/**
 * @license Copyright (c) 2003-2018, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */

( function() {
	'use strict';

	var stylesLoaded = false,
		WIDGET_NAME = 'easyimage',
		BUTTON_PREFIX = 'EasyImage';

	function capitalize( str ) {
		return CKEDITOR.tools.capitalize( str, true );
	}

	function getStylesForEditor( editor ) {
		var defaultStyles = {
			full: {
				attributes: {
					'class': 'easyimage-full'
				},
				label: editor.lang.easyimage.commands.fullImage
			},

			side: {
				attributes: {
					'class': 'easyimage-side'
				},
				label: editor.lang.easyimage.commands.sideImage
			},

			alignLeft: {
				attributes: {
					'class': 'easyimage-align-left'
				},
				label: editor.lang.common.alignLeft
			},

			alignCenter: {
				attributes: {
					'class': 'easyimage-align-center'
				},
				label: editor.lang.common.alignCenter
			},

			alignRight: {
				attributes: {
					'class': 'easyimage-align-right'
				},
				label: editor.lang.common.alignRight
			}
		};

		return CKEDITOR.tools.object.merge( defaultStyles, editor.config.easyimage_styles );
	}

	function addCommands( editor, styles ) {
		function createCommandRefresh( enableCheck ) {
			return function( editor, path ) {
				var widget = editor.widgets.focused,
					newState = CKEDITOR.TRISTATE_DISABLED;

				if ( widget && widget.name === WIDGET_NAME ) {
					var callbackResolution = enableCheck && enableCheck.call( this, widget, editor, path );

					newState = callbackResolution ? CKEDITOR.TRISTATE_ON : CKEDITOR.TRISTATE_OFF;
				}

				this.setState( newState );
			};
		}

		function createStyleCommand( editor, name, styleDefinition, commandName ) {
			styleDefinition.type = 'widget';
			styleDefinition.widget = 'easyimage';
			styleDefinition.group = styleDefinition.group || 'easyimage';
			styleDefinition.element = 'figure';
			var style = new CKEDITOR.style( styleDefinition );

			editor.filter.allow( style );

			// At this point cmd should be treated more as a definition due to #1582.
			var cmd = new CKEDITOR.styleCommand( style );
			cmd.contextSensitive = true;
			cmd.refresh = createCommandRefresh( function( widget, editor, path ) {
				return this.style.checkActive( path, editor );
			} );

			editor.addCommand( commandName, cmd );

			// Command needs to be refetched. Calling addCommand will… create a new command.
			cmd = editor.getCommand( commandName );

			// Enable is called at multiple occasions, especially in editor#mode event listeners.
			// Unfortunately it's even called with a timeout there.
			cmd.enable = function() {};

			// Without this the command is inited with a wrong state.
			cmd.refresh( editor, editor.elementPath() );

			return cmd;
		}

		function addDefaultCommands() {
			editor.addCommand( 'easyimageAlt', new CKEDITOR.dialogCommand( 'easyimageAlt', {
				startDisabled: true,
				contextSensitive: true,
				refresh: createCommandRefresh()
			} ) );
		}

		function addStylesCommands( styles ) {
			// Returns key of style associated with a given command or null if none.
			function getStyleNameFromCommand( commandName, styles ) {
				var match = commandName.match( /^easyimage(.+)$/ );

				if ( match ) {
					var lowered = ( match[ 1 ][ 0 ] || '' ).toLowerCase() + match[ 1 ].substr( 1 );
					if ( match[ 1 ] in styles ) {
						return match[ 1 ];
					} else if ( lowered in styles ) {
						return lowered;
					}
				}

				return null;
			}

			// These commands must trigger refresh.
			editor.on( 'afterCommandExec', function( evt ) {
				if ( getStyleNameFromCommand( evt.data.name, styles ) ) {
					editor.forceNextSelectionCheck();
					editor.selectionChange( true );
				}
			} );

			editor.on( 'beforeCommandExec', function( evt ) {
				// Style commands should not be toggled.
				if ( getStyleNameFromCommand( evt.data.name, styles ) && evt.data.command.style.checkActive( evt.editor.elementPath(), editor ) ) {
					evt.cancel();
					// Editor needs to be focused, otherwise balloon toolbar will hide.
					editor.focus();
				}
			} );

			for ( var style in styles ) {
				createStyleCommand( editor, style, styles[ style ], 'easyimage' + capitalize( style ) );
			}
		}

		addDefaultCommands();
		addStylesCommands( styles );
	}

	function addButtons( editor, styles ) {
		function addDefaultButtons() {
			editor.ui.addButton( BUTTON_PREFIX + 'Alt', {
				label: editor.lang.easyimage.commands.altText,
				command: 'easyimageAlt',
				toolbar: 'easyimage,3'
			} );
		}

		function addStylesButtons( styles ) {
			var style;

			for ( style in styles ) {
				editor.ui.addButton( BUTTON_PREFIX + capitalize( style ), {
					label: styles[ style ].label,
					command: 'easyimage' + capitalize( style ),
					toolbar: 'easyimage,99',
					icon: styles[ style ].icon,
					iconHiDpi: styles[ style ].iconHiDpi
				} );
			}
		}

		addDefaultButtons();
		addStylesButtons( styles );
	}

	function addToolbar( editor ) {
		var buttons = editor.config.easyimage_toolbar;

		editor._.easyImageToolbarContext = editor.balloonToolbars.create( {
			buttons: buttons.join ? buttons.join( ',' ) : buttons,
			widgets: [ WIDGET_NAME ]
		} );
	}

	function addContextMenuItems( editor ) {
		var buttons = editor.config.easyimage_toolbar;

		if ( !editor.plugins.contextmenu ) {
			return;
		}

		if ( buttons.split ) {
			buttons = buttons.split( ',' );
		}

		editor.addMenuGroup( 'easyimage' );
		CKEDITOR.tools.array.forEach( buttons, function( button ) {
			button = editor.ui.items[ button ];

			editor.addMenuItem( button.name, {
				label: button.label,
				command: button.command,
				group: 'easyimage'
			} );
		} );
	}

	function updateMenuItemsStates( evt ) {
		var editor = evt.sender.editor,
			buttons = editor.config.easyimage_toolbar;

		if ( buttons.split ) {
			buttons = buttons.split( ',' );
		}

		CKEDITOR.tools.array.forEach( buttons, function( button ) {
			button = editor.ui.items[ button ];

			evt.data[ button.name ] = editor.getCommand( button.command ).state;
		} );
	}

	function registerWidget( editor, styles ) {
		var config = editor.config,
			figureClass = config.easyimage_class,
			widgetDefinition = {
				name: WIDGET_NAME,

				allowedContent: {
					figure: {
						classes: config.easyimage_sideClass
					},

					img: {
						attributes: '!src,srcset,alt,width,sizes'
					}
				},

				requiredContent: 'figure; img[!src]',

				styleableElements: 'figure',

				supportedTypes: /image\/(jpeg|png|gif|bmp)/,

				loaderType: CKEDITOR.plugins.cloudservices.cloudServicesLoader,

				progressReporterType: CKEDITOR.plugins.imagebase.progressBar,

				upcasts: {
					figure: function( element ) {
						if ( ( !figureClass || element.hasClass( figureClass ) ) &&
							element.find( 'img', true ).length === 1 ) {
							return element;
						}
					}
				},

				init: function() {
					// Natural width of the image can be fetched only after image is loaded.
					// However cached images won't fire `load` event, but just mark themselves
					// as complete.
					function getNaturalWidth( image, callback ) {
						var $image = image.$;

						if ( $image.complete && $image.naturalWidth ) {
							return callback( $image.naturalWidth );
						}

						image.once( 'load', function() {
							callback( $image.naturalWidth );
						} );
					}

					function setImageWidth( widget, height ) {
						if ( !widget.parts.image.hasAttribute( 'width' ) ) {
							widget.editor.fire( 'lockSnapshot' );

							widget.parts.image.setAttribute( 'width', height );

							widget.editor.fire( 'unlockSnapshot' );
						}
					}

					var imagePart = this.parts.image;

					if ( imagePart && !imagePart.$.complete ) {
						// If widget begins with incomplete image, make sure to refresh balloon toolbar (if present)
						// once the image size is available.
						getNaturalWidth( imagePart, function() {
							// Currently we're breaking encapsulation, once #1496 is fixed, we could use a proper method to
							// update the position.
							var contextView = editor._.easyImageToolbarContext.toolbar._view;

							if ( contextView.rect.visible ) {
								// We have to disable focusing balloon toolbar to prevent loosing focus by an image (#1529).
								contextView.attach( contextView._pointedElement, { focusElement: false } );
							}
						} );
					}

					// There is a special handling in paste listener, where the element (figure) would gain upload id temporarily.
					// This value should be removed afterwards.
					var loaderId = this.element.data( 'cke-upload-id' );

					if ( typeof loaderId !== 'undefined' ) {
						this.setData( 'uploadId', loaderId );
						this.element.data( 'cke-upload-id', false );
					}

					this.on( 'contextMenu', updateMenuItemsStates );

					if ( editor.config.easyimage_class ) {
						this.addClass( editor.config.easyimage_class );
					}

					this.on( 'uploadStarted', function() {
						var widget = this;

						getNaturalWidth( widget.parts.image, function( width ) {
							setImageWidth( widget, width );
						} );
					} );

					this.on( 'uploadDone', function( evt ) {
						var loader = evt.data.loader,
							resp = loader.responseData.response,
							srcset = CKEDITOR.plugins.easyimage._parseSrcSet( resp );

						this.parts.image.setAttributes( {
							'data-cke-saved-src': resp[ 'default' ],
							src: resp[ 'default' ],
							srcset: srcset,
							sizes: '100vw'
						} );
					} );

					this.on( 'uploadFailed', function() {
						alert( this.editor.lang.easyimage.uploadFailed ); // jshint ignore:line
					} );

					this._loadDefaultStyle();
				},

				_loadDefaultStyle: function() {
					// Ensures that Easy Image widget uses a default Easy Image style if none other is applied.
					var styleMatched = false,
						defaultStyleName = editor.config.easyimage_defaultStyle;

					for ( var styleName in styles ) {
						var cmd = editor.getCommand( 'easyimage' + capitalize( styleName ) );

						if ( !styleMatched && cmd && cmd.style && CKEDITOR.tools.array.indexOf( cmd.style.group, 'easyimage' ) !== -1 && this.checkStyleActive( cmd.style ) ) {
							styleMatched = true;
						}
					}

					if ( !styleMatched && defaultStyleName && editor.getCommand( 'easyimage' + capitalize( defaultStyleName ) ) ) {
						this.applyStyle( editor.getCommand( 'easyimage' + capitalize( defaultStyleName ) ).style );
					}
				}
			};

		if ( figureClass ) {
			widgetDefinition.requiredContent += '(!' + figureClass + ')';
			widgetDefinition.allowedContent.figure.classes = '!' + figureClass + ',' + widgetDefinition.allowedContent.figure.classes;
		}

		if ( editor.plugins.link ) {
			widgetDefinition = CKEDITOR.plugins.imagebase.addFeature( editor, 'link', widgetDefinition );
		}

		widgetDefinition = CKEDITOR.plugins.imagebase.addFeature( editor, 'upload', widgetDefinition );
		widgetDefinition = CKEDITOR.plugins.imagebase.addFeature( editor, 'caption', widgetDefinition );

		CKEDITOR.plugins.imagebase.addImageWidget( editor, WIDGET_NAME, widgetDefinition );
	}

	function addPasteListener( editor ) {
		// Easy Image requires an img-specific paste listener for inlined images. This case happens in:
		// * IE11 when pasting images from the clipboard.
		// * FF when pasting a single image **file** from the clipboard.
		// In both cases image gets inlined as img[src="data:"] element.
		editor.on( 'paste', function( evt ) {
			if ( editor.isReadOnly ) {
				return;
			}

			// For performance reason do not parse data if it does not contain img tag and data attribute.
			if ( !evt.data.dataValue.match( /<img[\s\S]+data:/i ) ) {
				return;
			}

			var data = evt.data,
				// Prevent XSS attacks.
				tempDoc = document.implementation.createHTMLDocument( '' ),
				temp = new CKEDITOR.dom.element( tempDoc.body ),
				easyImageDef = editor.widgets.registered.easyimage,
				widgetsFound = 0,
				widgetElement,
				imgFormat,
				imgs,
				img,
				i;

			// Without this isReadOnly will not works properly.
			temp.data( 'cke-editable', 1 );

			temp.appendHtml( data.dataValue );

			imgs = temp.find( 'img' );

			for ( i = 0; i < imgs.count(); i++ ) {
				img = imgs.getItem( i );

				// Assign src once, as it might be a big string, so there's no point in duplicating it all over the place.
				var imgSrc = img.getAttribute( 'src' ),
					// Image have to contain src=data:...
					isDataInSrc = imgSrc && imgSrc.substring( 0, 5 ) == 'data:',
					isRealObject = img.data( 'cke-realelement' ) === null;

				// We are not uploading images in non-editable blocks and fake objects (https://dev.ckeditor.com/ticket/13003).
				if ( isDataInSrc && isRealObject && !img.isReadOnly( 1 ) ) {
					widgetsFound++;

					if ( widgetsFound > 1 ) {
						// Change the selection to avoid overwriting last widget (as it will be focused).
						var sel = editor.getSelection(),
							ranges = sel.getRanges();

						ranges[ 0 ].enlarge( CKEDITOR.ENLARGE_ELEMENT );
						ranges[ 0 ].collapse( false );
					}

					imgFormat = imgSrc.match( /image\/([a-z]+?);/i );
					imgFormat = ( imgFormat && imgFormat[ 1 ] ) || 'jpg';

					var loader = easyImageDef._spawnLoader( editor, imgSrc, easyImageDef );

					widgetElement = easyImageDef._insertWidget( editor, easyImageDef, imgSrc, false, {
						uploadId: loader.id
					} );

					// This id will be converted into widget data by widget#init method. Once that's done the core widget
					// upload feature will take care of keeping track of the loader.
					widgetElement.data( 'cke-upload-id', loader.id );
					widgetElement.replace( img );
				}
			}

			data.dataValue = temp.getHtml();
		} );
	}

	function loadStyles( editor, plugin ) {
		if ( !stylesLoaded ) {
			CKEDITOR.document.appendStyleSheet( plugin.path + 'styles/easyimage.css' );
			stylesLoaded = true;
		}

		if ( editor.addContentsCss ) {
			editor.addContentsCss( plugin.path + 'styles/easyimage.css' );
		}
	}

	/**
	 * Namespace providing a set of helper functions for the Easy Image plugin.
	 *
	 * @since 4.9.0
	 * @singleton
	 * @class CKEDITOR.plugins.easyimage
	 */
	CKEDITOR.plugins.easyimage = {
		/**
		 * Converts the response from the server into a proper `[srcset]` attribute.
		 *
		 * @since 4.9.0
		 * @private
		 * @param {Object} srcs Sources list to be parsed.
		 * @returns {String} The `img[srcset]` attribute.
		 */
		_parseSrcSet: function( srcs ) {
			var srcset = [],
				src;

			for ( src in srcs ) {
				if ( src === 'default' ) {
					continue;
				}

				srcset.push( srcs[ src ] + ' ' + src + 'w' );
			}

			return srcset.join( ', ' );
		}
	};

	function isSupportedBrowser() {
		return !CKEDITOR.env.ie || CKEDITOR.env.version >= 11;
	}

	function addUploadButtonToToolbar( editor ) {
		editor.ui.addButton( BUTTON_PREFIX + 'Upload', {
			label: editor.lang.easyimage.commands.upload,
			command: 'easyimageUpload',
			toolbar: 'insert,1'
		} );

		editor.addCommand( 'easyimageUpload', {
			exec: function() {
				// hiddenUploadElement is not attached to DOM, but it is still possible to `virtually` click into it.
				var hiddenUploadElement = CKEDITOR.dom.element.createFromHtml( '<input type="file" accept="image/*" multiple="multiple">' );
				hiddenUploadElement.once( 'change', function( evt ) {
					var targetElement = evt.data.getTarget();
					if ( targetElement.$.files.length ) {
						// Simulate paste event, to support all nice stuff from imagebase (e.g. loaders) (#1730).
						editor.fire( 'paste', {
							method: 'paste',
							dataValue: '',
							dataTransfer: new CKEDITOR.plugins.clipboard.dataTransfer( { files: targetElement.$.files } )
						} );
					}
				} );
				hiddenUploadElement.$.click();
			}
		} );
	}

	CKEDITOR.plugins.add( 'easyimage', {
		requires: 'imagebase,balloontoolbar,button,dialog,cloudservices',
		lang: 'en',
		icons: 'easyimagefull,easyimageside,easyimagealt,easyimagealignleft,easyimagealigncenter,easyimagealignright,easyimageupload', // %REMOVE_LINE_CORE%
		hidpi: true, // %REMOVE_LINE_CORE%

		onLoad: function() {
			CKEDITOR.dialog.add( 'easyimageAlt', this.path + 'dialogs/easyimagealt.js' );
		},

		init: function( editor ) {
			if ( !isSupportedBrowser() ) {
				return;
			}
			loadStyles( editor, this );
		},

		// Widget must be registered after init in case that link plugin is dynamically loaded e.g. via
		// `config.extraPlugins`.
		afterInit: function( editor ) {
			if ( !isSupportedBrowser() ) {
				return;
			}
			var styles = getStylesForEditor( editor );

			registerWidget( editor, styles );
			addPasteListener( editor );
			addCommands( editor, styles );
			addButtons( editor, styles );
			addContextMenuItems( editor );
			addToolbar( editor );
			addUploadButtonToToolbar( editor );
		}
	} );

	/**
	 * A CSS class applied to all Easy Image widgets. If set to `null`, all `<figure>` elements are converted into widgets.
	 *
	 * ```js
	 * // Changes the class to "my-image".
	 * config.easyimage_class = 'my-image';
	 *
	 * // This will cause the plugin to convert any figure into a widget.
	 * config.easyimage_class = null;
	 * ```
	 *
	 * @since 4.9.0
	 * @cfg {String/null} [easyimage_class='easyimage']
	 * @member CKEDITOR.config
	 */
	CKEDITOR.config.easyimage_class = 'easyimage';

	/**
	 * Custom styles that could be applied to the Easy Image widget.
	 * All styles must be [valid style definitions](#!/guide/dev_howtos_styles-section-how-do-i-customize-the-styles-drop-down-list%3F).
	 * There are three additional properties for each style definition:
	 *
	 * * `label` &ndash; A string used as a button label in the balloon toolbar for the widget.
	 * * `icon` &ndash; The path to the icon used in the balloon toolbar.
	 * * `iconHiDpi` &ndash; The path to the high DPI version of the icon.
	 *
	 * A few styles are available by default:
	 *
	 * * `full` &ndash; Adding an `easyimage-full` class to the `figure` element.
	 * * `side` &ndash; Adding an `easyimage-side` class to the `figure` element.
	 * * `alignLeft` &ndash; Adding an `easyimage-align-left` class to the `figure` element.
	 * * `alignCenter` &ndash; Adding an `easyimage-align-center` class to the `figure` element.
	 * * `alignRight` &ndash; Adding an `easyimage-align-right` class to the `figure` element.
	 *
	 * Every style added by this configuration variable will result in adding the `EasyImage<name>` button
	 * and the `easyimage<name>` command, where `<name>` is the name of the style in Pascal case. For example, the
	 * `left` style would produce an `EasyImageLeft` button and an `easyimageLeft` command.
	 *
	 *		// Adds a custom alignment style.
	 *		config.easyimage_styles = {
	 *			left: {
	 *				attributes: {
	 *					'class': 'left'
	 *				},
	 *				label: 'Align left',
	 *				icon: '/my/example/icons/left.png',
	 *				iconHiDpi: '/my/example/icons/hidpi/left.png'
	 *			}
	 *		};
	 *
	 * The following example changes the class added by the `full` style and adds more border styles:
	 *
	 *		config.easyimage_styles = {
	 *			full: {
	 *				// Changes just the class name, icon label remains unchanged.
	 *				attributes: {
	 *					'class': 'my-custom-full-class'
	 *				}
	 *			},
	 *			skipBorder: {
	 *				attributes: {
	 *					'class': 'skip-border'
	 *				},
	 *				group: 'borders',
	 *				label: 'Skip border'
	 *			},
	 *			thickBorder: {
	 *				attributes: {
	 *					'class': 'thick-border'
	 *				},
	 *				group: 'borders',
	 *				label: 'Thick border'
	 *			}
	 *		};
	 *
	 * @since 4.9.0
	 * @cfg {Object.<String, Object>} easyimage_styles
	 * @member CKEDITOR.config
	 */
	CKEDITOR.config.easyimage_styles = {};


	/**
	 * The default style to be applied to Easy Image widgets, based on keys in {@link #easyimage_styles}.
	 *
	 * If set to `null`, no default style is applied.
	 *
	 * ```js
	 * // Make side image a default style.
	 * config.easyimage_defaultStyle = 'side';
	 * ```
	 *
	 * @since 4.9.0
	 * @cfg {String/null} easyimage_defaultStyle
	 * @member CKEDITOR.config
	 */
	CKEDITOR.config.easyimage_defaultStyle = 'full';

	/**
	 * A list of buttons to be displayed in the balloon toolbar for the Easy Image widget.
	 *
	 * If the [Context Menu](https://ckeditor.com/cke4/addon/contextmenu) plugin is enabled, this
	 * configuration option will also be used to add items to the context menu for the Easy Image widget.
	 *
	 * You can find the list of available styles in {@link #easyimage_styles}.
	 *
	 * ```js
	 * // Change toolbar to alignment commands.
	 * config.easyimage_toolbar = [ 'EasyImageAlignLeft', 'EasyImageAlignCenter', 'EasyImageAlignRight' ];
	 * ```
	 *
	 * @since 4.9.0
	 * @cfg {String[]/String} [easyimage_toolbar=[ 'EasyImageFull', 'EasyImageSide', 'EasyImageAlt' ]]
	 * @member CKEDITOR.config
	 */
	CKEDITOR.config.easyimage_toolbar = [ BUTTON_PREFIX + 'Full', BUTTON_PREFIX + 'Side', BUTTON_PREFIX + 'Alt' ];
}() );
