discourse/app/controllers/users_controller.rb

require_dependency 'discourse_hub'
require_dependency 'user_name_suggester'
require_dependency 'rate_limiter'

class UsersController < ApplicationController

  skip_before_filter :authorize_mini_profiler, only: [:avatar]
  skip_before_filter :check_xhr, only: [:show, :password_reset, :update, :account_created, :activate_account, :perform_account_activation, :authorize_email, :user_preferences_redirect, :avatar, :my_redirect, :toggle_anon, :admin_login]

  before_filter :ensure_logged_in, only: [:username, :update, :change_email, :user_preferences_redirect, :upload_user_image, :pick_avatar, :destroy_user_image, :destroy, :check_emails]
  before_filter :respond_to_suspicious_request, only: [:create]

  # we need to allow account creation with bad CSRF tokens, if people are caching, the CSRF token on the
  #  page is going to be empty, this means that server will see an invalid CSRF and blow the session
  #  once that happens you can't log in with social
  skip_before_filter :verify_authenticity_token, only: [:create]
  skip_before_filter :redirect_to_login_if_required, only: [:check_username,
                                                            :create,
                                                            :get_honeypot_value,
                                                            :account_created,
                                                            :activate_account,
                                                            :perform_account_activation,
                                                            :send_activation_email,
                                                            :authorize_email,
                                                            :password_reset,
                                                            :admin_login]

  def index
  end

  def show
    @user = fetch_user_from_params
    user_serializer = UserSerializer.new(@user, scope: guardian, root: 'user')
    if params[:stats].to_s == "false"
      user_serializer.omit_stats = true
    end
    topic_id = params[:include_post_count_for].to_i
    if topic_id != 0
      user_serializer.topic_post_count = {topic_id => Post.where(topic_id: topic_id, user_id: @user.id).count }
    end

    # This is a hack to get around a Rails issue where values with periods aren't handled correctly
    # when used as part of a route.
    if params[:external_id] and params[:external_id].ends_with? '.json'
      return render_json_dump(user_serializer)
    end

    respond_to do |format|
      format.html do
        @restrict_fields = guardian.restrict_user_fields?(@user)
        store_preloaded("user_#{@user.username}", MultiJson.dump(user_serializer))
      end

      format.json do
        render_json_dump(user_serializer)
      end
    end
  end

  def card_badge
  end

  def update_card_badge
    user = fetch_user_from_params
    guardian.ensure_can_edit!(user)

    user_badge = UserBadge.find_by(id: params[:user_badge_id].to_i)
    if user_badge && user_badge.user == user && user_badge.badge.image.present?
      user.user_profile.update_column(:card_image_badge_id, user_badge.badge.id)
    else
      user.user_profile.update_column(:card_image_badge_id, nil)
    end

    render nothing: true
  end

  def user_preferences_redirect
    redirect_to email_preferences_path(current_user.username_lower)
  end

  def update
    user = fetch_user_from_params
    guardian.ensure_can_edit!(user)

    if params[:user_fields].present?
      params[:custom_fields] = {} unless params[:custom_fields].present?

      fields = UserField.all
      fields = fields.where(editable: true) unless current_user.staff?
      fields.each do |f|
        val = params[:user_fields][f.id.to_s]
        val = nil if val === "false"
        val = val[0...UserField.max_length] if val

        return render_json_error(I18n.t("login.missing_user_field")) if val.blank? && f.required?
        params[:custom_fields]["user_field_#{f.id}"] = val
      end
    end

    json_result(user, serializer: UserSerializer, additional_errors: [:user_profile]) do |u|
      updater = UserUpdater.new(current_user, user)
      updater.update(params)
    end
  end

  def username
    params.require(:new_username)

    user = fetch_user_from_params
    guardian.ensure_can_edit_username!(user)

    # TODO proper error surfacing (result is a Model#save call)
    result = UsernameChanger.change(user, params[:new_username], current_user)
    raise Discourse::InvalidParameters.new(:new_username) unless result

    render json: {
      id: user.id,
      username: user.username
    }
  end

  def check_emails
    user = fetch_user_from_params(include_inactive: true)
    guardian.ensure_can_check_emails!(user)

    StaffActionLogger.new(current_user).log_check_email(user, context: params[:context])

    render json: {
      email: user.email,
      associated_accounts: user.associated_accounts
    }
  rescue Discourse::InvalidAccess
    render json: failed_json, status: 403
  end

  def badge_title
    params.require(:user_badge_id)

    user = fetch_user_from_params
    guardian.ensure_can_edit!(user)

    user_badge = UserBadge.find_by(id: params[:user_badge_id])
    if user_badge && user_badge.user == user && user_badge.badge.allow_title?
      user.title = user_badge.badge.name
      user.user_profile.badge_granted_title = true
      user.save!
      user.user_profile.save!
    else
      user.title = ''
      user.save!
    end

    render nothing: true
  end

  def preferences
    render nothing: true
  end

  def my_redirect
    if current_user.present? && params[:path] =~ /^[a-z\-\/]+$/
      redirect_to path("/users/#{current_user.username}/#{params[:path]}")
      return
    end
    raise Discourse::NotFound
  end

  def invited
    inviter = fetch_user_from_params
    offset = params[:offset].to_i || 0

    invites = if guardian.can_see_invite_details?(inviter)
      Invite.find_all_invites_from(inviter, offset)
    else
      Invite.find_redeemed_invites_from(inviter, offset)
    end

    invites = invites.filter_by(params[:filter])
    render_json_dump invites: serialize_data(invites.to_a, InviteSerializer),
                     can_see_invite_details: guardian.can_see_invite_details?(inviter)
  end

  def is_local_username
    users = params[:usernames]
    users = [params[:username]] if users.blank?
    users.each(&:downcase!)

    result = User.where(username_lower: users).pluck(:username_lower)
    render json: {valid: result}
  end

  def render_available_true
    render(json: { available: true })
  end

  def changing_case_of_own_username(target_user, username)
    target_user and username.downcase == target_user.username.downcase
  end

  # Used for checking availability of a username and will return suggestions
  # if the username is not available.
  def check_username
    if !params[:username].present?
      params.require(:username) if !params[:email].present?
      return render(json: success_json)
    end
    username = params[:username]

    target_user = user_from_params_or_current_user

    # The special case where someone is changing the case of their own username
    return render_available_true if changing_case_of_own_username(target_user, username)

    checker = UsernameCheckerService.new
    email = params[:email] || target_user.try(:email)
    render json: checker.check_username(username, email)
  end

  def user_from_params_or_current_user
    params[:for_user_id] ? User.find(params[:for_user_id]) : current_user
  end

  def create
    params.permit(:user_fields)

    unless SiteSetting.allow_new_registrations
      return fail_with("login.new_registrations_disabled")
    end

    if params[:password] && params[:password].length > User.max_password_length
      return fail_with("login.password_too_long")
    end

    user = User.new(user_params)

    # Handle custom fields
    user_fields = UserField.all
    if user_fields.present?
      field_params = params[:user_fields] || {}
      fields = user.custom_fields

      user_fields.each do |f|
        field_val = field_params[f.id.to_s]
        if field_val.blank?
          return fail_with("login.missing_user_field") if f.required?
        else
          fields["user_field_#{f.id}"] = field_val[0...UserField.max_length]
        end
      end

      user.custom_fields = fields
    end

    authentication = UserAuthenticator.new(user, session)

    if !authentication.has_authenticator? && !SiteSetting.enable_local_logins
      return render nothing: true, status: 500
    end

    authentication.start

    activation = UserActivator.new(user, request, session, cookies)
    activation.start

    # just assign a password if we have an authenticator and no password
    # this is the case for Twitter
    user.password = SecureRandom.hex if user.password.blank? && authentication.has_authenticator?

    if user.save
      authentication.finish
      activation.finish

      # save user email in session, to show on account-created page
      session["user_created_message"] = activation.message

      render json: {
        success: true,
        active: user.active?,
        message: activation.message,
        user_id: user.id
      }
    else
      render json: {
        success: false,
        message: I18n.t(
          'login.errors',
          errors: user.errors.full_messages.join("\n")
        ),
        errors: user.errors.to_hash,
        values: user.attributes.slice('name', 'username', 'email')
      }
    end
  rescue ActiveRecord::StatementInvalid
    render json: {
      success: false,
      message: I18n.t("login.something_already_taken")
    }
  rescue RestClient::Forbidden
    render json: { errors: [I18n.t("discourse_hub.access_token_problem")] }
  end

  def get_honeypot_value
    render json: {value: honeypot_value, challenge: challenge_value}
  end

  def password_reset
    expires_now

    if EmailToken.valid_token_format?(params[:token])
      @user = EmailToken.confirm(params[:token])

      if @user
        session["password-#{params[:token]}"] = @user.id
      else
        user_id = session["password-#{params[:token]}"]
        @user = User.find(user_id) if user_id
      end
    else
      @invalid_token = true
    end

    if !@user
      @error = I18n.t('password_reset.no_token')
    elsif request.put?
      @invalid_password = params[:password].blank? || params[:password].length > User.max_password_length

      if @invalid_password
        @user.errors.add(:password, :invalid)
      else
        @user.password = params[:password]
        @user.password_required!
        @user.auth_token = nil
        if @user.save
          Invite.invalidate_for_email(@user.email) # invite link can't be used to log in anymore
          logon_after_password_reset
        end
      end
    end
    render layout: 'no_ember'
  end

  def logon_after_password_reset
    message = if Guardian.new(@user).can_access_forum?
                # Log in the user
                log_on_user(@user)
                'password_reset.success'
              else
                @requires_approval = true
                'password_reset.success_unapproved'
              end

    @success = I18n.t(message)
  end

  def admin_login
    if current_user
      return redirect_to path("/")
    end

    if request.put?
      RateLimiter.new(nil, "admin-login-hr-#{request.remote_ip}", 6, 1.hour).performed!
      RateLimiter.new(nil, "admin-login-min-#{request.remote_ip}", 3, 1.minute).performed!

      user = User.where(email: params[:email], admin: true).where.not(id: Discourse::SYSTEM_USER_ID).first
      if user
        email_token = user.email_tokens.create(email: user.email)
        Jobs.enqueue(:user_email, type: :admin_login, user_id: user.id, email_token: email_token.token)
        @message = I18n.t("admin_login.success")
      else
        @message = I18n.t("admin_login.error")
      end
    elsif params[:token].present?
      # token recieved, try to login
      if EmailToken.valid_token_format?(params[:token])
        @user = EmailToken.confirm(params[:token])
        if @user && @user.admin?
          # Log in user
          log_on_user(@user)
          return redirect_to path("/")
        else
          @message = I18n.t("admin_login.error")
        end
      else
        @message = I18n.t("admin_login.error")
      end
    end

    render layout: false
  rescue RateLimiter::LimitExceeded
    @message = I18n.t("rate_limiter.slow_down")
    render layout: false
  end

  def toggle_anon
    user = AnonymousShadowCreator.get_master(current_user) ||
           AnonymousShadowCreator.get(current_user)

    if user
      log_on_user(user)
      render json: success_json
    else
      render json: failed_json, status: 403
    end
  end

  def change_email
    params.require(:email)
    user = fetch_user_from_params
    guardian.ensure_can_edit_email!(user)
    lower_email = Email.downcase(params[:email]).strip

    RateLimiter.new(user, "change-email-hr-#{request.remote_ip}", 6, 1.hour).performed!
    RateLimiter.new(user, "change-email-min-#{request.remote_ip}", 3, 1.minute).performed!

    # Raise an error if the email is already in use
    if User.find_by_email(lower_email)
      raise Discourse::InvalidParameters.new(:email)
    end

    email_token = user.email_tokens.create(email: lower_email)
    Jobs.enqueue(
      :user_email,
      to_address: lower_email,
      type: :authorize_email,
      user_id: user.id,
      email_token: email_token.token
    )

    render nothing: true
  rescue RateLimiter::LimitExceeded
    render_json_error(I18n.t("rate_limiter.slow_down"))
  end

  def authorize_email
    expires_now()
    if @user = EmailToken.confirm(params[:token])
      log_on_user(@user)
    else
      flash[:error] = I18n.t('change_email.error')
    end
    render layout: 'no_ember'
  end

  def account_created
    @message = session['user_created_message'] || I18n.t('activation.missing_session')
    expires_now
    render layout: 'no_ember'
  end

  def activate_account
    expires_now
    render layout: 'no_ember'
  end

  def perform_account_activation
    raise Discourse::InvalidAccess.new if honeypot_or_challenge_fails?(params)
    if @user = EmailToken.confirm(params[:token])

      # Log in the user unless they need to be approved
      if Guardian.new(@user).can_access_forum?
        @user.enqueue_welcome_message('welcome_user') if @user.send_welcome_message
        log_on_user(@user)
      else
        @needs_approval = true
      end

    else
      flash[:error] = I18n.t('activation.already_done')
    end
    render layout: 'no_ember'
  end

  def send_activation_email
    RateLimiter.new(nil, "activate-hr-#{request.remote_ip}", 30, 1.hour).performed!
    RateLimiter.new(nil, "activate-min-#{request.remote_ip}", 6, 1.minute).performed!

    @user = User.find_by_username_or_email(params[:username].to_s)

    raise Discourse::NotFound unless @user

    @email_token = @user.email_tokens.unconfirmed.active.first
    enqueue_activation_email if @user
    render nothing: true
  end

  def enqueue_activation_email
    @email_token ||= @user.email_tokens.create(email: @user.email)
    Jobs.enqueue(:user_email, type: :signup, user_id: @user.id, email_token: @email_token.token)
  end

  def search_users
    term = params[:term].to_s.strip
    topic_id = params[:topic_id]
    topic_id = topic_id.to_i if topic_id
    topic_allowed_users = params[:topic_allowed_users] || false

    results = UserSearch.new(term, topic_id: topic_id, topic_allowed_users: topic_allowed_users, searching_user: current_user).search

    user_fields = [:username, :upload_avatar_template, :uploaded_avatar_id]
    user_fields << :name if SiteSetting.enable_names?

    to_render = { users: results.as_json(only: user_fields, methods: :avatar_template) }

    if params[:include_groups] == "true"
      to_render[:groups] = Group.search_group(term, current_user).map {|m| {:name=>m.name, :usernames=> m.usernames.split(",")} }
    end

    render json: to_render
  end

  def pick_avatar
    user = fetch_user_from_params
    guardian.ensure_can_edit!(user)

    upload_id = params[:upload_id]

    user.uploaded_avatar_id = upload_id

    # ensure we associate the custom avatar properly
    if upload_id && user.user_avatar.custom_upload_id != upload_id
      user.user_avatar.custom_upload_id = upload_id
    end

    user.save!
    user.user_avatar.save!

    render json: success_json
  end

  def destroy_user_image
    user = fetch_user_from_params
    guardian.ensure_can_edit!(user)

    case params.require(:type)
    when "profile_background"
      user.user_profile.clear_profile_background
    when "card_background"
      user.user_profile.clear_card_background
    else
      raise Discourse::InvalidParameters.new(:type)
    end

    render json: success_json
  end

  def destroy
    @user = fetch_user_from_params
    guardian.ensure_can_delete_user!(@user)

    UserDestroyer.new(current_user).destroy(@user, { delete_posts: true, context: params[:context] })

    render json: success_json
  end

  def read_faq
    if(user = current_user)
      user.user_stat.read_faq = 1.second.ago
      user.user_stat.save
    end

    render json: success_json
  end

  def staff_info
    @user = fetch_user_from_params
    guardian.ensure_can_see_staff_info!(@user)

    result = {}

    %W{number_of_deleted_posts number_of_flagged_posts number_of_flags_given number_of_suspensions number_of_warnings}.each do |info|
      result[info] = @user.send(info)
    end

    render json: result
  end

  private

    def honeypot_value
      Digest::SHA1::hexdigest("#{Discourse.current_hostname}:#{Discourse::Application.config.secret_token}")[0,15]
    end

    def challenge_value
      challenge = $redis.get('SECRET_CHALLENGE')
      unless challenge && challenge.length == 16*2
        challenge = SecureRandom.hex(16)
        $redis.set('SECRET_CHALLENGE',challenge)
      end

      challenge
    end

    def respond_to_suspicious_request
      if suspicious?(params)
        render json: {
          success: true,
          active: false,
          message: I18n.t("login.activate_email", email: params[:email])
        }
      end
    end

    def suspicious?(params)
      return false if current_user && is_api? && current_user.admin?
      honeypot_or_challenge_fails?(params) || SiteSetting.invite_only?
    end

    def honeypot_or_challenge_fails?(params)
      return false if is_api?
      params[:password_confirmation] != honeypot_value ||
      params[:challenge] != challenge_value.try(:reverse)
    end

    def user_params
      params.permit(:name, :email, :password, :username, :active)
            .merge(ip_address: request.remote_ip, registration_ip_address: request.remote_ip)
    end

    def fail_with(key)
      render json: { success: false, message: I18n.t(key) }
    end

end