const { MultimediaViewer, Thumbnail } = require( 'mmv' );
const { getMultimediaViewer } = require( './mmv.testhelpers.js' );
const { MultimediaViewerBootstrap } = require( 'mmv.bootstrap' );

( function () {
	QUnit.module( 'mmv', QUnit.newMwEnvironment( {
		beforeEach: function () {
			// prevent a real "back" navigation from taking place
			this.sandbox.stub( require( 'mediawiki.router' ), 'back' );
		}
	} ) );

	QUnit.test( 'eachPreloadableLightboxIndex()', function ( assert ) {
		const viewer = getMultimediaViewer();
		let expectedIndices;
		let i;

		viewer.preloadDistance = 3;
		viewer.thumbs = [];

		// 0..10
		for ( i = 0; i < 11; i++ ) {
			viewer.thumbs.push( { image: false } );
		}

		viewer.currentIndex = 2;
		i = 0;
		expectedIndices = [ 2, 3, 1, 4, 0, 5 ];
		viewer.eachPreloadableLightboxIndex( function ( index ) {
			assert.strictEqual( index, expectedIndices[ i++ ], 'preload on left edge' );
		} );

		viewer.currentIndex = 9;
		i = 0;
		expectedIndices = [ 9, 10, 8, 7, 6 ];
		viewer.eachPreloadableLightboxIndex( function ( index ) {
			assert.strictEqual( index, expectedIndices[ i++ ], 'preload on right edge' );
		} );
	} );

	QUnit.test( 'Progress', function ( assert ) {
		const imageDeferred = $.Deferred();
		const viewer = getMultimediaViewer();
		const fakeImage = {
			filePageTitle: new mw.Title( 'File:Stuff.jpg' )
		};
		// custom clock ensures progress handlers execute in correct sequence
		const clock = this.sandbox.useFakeTimers();

		viewer.thumbs = [];
		viewer.displayPlaceholderThumbnail = function () {};
		viewer.setImage = function () {};
		viewer.scroll = function () {};
		viewer.preloadFullscreenThumbnail = function () {};
		viewer.fetchSizeIndependentLightboxInfo = () => $.Deferred().resolve( {} );
		viewer.ui = {
			setFileReuseData: function () {},
			setupForLoad: function () {},
			canvas: { set: function () {},
				unblurWithAnimation: function () {},
				unblur: function () {},
				getCurrentImageWidths: function () {
					return { real: 0 };
				},
				getDimensions: function () {
					return {};
				}
			},
			panel: {
				setImageInfo: function () {},
				scroller: {
					animateMetadataOnce: function () {}
				},
				progressBar: {
					hide: this.sandbox.stub(),
					animateTo: this.sandbox.stub(),
					jumpTo: this.sandbox.stub()
				}
			},
			open: function () {} };

		viewer.imageProvider.get = () => imageDeferred.promise();
		viewer.imageInfoProvider.get = () => $.Deferred().resolve( {} );
		viewer.thumbnailInfoProvider.get = () => $.Deferred().resolve( {} );

		// loadImage will call setupProgressBar, which will attach done, fail &
		// progress handlers
		viewer.loadImage( fakeImage, new Image() );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.jumpTo.lastCall.calledWith( 0 ), true,
			'Percentage correctly reset by loadImage' );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.firstCall.calledWith( 5 ), true,
			'Percentage correctly animated to 5 by loadImage' );

		imageDeferred.notify( 'response', 45 );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.secondCall.calledWith( 45 ), true,
			'Percentage correctly funneled to panel UI' );

		imageDeferred.resolve( {}, {} );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.thirdCall.calledWith( 100 ), true,
			'Percentage correctly funneled to panel UI' );

		clock.restore();

		viewer.close();
	} );

	QUnit.test( 'Progress when switching images', function ( assert ) {
		const firstImageDeferred = $.Deferred();
		const secondImageDeferred = $.Deferred();
		const firstImage = {
			index: 1,
			filePageTitle: new mw.Title( 'File:First.jpg' )
		};
		const secondImage = {
			index: 2,
			filePageTitle: new mw.Title( 'File:Second.jpg' )
		};
		const viewer = getMultimediaViewer();
		// custom clock ensures progress handlers execute in correct sequence
		const clock = this.sandbox.useFakeTimers();

		// animation would keep running, conflict with other tests
		this.sandbox.stub( $.fn, 'animate' ).returnsThis();

		viewer.thumbs = [];
		viewer.displayPlaceholderThumbnail = function () {};
		viewer.setImage = function () {};
		viewer.scroll = function () {};
		viewer.preloadFullscreenThumbnail = function () {};
		viewer.preloadImagesMetadata = function () {};
		viewer.preloadThumbnails = function () {};
		viewer.fetchSizeIndependentLightboxInfo = () => $.Deferred().resolve( {} );
		viewer.ui = {
			setFileReuseData: function () {},
			setupForLoad: function () {},
			canvas: { set: function () {},
				unblurWithAnimation: function () {},
				unblur: function () {},
				getCurrentImageWidths: function () {
					return { real: 0 };
				},
				getDimensions: function () {
					return {};
				}
			},
			panel: {
				setImageInfo: function () {},
				scroller: {
					animateMetadataOnce: function () {}
				},
				progressBar: {
					hide: this.sandbox.stub(),
					animateTo: this.sandbox.stub(),
					jumpTo: this.sandbox.stub()
				}
			},
			open: function () {},
			empty: function () {} };

		viewer.imageInfoProvider.get = () => $.Deferred().resolve( {} );
		viewer.thumbnailInfoProvider.get = () => $.Deferred().resolve( {} );

		// load some image
		viewer.imageProvider.get = this.sandbox.stub().returns( firstImageDeferred );
		viewer.loadImage( firstImage, new Image() );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.jumpTo.getCall( 0 ).calledWith( 0 ), true,
			'Percentage correctly reset for new first image' );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.getCall( 0 ).calledWith( 5 ), true,
			'Percentage correctly animated to 5 for first new image' );

		// progress on active image
		firstImageDeferred.notify( 'response', 20 );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.getCall( 1 ).calledWith( 20 ), true,
			'Percentage correctly animated when active image is loading' );

		// change to another image
		viewer.imageProvider.get = this.sandbox.stub().returns( secondImageDeferred );
		viewer.loadImage( secondImage, new Image() );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.jumpTo.getCall( 1 ).calledWith( 0 ), true,
			'Percentage correctly reset for second new image' );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.getCall( 2 ).calledWith( 5 ), true,
			'Percentage correctly animated to 5 for second new image' );

		// progress on active image
		secondImageDeferred.notify( 'response', 30 );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.getCall( 3 ).calledWith( 30 ), true,
			'Percentage correctly animated when active image is loading' );

		// progress on inactive image
		firstImageDeferred.notify( 'response', 40 );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.callCount, 4,
			'Percentage not animated when inactive image is loading' );

		// progress on active image
		secondImageDeferred.notify( 'response', 50 );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.getCall( 4 ).calledWith( 50 ), true,
			'Percentage correctly ignored inactive image & only animated when active image is loading' );

		// change back to first image
		viewer.imageProvider.get = this.sandbox.stub().returns( firstImageDeferred );
		viewer.loadImage( firstImage, new Image() );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.jumpTo.getCall( 2 ).calledWith( 40 ), true,
			'Percentage jumps to right value when changing images' );

		secondImageDeferred.resolve( {}, {} );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.hide.called, false,
			'Progress bar not hidden when something finishes in the background' );

		// change back to second image, which has finished loading
		viewer.imageProvider.get = this.sandbox.stub().returns( secondImageDeferred );
		viewer.loadImage( secondImage, new Image() );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.hide.called, true,
			'Progress bar hidden when switching to finished image' );

		clock.restore();

		viewer.close();
	} );

	QUnit.test( 'resetBlurredThumbnailStates', function ( assert ) {
		const viewer = getMultimediaViewer();

		// animation would keep running, conflict with other tests
		this.sandbox.stub( $.fn, 'animate' ).returnsThis();

		assert.strictEqual( viewer.realThumbnailShown, false, 'Real thumbnail state is correct' );
		assert.strictEqual( viewer.blurredThumbnailShown, false, 'Placeholder state is correct' );

		viewer.realThumbnailShown = true;
		viewer.blurredThumbnailShown = true;

		viewer.resetBlurredThumbnailStates();

		assert.strictEqual( viewer.realThumbnailShown, false, 'Real thumbnail state is correct' );
		assert.strictEqual( viewer.blurredThumbnailShown, false, 'Placeholder state is correct' );
	} );

	QUnit.test( 'Placeholder first, then real thumbnail', function ( assert ) {
		const viewer = getMultimediaViewer();

		viewer.setImage = function () {};
		viewer.ui = { canvas: {
			unblurWithAnimation: function () {},
			unblur: function () {},
			maybeDisplayPlaceholder: function () {
				return true;
			}
		} };
		viewer.imageInfoProvider.get = this.sandbox.stub();

		viewer.displayPlaceholderThumbnail( { originalWidth: 100, originalHeight: 100 }, undefined, undefined );

		assert.strictEqual( viewer.blurredThumbnailShown, true, 'Placeholder state is correct' );
		assert.strictEqual( viewer.realThumbnailShown, false, 'Real thumbnail state is correct' );

		viewer.displayRealThumbnail( { url: undefined } );

		assert.strictEqual( viewer.realThumbnailShown, true, 'Real thumbnail state is correct' );
		assert.strictEqual( viewer.blurredThumbnailShown, true, 'Placeholder state is correct' );
	} );

	QUnit.test( 'Placeholder first, then real thumbnail - missing size', function ( assert ) {
		const viewer = getMultimediaViewer();

		viewer.currentIndex = 1;
		viewer.setImage = function () {};
		viewer.ui = { canvas: {
			unblurWithAnimation: function () {},
			unblur: function () {},
			maybeDisplayPlaceholder: function () {
				return true;
			}
		} };
		viewer.imageInfoProvider.get = this.sandbox.stub().returns( $.Deferred().resolve( { width: 100, height: 100 } ) );

		viewer.displayPlaceholderThumbnail( { index: 1 }, undefined, undefined );

		assert.strictEqual( viewer.blurredThumbnailShown, true, 'Placeholder state is correct' );
		assert.strictEqual( viewer.realThumbnailShown, false, 'Real thumbnail state is correct' );

		viewer.displayRealThumbnail( { url: undefined } );

		assert.strictEqual( viewer.realThumbnailShown, true, 'Real thumbnail state is correct' );
		assert.strictEqual( viewer.blurredThumbnailShown, true, 'Placeholder state is correct' );
	} );

	QUnit.test( 'Real thumbnail first, then placeholder', function ( assert ) {
		const viewer = getMultimediaViewer();

		viewer.setImage = function () {};
		viewer.ui = {
			showImage: function () {},
			canvas: {
				unblurWithAnimation: function () {},
				unblur: function () {}
			} };

		viewer.displayRealThumbnail( { url: undefined } );

		assert.strictEqual( viewer.realThumbnailShown, true, 'Real thumbnail state is correct' );
		assert.strictEqual( viewer.blurredThumbnailShown, false, 'Placeholder state is correct' );

		viewer.displayPlaceholderThumbnail( {}, undefined, undefined );

		assert.strictEqual( viewer.realThumbnailShown, true, 'Real thumbnail state is correct' );
		assert.strictEqual( viewer.blurredThumbnailShown, false, 'Placeholder state is correct' );
	} );

	QUnit.test( 'displayRealThumbnail', function ( assert ) {
		const viewer = getMultimediaViewer();

		viewer.setImage = function () {};
		viewer.ui = { canvas: {
			unblurWithAnimation: this.sandbox.stub(),
			unblur: function () {}
		} };
		viewer.blurredThumbnailShown = true;

		// Should not result in an unblurWithAnimation animation (image cache from cache)
		viewer.displayRealThumbnail( { url: undefined }, undefined, undefined, 5 );
		assert.strictEqual( viewer.ui.canvas.unblurWithAnimation.called, false, 'There should not be an unblurWithAnimation animation' );

		// Should result in an unblurWithAnimation (image didn't come from cache)
		viewer.displayRealThumbnail( { url: undefined }, undefined, undefined, 1000 );
		assert.strictEqual( viewer.ui.canvas.unblurWithAnimation.called, true, 'There should be an unblurWithAnimation animation' );
	} );

	QUnit.test( 'New image loaded while another one is loading', function ( assert ) {
		const viewer = getMultimediaViewer();
		const firstImageDeferred = $.Deferred();
		const secondImageDeferred = $.Deferred();
		const firstLigthboxInfoDeferred = $.Deferred();
		const secondLigthboxInfoDeferred = $.Deferred();
		const firstImage = {
			filePageTitle: new mw.Title( 'File:Foo.jpg' ),
			index: 0
		};
		const secondImage = {
			filePageTitle: new mw.Title( 'File:Bar.jpg' ),
			index: 1
		};
		// custom clock ensures progress handlers execute in correct sequence
		const clock = this.sandbox.useFakeTimers();

		viewer.preloadFullscreenThumbnail = function () {};
		viewer.fetchSizeIndependentLightboxInfo = this.sandbox.stub();
		viewer.ui = {
			setFileReuseData: function () {},
			setupForLoad: function () {},
			canvas: {
				set: function () {},
				getCurrentImageWidths: function () {
					return { real: 0 };
				},
				getDimensions: function () {
					return {};
				}
			},
			panel: {
				setImageInfo: this.sandbox.stub(),
				scroller: {
					animateMetadataOnce: function () {}
				},
				progressBar: {
					hide: this.sandbox.stub(),
					animateTo: this.sandbox.stub(),
					jumpTo: this.sandbox.stub()
				},
				empty: function () {}
			},
			open: function () {},
			empty: function () {} };
		viewer.displayRealThumbnail = this.sandbox.stub();
		viewer.eachPreloadableLightboxIndex = function () {};
		viewer.animateMetadataDivOnce = this.sandbox.stub().returns( $.Deferred().reject() );
		viewer.imageProvider.get = this.sandbox.stub();
		viewer.imageInfoProvider.get = () => $.Deferred().reject( {} );
		viewer.thumbnailInfoProvider.get = () => $.Deferred().resolve( {} );

		viewer.imageProvider.get.returns( firstImageDeferred.promise() );
		viewer.fetchSizeIndependentLightboxInfo.returns( firstLigthboxInfoDeferred.promise() );
		viewer.loadImage( firstImage, new Image() );
		clock.tick( 10 );
		assert.strictEqual( viewer.animateMetadataDivOnce.called, false, 'Metadata of the first image should not be animated' );
		assert.strictEqual( viewer.ui.panel.setImageInfo.called, false, 'Metadata of the first image should not be shown' );

		viewer.imageProvider.get.returns( secondImageDeferred.promise() );
		viewer.fetchSizeIndependentLightboxInfo.returns( secondLigthboxInfoDeferred.promise() );
		viewer.loadImage( secondImage, new Image() );
		clock.tick( 10 );

		viewer.ui.panel.progressBar.animateTo.reset();
		firstImageDeferred.notify( undefined, 45 );
		clock.tick( 10 );
		assert.strictEqual( viewer.ui.panel.progressBar.animateTo.reset.called, undefined, 'Progress of the first image should not be shown' );

		firstImageDeferred.resolve( {}, {} );
		firstLigthboxInfoDeferred.resolve( {} );
		clock.tick( 10 );
		assert.strictEqual( viewer.displayRealThumbnail.called, false, 'The first image being done loading should have no effect' );

		viewer.displayRealThumbnail = this.sandbox.spy( () => viewer.close() );
		secondImageDeferred.resolve( {}, {} );
		secondLigthboxInfoDeferred.resolve( {} );
		clock.tick( 10 );
		assert.strictEqual( viewer.displayRealThumbnail.called, true, 'The second image being done loading should result in the image being shown' );

		clock.restore();
	} );

	QUnit.test( 'Events are not trapped after the viewer is closed', function ( assert ) {
		const viewer = getMultimediaViewer();
		const $document = $( document );
		const $qf = $( '#qunit-fixture' );
		const eventTypes = [ 'keydown', 'keyup', 'keypress', 'click', 'mousedown', 'mouseup' ];
		const modifiers = [ undefined, 'altKey', 'ctrlKey', 'shiftKey', 'metaKey' ];
		// Events are async, we need to wait for the last event to be caught before ending the test
		const done = assert.async();
		const oldScrollTo = $.scrollTo;

		assert.expect( 0 );

		// animation would keep running, conflict with other tests
		this.sandbox.stub( $.fn, 'animate' ).returnsThis();

		$.scrollTo = function () {
			return { scrollTop: () => {}, on: () => {}, off: () => {} };
		};

		viewer.setupEventHandlers();

		viewer.imageProvider.get = () => $.Deferred().reject();
		viewer.imageInfoProvider.get = () => $.Deferred().reject();
		viewer.thumbnailInfoProvider.get = () => $.Deferred().reject();
		viewer.fileRepoInfoProvider.get = () => $.Deferred().reject();

		viewer.preloadFullscreenThumbnail = function () {};
		viewer.initWithThumbs( [] );

		viewer.loadImage(
			{
				filePageTitle: new mw.Title( 'File:Stuff.jpg' ),
				thumbnail: new Thumbnail( 'foo', 10, 10 )
			},
			new Image()
		);

		viewer.ui.$closeButton.trigger( 'click' );

		function eventHandler( e ) {
			if ( e.isDefaultPrevented() ) {
				assert.true( false, 'Event was incorrectly trapped: ' + e.which );
			}

			e.preventDefault();

			// Wait for the last event
			if ( e.which === 32 && e.type === 'mouseup' ) {
				$document.off( '.mmvtest' );
				viewer.cleanupEventHandlers();
				$.scrollTo = oldScrollTo;
				done();
			}
		}

		for ( let j = 0; j < eventTypes.length; j++ ) {
			$document.on( eventTypes[ j ] + '.mmvtest', eventHandler );

			eventloop:
			for ( let i = 0; i < 256; i++ ) {
				// Save some time by not testing unlikely values for mouse events
				if ( i > 32 ) {
					switch ( eventTypes[ j ] ) {
						case 'click':
						case 'mousedown':
						case 'mouseup':
							break eventloop;
					}
				}

				for ( let k = 0; k < modifiers.length; k++ ) {
					const eventParameters = { which: i };
					if ( modifiers[ k ] !== undefined ) {
						eventParameters[ modifiers[ k ] ] = true;
					}
					$qf.trigger( $.Event( eventTypes[ j ], eventParameters ) );
				}
			}
		}
	} );

	QUnit.test( 'Refuse to load too-big thumbnails', function ( assert ) {
		let expectedWidth;
		const reuestedWidth = 1000;
		const originalWidth = 50;
		const viewer = getMultimediaViewer();

		viewer.thumbnailInfoProvider.get = function ( fileTitle, width ) {
			assert.strictEqual( width, expectedWidth );
			return $.Deferred().reject();
		};

		// non-vector should be capped to original size
		let title = mw.Title.newFromText( 'File:Foobar.png' );
		expectedWidth = originalWidth;
		viewer.fetchThumbnail( title, reuestedWidth, null, originalWidth, 60 );

		// vector images can be aritrarily large
		title = mw.Title.newFromText( 'File:Foobar.svg' );
		expectedWidth = reuestedWidth;
		viewer.fetchThumbnail( title, reuestedWidth, null, originalWidth, 60 );
	} );

	QUnit.test( 'fetchThumbnail()', function ( assert ) {
		let guessedThumbnailInfoStub;
		let thumbnailInfoStub;
		let imageStub;
		let promise;
		let useThumbnailGuessing;
		const viewer = new MultimediaViewer( {
			imageQueryParameter: function () {},
			language: function () {},
			recordVirtualViewBeaconURI: function () {},
			extensions: function () {
				return { jpg: 'default' };
			},
			useThumbnailGuessing: () => useThumbnailGuessing
		} );
		const sandbox = this.sandbox;
		const file = new mw.Title( 'File:Copyleft.svg' );
		const sampleURL = 'http://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Copyleft.svg/300px-Copyleft.svg.png';
		const width = 100;
		const originalWidth = 1000;
		const originalHeight = 1000;
		const image = {};
		// custom clock ensures progress handlers execute in correct sequence
		const clock = this.sandbox.useFakeTimers();

		function setupStubs() {
			guessedThumbnailInfoStub = viewer.guessedThumbnailInfoProvider.get = sandbox.stub();
			thumbnailInfoStub = viewer.thumbnailInfoProvider.get = sandbox.stub();
			imageStub = viewer.imageProvider.get = sandbox.stub();
		}

		useThumbnailGuessing = true;

		// When we lack sample URL and original dimensions, the classic provider should be used
		setupStubs();
		guessedThumbnailInfoStub.returns( $.Deferred().resolve( { url: 'guessedURL' } ) );
		thumbnailInfoStub.returns( $.Deferred().resolve( { url: 'apiURL' } ) );
		imageStub.returns( $.Deferred().resolve( image ) );
		promise = viewer.fetchThumbnail( file, width );
		clock.tick( 10 );
		assert.strictEqual( guessedThumbnailInfoStub.called, false, 'When we lack sample URL and original dimensions, GuessedThumbnailInfoProvider is not called' );
		assert.strictEqual( thumbnailInfoStub.calledOnce, true, 'When we lack sample URL and original dimensions, ThumbnailInfoProvider is called once' );
		assert.strictEqual( imageStub.calledOnce, true, 'When we lack sample URL and original dimensions, ImageProvider is called once' );
		assert.strictEqual( imageStub.calledWith( 'apiURL' ), true, 'When we lack sample URL and original dimensions, ImageProvider is called with the API url' );
		assert.strictEqual( promise.state(), 'resolved', 'When we lack sample URL and original dimensions, fetchThumbnail resolves' );

		// When the guesser bails out, the classic provider should be used
		setupStubs();
		guessedThumbnailInfoStub.returns( $.Deferred().reject() );
		thumbnailInfoStub.returns( $.Deferred().resolve( { url: 'apiURL' } ) );
		imageStub.returns( $.Deferred().resolve( image ) );
		promise = viewer.fetchThumbnail( file, width, sampleURL, originalWidth, originalHeight );
		clock.tick( 10 );
		assert.strictEqual( guessedThumbnailInfoStub.calledOnce, true, 'When the guesser bails out, GuessedThumbnailInfoProvider is called once' );
		assert.strictEqual( thumbnailInfoStub.calledOnce, true, 'When the guesser bails out, ThumbnailInfoProvider is called once' );
		assert.strictEqual( imageStub.calledOnce, true, 'When the guesser bails out, ImageProvider is called once' );
		assert.strictEqual( imageStub.calledWith( 'apiURL' ), true, 'When the guesser bails out, ImageProvider is called with the API url' );
		assert.strictEqual( promise.state(), 'resolved', 'When the guesser bails out, fetchThumbnail resolves' );

		// When the guesser returns an URL, that should be used
		setupStubs();
		guessedThumbnailInfoStub.returns( $.Deferred().resolve( { url: 'guessedURL' } ) );
		thumbnailInfoStub.returns( $.Deferred().resolve( { url: 'apiURL' } ) );
		imageStub.returns( $.Deferred().resolve( image ) );
		promise = viewer.fetchThumbnail( file, width, sampleURL, originalWidth, originalHeight );
		clock.tick( 10 );
		assert.strictEqual( guessedThumbnailInfoStub.calledOnce, true, 'When the guesser returns an URL, GuessedThumbnailInfoProvider is called once' );
		assert.strictEqual( thumbnailInfoStub.called, false, 'When the guesser returns an URL, ThumbnailInfoProvider is not called' );
		assert.strictEqual( imageStub.calledOnce, true, 'When the guesser returns an URL, ImageProvider is called once' );
		assert.strictEqual( imageStub.calledWith( 'guessedURL' ), true, 'When the guesser returns an URL, ImageProvider is called with the guessed url' );
		assert.strictEqual( promise.state(), 'resolved', 'When the guesser returns an URL, fetchThumbnail resolves' );

		// When the guesser returns an URL, but that returns 404, image loading should be retried with the classic provider
		setupStubs();
		guessedThumbnailInfoStub.returns( $.Deferred().resolve( { url: 'guessedURL' } ) );
		thumbnailInfoStub.returns( $.Deferred().resolve( { url: 'apiURL' } ) );
		imageStub.withArgs( 'guessedURL' ).returns( $.Deferred().reject() );
		imageStub.withArgs( 'apiURL' ).returns( $.Deferred().resolve( image ) );
		promise = viewer.fetchThumbnail( file, width, sampleURL, originalWidth, originalHeight );
		clock.tick( 10 );
		assert.strictEqual( guessedThumbnailInfoStub.calledOnce, true, 'When the guesser returns an URL, but that returns 404, GuessedThumbnailInfoProvider is called once' );
		assert.strictEqual( thumbnailInfoStub.calledOnce, true, 'When the guesser returns an URL, but that returns 404, ThumbnailInfoProvider is called once' );
		assert.strictEqual( imageStub.calledTwice, true, 'When the guesser returns an URL, but that returns 404, ImageProvider is called twice' );
		assert.strictEqual( imageStub.getCall( 0 ).calledWith( 'guessedURL' ), true, 'When the guesser returns an URL, but that returns 404, ImageProvider is called first with the guessed url' );
		assert.strictEqual( imageStub.getCall( 1 ).calledWith( 'apiURL' ), true, 'When the guesser returns an URL, but that returns 404, ImageProvider is called second with the guessed url' );
		assert.strictEqual( promise.state(), 'resolved', 'When the guesser returns an URL, but that returns 404, fetchThumbnail resolves' );

		// When even the retry fails, fetchThumbnail() should reject
		setupStubs();
		guessedThumbnailInfoStub.returns( $.Deferred().resolve( { url: 'guessedURL' } ) );
		thumbnailInfoStub.returns( $.Deferred().resolve( { url: 'apiURL' } ) );
		imageStub.withArgs( 'guessedURL' ).returns( $.Deferred().reject() );
		imageStub.withArgs( 'apiURL' ).returns( $.Deferred().reject() );
		promise = viewer.fetchThumbnail( file, width, sampleURL, originalWidth, originalHeight );
		clock.tick( 10 );
		assert.strictEqual( guessedThumbnailInfoStub.calledOnce, true, 'When even the retry fails, GuessedThumbnailInfoProvider is called once' );
		assert.strictEqual( thumbnailInfoStub.calledOnce, true, 'When even the retry fails, ThumbnailInfoProvider is called once' );
		assert.strictEqual( imageStub.calledTwice, true, 'When even the retry fails, ImageProvider is called twice' );
		assert.strictEqual( imageStub.getCall( 0 ).calledWith( 'guessedURL' ), true, 'When even the retry fails, ImageProvider is called first with the guessed url' );
		assert.strictEqual( imageStub.getCall( 1 ).calledWith( 'apiURL' ), true, 'When even the retry fails, ImageProvider is called second with the guessed url' );
		assert.strictEqual( promise.state(), 'rejected', 'When even the retry fails, fetchThumbnail rejects' );

		useThumbnailGuessing = false;

		// When guessing is disabled, the classic provider is used
		setupStubs();
		guessedThumbnailInfoStub.returns( $.Deferred().resolve( { url: 'guessedURL' } ) );
		thumbnailInfoStub.returns( $.Deferred().resolve( { url: 'apiURL' } ) );
		imageStub.returns( $.Deferred().resolve( image ) );
		promise = viewer.fetchThumbnail( file, width );
		clock.tick( 10 );
		assert.strictEqual( guessedThumbnailInfoStub.called, false, 'When guessing is disabled, GuessedThumbnailInfoProvider is not called' );
		assert.strictEqual( thumbnailInfoStub.calledOnce, true, 'When guessing is disabled, ThumbnailInfoProvider is called once' );
		assert.strictEqual( imageStub.calledOnce, true, 'When guessing is disabled, ImageProvider is called once' );
		assert.strictEqual( imageStub.calledWith( 'apiURL' ), true, 'When guessing is disabled, ImageProvider is called with the API url' );
		assert.strictEqual( promise.state(), 'resolved', 'When guessing is disabled, fetchThumbnail resolves' );

		clock.restore();
	} );

	QUnit.test( 'document.title', function ( assert ) {
		const viewer = getMultimediaViewer();
		const bootstrap = new MultimediaViewerBootstrap();
		const title = new mw.Title( 'File:This_should_show_up_in_document_title.png' );
		const oldDocumentTitle = document.title;

		this.sandbox.stub( mw.loader, 'using' ).returns( $.Deferred().resolve( viewer ) );
		viewer.currentImageFileTitle = title;
		bootstrap.setupEventHandlers();
		viewer.setTitle();

		assert.notStrictEqual( document.title.match( title.getNameText() ), null, 'File name is visible in title' );

		viewer.close();
		bootstrap.cleanupEventHandlers();

		assert.strictEqual( document.title, oldDocumentTitle, 'Original title restored after viewer is closed' );
	} );
}() );