require 'test_helper'
require 'concurrent'

require 'active_support/core_ext/hash/indifferent_access'
require 'pathname'

module CommonSubscriptionAdapterTest
  WAIT_WHEN_EXPECTING_EVENT = 3
  WAIT_WHEN_NOT_EXPECTING_EVENT = 0.2

  def setup
    # TODO: ActionCable requires a *lot* of setup at the moment...
    ::Object.const_set(:ApplicationCable, Module.new)
    ::ApplicationCable.const_set(:Connection, Class.new(ActionCable::Connection::Base))

    ::Object.const_set(:Rails, Module.new)
    ::Rails.singleton_class.send(:define_method, :root) { Pathname.new(__dir__) }

    server = ActionCable::Server::Base.new
    server.config = ActionCable::Server::Configuration.new
    inner_logger = Logger.new(StringIO.new).tap { |l| l.level = Logger::UNKNOWN }
    server.config.logger = ActionCable::Connection::TaggedLoggerProxy.new(inner_logger, tags: [])


    # and now the "real" setup for our test:
    server.config.cable = cable_config.with_indifferent_access

    adapter_klass = server.config.pubsub_adapter

    @rx_adapter = adapter_klass.new(server)
    @tx_adapter = adapter_klass.new(server)
  end

  def teardown
    @tx_adapter.shutdown if @tx_adapter && @tx_adapter != @rx_adapter
    @rx_adapter.shutdown if @rx_adapter

    begin
      ::Object.send(:remove_const, :ApplicationCable)
    rescue NameError
    end
    begin
      ::Object.send(:remove_const, :Rails)
    rescue NameError
    end
  end


  def subscribe_as_queue(channel, adapter = @rx_adapter)
    queue = Queue.new

    callback = -> data { queue << data }
    subscribed = Concurrent::Event.new
    adapter.subscribe(channel, callback, Proc.new { subscribed.set })
    subscribed.wait(WAIT_WHEN_EXPECTING_EVENT)
    assert subscribed.set?

    yield queue

    sleep WAIT_WHEN_NOT_EXPECTING_EVENT
    assert_empty queue
  ensure
    adapter.unsubscribe(channel, callback) if subscribed.set?
  end


  def test_subscribe_and_unsubscribe
    subscribe_as_queue('channel') do |queue|
    end
  end

  def test_basic_broadcast
    subscribe_as_queue('channel') do |queue|
      @tx_adapter.broadcast('channel', 'hello world')

      assert_equal 'hello world', queue.pop
    end
  end

  def test_broadcast_after_unsubscribe
    keep_queue = nil
    subscribe_as_queue('channel') do |queue|
      keep_queue = queue

      @tx_adapter.broadcast('channel', 'hello world')

      assert_equal 'hello world', queue.pop
    end

    @tx_adapter.broadcast('channel', 'hello void')

    sleep WAIT_WHEN_NOT_EXPECTING_EVENT
    assert_empty keep_queue
  end

  def test_multiple_broadcast
    subscribe_as_queue('channel') do |queue|
      @tx_adapter.broadcast('channel', 'bananas')
      @tx_adapter.broadcast('channel', 'apples')

      received = []
      2.times { received << queue.pop }
      assert_equal ['apples', 'bananas'], received.sort
    end
  end

  def test_identical_subscriptions
    subscribe_as_queue('channel') do |queue|
      subscribe_as_queue('channel') do |queue_2|
        @tx_adapter.broadcast('channel', 'hello')

        assert_equal 'hello', queue_2.pop
      end

      assert_equal 'hello', queue.pop
    end
  end

  def test_simultaneous_subscriptions
    subscribe_as_queue('channel') do |queue|
      subscribe_as_queue('other channel') do |queue_2|
        @tx_adapter.broadcast('channel', 'apples')
        @tx_adapter.broadcast('other channel', 'oranges')

        assert_equal 'apples', queue.pop
        assert_equal 'oranges', queue_2.pop
      end
    end
  end

  def test_channel_filtered_broadcast
    subscribe_as_queue('channel') do |queue|
      @tx_adapter.broadcast('other channel', 'one')
      @tx_adapter.broadcast('channel', 'two')

      assert_equal 'two', queue.pop
    end
  end
end