# encoding: utf-8
require 'spec_helper'

describe Ably::Realtime::Connection, 'failures', :event_machine do
  let(:connection) { client.connection }

  vary_by_protocol do
    let(:default_options) do
      { api_key: api_key, environment: environment, protocol: protocol }
    end

    let(:client_options) { default_options }
    let(:client) do
      Ably::Realtime::Client.new(client_options)
    end

    context 'authentication failure' do
      let(:client_options) do
        default_options.merge(api_key: invalid_key, log_level: :none)
      end

      context 'when API key is invalid' do
        context 'with invalid app part of the key' do
          let(:invalid_key) { 'not_an_app.invalid_key_id:invalid_key_value' }

          it 'enters the failed state and returns a not found error' do
            connection.on(:failed) do |error|
              expect(connection.state).to eq(:failed)
              # TODO: Check error type is an InvalidToken exception
              expect(error.status).to eq(404)
              expect(error.code).to eq(40400) # not found
              stop_reactor
            end
          end
        end

        context 'with invalid key ID part of the key' do
          let(:invalid_key) { "#{app_id}.invalid_key_id:invalid_key_value" }

          it 'enters the failed state and returns an authorization error' do
            connection.on(:failed) do |error|
              expect(connection.state).to eq(:failed)
              # TODO: Check error type is a TokenNotFOund exception
              expect(error.status).to eq(401)
              expect(error.code).to eq(40400) # not found
              stop_reactor
            end
          end
        end
      end
    end

    context 'automatic connection retry' do
      let(:client_failure_options) { default_options.merge(log_level: :none) }

      context 'with invalid WebSocket host' do
        let(:retry_every_for_tests)       { 0.2 }
        let(:max_time_in_state_for_tests) { 0.6 }

        before do
          # Reconfigure client library retry periods and timeouts so that tests run quickly
          stub_const 'Ably::Realtime::Connection::ConnectionManager::CONNECT_RETRY_CONFIG',
                      Ably::Realtime::Connection::ConnectionManager::CONNECT_RETRY_CONFIG.merge(
                        disconnected: { retry_every: retry_every_for_tests, max_time_in_state: max_time_in_state_for_tests },
                        suspended:    { retry_every: retry_every_for_tests, max_time_in_state: max_time_in_state_for_tests },
                      )
        end

        let(:expected_retry_attempts) { (max_time_in_state_for_tests / retry_every_for_tests).round }
        let(:state_changes)           { Hash.new { |hash, key| hash[key] = 0 } }
        let(:timer)                   { Hash.new }

        let(:client_options) do
          client_failure_options.merge(realtime_host: 'non.existent.host')
        end

        def count_state_changes
          EventMachine.next_tick do
            %w(connecting disconnected failed suspended).each do |state|
              connection.on(state.to_sym) { state_changes[state.to_sym] += 1 }
            end
          end
        end

        def start_timer
          timer[:start] = Time.now
        end

        def time_passed
          Time.now.to_f - timer[:start].to_f
        end

        context 'when disconnected' do
          it 'enters the suspended state after multiple attempts to connect' do
            connection.on(:failed) { raise 'Connection should not have reached :failed state yet' }

            count_state_changes && start_timer

            connection.once(:suspended) do
              expect(connection.state).to eq(:suspended)

              expect(state_changes[:connecting]).to   eql(expected_retry_attempts)
              expect(state_changes[:disconnected]).to eql(expected_retry_attempts)

              expect(time_passed).to be > max_time_in_state_for_tests
              stop_reactor
            end
          end

          describe '#close' do
            it 'transitions connection state to :closed' do
              connection.on(:connected) { raise 'Connection should not have reached :connected state' }
              connection.on(:failed)    { raise 'Connection should not have reached :failed state yet' }

              connection.once(:disconnected) do
                expect(connection.state).to eq(:disconnected)

                connection.on(:closed) do
                  expect(connection.state).to eq(:closed)
                  stop_reactor
                end

                connection.close
              end
            end
          end
        end

        context 'when connection state is :suspended' do
          it 'enters the failed state after multiple attempts if the max_time_in_state is set' do
            connection.on(:connected) { raise 'Connection should not have reached :connected state' }

            connection.once(:suspended) do
              count_state_changes && start_timer

              connection.on(:failed) do
                expect(connection.state).to eq(:failed)

                expect(state_changes[:connecting]).to   eql(expected_retry_attempts)
                expect(state_changes[:suspended]).to    eql(expected_retry_attempts)
                expect(state_changes[:disconnected]).to eql(0)

                expect(time_passed).to be > max_time_in_state_for_tests
                stop_reactor
              end
            end
          end

          describe '#close' do
            it 'transitions connection state to :closed' do
              connection.on(:connected) { raise 'Connection should not have reached :connected state' }

              connection.once(:suspended) do
                expect(connection.state).to eq(:suspended)

                connection.on(:closed) do
                  expect(connection.state).to eq(:closed)
                  stop_reactor
                end

                connection.close
              end
            end
          end
        end

        context 'when connection state is :failed' do
          describe '#close' do
            it 'will not transition state to :close and raises a StateChangeError exception' do
              connection.on(:connected) { raise 'Connection should not have reached :connected state' }

              connection.once(:failed) do
                expect(connection.state).to eq(:failed)
                expect { connection.close }.to raise_error Ably::Exceptions::StateChangeError, /Unable to transition from failed => closing/
                stop_reactor
              end
            end
          end
        end

        context '#error_reason' do
          [:disconnected, :suspended, :failed].each do |state|
            it "contains the error when state is #{state}" do
              connection.on(state) do |error|
                expect(connection.error_reason).to eq(error)
                expect(connection.error_reason.code).to eql(80000)
                stop_reactor
              end
            end
          end

          it 'is reset to nil when :connected' do
            connection.once(:disconnected) do |error|
              # stub the host so that the connection connects
              allow(connection).to receive(:determine_host).and_yield(TestApp.instance.realtime_host)
              connection.once(:connected) do
                expect(connection.error_reason).to be_nil
                stop_reactor
              end
            end
          end

          it 'is reset to nil when :closed' do
            connection.once(:disconnected) do |error|
              connection.close do
                expect(connection.error_reason).to be_nil
                stop_reactor
              end
            end
          end
        end
      end

      describe '#connect' do
        let(:timeouts) { Ably::Realtime::Connection::ConnectionManager::TIMEOUTS }

        before do
          stub_const 'Ably::Realtime::Connection::ConnectionManager::TIMEOUTS',
                      Ably::Realtime::Connection::ConnectionManager::TIMEOUTS.merge(open: 1.5)

          connection.on(:connected) { raise "Connection should not open in this test as CONNECTED ProtocolMessage is never received" }

          connection.once(:connecting) do
            # don't process any incoming ProtocolMessages so the connection never opens
            connection.__incoming_protocol_msgbus__.unsubscribe
          end
        end

        context 'connection opening times out' do
          it 'attempts to reconnect' do
            started_at = Time.now

            connection.once(:disconnected) do
              expect(Time.now.to_f - started_at.to_f).to be > timeouts.fetch(:open)
              connection.once(:connecting) do
                stop_reactor
              end
            end

            connection.connect
          end

          it 'calls the errback of the returned Deferrable object when first connection attempt fails' do
            connection.connect.errback do |error|
              expect(connection.state).to eq(:disconnected)
              stop_reactor
            end
          end

          context 'when retry intervals are stubbed to attempt reconnection quickly' do
            let(:client_options) { client_failure_options }

            before do
              # Reconfigure client library retry periods and timeouts so that tests run quickly
              stub_const 'Ably::Realtime::Connection::ConnectionManager::CONNECT_RETRY_CONFIG',
                Ably::Realtime::Connection::ConnectionManager::CONNECT_RETRY_CONFIG.merge(
                  disconnected: { retry_every: 0.1, max_time_in_state: 0.2 },
                  suspended:    { retry_every: 0.1, max_time_in_state: 0.2 },
                )
            end

            it 'never calls the provided success block', em_timeout: 10 do
              connection.connect do
                raise 'success block should not have been called'
              end

              connection.once(:failed) do
                stop_reactor
              end
            end
          end
        end
      end
    end

    context 'connection resume' do
      let(:channel_name) { random_str }
      let(:channel) { client.channel(channel_name) }
      let(:publishing_client) do
        Ably::Realtime::Client.new(client_options)
      end
      let(:publishing_client_channel) { publishing_client.channel(channel_name) }
      let(:client_options) { default_options.merge(log_level: :none) }

      def fail_if_suspended_or_failed
        connection.on(:suspended) { raise 'Connection should not have reached :suspended state' }
        connection.on(:failed)    { raise 'Connection should not have reached :failed state' }
      end

      context 'when DISCONNECTED ProtocolMessage received from the server' do
        it 'reconnects automatically' do
          fail_if_suspended_or_failed

          connection.once(:connected) do
            connection.once(:disconnected) do
              connection.once(:connected) do
                state_history = connection.state_history.map { |transition| transition[:state].to_sym }
                expect(state_history).to eql([:connecting, :connected, :disconnected, :connecting, :connected])
                stop_reactor
              end
            end
            protocol_message = Ably::Models::ProtocolMessage.new(action: Ably::Models::ProtocolMessage::ACTION.Disconnected.to_i)
            connection.__incoming_protocol_msgbus__.publish :protocol_message, protocol_message
          end
        end
      end

      context 'when websocket transport is closed' do
        it 'reconnects automatically' do
          fail_if_suspended_or_failed

          connection.once(:connected) do
            connection.once(:disconnected) do
              connection.once(:connected) do
                state_history = connection.state_history.map { |transition| transition[:state].to_sym }
                expect(state_history).to eql([:connecting, :connected, :disconnected, :connecting, :connected])
                stop_reactor
              end
            end
            connection.transport.close_connection_after_writing
          end
        end
      end

      context 'after successfully reconnecting and resuming' do
        it 'retains connection_id and connection_key' do
          previous_connection_id  = nil
          previous_connection_key = nil

          connection.once(:connected) do
            previous_connection_id  = connection.id
            previous_connection_key = connection.key
            connection.transport.close_connection_after_writing

            connection.once(:connected) do
              expect(connection.key).to eql(previous_connection_key)
              expect(connection.id).to eql(previous_connection_id)
              stop_reactor
            end
          end
        end

        it 'retains channel subscription state' do
          messages_received = false

          channel.subscribe('event') do |message|
            expect(message.data).to eql('message')
            stop_reactor
          end

          channel.attach do
            publishing_client_channel.attach do
              connection.transport.close_connection_after_writing

              connection.once(:connected) do
                publishing_client_channel.publish 'event', 'message'
              end
            end
          end
        end

        context 'when messages were published whilst the client was disconnected' do
          it 'receives the messages published whilst offline' do
            messages_received = false

            channel.subscribe('event') do |message|
              expect(message.data).to eql('message')
              messages_received = true
            end

            channel.attach do
              publishing_client_channel.attach do
                connection.transport.off # remove all event handlers that detect socket connection state has changed
                connection.transport.close_connection_after_writing

                publishing_client_channel.publish('event', 'message') do
                  EventMachine.add_timer(1) do
                    expect(messages_received).to eql(false)
                    # simulate connection dropped to re-establish web socket
                    connection.transition_state_machine :disconnected
                  end
                end

                # subsequent connection will receive message sent whilst disconnected
                connection.once(:connected) do
                  EventMachine.add_timer(1) do
                    expect(messages_received).to eql(true)
                    stop_reactor
                  end
                end
              end
            end
          end
        end
      end

      context 'when failing to resume because the connection_key is not or no longer valid' do
        def kill_connection_transport_and_prevent_valid_resume
          connection.transport.close_connection_after_writing
          connection.configure_new '0123456789abcdef', '0123456789abcdef', -1 # force the resume connection key to be invalid
        end

        it 'updates the connection_id and connection_key' do
          connection.once(:connected) do
            previous_connection_id  = connection.id
            previous_connection_key = connection.key

            connection.once(:connected) do
              expect(connection.key).to_not eql(previous_connection_key)
              expect(connection.id).to_not eql(previous_connection_id)
              stop_reactor
            end

            kill_connection_transport_and_prevent_valid_resume
          end
        end

        it 'detaches all channels' do
          channel_count = 10
          channels = channel_count.times.map { |index| client.channel("channel-#{index}") }
          when_all(*channels.map(&:attach)) do
            detached_channels = []
            channels.each do |channel|
              channel.on(:detached) do
                detached_channels << channel
                next unless detached_channels.count == channel_count
                expect(detached_channels.count).to eql(channel_count)
                stop_reactor
              end
            end

            kill_connection_transport_and_prevent_valid_resume
          end
        end

        it 'emits an error on the channel and sets the error reason' do
          client.channel(random_str).attach do |channel|
            channel.on(:error) do |error|
              expect(error.message).to match(/Invalid connection key/i)
              expect(error.code).to eql(80008)
              expect(channel.error_reason).to eql(error)
              stop_reactor
            end

            kill_connection_transport_and_prevent_valid_resume
          end
        end
      end
    end

    describe 'fallback host feature' do
      let(:retry_every_for_tests)       { 0.1 }
      let(:max_time_in_state_for_tests) { 0.3 }

      before do
        # Reconfigure client library retry periods and timeouts so that tests run quickly
        stub_const 'Ably::Realtime::Connection::ConnectionManager::CONNECT_RETRY_CONFIG',
                    Ably::Realtime::Connection::ConnectionManager::CONNECT_RETRY_CONFIG.merge(
                      disconnected: { retry_every: retry_every_for_tests, max_time_in_state: max_time_in_state_for_tests },
                      suspended:    { retry_every: retry_every_for_tests, max_time_in_state: max_time_in_state_for_tests },
                    )
      end

      let(:expected_retry_attempts) { (max_time_in_state_for_tests / retry_every_for_tests).round }
      let(:retry_count_for_one_state)  { 1 + expected_retry_attempts } # initial connect then disconnected
      let(:retry_count_for_all_states) { 1 + expected_retry_attempts * 2 } # initial connection, disconnected & then suspended

      context 'with custom realtime websocket host option' do
        let(:expected_host) { 'this.host.does.not.exist' }
        let(:client_options) { default_options.merge(realtime_host: expected_host, log_level: :none) }

        it 'never uses a fallback host' do
          expect(EventMachine).to receive(:connect).exactly(retry_count_for_all_states).times do |host|
            expect(host).to eql(expected_host)
            raise EventMachine::ConnectionError
          end

          connection.on(:failed) do
            stop_reactor
          end
        end
      end

      context 'with non-production environment' do
        let(:environment)    { 'sandbox' }
        let(:expected_host)  { "#{environment}-#{Ably::Realtime::Client::DOMAIN}" }
        let(:client_options) { default_options.merge(environment: environment, log_level: :none) }

        it 'never uses a fallback host' do
          expect(EventMachine).to receive(:connect).exactly(retry_count_for_all_states).times do |host|
            expect(host).to eql(expected_host)
            raise EventMachine::ConnectionError
          end

          connection.on(:failed) do
            stop_reactor
          end
        end
      end

      context 'with production environment' do
        let(:custom_hosts)   { %w(A.ably-realtime.com B.ably-realtime.com) }
        before do
          stub_const 'Ably::FALLBACK_HOSTS', custom_hosts
        end

        let(:expected_host)  { Ably::Realtime::Client::DOMAIN }
        let(:client_options) { default_options.merge(environment: nil, log_level: :none) }

        let(:fallback_hosts_used) { Array.new }

        context 'when the Internet is down' do
          before do
            allow(connection).to receive(:internet_up?).and_yield(false)
          end

          it 'never uses a fallback host' do
            expect(EventMachine).to receive(:connect).exactly(retry_count_for_all_states).times do |host|
              expect(host).to eql(expected_host)
              raise EventMachine::ConnectionError
            end

            connection.on(:failed) do
              stop_reactor
            end
          end
        end

        context 'when the Internet is up' do
          before do
            allow(connection).to receive(:internet_up?).and_yield(true)
          end

          it 'uses a fallback host on every subsequent disconnected attempt until suspended' do
            request = 0
            expect(EventMachine).to receive(:connect).exactly(retry_count_for_one_state).times do |host|
              if request == 0
                expect(host).to eql(expected_host)
              else
                expect(custom_hosts).to include(host)
                fallback_hosts_used << host
              end
              request += 1
              raise EventMachine::ConnectionError
            end

            connection.on(:suspended) do
              expect(fallback_hosts_used.uniq).to match_array(custom_hosts)
              stop_reactor
            end
          end

          it 'uses the primary host when suspended, and a fallback host on every subsequent suspended attempt' do
            request = 0
            expect(EventMachine).to receive(:connect).exactly(retry_count_for_all_states).times do |host|
              if request == 0 || request == expected_retry_attempts + 1
                expect(host).to eql(expected_host)
              else
                expect(custom_hosts).to include(host)
                fallback_hosts_used << host
              end
              request += 1
              raise EventMachine::ConnectionError
            end

            connection.on(:failed) do
              expect(fallback_hosts_used.uniq).to match_array(custom_hosts)
              stop_reactor
            end
          end
        end
      end
    end
  end
end