/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.equinox.internal.p2.metadata.generator.features;

import java.io.*;
import java.net.URL;
import java.util.Properties;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import javax.xml.parsers.*;
import org.eclipse.equinox.internal.provisional.p2.metadata.generator.Feature;
import org.eclipse.equinox.internal.provisional.p2.metadata.generator.FeatureEntry;
import org.eclipse.osgi.util.NLS;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Default feature parser.
 * Parses the feature manifest file as defined by the platform.
 * 
 * @since 3.0
 */
public class FeatureParser extends DefaultHandler {

	private final static SAXParserFactory parserFactory = SAXParserFactory.newInstance();
	private SAXParser parser;
	private Feature result;
	private URL url;
	private StringBuffer characters = null;

	private Properties messages = null;

	public FeatureParser() {
		this(true);
	}

	protected FeatureParser(boolean createParser) {
		super();
		if (!createParser)
			return;
		try {
			parserFactory.setNamespaceAware(true);
			this.parser = parserFactory.newSAXParser();
		} catch (ParserConfigurationException e) {
			System.out.println(e);
		} catch (SAXException e) {
			System.out.println(e);
		}
	}

	public void characters(char[] ch, int start, int length) throws SAXException {
		if (characters == null)
			return;
		characters.append(ch, start, length);
	}

	protected Feature createFeature(String id, String version) {
		return new Feature(id, version);
	}

	public void endElement(String uri, String localName, String qName) throws SAXException {
		if (characters == null)
			return;
		if ("description".equals(localName)) { //$NON-NLS-1$
			result.setDescription(localize(characters.toString().trim()));
		} else if ("license".equals(localName)) { //$NON-NLS-1$
			result.setLicense(localize(characters.toString().trim()));
		} else if ("copyright".equals(localName)) { //$NON-NLS-1$
			result.setCopyright(localize(characters.toString().trim()));
		}
		characters = null;
	}

	public Feature getResult() {
		return result;
	}

	private Properties loadProperties(File directory) {
		//skip directories that don't contain a feature.properties file
		File file = new File(directory, "feature.properties"); //$NON-NLS-1$
		if (!file.exists())
			return null;
		try {
			InputStream input = new BufferedInputStream(new FileInputStream(file));
			try {
				Properties result = new Properties();
				result.load(input);
				return result;
			} finally {
				if (input != null)
					input.close();
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

	private Properties loadProperties(JarFile jar) {
		JarEntry entry = jar.getJarEntry("feature.properties"); //$NON-NLS-1$
		if (entry == null)
			return null;
		try {
			InputStream input = new BufferedInputStream(jar.getInputStream(entry));
			try {
				Properties result = new Properties();
				result.load(input);
				return result;
			} finally {
				if (input != null)
					input.close();
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

	private String localize(String value) {
		if (messages == null || value == null)
			return value;
		if (!value.startsWith("%")) //$NON-NLS-1$
			return value;
		return messages.getProperty(value.substring(1), value);
	}

	/**
	 * Parses the specified location and constructs a feature. The given location 
	 * should be either the location of the feature JAR or the directory containing
	 * the feature.
	 * 
	 * @param location the location of the feature to parse.  
	 */
	public Feature parse(File location) {
		if (!location.exists())
			return null;
		if (location.isDirectory()) {
			//skip directories that don't contain a feature.xml file
			File file = new File(location, "feature.xml"); //$NON-NLS-1$
			if (!file.exists())
				return null;
			Properties properties = loadProperties(location);
			try {
				InputStream input = new BufferedInputStream(new FileInputStream(file));
				return parse(input, properties);
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			}
		} else if (location.getName().endsWith(".jar")) { //$NON-NLS-1$
			try {
				JarFile jar = new JarFile(location);
				Properties properties = loadProperties(jar);
				JarEntry entry = jar.getJarEntry("feature.xml"); //$NON-NLS-1$
				if (entry == null)
					return null;
				InputStream input = new BufferedInputStream(jar.getInputStream(entry));
				return parse(input, properties);
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return null;
	}

	/**
	 * Parse the given input stream and return a feature object
	 * or null. This method closes the input stream.
	 */
	public Feature parse(InputStream in, Properties messages) {
		this.messages = messages;
		result = null;
		try {
			parser.parse(new InputSource(in), this);
		} catch (SAXException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				in.close();
			} catch (IOException e1) {
				//					Utils.log(e1.getLocalizedMessage());
			}
		}
		return result;
	}

	private void processCopyright(Attributes attributes) {
		result.setCopyrightURL(attributes.getValue("url")); //$NON-NLS-1$
		characters = new StringBuffer();
	}

	private void processDescription(Attributes attributes) {
		result.setDescriptionURL(attributes.getValue("url")); //$NON-NLS-1$
		characters = new StringBuffer();
	}

	private void processDiscoverySite(Attributes attributes) {
		result.addDiscoverySite(attributes.getValue("url"), attributes.getValue("label")); //$NON-NLS-1$ //$NON-NLS-2$
	}

	protected void processFeature(Attributes attributes) {
		String id = attributes.getValue("id"); //$NON-NLS-1$
		String ver = attributes.getValue("version"); //$NON-NLS-1$

		if (id == null || id.trim().equals("") //$NON-NLS-1$
				|| ver == null || ver.trim().equals("")) { //$NON-NLS-1$
			//			System.out.println(NLS.bind(Messages.FeatureParser_IdOrVersionInvalid, (new String[] { id, ver})));
		} else {
			result = createFeature(id, ver);

			String os = attributes.getValue("os"); //$NON-NLS-1$
			String ws = attributes.getValue("ws"); //$NON-NLS-1$
			String nl = attributes.getValue("nl"); //$NON-NLS-1$
			String arch = attributes.getValue("arch"); //$NON-NLS-1$
			result.setEnvironment(os, ws, arch, nl);

			//TODO rootURLs
			if (url != null && "file".equals(url.getProtocol())) { //$NON-NLS-1$
				File f = new File(url.getFile().replace('/', File.separatorChar));
				result.setURL("features" + "/" + f.getParentFile().getName() + "/");// + f.getName()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
			} else {
				// externalized URLs might be in relative form, ensure they are absolute				
				//				feature.setURL(Utils.makeAbsolute(Utils.getInstallURL(), url).toExternalForm());
			}

			result.setProviderName(localize(attributes.getValue("provider-name"))); //$NON-NLS-1$
			result.setLabel(localize(attributes.getValue("label"))); //$NON-NLS-1$
			result.setImage(attributes.getValue("image")); //$NON-NLS-1$

			//			Utils.debug("End process DefaultFeature tag: id:" +id + " ver:" +ver + " url:" + feature.getURL()); 	 //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		}
	}

	private void processImport(Attributes attributes) {
		String id = attributes.getValue("feature"); //$NON-NLS-1$
		FeatureEntry entry = null;
		if (id != null) {
			entry = FeatureEntry.createRequires(id, attributes.getValue("version"), attributes.getValue("match"), attributes.getValue("filter"), false); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		} else {
			id = attributes.getValue("plugin"); //$NON-NLS-1$
			entry = FeatureEntry.createRequires(id, attributes.getValue("version"), attributes.getValue("match"), attributes.getValue("filter"), true); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		}
		result.addEntry(entry);
	}

	private void processIncludes(Attributes attributes) {
		FeatureEntry entry = new FeatureEntry(attributes.getValue("id"), attributes.getValue("version"), false); //$NON-NLS-1$ //$NON-NLS-2$
		String flag = attributes.getValue("optional"); //$NON-NLS-1$
		if (flag != null)
			entry.setOptional(Boolean.valueOf(flag).booleanValue());
		setEnvironment(attributes, entry);
		result.addEntry(entry);
	}

	private void processInstallHandler(Attributes attributes) {
		result.setInstallHandler(attributes.getValue("handler")); //$NON-NLS-1$
		result.setInstallHandlerLibrary(attributes.getValue("library")); //$NON-NLS-1$
		result.setInstallHandlerURL(attributes.getValue("url")); //$NON-NLS-1$
	}

	private void processLicense(Attributes attributes) {
		result.setLicenseURL(attributes.getValue("url")); //$NON-NLS-1$
		characters = new StringBuffer();
	}

	private void processPlugin(Attributes attributes) {
		String id = attributes.getValue("id"); //$NON-NLS-1$
		String version = attributes.getValue("version"); //$NON-NLS-1$

		if (id == null || id.trim().equals("") || version == null || version.trim().equals("")) { //$NON-NLS-1$ //$NON-NLS-2$
			System.out.println(NLS.bind("FeatureParser#processPlugin, ID {0} or version {1} invalid", (new String[] {id, version}))); //$NON-NLS-1$
		} else {
			FeatureEntry plugin = new FeatureEntry(id, version, true);
			setEnvironment(attributes, plugin);
			String unpack = attributes.getValue("unpack"); //$NON-NLS-1$
			if (unpack != null)
				plugin.setUnpack(Boolean.valueOf(unpack).booleanValue());
			String fragment = attributes.getValue("fragment"); //$NON-NLS-1$
			if (fragment != null)
				plugin.setFragment(Boolean.valueOf(fragment).booleanValue());
			String filter = attributes.getValue("filter"); //$NON-NLS-1$
			if (filter != null)
				plugin.setFilter(filter);
			result.addEntry(plugin);

			//			Utils.debug("End process DefaultFeature tag: id:" + id + " ver:" + ver + " url:" + feature.getURL()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		}
	}

	private void processUpdateSite(Attributes attributes) {
		result.setUpdateSiteLabel(attributes.getValue("label")); //$NON-NLS-1$
		result.setUpdateSiteURL(attributes.getValue("url")); //$NON-NLS-1$
	}

	private void setEnvironment(Attributes attributes, FeatureEntry entry) {
		String os = attributes.getValue("os"); //$NON-NLS-1$
		String ws = attributes.getValue("ws"); //$NON-NLS-1$
		String nl = attributes.getValue("nl"); //$NON-NLS-1$
		String arch = attributes.getValue("arch"); //$NON-NLS-1$
		entry.setEnvironment(os, ws, arch, nl);
	}

	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
		//		Utils.debug("Start Element: uri:" + uri + " local Name:" + localName + " qName:" + qName); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		if ("plugin".equals(localName)) { //$NON-NLS-1$
			processPlugin(attributes);
		} else if ("description".equals(localName)) { //$NON-NLS-1$
			processDescription(attributes);
		} else if ("license".equals(localName)) { //$NON-NLS-1$
			processLicense(attributes);
		} else if ("copyright".equals(localName)) { //$NON-NLS-1$
			processCopyright(attributes);
		} else if ("feature".equals(localName)) { //$NON-NLS-1$
			processFeature(attributes);
		} else if ("import".equals(localName)) { //$NON-NLS-1$
			processImport(attributes);
		} else if ("includes".equals(localName)) { //$NON-NLS-1$
			processIncludes(attributes);
		} else if ("install-handler".equals(localName)) { //$NON-NLS-1$
			processInstallHandler(attributes);
		} else if ("update".equals(localName)) { //$NON-NLS-1$
			processUpdateSite(attributes);
		} else if ("discovery".equals(localName)) { //$NON-NLS-1$
			processDiscoverySite(attributes);
		}
	}

}