/**
 * License Agreement.
 *
 * Rich Faces - Natural Ajax for Java Server Faces (JSF)
 *
 * Copyright (C) 2007 Exadel, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */
package org.richfaces.cdk.rd.generator;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import org.ajax4jsf.builder.config.ParsingException;
import org.ajax4jsf.builder.xml.XMLBody;
import org.apache.maven.plugin.logging.Log;
import org.apache.maven.plugin.logging.SystemStreamLog;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.codehaus.plexus.util.IOUtil;
import org.codehaus.plexus.velocity.VelocityComponent;


/**
 * @author Anton Belevich
 *
 */

public class StyleAssembler implements ResourceAssembler {
	
	private static final String PLAIN_CSS_BLOCK_START = "<f:verbatim><![CDATA[";

	private static final String PLAIN_CSS_BLOCK_END = "]]></f:verbatim>";
	
	protected Log log = new SystemStreamLog(); 
	
	private VelocityComponent velocityComponent;
	
	private StringBuilder builder = new StringBuilder();
	
	public StyleAssembler(Log log) {
		this.log = log;
	}
	
	public void assembly(URL resource) {
		
		String file = resource.getFile();
		
		if(log.isDebugEnabled()) {
			log.debug("process resource:  "  + file);
		}	
		
		try {
			InputStream resourceInputStream = resource.openStream();
		
			try {
			
				if(file.endsWith(".xcss")) {
					XMLBody xmlBody = new XMLBody();
				
					try {
						xmlBody.loadXML(resourceInputStream,true);
						builder.append(xmlBody.getContent());
					} catch (ParsingException e) {
						log.error("Error process xcss: " + e.getMessage(), e);
					}
					
				} else {
					builder.append(PLAIN_CSS_BLOCK_START);
					builder.append(IOUtil.toString(resourceInputStream));
					builder.append(PLAIN_CSS_BLOCK_END);
				}
				
			} finally {
				resourceInputStream.close();
			}
		
		} catch (IOException e) {
			log.error("Error process css file " + file + " : " + e.getMessage(), e);
		}
	}
	
	public VelocityComponent getVelocityComponent() {
		return velocityComponent;
	}

	public void setVelocityComponent(VelocityComponent velocityComponent) {
		this.velocityComponent = velocityComponent;
	}

	public void writeToFile(File file) {
		try {
		
			if(builder.length() > 0 && velocityComponent != null) {
			
				VelocityContext context = new VelocityContext();
				context.put("content", builder);
				VelocityEngine engine = velocityComponent.getEngine();
				FileWriter fileWriter = new FileWriter(file);
				log.info("write result to the: " + file.getPath());
				try {
					Template velocityTemplate = engine.getTemplate("templates12/xcss.vm");
					velocityTemplate.merge(context, fileWriter);
					fileWriter.flush();
				} finally {
					fileWriter.close();
				}
				
			}
			
		} catch (Exception e) {
			log.error("Error write file: " + file.getAbsolutePath(),e);
		}
	}
	
}
