module Syncable
  extend ActiveSupport::Concern

  included do
    has_many :syncs, as: :syncable, dependent: :destroy
  end

  def syncing?
    raise NotImplementedError, "Subclasses must implement the syncing? method"
  end

  def sync_later(parent_sync: nil, window_start_date: nil, window_end_date: nil)
    Sync.transaction do
      # Since we're scheduling a new sync, mark old syncs for this syncable as stale
      self.syncs.incomplete.find_each(&:mark_stale!)

      new_sync = self.syncs.create!(
        parent: parent_sync,
        window_start_date: window_start_date,
        window_end_date: window_end_date
      )

      SyncJob.perform_later(new_sync)

      new_sync
    end
  end

  def perform_sync(sync)
    syncer.perform_sync(sync)
  end

  def perform_post_sync
    syncer.perform_post_sync
  end

  def broadcast_sync_complete
    sync_broadcaster.broadcast
  end

  def sync_error
    latest_sync&.error
  end

  def last_synced_at
    latest_sync&.completed_at
  end

  def last_sync_created_at
    latest_sync&.created_at
  end

  private
    def latest_sync
      syncs.ordered.first
    end

    def syncer
      self.class::Syncer.new(self)
    end

    def sync_broadcaster
      self.class::SyncCompleteEvent.new(self)
    end
end