'use strict';

describe('$defer', function() {
  var scope, $browser, $defer, $exceptionHandler;

  beforeEach(function() {
    scope = angular.scope(angular.service,
                          {'$exceptionHandler': jasmine.createSpy('$exceptionHandler')});
    $browser = scope.$service('$browser');
    $defer = scope.$service('$defer');
    $exceptionHandler = scope.$service('$exceptionHandler');
  });

  afterEach(function() {
    dealoc(scope);
  });


  it('should delegate functions to $browser.defer', function() {
    var counter = 0;
    $defer(function() { counter++; });

    expect(counter).toBe(0);

    $browser.defer.flush();
    expect(counter).toBe(1);

    $browser.defer.flush(); //does nothing
    expect(counter).toBe(1);

    expect($exceptionHandler).not.toHaveBeenCalled();
  });


  it('should delegate exception to the $exceptionHandler service', function() {
    $defer(function() {throw "Test Error";});
    expect($exceptionHandler).not.toHaveBeenCalled();

    $browser.defer.flush();
    expect($exceptionHandler).toHaveBeenCalledWith("Test Error");
  });


  it('should call $apply after each callback is executed', function() {
    var applySpy = this.spyOn(scope, '$apply').andCallThrough();

    $defer(function() {});
    expect(applySpy).not.toHaveBeenCalled();

    $browser.defer.flush();
    expect(applySpy).toHaveBeenCalled();

    applySpy.reset(); //reset the spy;

    $defer(function() {});
    $defer(function() {});
    $browser.defer.flush();
    expect(applySpy.callCount).toBe(2);
  });


  it('should call $apply even if an exception is thrown in callback', function() {
    var applySpy = this.spyOn(scope, '$apply').andCallThrough();

    $defer(function() {throw "Test Error";});
    expect(applySpy).not.toHaveBeenCalled();

    $browser.defer.flush();
    expect(applySpy).toHaveBeenCalled();
  });


  it('should allow you to specify the delay time', function() {
    var defer = this.spyOn($browser, 'defer');
    $defer(noop, 123);
    expect(defer.callCount).toEqual(1);
    expect(defer.mostRecentCall.args[1]).toEqual(123);
  });


  it('should return a cancelation token', function() {
    var defer = this.spyOn($browser, 'defer').andReturn('xxx');
    expect($defer(noop)).toEqual('xxx');
  });


  describe('cancel', function() {
    it('should cancel tasks', function() {
      var task1 = jasmine.createSpy('task1'),
          task2 = jasmine.createSpy('task2'),
          task3 = jasmine.createSpy('task3'),
          token1, token3;

      token1 = $defer(task1);
      $defer(task2);
      token3 = $defer(task3, 333);

      $defer.cancel(token3);
      $defer.cancel(token1);
      $browser.defer.flush();

      expect(task1).not.toHaveBeenCalled();
      expect(task2).toHaveBeenCalledOnce();
      expect(task3).not.toHaveBeenCalled();
    });


    it('should return true if a task was succesffuly canceled', function() {
      var task1 = jasmine.createSpy('task1'),
          task2 = jasmine.createSpy('task2'),
          token1, token2;

      token1 = $defer(task1);
      $browser.defer.flush();
      token2 = $defer(task2);

      expect($defer.cancel(token1)).toBe(false);
      expect($defer.cancel(token2)).toBe(true);
    });
  });
});