import * as express from 'express'
import 'express-validator'
import { body, param } from 'express-validator/check'
import {
  isIdOrUUIDValid,
  isSignupAllowed,
  isUserDisplayNSFWValid,
  isUserPasswordValid,
  isUserRoleValid,
  isUserUsernameValid,
  isUserVideoQuotaValid,
  logger
} from '../../helpers'
import { isVideoExist } from '../../helpers/custom-validators/videos'
import { database as db } from '../../initializers/database'
import { areValidationErrors } from './utils'

const usersAddValidator = [
  body('username').custom(isUserUsernameValid).withMessage('Should have a valid username (lowercase alphanumeric characters)'),
  body('password').custom(isUserPasswordValid).withMessage('Should have a valid password'),
  body('email').isEmail().withMessage('Should have a valid email'),
  body('videoQuota').custom(isUserVideoQuotaValid).withMessage('Should have a valid user quota'),
  body('role').custom(isUserRoleValid).withMessage('Should have a valid role'),

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

    if (areValidationErrors(req, res)) return
    if (!await checkUserNameOrEmailDoesNotAlreadyExist(req.body.username, req.body.email, res)) return

    return next()
  }
]

const usersRegisterValidator = [
  body('username').custom(isUserUsernameValid).withMessage('Should have a valid username'),
  body('password').custom(isUserPasswordValid).withMessage('Should have a valid password'),
  body('email').isEmail().withMessage('Should have a valid email'),

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

    if (areValidationErrors(req, res)) return
    if (!await checkUserNameOrEmailDoesNotAlreadyExist(req.body.username, req.body.email, res)) return

    return next()
  }
]

const usersRemoveValidator = [
  param('id').isInt().not().isEmpty().withMessage('Should have a valid id'),

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

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

    const user = res.locals.user
    if (user.username === 'root') {
      return res.status(400)
                .send({ error: 'Cannot remove the root user' })
                .end()
    }

    return next()
  }
]

const usersUpdateValidator = [
  param('id').isInt().not().isEmpty().withMessage('Should have a valid id'),
  body('email').optional().isEmail().withMessage('Should have a valid email attribute'),
  body('videoQuota').optional().custom(isUserVideoQuotaValid).withMessage('Should have a valid user quota'),
  body('role').optional().custom(isUserRoleValid).withMessage('Should have a valid role'),

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

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

    return next()
  }
]

const usersUpdateMeValidator = [
  body('password').optional().custom(isUserPasswordValid).withMessage('Should have a valid password'),
  body('email').optional().isEmail().withMessage('Should have a valid email attribute'),
  body('displayNSFW').optional().custom(isUserDisplayNSFWValid).withMessage('Should have a valid display Not Safe For Work attribute'),

  (req: express.Request, res: express.Response, next: express.NextFunction) => {
    // TODO: Add old password verification
    logger.debug('Checking usersUpdateMe parameters', { parameters: req.body })

    if (areValidationErrors(req, res)) return

    return next()
  }
]

const usersGetValidator = [
  param('id').isInt().not().isEmpty().withMessage('Should have a valid id'),

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

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

    return next()
  }
]

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

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

    if (areValidationErrors(req, res)) return
    if (!await isVideoExist(req.params.videoId, res)) return

    return next()
  }
]

const ensureUserRegistrationAllowed = [
  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    const allowed = await isSignupAllowed()
    if (allowed === false) {
      return res.status(403)
                .send({ error: 'User registration is not enabled or user limit is reached.' })
                .end()
    }

    return next()
  }
]

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

export {
  usersAddValidator,
  usersRegisterValidator,
  usersRemoveValidator,
  usersUpdateValidator,
  usersUpdateMeValidator,
  usersVideoRatingValidator,
  ensureUserRegistrationAllowed,
  usersGetValidator
}

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

async function checkUserIdExist (id: number, res: express.Response) {
  const user = await db.User.loadById(id)

  if (!user) {
    res.status(404)
              .send({ error: 'User not found' })
              .end()

    return false
  }

  res.locals.user = user
  return true
}

async function checkUserNameOrEmailDoesNotAlreadyExist (username: string, email: string, res: express.Response) {
  const user = await db.User.loadByUsernameOrEmail(username, email)

  if (user) {
    res.status(409)
              .send({ error: 'User with this username of email already exists.' })
              .end()
    return false
  }

  return true
}