once-campfire/app/controllers/rooms_controller.rb

class RoomsController < ApplicationController
  before_action :set_room, only: %i[ show destroy ]
  before_action :ensure_can_administer, only: %i[ destroy ]
  before_action :remember_last_room_visited, only: :show
  around_action :cache_read_response, only: :show

  def index
    redirect_to room_url(Current.user.rooms.last)
  end

  def show
    @messages = find_messages
  end

  def destroy
    @room.destroy_later

    broadcast_remove_room
    redirect_to root_url
  end

  private
    def set_room
      room = RecordCache.fetch([ "room", self.class.name, Current.user.id, params[:room_id] || params[:id] ], read_record_cache_version) do
        [ room_scope.find_by(id: params[:room_id] || params[:id]) ]
      end.first
      if room
        @room = room
      else
        redirect_to root_url, alert: "Room not found or inaccessible"
      end
    end

    # Subclasses narrow this to the room types they're allowed to act on, so that one
    # room namespace can't be used to reach another's rooms.
    def room_scope
      Current.user.rooms
    end

    def ensure_can_administer
      head :forbidden unless Current.user.can_administer?(@room)
    end

    def ensure_permission_to_create_rooms
      if Current.account.settings.restrict_room_creation_to_administrators? && !Current.user.administrator?
        head :forbidden
      end
    end

    def find_messages
      messages = @room.messages.with_presentation

      if params[:message_id].present? && (show_first_message = messages.find_by(id: params[:message_id]))
        @messages = messages.page_around(show_first_message)
      else
        @messages = messages.last_page
      end
    end

    def room_params
      params.require(:room).permit(:name)
    end

    def broadcast_remove_room
      broadcast_remove_to :rooms, target: [ @room, :list ]
    end
end