/*
 * Copyright 2016 Red Hat Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
'use strict'

const UUID = require('./../uuid')

function forceLogin (keycloak, request, response) {
  const host = request.hostname
  const headerHost = request.headers.host.split(':')
  const port = headerHost[1] || ''
  const protocol = request.protocol
  const hasQuery = ~(request.originalUrl || request.url).indexOf('?')

  const redirectUrl = protocol + '://' + host + (port === '' ? '' : ':' + port) + (request.originalUrl || request.url) + (hasQuery ? '&' : '?') + 'auth_callback=1'

  if (request.session) {
    request.session.auth_redirect_uri = redirectUrl
  }

  const uuid = UUID()
  const loginURL = keycloak.loginUrl(uuid, redirectUrl)
  response.redirect(loginURL)
}

function simpleGuard (role, token) {
  return token.hasRole(role)
}

module.exports = function (keycloak, spec) {
  let guard

  if (typeof spec === 'function') {
    guard = spec
  } else if (typeof spec === 'string') {
    guard = simpleGuard.bind(undefined, spec)
  }

  return function protect (request, response, next) {
    if (request.kauth && request.kauth.grant) {
      if (!guard || guard(request.kauth.grant.access_token, request, response)) {
        return next()
      }

      return keycloak.accessDenied(request, response, next)
    }

    if (keycloak.redirectToLogin(request)) {
      forceLogin(keycloak, request, response)
    } else {
      return keycloak.accessDenied(request, response, next)
    }
  }
}
