/****************************************************************
 * Copyright (C) 2006 LAMS Foundation (http://lamsfoundation.org)
 * =============================================================
 * License Information: http://lamsfoundation.org/licensing/lams/2.0/
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2.0 
 * as published by the Free Software Foundation.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 * 
 * http://www.gnu.org/licenses/gpl.txt
 * ****************************************************************
 */

package org.lamsfoundation.lams.build;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.util.zip.ZipEntry;

/**
 * <p>
 * <a href="Jar.java.html"><i>View Source</i><a>
 * </p>
 *
 * @author <a href="mailto:fyang@melcoe.mq.edu.au">Fei Yang</a>
 */
public class Jar implements Comparable {
	
	static final String[] VERSION_ATT_NAMES = {"Implementation-Version","HttpUnit-Version","Hibernate-Version"};
	static final String[] VENDOR_ATT_NAMES = {"Implementation-Vendor"};
	static final String[] LICENSE_FILE_NAMES = {"LICENSE","LICENSE.txt"};
	static final String[] DESC_ATT_NAMES = {"Specification-Title"};
	static final String[] LICENSES = {"Apache License","Apache Software License","Joda Software License","GPL","LGPL"};

	String name;
	String version;
	String license;
	String vendor;
	String description;

	public int compareTo(Object o) {
		return name.compareTo(((Jar)o).name);
	}
	
	static Jar buildJar(File file) throws IOException{
		Jar jar = new Jar();
		jar.name = file.getName();
		JarFile jarFile = new JarFile(file);
		Manifest manifest = jarFile.getManifest();
		Attributes mainAttributes = manifest.getMainAttributes();
		for(String versionAtt : VERSION_ATT_NAMES){
			jar.version = mainAttributes.getValue(versionAtt);
			if(jar.version != null){
				int index = jar.version.indexOf(' ');
				if(index!=-1)
					jar.version = jar.version.substring(0, index).trim();
				break;
			}
		}
		if(jar.version == null){//try parsing file name
			int index1 = jar.name.lastIndexOf('-');
			if(index1!=-1){
				int index2 = jar.name.indexOf(".jar");
				jar.version = jar.name.substring(index1+1, index2);
				int index = index1;
				while(jar.version.indexOf('.')==-1){
					String s = jar.name.substring(0, index);
					index = s.lastIndexOf('-');
					if(index==-1)
						break;
					else{
						jar.version = jar.name.substring(index+1,index2);
					}
				}
			}
		}
		for(String vendorAtt:VENDOR_ATT_NAMES){
			jar.vendor = mainAttributes.getValue(vendorAtt);
			if(jar.vendor!=null)
				break;
		}
		for(String descAtt:DESC_ATT_NAMES){
			jar.description = mainAttributes.getValue(descAtt);
			if(jar.description!=null)
				break;
		}
		ZipEntry licenseZipEntry = null;
		for(String licenseFilename:LICENSE_FILE_NAMES){
			licenseZipEntry = jarFile.getEntry("META-INF/"+licenseFilename);
			if(licenseZipEntry!=null)
				break;
		}
		if(licenseZipEntry!=null){
			BufferedInputStream is = new BufferedInputStream(jarFile.getInputStream(licenseZipEntry));
			List<Byte> bytes = new LinkedList<Byte>();
			byte b;
			while((b=(byte)is.read())!=-1){
				bytes.add(b);
			}
			byte[] bs = new byte[bytes.size()];
			int i = 0;
			for(Byte B : bytes){
				bs[i] = B;
				i++;
			}
			String licenseTxt = new String(bs);
			//out.println(licenseTxt);
			//out.println();
			jar.license = parse(licenseTxt);
			//out.println("License:"+jar.license);
			//out.println();
			is.close();
		}
		if(jar.version!=null) jar.version = cleanQuotes(jar.version);
		if(jar.description!=null) jar.description = cleanQuotes(jar.description);
		if(jar.vendor!=null) jar.vendor = cleanQuotes(jar.vendor);
		return jar;
	}
	
	static String parse(String licenseTxt){
		String licenseName = "";
		int licenseIndex = -1;
		for(String license:LICENSES){
			licenseIndex = licenseTxt.indexOf(license);
			if(licenseIndex!=-1){
				licenseName = license;
				break;
			}
		}
		int versionIndex = licenseTxt.indexOf("Version");
		String version = "";
		if(versionIndex!=-1){
			int i = licenseTxt.indexOf(' ', versionIndex);
			int i1 = licenseTxt.indexOf(',', i+1);
			int i2 = licenseTxt.indexOf(' ', i+1);
			version = licenseTxt.substring(i, Math.min(i1, i2)).trim();
		}
		StringBuilder result = new StringBuilder();
		if(licenseName.length()>0){
			result.append(licenseName);
			if(version.length()>0){
				result.append(' ').append(version);
			}
		}
		return result.toString();
	}
	
	static String cleanQuotes(String txt){
		if(txt.indexOf('"')!=-1&&txt.indexOf('"')==0&&txt.lastIndexOf('"')==txt.length()-1){
			txt = txt.substring(1, txt.length()-1);
		}
		return txt;
	}

}