Copyright (c) 2003, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Sergey Prigogin (Google) - use parameterized types (bug 442021)
/*******************************************************************************
 * Copyright (c) 2003, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Sergey Prigogin (Google) - use parameterized types (bug 442021)
 *******************************************************************************/
package org.eclipse.core.internal.runtime;

import java.net.URL;
import java.net.URLClassLoader;
import java.util.*;
import org.eclipse.osgi.util.ManifestElement;
import org.osgi.framework.*;

This class can only be used if OSGi plugin is available.
/**
 * This class can only be used if OSGi plugin is available.
 */
public class ResourceTranslator {
	private static final String KEY_PREFIX = "%"; //$NON-NLS-1$
	private static final String KEY_DOUBLE_PREFIX = "%%"; //$NON-NLS-1$	

	public static String getResourceString(Bundle bundle, String value) {
		return getResourceString(bundle, value, null);
	}

	public static String getResourceString(Bundle bundle, String value, ResourceBundle resourceBundle) {
		String s = value.trim();
		if (!s.startsWith(KEY_PREFIX, 0))
			return s;
		if (s.startsWith(KEY_DOUBLE_PREFIX, 0))
			return s.substring(1);

		int ix = s.indexOf(' ');
		String key = ix == -1 ? s : s.substring(0, ix);
		String dflt = ix == -1 ? s : s.substring(ix + 1);

		if (resourceBundle == null && bundle != null) {
			try {
				resourceBundle = getResourceBundle(bundle);
			} catch (MissingResourceException e) {
				// just return the default (dflt)
			}
		}

		if (resourceBundle == null)
			return dflt;

		try {
			return resourceBundle.getString(key.substring(1));
		} catch (MissingResourceException e) {
			//this will avoid requiring a bundle access on the next lookup
			return dflt;
		}
	}

	public static ResourceBundle getResourceBundle(Bundle bundle) throws MissingResourceException {
		return getResourceBundle(bundle, null);
	}

	private static ResourceBundle getResourceBundle(Bundle bundle, String language) throws MissingResourceException {
		if (hasRuntime21(bundle)) {
			Locale locale = (language == null) ? Locale.getDefault() : new Locale(language);
			return ResourceBundle.getBundle("plugin", locale, createTempClassloader(bundle)); //$NON-NLS-1$
		}
		return Activator.getDefault().getLocalization(bundle, language);
	}

	public static String[] getResourceString(Bundle bundle, String[] nonTranslated, String locale) {
		if (bundle == null)
			return nonTranslated;

		ResourceBundle resourceBundle = null;
		try {
			resourceBundle = getResourceBundle(bundle, locale);
		} catch (MissingResourceException e) {
			// ignore - bug 371103
		}
		String[] translated = new String[nonTranslated.length];
		for (int i = 0; i < nonTranslated.length; i++) {
			translated[i] = getResourceString(bundle, nonTranslated[i], resourceBundle);
		}
		return translated;
	}

	private static boolean hasRuntime21(Bundle b) {
		try {
			ManifestElement[] prereqs = ManifestElement.parseHeader(Constants.REQUIRE_BUNDLE, b.getHeaders("").get(Constants.REQUIRE_BUNDLE)); //$NON-NLS-1$
			if (prereqs == null)
				return false;
			for (ManifestElement prereq : prereqs) {
				if ("2.1".equals(prereq.getAttribute(Constants.BUNDLE_VERSION_ATTRIBUTE)) && "org.eclipse.core.runtime".equals(prereq.getValue())) {//$NON-NLS-1$//$NON-NLS-2$
					return true;
				}
			}
		} catch (BundleException e) {
			return false;
		}
		return false;
	}

	private static ClassLoader createTempClassloader(Bundle b) {
		ArrayList<URL> classpath = new ArrayList<>();
		addClasspathEntries(b, classpath);
		addBundleRoot(b, classpath);
		addDevEntries(b, classpath);
		addFragments(b, classpath);
		URL[] urls = new URL[classpath.size()];
		return new URLClassLoader(classpath.toArray(urls));
	}

	private static void addFragments(Bundle host, ArrayList<URL> classpath) {
		Activator activator = Activator.getDefault();
		if (activator == null)
			return;
		Bundle[] fragments = activator.getFragments(host);
		if (fragments == null)
			return;

		for (Bundle fragment : fragments) {
			addClasspathEntries(fragment, classpath);
			addDevEntries(fragment, classpath);
		}
	}

	private static void addClasspathEntries(Bundle b, ArrayList<URL> classpath) {
		ManifestElement[] classpathElements;
		try {
			classpathElements = ManifestElement.parseHeader(Constants.BUNDLE_CLASSPATH, b.getHeaders("").get(Constants.BUNDLE_CLASSPATH)); //$NON-NLS-1$
			if (classpathElements == null)
				return;
			for (ManifestElement classpathElement : classpathElements) {
				URL classpathEntry = b.getEntry(classpathElement.getValue());
				if (classpathEntry != null)
					classpath.add(classpathEntry);
			}
		} catch (BundleException e) {
			//ignore
		}
	}

	private static void addBundleRoot(Bundle b, ArrayList<URL> classpath) {
		classpath.add(b.getEntry("/")); //$NON-NLS-1$
	}

	private static void addDevEntries(Bundle b, ArrayList<URL> classpath) {
		if (!DevClassPathHelper.inDevelopmentMode())
			return;

		String[] binaryPaths = DevClassPathHelper.getDevClassPath(b.getSymbolicName());
		for (String binaryPath : binaryPaths) {
			URL classpathEntry = b.getEntry(binaryPath);
			if (classpathEntry != null)
				classpath.add(classpathEntry);
		}
	}
}