/*=============================================================================#
 # Copyright (c) 2008, 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ecommons.text.ui;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.eclipse.jface.internal.text.html.BrowserInformationControlInput;
import org.eclipse.jface.internal.text.html.HTMLPrinter;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.graphics.FontData;

import org.eclipse.statet.jcommons.lang.Disposable;

import org.eclipse.statet.internal.ltk.ui.LTKUIPlugin;


/**
 * 
 */
public class DefaultBrowserInformationInput extends BrowserInformationControlInput {
	
	
	private static Formatter FORMATTER;
	
	private static class Formatter implements IPropertyChangeListener, Disposable {
		
		private static final Pattern TAB_PATTERN= Pattern.compile("\\\t"); //$NON-NLS-1$
		
		private String STYLE_SHEET;
		
		public Formatter() {
			JFaceResources.getFontRegistry().addListener(this);
			LTKUIPlugin.getInstance().addStoppingListener(this);
			updateStyleSheet();
		}
		
		@Override
		public void dispose() {
			JFaceResources.getFontRegistry().removeListener(this);
			FORMATTER= null;
		}
		
		@Override
		public void propertyChange(final PropertyChangeEvent event) {
			if (event.getProperty().equals(JFaceResources.DIALOG_FONT)) {
				updateStyleSheet();
			}
		}
		
		private void updateStyleSheet() {
			String style =
				// Font definitions
				"html         { font-family: sans-serif; font-size: 9pt; font-style: normal; font-weight: normal; }\n"+
				"body, h1, h2, h3, h4, h5, h6, p, table, td, caption, th, ul, ol, dl, li, dd, dt { font-size: 1em; }\n"+
				"pre          { font-family: monospace; }\n"+
				// Margins
				"html         { margin: 0px; padding: 0px }"+
				"body         { overflow: auto; margin-top: 0.25em; margin-bottom: 0.5em; margin-left: 0.25em; margin-right: 0.25em; }\n"+
				"h1           { margin-top: 0.3em; margin-bottom: 0.04em; }\n"+
				"h2           { margin-top: 2em; margin-bottom: 0.25em; }\n"+
				"h3           { margin-top: 1.7em; margin-bottom: 0.25em; }\n"+
				"h4           { margin-top: 2em; margin-bottom: 0.3em; }\n"+
				"h5           { margin-top: 0px; margin-bottom: 0px; }\n"+
				"p            { margin-top: 1em; margin-bottom: 1em; }\n"+
//				"pre          { margin-left: 0.6em; }\n"+
				"ul           { margin-top: 0px; margin-bottom: 1em; }\n"+
				"li           { margin-top: 0px; margin-bottom: 0px; }\n"+
				"li p         { margin-top: 0px; margin-bottom: 0px; }\n"+
				"ol           { margin-top: 0px; margin-bottom: 1em; }\n"+
				"dl           { margin-top: 0px; margin-bottom: 1em; }\n"+
				"dt           { margin-top: 0px; margin-bottom: 0px; font-weight: bold; }\n"+
				"dd           { margin-top: 0px; margin-bottom: 0px; }\n"+
				// Styles and colors
				"a:link       { color: #0000FF; }\n"+
				"a:hover      { color: #000080; }\n"+
				"a:visited    { text-decoration: underline; }\n"+
				"h4           { font-style: italic; }\n"+
				"strong       { font-weight: bold; }\n"+
				"em           { font-style: italic; }\n"+
				"var          { font-style: italic; }\n"+
				"th           { font-weight: bold; }\n";
			try {
				final FontData[] fontData= JFaceResources.getFontRegistry().getFontData(JFaceResources.DIALOG_FONT);
				if (fontData != null && fontData.length > 0) {
					style= style.replace("9pt", fontData[0].getHeight()+"pt");
					style= style.replace("sans-serif", "sans-serif, '"+fontData[0].getName()+"'");
				}
			}
			catch (final Throwable e) {
			}
			this.STYLE_SHEET= style;
		}
		
		String format(String content, final int formatting) {
			final StringBuilder s;
			switch (formatting) {
			case FORMAT_NONE:
				return content;
			case FORMAT_TEXT_INPUT:
				content= HTMLPrinter.convertToHTMLContent(content);
				s= new StringBuilder(content.length() + 1000);
				s.append(content);
				break;
			case FORMAT_SOURCE_INPUT:
				content= HTMLPrinter.convertToHTMLContent(content);
				final Matcher matcher= TAB_PATTERN.matcher(content);
				if (matcher.find()) {
					content= matcher.replaceAll("    "); //$NON-NLS-1$
				}
				s= new StringBuilder(content.length() + 1000);
				s.append("<pre>"); //$NON-NLS-1$
				s.append(content);
				s.append("</pre>"); //$NON-NLS-1$
				break;
			case FORMAT_HTMLBODY_INPUT:
				s= new StringBuilder(content.length() + 1000);
				s.append(content);
				break;
			default:
				throw new IllegalArgumentException("Unsupported format"); //$NON-NLS-1$
			}
			
			HTMLPrinter.insertPageProlog(s, 0, this.STYLE_SHEET);
			HTMLPrinter.addPageEpilog(s);
			return s.toString();
		}
		
	}
	
	
	public static final int FORMAT_NONE= 0;
	public static final int FORMAT_HTMLBODY_INPUT= 1;
	public static final int FORMAT_TEXT_INPUT= 2;
	public static final int FORMAT_SOURCE_INPUT= 3;
	
	
	private final String fName;
	private final String fHtml;
	
	
	public DefaultBrowserInformationInput(final BrowserInformationControlInput previous, final String name, final String content, final int formatting) {
		super(previous);
		
		this.fName= name;
		this.fHtml= getFormatter().format(content, formatting);
	}
	
	protected Formatter getFormatter() {
		synchronized (DefaultBrowserInformationInput.class) {
			if (FORMATTER == null) {
				FORMATTER= new Formatter();
			}
			return FORMATTER;
		}
	}
	
	
	@Override
	public String getInputName() {
		return this.fName;
	}
	
	@Override
	public Object getInputElement() {
		return this.fHtml;
	}
	
	@Override
	public String getHtml() {
		return this.fHtml;
	}
	
}