var noop = function() {}, clock, oldTextTracks;

import extendsFn from '../../../src/js/extends.js';
import Tech from '../../../src/js/tech/tech.js';
import { createTimeRange } from '../../../src/js/utils/time-ranges.js';

q.module('Media Tech', {
  'setup': function() {
    this.noop = function() {};
    this.clock = sinon.useFakeTimers();
    this.featuresProgessEvents = Tech.prototype['featuresProgessEvents'];
    Tech.prototype['featuresProgressEvents'] = false;
    Tech.prototype['featuresNativeTextTracks'] = true;
    oldTextTracks = Tech.prototype.textTracks;
    Tech.prototype.textTracks = function() {
      return {
        addEventListener: Function.prototype,
        removeEventListener: Function.prototype
      };
    };
  },
  'teardown': function() {
    this.clock.restore();
    Tech.prototype['featuresProgessEvents'] = this.featuresProgessEvents;
    Tech.prototype['featuresNativeTextTracks'] = false;
    Tech.prototype.textTracks = oldTextTracks;
  }
});

test('should synthesize timeupdate events by default', function() {
  var timeupdates = 0, tech;

  tech = new Tech();
  tech.on('timeupdate', function() {
    timeupdates++;
  });

  tech.trigger('play');

  this.clock.tick(250);
  equal(timeupdates, 1, 'triggered at least one timeupdate');
});

test('stops manual timeupdates while paused', function() {
  var timeupdates = 0, tech, expected;
  tech = new Tech();
  tech.on('timeupdate', function() {
    timeupdates++;
  });

  tech.trigger('play');
  this.clock.tick(10 * 250);
  ok(timeupdates > 0, 'timeupdates fire during playback');

  tech.trigger('pause');
  timeupdates = 0;
  this.clock.tick(10 * 250);
  equal(timeupdates, 0, 'timeupdates do not fire when paused');

  tech.trigger('play');
  this.clock.tick(10 * 250);
  ok(timeupdates > 0, 'timeupdates fire when playback resumes');
});

test('should synthesize progress events by default', function() {
  var progresses = 0, bufferedPercent = 0.5, tech;
  tech = new Tech();
  tech.on('progress', function() {
    progresses++;
  });
  tech.bufferedPercent = function() {
    return bufferedPercent;
  };

  this.clock.tick(500);
  equal(progresses, 0, 'waits until ready');

  tech.trigger('ready');
  this.clock.tick(500);
  equal(progresses, 1, 'triggered one event');

  tech.trigger('ready');
  bufferedPercent = 0.75;
  this.clock.tick(500);
  equal(progresses, 2, 'repeated readies are ok');
});

test('dispose() should stop time tracking', function() {
  var tech = new Tech();
  tech.dispose();

  // progress and timeupdate events will throw exceptions after the
  // tech is disposed
  try {
    this.clock.tick(10 * 1000);
  } catch (e) {
    return equal(e, undefined, 'threw an exception');
  }
  ok(true, 'no exception was thrown');
});

test('should add the source handler interface to a tech', function(){
  var sourceA = { src: 'foo.mp4', type: 'video/mp4' };
  var sourceB = { src: 'no-support', type: 'no-support' };

  // Define a new tech class
  var MyTech = extendsFn(Tech);

  // Extend Tech with source handlers
  Tech.withSourceHandlers(MyTech);

  // Check for the expected class methods
  ok(MyTech.registerSourceHandler, 'added a registerSourceHandler function to the Tech');
  ok(MyTech.selectSourceHandler, 'added a selectSourceHandler function to the Tech');

  // Create an instance of Tech
  var tech = new MyTech();

  // Check for the expected instance methods
  ok(tech.setSource, 'added a setSource function to the tech instance');

  // Create an internal state class for the source handler
  // The internal class would be used by a source handler to maintain state
  // and provde a dispose method for the handler.
  // This is optional for source handlers
  var disposeCalled = false;
  var handlerInternalState = function(){};
  handlerInternalState.prototype.dispose = function(){
    disposeCalled = true;
  };

  // Create source handlers
  var handlerOne = {
    canHandleSource: function(source){
      if (source.type !=='no-support') {
        return 'probably';
      }
      return '';
    },
    handleSource: function(s, t){
      strictEqual(tech, t, 'the tech instance was passed to the source handler');
      strictEqual(sourceA, s, 'the tech instance was passed to the source handler');
      return new handlerInternalState();
    }
  };

  var handlerTwo = {
    canHandleSource: function(source){
      return ''; // no support
    },
    handleSource: function(source, tech){
      ok(false, 'handlerTwo supports nothing and should never be called');
    }
  };

  // Test registering source handlers
  MyTech.registerSourceHandler(handlerOne);
  strictEqual(MyTech.sourceHandlers[0], handlerOne, 'handlerOne was added to the source handler array');
  MyTech.registerSourceHandler(handlerTwo, 0);
  strictEqual(MyTech.sourceHandlers[0], handlerTwo, 'handlerTwo was registered at the correct index (0)');

  // Test handler selection
  strictEqual(MyTech.selectSourceHandler(sourceA), handlerOne, 'handlerOne was selected to handle the valid source');
  strictEqual(MyTech.selectSourceHandler(sourceB), null, 'no handler was selected to handle the invalid source');

  // Test canPlaySource return values
  strictEqual(MyTech.canPlaySource(sourceA), 'probably', 'the Tech returned probably for the valid source');
  strictEqual(MyTech.canPlaySource(sourceB), '', 'the Tech returned an empty string for the invalid source');

  // Pass a source through the source handler process of a tech instance
  tech.setSource(sourceA);
  strictEqual(tech.currentSource_, sourceA, 'sourceA was handled and stored');
  ok(tech.sourceHandler_.dispose, 'the handlerOne state instance was stored');

  // Check that the handler dipose method works
  ok(!disposeCalled, 'dispose has not been called for the handler yet');
  tech.dispose();
  ok(disposeCalled, 'the handler dispose method was called when the tech was disposed');
});

test('should handle unsupported sources with the source handler API', function(){
  // Define a new tech class
  var MyTech = extendsFn(Tech);
  // Extend Tech with source handlers
  Tech.withSourceHandlers(MyTech);
  // Create an instance of Tech
  var tech = new MyTech();

  var usedNative;
  MyTech.nativeSourceHandler = {
    handleSource: function(){ usedNative = true; }
  };

  tech.setSource('');
  ok(usedNative, 'native source handler was used when an unsupported source was set');
});

test('should track whether a video has played', function() {
  let tech = new Tech();

  equal(tech.played().length, 0, 'starts with zero length');
  tech.trigger('playing');
  equal(tech.played().length, 1, 'has length after playing');
});

test('delegates seekable to the source handler', function(){
  let MyTech = Tech.extend({
    seekable: function() {
      throw new Error('You should not be calling me!');
    }
  });
  Tech.withSourceHandlers(MyTech);

  let seekableCount = 0;
  let handler = {
    seekable: function() {
      seekableCount++;
      return createTimeRange(0, 0);
    }
  };

  MyTech.registerSourceHandler({
    canHandleSource: function() {
      return true;
    },
    handleSource: function(source, tech) {
      return handler;
    }
  });

  let tech = new MyTech();
  tech.setSource({
    src: 'example.mp4',
    type: 'video/mp4'
  });
  tech.seekable();
  equal(seekableCount, 1, 'called the source handler');
});