/*******************************************************************************
 * 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 java.util.Collections;
import java.util.List;
import java.util.Optional;
import org.eclipse.osgi.container.ModuleCapability;
import org.eclipse.osgi.container.namespaces.EquinoxModuleDataNamespace;
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.ClasspathEntry;
import org.eclipse.osgi.internal.loader.classpath.ClasspathManager;
import org.eclipse.osgi.internal.loader.classpath.FragmentClasspath;
import org.eclipse.osgi.storage.BundleInfo.Generation;
import org.eclipse.osgi.storage.ContentProvider.Type;
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) {
		// if this is a connect bundle just ignore
		if (sourceGeneration.getContentType() == Type.CONNECT) {
			return false;
		}
		// 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.

		// get the specified classpath from the Bundle-ClassPath header to check for dups
		List<ModuleCapability> moduleDatas = sourceGeneration.getRevision().getModuleCapabilities(EquinoxModuleDataNamespace.MODULE_DATA_NAMESPACE);
		@SuppressWarnings("unchecked")
		List<String> specifiedCP = Optional.ofNullable(moduleDatas.isEmpty()
				?
				null
				: (List<String>) moduleDatas.get(0).getAttributes().get(EquinoxModuleDataNamespace.CAPABILITY_CLASSPATH))
				.orElse(Collections.singletonList(".")); //$NON-NLS-1$
		boolean result = false;
		for (String devClassPath : devClassPaths) {
			if (specifiedCP.contains(devClassPath)) {
				// dev properties contained a duplicate of an entry on the Bundle-ClassPath header
				// don't add anything, the framework will do it for us
				continue;
			}
			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 != null && 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;
	}

}