Copyright (c) 2003, 2013 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) 2003, 2013 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.loader;

import java.security.AccessController;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.eclipse.osgi.container.ModuleCapability;
import org.eclipse.osgi.framework.util.SecureAction;
import org.eclipse.osgi.internal.loader.sources.FilteredSourcePackage;
import org.eclipse.osgi.internal.loader.sources.PackageSource;
import org.eclipse.osgi.internal.loader.sources.SingleSourcePackage;
import org.osgi.framework.namespace.PackageNamespace;

public class BundleLoaderSources {
	static SecureAction secureAction = AccessController.doPrivileged(SecureAction.createSecureAction());
	private final ConcurrentMap<String, PackageSource> pkgSources;
	private final BundleLoader loader;

	public BundleLoaderSources(BundleLoader loader) {
		this.pkgSources = new ConcurrentHashMap<>();
		this.loader = loader;
	}

	PackageSource getPackageSource(String pkgName) {
		PackageSource pkgSource = pkgSources.get(pkgName);
		if (pkgSource != null) {
			return pkgSource;
		}
		PackageSource newSource = new SingleSourcePackage(pkgName, loader);
		PackageSource existingSource = pkgSources.putIfAbsent(newSource.getId(), newSource);
		return existingSource != null ? existingSource : newSource;
	}

	boolean forceSourceCreation(ModuleCapability packageCapability) {
		Map<String, String> directives = packageCapability.getDirectives();
		return directives.get(PackageNamespace.CAPABILITY_EXCLUDE_DIRECTIVE) != null || directives.get(PackageNamespace.CAPABILITY_EXCLUDE_DIRECTIVE) != null;
	}

	// creates a PackageSource from an ExportPackageDescription.  This is called when initializing
	// a BundleLoader to ensure that the proper PackageSource gets created and used for
	// filtered and reexport packages.  The storeSource flag is used by initialize to indicate
	// that the source for special case package sources (filtered or re-exported should be stored 
	// in the cache.  if this flag is set then a normal SinglePackageSource will not be created
	// (i.e. it will be created lazily)
	public PackageSource createPackageSource(ModuleCapability packageCapability, boolean storeSource) {
		PackageSource pkgSource = null;

		String name = (String) packageCapability.getAttributes().get(PackageNamespace.PACKAGE_NAMESPACE);
		// check to see if it is a filtered export
		String includes = packageCapability.getDirectives().get(PackageNamespace.CAPABILITY_INCLUDE_DIRECTIVE);
		String excludes = packageCapability.getDirectives().get(PackageNamespace.CAPABILITY_EXCLUDE_DIRECTIVE);
		if (includes != null || excludes != null) {
			pkgSource = new FilteredSourcePackage(name, loader, includes, excludes);
		}

		if (storeSource) {
			if (pkgSource != null) {
				PackageSource existingSource = pkgSources.putIfAbsent(pkgSource.getId(), pkgSource);
				if (existingSource != null) {
					pkgSource = existingSource;
				}
			}
		} else {
			// we are not storing the special case sources, but pkgSource == null this means this
			// is a normal package source; get it and return it.
			if (pkgSource == null) {
				pkgSource = getPackageSource(name);
				// the first export cached may not be a simple single source like we need.
				if (pkgSource.getClass() != SingleSourcePackage.class)
					return new SingleSourcePackage(name, loader);
			}
		}

		return pkgSource;
	}
}