module Softwear
  module Lib
    module ControllerAuthentication
      extend ActiveSupport::Concern

      class NotSignedInError < StandardError
      end

      included do
        rescue_from NotSignedInError, with: :user_not_signed_in
        rescue_from Softwear::Auth::Model::AuthServerDown, with: :auth_server_down

        helper_method :current_user
        helper_method :user_signed_in?

        helper_method :destroy_user_session_path
        helper_method :users_path
        helper_method :user_path
        helper_method :edit_user_path
      end

      def user_class
        if Softwear::Auth::Model.descendants.size > 1
          raise "More than one descendent of Softwear::Auth::Model is not supported."
        elsif Softwear::Auth::Model.descendants.size == 0
          raise "Please define a user model that extends Softwear::Auth::Model."
        end
        Softwear::Auth::Model.descendants.first
      end

      # ====================
      # Action called when a NotSignedInError is raised.
      # ====================
      def user_not_signed_in
        redirect_to Figaro.env.softwear_hub_url + "/users/sign_in?#{{return_to: request.original_url}.to_param}"
      end

      # ====================
      # Action called when a NotSignedInError is raised.
      # ====================
      def auth_server_down(error)
        respond_to do |format|
          format.html do
            render inline: \
              "<h1>#{error.message}</h1><div>Not all site functions will work until the problem is resolved. "\
              "<a href='javascripr' onclick='history.go(-1);return false;' class='btn btn-default'>Go back.</a></div>"
          end

          format.js do
            render inline: "alert(\"#{error.message.gsub('"', '\"')}\");"
          end
        end
      end

      # ====================
      # Drop this into a before_filter to require a user be signed in on every request -
      # just like in Devise.
      # ====================
      def authenticate_user!
        token = session[:user_token]

        if token.blank?
          raise NotSignedInError, "No token"
        end

        if user = user_class.auth(token)
          @current_user = user
        else
          session[:user_token] = nil
          raise NotSignedInError, "Invalid token"
        end
      end

      def current_user
        @current_user
      end

      def user_signed_in?
        !@current_user.nil?
      end

      # -- url uelpers --

      def destroy_user_session_path
        Figaro.env.softwear_hub_url + "/users/sign_out"
      end

      def user_path(user)
        user_id = user.is_a?(user_class) ? user.id : user
        Figaro.env.softwear_hub_url + "/users/#{user_id}"
      end

      def edit_user_path(user)
        user_id = user.is_a?(user_class) ? user.id : user
        Figaro.env.softwear_hub_url + "/users/#{user_id}/edit"
      end

      def users_path
        Figaro.env.softwear_hub_url + "/users"
      end
    end
  end
end