f.path))
  }
}

function getHostWithPort (host: string) {
  const splitted = host.split(':')

  // The port was not specified
  if (splitted.length === 1) {
    if (REMOTE_SCHEME.HTTP === 'https') return host + ':443'

    return host + ':80'
  }

  return host
}

function badRequest (req: express.Request, res: express.Response) {
  return res.type('json')
            .status(HttpStatusCode.BAD_REQUEST_400)
            .end()
}

function createReqFiles (
  fieldNames: string[],
  mimeTypes: { [id: string]: string | string[] },
  destinations: { [fieldName: string]: string }
) {
  const storage = multer.diskStorage({
    destination: (req, file, cb) => {
      cb(null, destinations[file.fieldname])
    },

    filename: async (req, file, cb) => {
      let extension: string
      const fileExtension = extname(file.originalname)
      const extensionFromMimetype = getExtFromMimetype(mimeTypes, file.mimetype)

      // Take the file extension if we don't understand the mime type
      if (!extensionFromMimetype) {
        extension = fileExtension
      } else {
        // Take the first available extension for this mimetype
        extension = extensionFromMimetype
      }

      let randomString = ''

      try {
        randomString = await generateRandomString(16)
      } catch (err) {
        logger.error('Cannot generate random string for file name.', { err })
        randomString = 'fake-random-string'
      }

      cb(null, randomString + extension)
    }
  })

  const fields: { name: string, maxCount: number }[] = []
  for (const fieldName of fieldNames) {
    fields.push({
      name: fieldName,
      maxCount: 1
    })
  }

  return multer({ storage }).fields(fields)
}

function isUserAbleToSearchRemoteURI (res: express.Response) {
  const user = res.locals.oauth ? res.locals.oauth.token.User : undefined

  return CONFIG.SEARCH.REMOTE_URI.ANONYMOUS === true ||
    (CONFIG.SEARCH.REMOTE_URI.USERS === true && user !== undefined)
}

function getCountVideos (req: express.Request) {
  return req.query.skipCount !== true
}

// helpers added in server.ts and used in subsequent controllers used
const apiResponseHelpers = (req, res: express.Response, next = null) => {
  res.fail = (options) => {
    const { data, status = HttpStatusCode.BAD_REQUEST_400, message, title, type, docs = res.docs, instance } = options

    const extension = new ProblemDocumentExtension({
      ...data,
      docs,
      // fields for <= 3.2 compatibility, deprecated
      error: message,
      code: type
    })

    res.status(status)
    res.setHeader('Content-Type', 'application/problem+json')
    res.json(new ProblemDocument({
      status,
      title,
      instance,
      // fields intended to replace 'error' and 'code' respectively
      detail: message,
      type: type && 'https://docs.joinpeertube.org/api-rest-reference.html#section/Errors/' + type
    }, extension))
  }

  if (next) next()
}

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

export {
  buildNSFWFilter,
  getHostWithPort,
  isUserAbleToSearchRemoteURI,
  badRequest,
  createReqFiles,
  cleanUpReqFiles,
  getCountVideos,
  apiResponseHelpers
}