Copyright (c) 2006, 2017 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
/*******************************************************************************
 * Copyright (c) 2006, 2017 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
 *******************************************************************************/

package org.eclipse.osgi.internal.hooks;

import java.io.File;
import java.util.ArrayList;
import org.eclipse.osgi.framework.util.KeyedElement;
import org.eclipse.osgi.internal.framework.EquinoxConfiguration;
import org.eclipse.osgi.internal.hookregistry.ClassLoaderHook;
import org.eclipse.osgi.internal.loader.classpath.*;
import org.eclipse.osgi.storage.BundleInfo.Generation;
import org.eclipse.osgi.storage.bundlefile.BundleFile;

public class DevClassLoadingHook extends ClassLoaderHook implements KeyedElement {
	public static final String KEY = DevClassLoadingHook.class.getName();
	public static final int HASHCODE = KEY.hashCode();
	private static final String FRAGMENT = "@fragment@"; //$NON-NLS-1$

	private final EquinoxConfiguration configuration;

	public DevClassLoadingHook(EquinoxConfiguration configuration) {
		this.configuration = configuration;
	}

	@Override
	public boolean addClassPathEntry(ArrayList<ClasspathEntry> cpEntries, String cp, ClasspathManager hostmanager, Generation sourceGeneration) {
		// first check that we are in devmode for this sourcedata
		String[] devClassPaths = !configuration.inDevelopmentMode() ? null : configuration.getDevClassPath(sourceGeneration.getRevision().getSymbolicName());
		if (devClassPaths == null || devClassPaths.length == 0)
			return false; // not in dev mode return
		// check that dev classpath entries have not already been added; we mark this in the first entry below
		if (cpEntries.size() > 0 && cpEntries.get(0).getUserObject(KEY) != null)
			return false; // this source has already had its dev classpath entries added.
		boolean result = false;
		for (String devClassPath : devClassPaths) {
			if (hostmanager.addClassPathEntry(cpEntries, devClassPath, hostmanager, sourceGeneration)) {
				result = true;
			} else {
				String devCP = devClassPath;
				boolean fromFragment = devCP.endsWith(FRAGMENT);
				if (!fromFragment && devCP.indexOf("..") >= 0) { //$NON-NLS-1$
					// if in dev mode, try using cp as a relative path from the base bundle file
					File base = sourceGeneration.getBundleFile().getBaseFile();
					if (base.isDirectory()) {
						// this is only supported for directory bundles
						ClasspathEntry entry = hostmanager.getExternalClassPath(new File(base, devCP).getAbsolutePath(), sourceGeneration);
						if (entry != null) {
							cpEntries.add(entry);
							result = true;
						}
					}
				} else {
					// if in dev mode, try using the cp as an absolute path
					// we assume absolute entries come from fragments.  Find the source
					if (fromFragment)
						devCP = devCP.substring(0, devCP.length() - FRAGMENT.length());
					Generation fragSource = findFragmentSource(sourceGeneration, devCP, hostmanager, fromFragment);
					if (fragSource != null) {
						ClasspathEntry entry = hostmanager.getExternalClassPath(devCP, fragSource);
						if (entry != null) {
							cpEntries.add(entry);
							result = true;
						}
					}
				}
			}
		}
		// mark the first entry of the list.  
		// This way we can quickly tell that dev classpath entries have been added to the list
		if (result && cpEntries.size() > 0)
			cpEntries.get(0).addUserObject(this);
		return result;
	}

	private Generation findFragmentSource(Generation hostGeneration, String cp, ClasspathManager manager, boolean fromFragment) {
		if (hostGeneration != manager.getGeneration())
			return hostGeneration;

		File file = new File(cp);
		if (!file.isAbsolute())
			return hostGeneration;
		FragmentClasspath[] fragCPs = manager.getFragmentClasspaths();
		for (FragmentClasspath fragCP : fragCPs) {
			BundleFile fragBase = fragCP.getGeneration().getBundleFile();
			File fragFile = fragBase.getBaseFile();
			if (fragFile != null && file.getPath().startsWith(fragFile.getPath())) {
				return fragCP.getGeneration();
			}
		}
		return fromFragment ? null : hostGeneration;
	}

	@Override
	public boolean compare(KeyedElement other) {
		return other.getKey() == KEY;
	}

	@Override
	public Object getKey() {
		return KEY;
	}

	@Override
	public int getKeyHashCode() {
		return HASHCODE;
	}

	@Override
	public boolean isProcessClassRecursionSupported() {
		return true;
	}

}