NullVoxPopuli/action_cable_client

# frozen_string_literal: true

class ActionCableClient
  class Message
    IDENTIFIER_KEY = 'identifier'
    IDENTIFIER_PING = 'ping'
    IDENTIFIER_WELCOME = 'welcome'
    # Type is never sent, but is received
    # TODO: find a better place for this constant
    TYPE_KEY = 'type'
    TYPE_CONFIRM_SUBSCRIPTION = 'confirm_subscription'
    TYPE_REJECT_SUBSCRIPTION = 'reject_subscription'

    attr_reader :_command, :_identifier, :_data

    # @param [String] command - the type of message that this is
    # @param [Hash] identifier - the channel we are subscribed to
    # @param [Hash] data - the data to be sent in this message
    def initialize(command, identifier, data)
      @_command = command
      @_identifier = identifier
      @_data = data
    end

    def to_json
      hash = {
        command: _command,
        identifier: _identifier.to_json
      }

      hash[:data] = _data.to_json if present?(_data)

      hash.to_json
    end

    private

    def present?(data)
      case data
      when String
        !(data.empty? || /\A[[:space:]]*\z/.match(data))
      else
        data.respond_to?(:empty?) ? !data.empty? : !!data
      end
    end
  end
end