// Copyright 2013 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/**
 * @fileoverview Unit tests for goog.labs.net.webChannel.ChannelRequest.
 *
 */


goog.provide('goog.labs.net.webChannel.channelRequestTest');

goog.require('goog.Uri');
goog.require('goog.functions');
goog.require('goog.labs.net.webChannel.ChannelRequest');
goog.require('goog.labs.net.webChannel.WebChannelDebug');
goog.require('goog.labs.net.webChannel.requestStats');
goog.require('goog.labs.net.webChannel.requestStats.ServerReachability');
goog.require('goog.testing.MockClock');
goog.require('goog.testing.PropertyReplacer');
goog.require('goog.testing.jsunit');
goog.require('goog.testing.net.XhrIo');
goog.require('goog.testing.recordFunction');

goog.setTestOnly('goog.labs.net.webChannel.channelRequestTest');


var channelRequest;
var mockChannel;
var mockClock;
var stubs;
var xhrIo;
var reachabilityEvents;


/**
 * Time to wait for a network request to time out, before aborting.
 */
var WATCHDOG_TIME = 2000;


/**
 * Time to throttle readystatechange events.
 */
var THROTTLE_TIME = 500;


/**
 * A really long time - used to make sure no more timeouts will fire.
 */
var ALL_DAY_MS = 1000 * 60 * 60 * 24;


function shouldRunTests() {
  return goog.labs.net.webChannel.ChannelRequest.supportsXhrStreaming();
}


function setUp() {
  mockClock = new goog.testing.MockClock();
  mockClock.install();
  reachabilityEvents = {};
  stubs = new goog.testing.PropertyReplacer();

  // Mock out the stat notification code.
  var notifyServerReachabilityEvent = function(reachabilityType) {
    if (!reachabilityEvents[reachabilityType]) {
      reachabilityEvents[reachabilityType] = 0;
    }
    reachabilityEvents[reachabilityType]++;
  };
  stubs.set(
      goog.labs.net.webChannel.requestStats, 'notifyServerReachabilityEvent',
      notifyServerReachabilityEvent);
}


function tearDown() {
  stubs.reset();
  mockClock.uninstall();
}



/**
 * Constructs a duck-type WebChannelBase that tracks the completed requests.
 * @constructor
 * @struct
 * @final
 */
function MockWebChannelBase() {
  this.isClosed = function() { return false; };
  this.isActive = function() { return true; };
  this.shouldUseSecondaryDomains = function() { return false; };
  this.completedRequests = [];
  this.onRequestComplete = function(request) {
    this.completedRequests.push(request);
  };
  this.onRequestData = function(request, data) {};
}


/**
 * Creates a real ChannelRequest object, with some modifications for
 * testability:
 * <ul>
 * <li>The channel is a mock channel.
 * <li>The new watchdogTimeoutCallCount property tracks onWatchDogTimeout_()
 *     calls.
 * <li>The timeout is set to WATCHDOG_TIME.
 * </ul>
 */
function createChannelRequest() {
  xhrIo = new goog.testing.net.XhrIo();
  xhrIo.abort = xhrIo.abort || function() { this.active_ = false; };

  // Install mock channel and no-op debug logger.
  mockChannel = new MockWebChannelBase();
  channelRequest = new goog.labs.net.webChannel.ChannelRequest(
      mockChannel, new goog.labs.net.webChannel.WebChannelDebug());

  // Install test XhrIo.
  mockChannel.createXhrIo = function() { return xhrIo; };

  // Install watchdogTimeoutCallCount.
  channelRequest.watchdogTimeoutCallCount = 0;
  channelRequest.originalOnWatchDogTimeout = channelRequest.onWatchDogTimeout_;
  channelRequest.onWatchDogTimeout_ = function() {
    channelRequest.watchdogTimeoutCallCount++;
    return channelRequest.originalOnWatchDogTimeout();
  };

  channelRequest.setTimeout(WATCHDOG_TIME);
}


/**
 * Run through the lifecycle of a long lived request, checking that the right
 * network events are reported.
 */
function testNetworkEvents() {
  createChannelRequest();

  channelRequest.xmlHttpPost(new goog.Uri('some_uri'), 'some_postdata', true);
  checkReachabilityEvents(1, 0, 0, 0);
  if (goog.labs.net.webChannel.ChannelRequest.supportsXhrStreaming()) {
    xhrIo.simulatePartialResponse('17\nI am a BC Message');
    checkReachabilityEvents(1, 0, 0, 1);
    xhrIo.simulatePartialResponse('23\nI am another BC Message');
    checkReachabilityEvents(1, 0, 0, 2);
    xhrIo.simulateResponse(200, '16\Final BC Message');
    checkReachabilityEvents(1, 1, 0, 2);
  } else {
    xhrIo.simulateResponse(200, '16\Final BC Message');
    checkReachabilityEvents(1, 1, 0, 0);
  }
}


/**
 * Test throttling of readystatechange events.
 */
function testNetworkEvents_throttleReadyStateChange() {
  createChannelRequest();
  channelRequest.setReadyStateChangeThrottle(THROTTLE_TIME);

  var recordedHandler =
      goog.testing.recordFunction(channelRequest.xmlHttpHandler_);
  stubs.set(channelRequest, 'xmlHttpHandler_', recordedHandler);

  channelRequest.xmlHttpPost(new goog.Uri('some_uri'), 'some_postdata', true);
  assertEquals(1, recordedHandler.getCallCount());

  checkReachabilityEvents(1, 0, 0, 0);
  if (goog.labs.net.webChannel.ChannelRequest.supportsXhrStreaming()) {
    xhrIo.simulatePartialResponse('17\nI am a BC Message');
    checkReachabilityEvents(1, 0, 0, 1);
    assertEquals(3, recordedHandler.getCallCount());

    // Second event should be throttled
    xhrIo.simulatePartialResponse('23\nI am another BC Message');
    assertEquals(3, recordedHandler.getCallCount());

    xhrIo.simulatePartialResponse('27\nI am yet another BC Message');
    assertEquals(3, recordedHandler.getCallCount());
    mockClock.tick(THROTTLE_TIME);

    checkReachabilityEvents(1, 0, 0, 3);
    // Only one more call because of throttling.
    assertEquals(4, recordedHandler.getCallCount());

    xhrIo.simulateResponse(200, '16\Final BC Message');
    checkReachabilityEvents(1, 1, 0, 3);
    assertEquals(5, recordedHandler.getCallCount());
  } else {
    xhrIo.simulateResponse(200, '16\Final BC Message');
    checkReachabilityEvents(1, 1, 0, 0);
  }
}


/**
 * Make sure that the request "completes" with an error when the timeout
 * expires.
 */
function testRequestTimeout() {
  createChannelRequest();

  channelRequest.xmlHttpPost(new goog.Uri('some_uri'), 'some_postdata', true);
  assertEquals(0, channelRequest.watchdogTimeoutCallCount);
  assertEquals(0, channelRequest.channel_.completedRequests.length);

  // Watchdog timeout.
  mockClock.tick(WATCHDOG_TIME);
  assertEquals(1, channelRequest.watchdogTimeoutCallCount);
  assertEquals(1, channelRequest.channel_.completedRequests.length);
  assertFalse(channelRequest.getSuccess());

  // Make sure no more timers are firing.
  mockClock.tick(ALL_DAY_MS);
  assertEquals(1, channelRequest.watchdogTimeoutCallCount);
  assertEquals(1, channelRequest.channel_.completedRequests.length);

  checkReachabilityEvents(1, 0, 1, 0);
}


function testRequestTimeoutWithUnexpectedException() {
  createChannelRequest();
  channelRequest.channel_.createXhrIo = goog.functions.error('Weird error');

  try {
    channelRequest.xmlHttpGet(new goog.Uri('some_uri'), true, null);
    fail('Expected error');
  } catch (e) {
    assertEquals('Weird error', e.message);
  }

  assertEquals(0, channelRequest.watchdogTimeoutCallCount);
  assertEquals(0, channelRequest.channel_.completedRequests.length);

  // Watchdog timeout.
  mockClock.tick(WATCHDOG_TIME);
  assertEquals(1, channelRequest.watchdogTimeoutCallCount);
  assertEquals(1, channelRequest.channel_.completedRequests.length);
  assertFalse(channelRequest.getSuccess());

  // Make sure no more timers are firing.
  mockClock.tick(ALL_DAY_MS);
  assertEquals(1, channelRequest.watchdogTimeoutCallCount);
  assertEquals(1, channelRequest.channel_.completedRequests.length);

  checkReachabilityEvents(0, 0, 1, 0);
}


function checkReachabilityEvents(reqMade, reqSucceeded, reqFail, backChannel) {
  var Reachability = goog.labs.net.webChannel.requestStats.ServerReachability;
  assertEquals(reqMade, reachabilityEvents[Reachability.REQUEST_MADE] || 0);
  assertEquals(
      reqSucceeded, reachabilityEvents[Reachability.REQUEST_SUCCEEDED] || 0);
  assertEquals(reqFail, reachabilityEvents[Reachability.REQUEST_FAILED] || 0);
  assertEquals(
      backChannel, reachabilityEvents[Reachability.BACK_CHANNEL_ACTIVITY] || 0);
}