update_player_service.rb

class UpdatePlayerService
  def initialize
    @pn_service = PlayerPushNotification
  end

  def update(current_user: nil, player: nil, changes: nil)
    fail '[UpdatePlayerService#update] Must supply current_user' if current_user.nil?
    fail '[UpdatePlayerService#update] Must supply player' if player.nil?
    fail '[UpdatePlayerService#update] Must supply changes' if changes.nil?
    player.update_attributes(changes)
    push_if_necessary('update', current_user, player, changes)
    player
  end

  def create(current_user: nil, player: nil, initial_creation: false)
    fail '[UpdatePlayerService#create] Must supply current_user' if current_user.nil?
    fail '[UpdatePlayerService#create] Must supply player' if player.nil?
    player.save
    push_if_necessary('create', current_user, player, initial_creation)
    player
  end

  private

  # Only send a Push Notification if the changes made in the last
  # player update have modified the state of the player.
  def push_if_necessary(kind, current_user, player, changes)
    case kind
    when 'update'
      return if changes[:state].nil? || !player.state_changed?
      @pn_service.new(
        player: player,
        current_user: current_user,
        data: player.play.to_uri
      )
      return
    when 'create'
      @pn_service.new(
        player: player,
        current_user: current_user,
        data: player.play.to_uri,
        initial_creation: changes
      )
      return
    end
  end
end