/*******************************************************************************
 * Copyright (c) 2007, 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
 *     Code 9 - ongoing development
 *******************************************************************************/
package org.eclipse.equinox.internal.p2.installer;

import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.*;
import org.eclipse.core.runtime.*;
import org.eclipse.equinox.internal.p2.core.helpers.LogHelper;
import org.eclipse.equinox.internal.provisional.p2.installer.InstallDescription;

/**
 * This class is responsible for loading install descriptions from a stream.
 */
public class InstallDescriptionParser {
	private static final String PROP_AGENT_LOCATION = "eclipse.p2.agentLocation"; //$NON-NLS-1$
	private static final String PROP_ARTIFACT_REPOSITORY = "eclipse.p2.artifacts";//$NON-NLS-1$
	private static final String PROP_BUNDLE_LOCATION = "eclipse.p2.bundleLocation";//$NON-NLS-1$
	private static final String PROP_INSTALL_LOCATION = "eclipse.p2.installLocation";//$NON-NLS-1$
	private static final String PROP_IS_AUTO_START = "eclipse.p2.autoStart";//$NON-NLS-1$
	private static final String PROP_LAUNCHER_NAME = "eclipse.p2.launcherName";//$NON-NLS-1$
	private static final String PROP_METADATA_REPOSITORY = "eclipse.p2.metadata";//$NON-NLS-1$
	private static final String PROP_PROFILE_NAME = "eclipse.p2.profileName";//$NON-NLS-1$
	private static final String PROP_ROOT_ID = "eclipse.p2.rootId";//$NON-NLS-1$
	private static final String PROP_ROOT_VERSION = "eclipse.p2.rootVersion";//$NON-NLS-1$
	private static final String PROP_ROOTS = "eclipse.p2.roots";//$NON-NLS-1$

	/**
	 * Loads and returns an install description that is stored in a properties file.
	 * @param site The URL of the install properties file.
	 */
	public static InstallDescription createDescription(String site, SubMonitor monitor) throws IOException {
		// if no description URL was given from the outside, look for an "install.properties" file 
		// in relative to where the installer is running.  This allows the installer to be self-contained
		InputStream in = null;
		if (site == null) {
			File file = new File("installer.properties").getAbsoluteFile(); //$NON-NLS-1$
			if (file.exists())
				in = new FileInputStream(file);
		} else
			in = new URL(site).openStream();

		Properties properties = new Properties();
		try {
			if (in != null)
				properties.load(in);
		} finally {
			safeClose(in);
		}
		InstallDescription result = new InstallDescription();
		result = initiailize(result, properties);
		initializeProfileProperties(result, properties);

		// now override the properties from anything interesting in system properties
		result = initiailize(result, System.getProperties());
		return result;
	}

	private static InstallDescription initiailize(InstallDescription description, Properties properties) {
		String property = properties.getProperty(PROP_ARTIFACT_REPOSITORY);
		if (property != null)
			description.setArtifactRepositories(getURLs(property));

		property = properties.getProperty(PROP_METADATA_REPOSITORY);
		if (property != null)
			description.setMetadataRepositories(getURLs(property));

		property = properties.getProperty(PROP_IS_AUTO_START);
		if (property != null)
			description.setAutoStart(Boolean.TRUE.toString().equalsIgnoreCase(property));

		property = properties.getProperty(PROP_LAUNCHER_NAME);
		if (property != null)
			description.setLauncherName(property);

		property = properties.getProperty(PROP_INSTALL_LOCATION);
		if (property != null)
			description.setInstallLocation(new Path(property));

		property = properties.getProperty(PROP_AGENT_LOCATION);
		if (property != null)
			description.setAgentLocation(new Path(property));

		property = properties.getProperty(PROP_BUNDLE_LOCATION);
		if (property != null)
			description.setBundleLocation(new Path(property));

		property = properties.getProperty(PROP_PROFILE_NAME);
		if (property != null)
			description.setProductName(property);

		// Process the retro root id and rootVersion properties
		String id = properties.getProperty(PROP_ROOT_ID);
		if (id != null) {
			String version = properties.getProperty(PROP_ROOT_VERSION);
			description.setRoots(new VersionedName[] {new VersionedName(id, version)});
		}

		String rootSpec = properties.getProperty(PROP_ROOTS);
		if (rootSpec != null) {
			String[] rootList = getArrayFromString(rootSpec, ",");
			VersionedName[] roots = new VersionedName[rootList.length];
			for (int i = 0; i < rootList.length; i++)
				roots[i] = VersionedName.parse(rootList[i]);
			description.setRoots(roots);
		}
		return description;
	}

	/**
	 * Add all of the given properties to profile properties of the given description 
	 * after removing the keys known to be for the installer.  This allows install descriptions 
	 * to also set random profile properties.
	 * @param description
	 * @param properties
	 */
	private static void initializeProfileProperties(InstallDescription description, Properties properties) {
		//any remaining properties are profile properties
		Map profileProperties = new HashMap(properties);
		profileProperties.remove(PROP_PROFILE_NAME);
		profileProperties.remove(PROP_ARTIFACT_REPOSITORY);
		profileProperties.remove(PROP_METADATA_REPOSITORY);
		profileProperties.remove(PROP_IS_AUTO_START);
		profileProperties.remove(PROP_LAUNCHER_NAME);
		profileProperties.remove(PROP_AGENT_LOCATION);
		profileProperties.remove(PROP_BUNDLE_LOCATION);
		profileProperties.remove(PROP_ROOT_ID);
		profileProperties.remove(PROP_ROOT_VERSION);
		profileProperties.remove(PROP_ROOTS);
		description.setProfileProperties(profileProperties);
	}

	private static URL[] getURLs(String spec) {
		if (spec == null)
			return null;
		String[] urlSpecs = getArrayFromString(spec, ","); //$NON-NLS-1$
		ArrayList result = new ArrayList(urlSpecs.length);
		for (int i = 0; i < urlSpecs.length; i++) {
			try {
				result.add(new URL(urlSpecs[i]));
			} catch (MalformedURLException e) {
				LogHelper.log(new Status(IStatus.ERROR, InstallerActivator.PI_INSTALLER, "Invalid URL in install description: " + urlSpecs[i], e)); //$NON-NLS-1$
			}
		}
		return (URL[]) result.toArray(new URL[result.size()]);
	}

	private static void safeClose(InputStream in) {
		try {
			if (in != null)
				in.close();
		} catch (IOException e) {
			//ignore secondary failure during close
		}
	}

	/**
	 * Convert a list of tokens into an array. The list separator has to be
	 * specified.
	 */
	public static String[] getArrayFromString(String list, String separator) {
		if (list == null || list.trim().equals("")) //$NON-NLS-1$
			return new String[0];
		List result = new ArrayList();
		for (StringTokenizer tokens = new StringTokenizer(list, separator); tokens.hasMoreTokens();) {
			String token = tokens.nextToken().trim();
			if (!token.equals("")) //$NON-NLS-1$
				result.add(token);
		}
		return (String[]) result.toArray(new String[result.size()]);
	}

}