// Copyright (C) 2010-2015 Yozons, Inc.
   // CKEditor for Vaadin - Widget linkage for using CKEditor within a Vaadin application.
   //
   // This software is released under the Apache License 2.0 <http://www.apache.org/licenses/LICENSE-2.0.html>
   //
   // This software was originally based on the Vaadin incubator component TinyMCEEditor written by Matti Tahvonen.
   //
   package org.vaadin.openesignforms.ckeditor.widgetset.client.ui;
   
  import java.util.ArrayList;
  import java.util.List;
  
  import com.google.gwt.core.client.GWT;
  import com.google.gwt.core.client.JavaScriptObject;
  import com.google.gwt.core.client.Scheduler;
  import com.google.gwt.core.client.Scheduler.RepeatingCommand;
  import com.google.gwt.core.client.Scheduler.ScheduledCommand;
  import com.google.gwt.dom.client.Document;
  import com.google.gwt.dom.client.ScriptElement;
  
  /**
   * GWT wrapper for CKEDITOR for use by our Vaadin-based CKEditorService.
   */
  public class CKEditorService {
  	
  	private static boolean libraryLoadInited = false;
  	private static boolean libraryLoaded = false;
  	private static List<ScheduledCommand> afterLoadedStack = new ArrayList<ScheduledCommand>();
  	
  	public static synchronized void loadLibrary(ScheduledCommand afterLoad) {
  		if (! libraryLoadInited) {
  			libraryLoadInited = true;
  			String url = GWT.getModuleBaseURL() + "ckeditor/ckeditor.js";
  			ScriptElement se = Document.get().createScriptElement();
  			se.setSrc(url);
  			se.setType("text/javascript");
  			Document.get().getElementsByTagName("head").getItem(0).appendChild(se);
  			Scheduler.get().scheduleFixedDelay(new RepeatingCommand() {				
  				@Override
  				public boolean execute() {
  					if (libraryReady()) {
  						reduceBlurDelay();
  						for (ScheduledCommand sc: afterLoadedStack) {
  							sc.execute();
  						}
  						libraryLoaded = true;
  						return false;
  					}
  					return true;
  				}
  			}, 50);
  		}
  		if (libraryLoaded) {
  			afterLoad.execute();
  		} else {
  			afterLoadedStack.add(afterLoad);
  		}
  	}
  	
  	public static native boolean libraryReady()
  	/*-{
  		if($wnd.CKEDITOR) {
  			return true;
  		} 
  		return false;
  	}-*/;
  	
  	/**
  	 * Use this method to load editor to given identifier.
  	 * 
  	 * @param id the string DOM <div> 'id' attribute value for the element you want to replace with CKEditor
  	 * @param listener the CKEditorService.CKEditorListener will get notified when the editor instance is ready, changed, etc.
  	 * @param jsInPageConfig the String possible custom "in page" configuration; note that this must be an expected JSON for the CKEDITOR in page config.
  	 * sent "as is" without any real syntax or security testing, so be sure you know it's valid and not malicious, 
  	 * such as: <code>{toolbar : 'Basic', language : 'en'}</code>
  	 */
  	public static native JavaScriptObject loadEditor(String id, CKEditorService.CKEditorListener listener, String jsInPageConfig, int compWidth, int compHeight)
  	/*-{
  	 	// Build our inPageConfig object based on the JSON jsInPageConfig sent to us.
  	 	var inPageConfig = @org.vaadin.openesignforms.ckeditor.widgetset.client.ui.CKEditorService::convertJavaScriptStringToObject(Ljava/lang/String;)(jsInPageConfig);
  	 	
  	 	var myEditor;
  	 	
  	 	if (inPageConfig == null) {
  	 		inPageConfig = new Object;
  	 		inPageConfig.width = compWidth;
  	 		inPageConfig.height = compHeight;
  	 	} else {
  	 		if (!inPageConfig.width) inPageConfig.width = compWidth;
  	 		if (!inPageConfig.height) inPageConfig.height = compHeight;
  	 	}
  	 	
  	 	myEditor = $wnd.CKEDITOR.appendTo( id, inPageConfig );
  	 		 	
  	 	// The 'listener' passed to us is used as 'listenerData' for the callback.
  		myEditor.on( 'instanceReady', function( ev ) {
      		ev.listenerData.@org.vaadin.openesignforms.ckeditor.widgetset.client.ui.CKEditorService.CKEditorListener::onInstanceReady()();
  		}, null, listener);
  		
 		return myEditor;
 
 	}-*/;
 	
 	public native static String version()
 	/*-{
 		return $wnd.CKEDITOR.version;
 	}-*/;
 	
 	// This is a hack attempt to resolve issues with Vaadin when the CKEditorTextField widget is set with BLUR and FOCUS listeners.
 	// In particular, the Safari browser could not deal well with PASTE, right clicking in a table cell, etc.
 	// because those operations resulted in BLUR then FOCUS events in rapid succession, causing the UI to update.
 	// But the 200 value is too long and we find that often the button acts faster than the BLUR can fire from CKEditor
 	// so Vaadin doesn't get the latest contents.
 	// Even though CKEditor 4.2 introduced a change event, it doesn't appear to fire if you stay in SOURCE mode, which many people do use.
 	public native static void reduceBlurDelay()
 	/*-{
 		$wnd.CKEDITOR.focusManager._.blurDelay = 20; // the default is 200 even if the documentation says it's only 100
 	}-*/;
 	
 	/**
 	 * Returns a javascript CKEDITOR.editor instance for given id.
 	 * 
 	 * @param id the String id of the editor instance
 	 * @return the overlay for CKEDITOR.editor or null if not yet initialized
 	 */
 	public native static CKEditor get(String id)
 	/*-{
 		return $wnd.CKEDITOR.instances[ id ];
 	}-*/;
 	
 	// TODO: Never tested yet
 	public native static void addStylesSet(String name, String jsStyles)
 	/*-{
 	 	var styles = @org.vaadin.openesignforms.ckeditor.widgetset.client.ui.CKEditorService::convertJavaScriptStringToObject(Ljava/lang/String;)(jsStyles);
 		$wnd.CKEDITOR.addStylesSet(name,styles);
 	}-*/;
 	
 	// TODO: Never tested yet
 	public native static void addTemplates(String name, String jsDefinition)
 	/*-{
 	 	var definition = @org.vaadin.openesignforms.ckeditor.widgetset.client.ui.CKEditorService::convertJavaScriptStringToObject(Ljava/lang/String;)(jsDefinition);
 		$wnd.CKEDITOR.addTemplates(name,definition);
 	}-*/;
 
 	public native static JavaScriptObject convertJavaScriptStringToObject(String jsString)
 	/*-{
 	    try {
 	 		return eval('('+jsString+')');
 	 	} catch (e) { 
 	 		alert('convertJavaScriptStringToObject() INVALID JAVASCRIPT: ' + jsString); 
 	 		return {}; 
 	 	}
 	}-*/;
 
 
 	/**
 	 * An interface for the VCKEditorTextField to get events from the CKEditor.
 	 */
 	public interface CKEditorListener {
 		public void onInstanceReady();
 		public void onChange();
 		public void onSelectionChange();
 		public void onModeChange(String mode);
 		public void onDataReady();
 		public void onBlur();
 		public void onFocus();
 		public void onSave();
 	}
 
 }