import express from 'express'
import { body, param, query, ValidationChain } from 'express-validator'
import { exists, isIdValid } from '@server/helpers/custom-validators/misc'
import { isRegistrationModerationResponseValid, isRegistrationReasonValid } from '@server/helpers/custom-validators/user-registration'
import { CONFIG } from '@server/initializers/config'
import { Hooks } from '@server/lib/plugins/hooks'
import { HttpStatusCode, UserRegister, UserRegistrationRequest, UserRegistrationState } from '@shared/models'
import { isUserDisplayNameValid, isUserPasswordValid, isUserUsernameValid } from '../../helpers/custom-validators/users'
import { isVideoChannelDisplayNameValid, isVideoChannelUsernameValid } from '../../helpers/custom-validators/video-channels'
import { isSignupAllowed, isSignupAllowedForCurrentIP, SignupMode } from '../../lib/signup'
import { ActorModel } from '../../models/actor/actor'
import { areValidationErrors, checkUserNameOrEmailDoNotAlreadyExist } from './shared'
import { checkRegistrationHandlesDoNotAlreadyExist, checkRegistrationIdExist } from './shared/user-registrations'

const usersDirectRegistrationValidator = usersCommonRegistrationValidatorFactory()

const usersRequestRegistrationValidator = [
  ...usersCommonRegistrationValidatorFactory([
    body('registrationReason')
      .custom(isRegistrationReasonValid)
  ]),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    const body: UserRegistrationRequest = req.body

    if (CONFIG.SIGNUP.REQUIRES_APPROVAL !== true) {
      return res.fail({
        status: HttpStatusCode.BAD_REQUEST_400,
        message: 'Signup approval is not enabled on this instance'
      })
    }

    const options = { username: body.username, email: body.email, channelHandle: body.channel?.name, res }
    if (!await checkRegistrationHandlesDoNotAlreadyExist(options)) return

    return next()
  }
]

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

function ensureUserRegistrationAllowedFactory (signupMode: SignupMode) {
  return async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    const allowedParams = {
      body: req.body,
      ip: req.ip,
      signupMode
    }

    const allowedResult = await Hooks.wrapPromiseFun(
      isSignupAllowed,
      allowedParams,

      signupMode === 'direct-registration'
        ? 'filter:api.user.signup.allowed.result'
        : 'filter:api.user.request-signup.allowed.result'
    )

    if (allowedResult.allowed === false) {
      return res.fail({
        status: HttpStatusCode.FORBIDDEN_403,
        message: allowedResult.errorMessage || 'User registration is not enabled, user limit is reached or registration requires approval.'
      })
    }

    return next()
  }
}

const ensureUserRegistrationAllowedForIP = [
  (req: express.Request, res: express.Response, next: express.NextFunction) => {
    const allowed = isSignupAllowedForCurrentIP(req.ip)

    if (allowed === false) {
      return res.fail({
        status: HttpStatusCode.FORBIDDEN_403,
        message: 'You are not on a network authorized for registration.'
      })
    }

    return next()
  }
]

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

const acceptOrRejectRegistrationValidator = [
  param('registrationId')
    .custom(isIdValid),

  body('moderationResponse')
    .custom(isRegistrationModerationResponseValid),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    if (areValidationErrors(req, res)) return
    if (!await checkRegistrationIdExist(req.params.registrationId, res)) return

    if (res.locals.userRegistration.state !== UserRegistrationState.PENDING) {
      return res.fail({
        status: HttpStatusCode.CONFLICT_409,
        message: 'This registration is already accepted or rejected.'
      })
    }

    return next()
  }
]

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

const getRegistrationValidator = [
  param('registrationId')
    .custom(isIdValid),

  async (req: express.Request, res: express.Response, next: express.NextFunction) => {
    if (areValidationErrors(req, res)) return
    if (!await checkRegistrationIdExist(req.params.registrationId, res)) return

    return next()
  }
]

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

const listRegistrationsValidator = [
  query('search')
    .optional()
    .custom(exists),

  (req: express.Request, res: express.Response, next: express.NextFunction) => {
    if (areValidationErrors(req, res)) return

    return next()
  }
]

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

export {
  usersDirectRegistrationValidator,
  usersRequestRegistrationValidator,

  ensureUserRegistrationAllowedFactory,
  ensureUserRegistrationAllowedForIP,

  getRegistrationValidator,
  listRegistrationsValidator,

  acceptOrRejectRegistrationValidator
}

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

function usersCommonRegistrationValidatorFactory (additionalValidationChain: ValidationChain[] = []) {
  return [
    body('username')
      .custom(isUserUsernameValid),
    body('password')
      .custom(isUserPasswordValid),
    body('email')
      .isEmail(),
    body('displayName')
      .optional()
      .custom(isUserDisplayNameValid),

    body('channel.name')
      .optional()
      .custom(isVideoChannelUsernameValid),
    body('channel.displayName')
      .optional()
      .custom(isVideoChannelDisplayNameValid),

    ...additionalValidationChain,

    async (req: express.Request, res: express.Response, next: express.NextFunction) => {
      if (areValidationErrors(req, res, { omitBodyLog: true })) return

      const body: UserRegister | UserRegistrationRequest = req.body

      if (!await checkUserNameOrEmailDoNotAlreadyExist(body.username, body.email, res)) return

      if (body.channel) {
        if (!body.channel.name || !body.channel.displayName) {
          return res.fail({ message: 'Channel is optional but if you specify it, channel.name and channel.displayName are required.' })
        }

        if (body.channel.name === body.username) {
          return res.fail({ message: 'Channel name cannot be the same as user username.' })
        }

        const existing = await ActorModel.loadLocalByName(body.channel.name)
        if (existing) {
          return res.fail({
            status: HttpStatusCode.CONFLICT_409,
            message: `Channel with name ${body.channel.name} already exists.`
          })
        }
      }

      return next()
    }
  ]
}