class FullCalendarFormatter
  def self.rooms_to_resources(rooms)
    rooms.map { |room| room_to_resource(room) }.to_json
  end

  def self.event_schedules_to_resources(event_schedules)
    return '[]' if event_schedules.empty?

    conference = event_schedules.first.schedule.program.conference
    event_schedules.map { |event_schedule| event_schedule_to_resource(conference, event_schedule) }.to_json
  end

  class << self
    include FormatHelper

    private

    def room_to_resource(room)
      {
        id:    room.guid,
        title: room.name
      }
    end

    def event_schedule_to_resource(conference, event_schedule)
      event_type_color = event_schedule.event.event_type.color
      url = Rails.application.routes.url_helpers.conference_program_proposal_path(conference.short_title, event_schedule.event.id)

      {
        id:              event_schedule.event.guid,
        title:           event_schedule.event.title,
        start:           event_schedule.start_time,
        end:             event_schedule.end_time,
        resourceId:      event_schedule.room.guid,
        url:             url,
        backgroundColor: event_type_color,
        textColor:       contrast_color(event_type_color)
      }
    end
  end
end