describe('$httpBackend', function() {

  var $backend, $browser, callbacks,
      xhr, fakeDocument, callback;

  // TODO(vojta): should be replaced by $defer mock
  function fakeTimeout(fn, delay) {
    fakeTimeout.fns.push(fn);
    fakeTimeout.delays.push(delay);
  }

  fakeTimeout.fns = [];
  fakeTimeout.delays = [];
  fakeTimeout.flush = function() {
    var len = fakeTimeout.fns.length;
    fakeTimeout.delays = [];
    while (len--) fakeTimeout.fns.shift()();
  };


  beforeEach(inject(function($injector) {
    callbacks = {counter: 0};
    $browser = $injector.get('$browser');
    fakeDocument = {
      $$scripts: [],
      createElement: jasmine.createSpy('createElement').andCallFake(function() {
        return {};
      }),
      body: {
        appendChild: jasmine.createSpy('body.appendChid').andCallFake(function(script) {
          fakeDocument.$$scripts.push(script);
        }),
        removeChild: jasmine.createSpy('body.removeChild').andCallFake(function(script) {
          var index = indexOf(fakeDocument.$$scripts, script);
          if (index != -1) {
            fakeDocument.$$scripts.splice(index, 1);
          }
        })
      }
    };
    $backend = createHttpBackend($browser, MockXhr, fakeTimeout, callbacks, fakeDocument);
    callback = jasmine.createSpy('done');
  }));


  it('should do basics - open async xhr and send data', function() {
    $backend('GET', '/some-url', 'some-data', noop);
    xhr = MockXhr.$$lastInstance;

    expect(xhr.$$method).toBe('GET');
    expect(xhr.$$url).toBe('/some-url');
    expect(xhr.$$data).toBe('some-data');
    expect(xhr.$$async).toBe(true);
  });


  it('should normalize IE\'s 1223 status code into 204', function() {
    callback.andCallFake(function(status) {
      expect(status).toBe(204);
    });

    $backend('GET', 'URL', null, callback);
    xhr = MockXhr.$$lastInstance;

    xhr.status = 1223;
    xhr.readyState = 4;
    xhr.onreadystatechange();

    expect(callback).toHaveBeenCalledOnce();
  });


  it('should set only the requested headers', function() {
    $backend('POST', 'URL', null, noop, {'X-header1': 'value1', 'X-header2': 'value2'});
    xhr = MockXhr.$$lastInstance;

    expect(xhr.$$reqHeaders).toEqual({
      'X-header1': 'value1',
      'X-header2': 'value2'
    });
  });


  it('should abort request on timeout', function() {
    callback.andCallFake(function(status, response) {
      expect(status).toBe(-1);
    });

    $backend('GET', '/url', null, callback, {}, 2000);
    xhr = MockXhr.$$lastInstance;
    spyOn(xhr, 'abort');

    expect(fakeTimeout.delays[0]).toBe(2000);

    fakeTimeout.flush();
    expect(xhr.abort).toHaveBeenCalledOnce();

    xhr.status = 0;
    xhr.readyState = 4;
    xhr.onreadystatechange();
    expect(callback).toHaveBeenCalledOnce();
  });


  it('should register onreadystatechange callback before sending', function() {
    // send() in IE6, IE7 is sync when serving from cache
    function SyncXhr() {
      xhr = this;
      this.open = this.setRequestHeader = noop;

      this.send = function() {
        this.status = 200;
        this.responseText = 'response';
        this.readyState = 4;
        this.onreadystatechange();
      };

      this.getAllResponseHeaders = valueFn('');
    }

    callback.andCallFake(function(status, response) {
      expect(status).toBe(200);
      expect(response).toBe('response');
    });

    $backend = createHttpBackend($browser, SyncXhr);
    $backend('GET', '/url', null, callback);
    expect(callback).toHaveBeenCalledOnce();
  });


  it('should set withCredentials', function() {
    $backend('GET', '/some.url', null, callback, {}, null, true);
    expect(MockXhr.$$lastInstance.withCredentials).toBe(true);
  });


  describe('JSONP', function() {

    var SCRIPT_URL = /([^\?]*)\?cb=angular\.callbacks\.(.*)/;


    it('should add script tag for JSONP request', function() {
      callback.andCallFake(function(status, response) {
        expect(status).toBe(200);
        expect(response).toBe('some-data');
      });

      $backend('JSONP', 'http://example.org/path?cb=JSON_CALLBACK', null, callback);
      expect(fakeDocument.$$scripts.length).toBe(1);

      var script = fakeDocument.$$scripts.shift(),
          url = script.src.match(SCRIPT_URL);

      expect(url[1]).toBe('http://example.org/path');
      callbacks[url[2]]('some-data');

      if (script.onreadystatechange) {
        script.readyState = 'complete';
        script.onreadystatechange();
      } else {
        script.onload()
      }

      expect(callback).toHaveBeenCalledOnce();
    });


    it('should clean up the callback and remove the script', function() {
      $backend('JSONP', 'http://example.org/path?cb=JSON_CALLBACK', null, callback);
      expect(fakeDocument.$$scripts.length).toBe(1);


      var script = fakeDocument.$$scripts.shift(),
          callbackId = script.src.match(SCRIPT_URL)[2];

      callbacks[callbackId]('some-data');

      if (script.onreadystatechange) {
        script.readyState = 'complete';
        script.onreadystatechange();
      } else {
        script.onload()
      }

      expect(callbacks[callbackId]).toBeUndefined();
      expect(fakeDocument.body.removeChild).toHaveBeenCalledOnceWith(script);
    });


    it('should call callback with status -2 when script fails to load', function() {
      callback.andCallFake(function(status, response) {
        expect(status).toBe(-2);
        expect(response).toBeUndefined();
      });

      $backend('JSONP', 'http://example.org/path?cb=JSON_CALLBACK', null, callback);
      expect(fakeDocument.$$scripts.length).toBe(1);

      var script = fakeDocument.$$scripts.shift();
      if (script.onreadystatechange) {
        script.readyState = 'complete';
        script.onreadystatechange();
      } else {
        script.onload()
      }
      expect(callback).toHaveBeenCalledOnce();
    });


    it('should set url to current location if not specified or empty string', function() {
      $backend('JSONP', undefined, null, callback);
      expect(fakeDocument.$$scripts[0].src).toBe($browser.url());
      fakeDocument.$$scripts.shift();

      $backend('JSONP', '', null, callback);
      expect(fakeDocument.$$scripts[0].src).toBe($browser.url());
    });


    // TODO(vojta): test whether it fires "async-start"
    // TODO(vojta): test whether it fires "async-end" on both success and error
  });

  describe('file protocol', function() {

    function respond(status, content) {
      xhr = MockXhr.$$lastInstance;
      xhr.status = status;
      xhr.responseText = content;
      xhr.readyState = 4;
      xhr.onreadystatechange();
    }


    it('should convert 0 to 200 if content', function() {
      $backend = createHttpBackend($browser, MockXhr, null, null, null, 'http');

      $backend('GET', 'file:///whatever/index.html', null, callback);
      respond(0, 'SOME CONTENT');

      expect(callback).toHaveBeenCalled();
      expect(callback.mostRecentCall.args[0]).toBe(200);
    });


    it('should convert 0 to 200 if content - relative url', function() {
      $backend = createHttpBackend($browser, MockXhr, null, null, null, 'file');

      $backend('GET', '/whatever/index.html', null, callback);
      respond(0, 'SOME CONTENT');

      expect(callback).toHaveBeenCalled();
      expect(callback.mostRecentCall.args[0]).toBe(200);
    });


    it('should convert 0 to 404 if no content', function() {
      $backend = createHttpBackend($browser, MockXhr, null, null, null, 'http');

      $backend('GET', 'file:///whatever/index.html', null, callback);
      respond(0, '');

      expect(callback).toHaveBeenCalled();
      expect(callback.mostRecentCall.args[0]).toBe(404);
    });


    it('should convert 0 to 200 if content - relative url', function() {
      $backend = createHttpBackend($browser, MockXhr, null, null, null, 'file');

      $backend('GET', '/whatever/index.html', null, callback);
      respond(0, '');

      expect(callback).toHaveBeenCalled();
      expect(callback.mostRecentCall.args[0]).toBe(404);
    });
  });
});

