Copyright (c) 2012, 2016 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) 2012, 2016 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.container;

import java.util.HashMap;
import java.util.Map;
import org.eclipse.osgi.internal.container.Capabilities;
import org.eclipse.osgi.internal.framework.FilterImpl;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.namespace.*;
import org.osgi.framework.wiring.BundleCapability;
import org.osgi.framework.wiring.BundleRequirement;
import org.osgi.resource.Namespace;

An implementation of BundleRequirement. This requirement implements the matches method according to the OSGi specification which includes implementing the mandatory directive for the osgi.wiring.* namespaces. 
Since:
3.10
@noextend
This class is not intended to be subclassed by clients./**
 * An implementation of {@link BundleRequirement}.  This requirement implements 
 * the matches method according to the OSGi specification which includes
 * implementing the mandatory directive for the osgi.wiring.* namespaces.
 * @since 3.10
 * @noextend This class is not intended to be subclassed by clients.
 */
public class ModuleRequirement implements BundleRequirement {
	private final String namespace;
	private final Map<String, String> directives;
	private final Map<String, Object> attributes;
	private final ModuleRevision revision;

	ModuleRequirement(String namespace, Map<String, String> directives, Map<String, ?> attributes, ModuleRevision revision) {
		this.namespace = namespace;
		this.directives = ModuleRevisionBuilder.unmodifiableMap(directives);
		this.attributes = ModuleRevisionBuilder.unmodifiableMap(attributes);
		this.revision = revision;
	}

	@Override
	public ModuleRevision getRevision() {
		return revision;
	}

	@Override
	public boolean matches(BundleCapability capability) {
		if (!namespace.equals(capability.getNamespace()))
			return false;
		String filterSpec = directives.get(Namespace.REQUIREMENT_FILTER_DIRECTIVE);
		FilterImpl f = null;
		if (filterSpec != null) {
			try {
				f = FilterImpl.newInstance(filterSpec);
			} catch (InvalidSyntaxException e) {
				return false;
			}
		}
		boolean matchMandatory = PackageNamespace.PACKAGE_NAMESPACE.equals(namespace) || BundleNamespace.BUNDLE_NAMESPACE.equals(namespace) || HostNamespace.HOST_NAMESPACE.equals(namespace);
		return Capabilities.matches(f, capability, matchMandatory);
	}

	@Override
	public String getNamespace() {
		return namespace;
	}

	@Override
	public Map<String, String> getDirectives() {
		return directives;
	}

	@Override
	public Map<String, Object> getAttributes() {
		return attributes;
	}

	@Override
	public ModuleRevision getResource() {
		return revision;
	}

	@Override
	public String toString() {
		return namespace + ModuleRevision.toString(attributes, false) + ModuleRevision.toString(directives, true);
	}

	private static final String PACKAGENAME_FILTER_COMPONENT = PackageNamespace.PACKAGE_NAMESPACE + "="; //$NON-NLS-1$

	DynamicModuleRequirement getDynamicPackageRequirement(ModuleRevision host, String dynamicPkgName) {
		if (!PackageNamespace.PACKAGE_NAMESPACE.equals(namespace)) {
			return null;
		}
		if (!PackageNamespace.RESOLUTION_DYNAMIC.equals(directives.get(PackageNamespace.REQUIREMENT_RESOLUTION_DIRECTIVE))) {
			// not dynamic
			return null;
		}
		String dynamicFilter = directives.get(PackageNamespace.REQUIREMENT_FILTER_DIRECTIVE);
		// TODO we make some assumptions here on the format of the filter string
		int packageNameBegin = dynamicFilter.indexOf(PACKAGENAME_FILTER_COMPONENT);
		if (packageNameBegin == -1) {
			// not much we can do
			return null;
		}
		packageNameBegin += PACKAGENAME_FILTER_COMPONENT.length();
		int packageNameEnd = dynamicFilter.indexOf(')', packageNameBegin);
		if (packageNameEnd == -1) {
			// not much we can do
			return null;
		}
		String filterPackageName = dynamicFilter.substring(packageNameBegin, packageNameEnd);
		String specificPackageFilter = null;
		if ("*".equals(filterPackageName)) { //$NON-NLS-1$
			// matches all
			specificPackageFilter = dynamicFilter.replace(PACKAGENAME_FILTER_COMPONENT + filterPackageName, PACKAGENAME_FILTER_COMPONENT + dynamicPkgName);
		} else if (filterPackageName.endsWith(".*")) { //$NON-NLS-1$
			if (dynamicPkgName.startsWith(filterPackageName.substring(0, filterPackageName.length() - 1))) {
				specificPackageFilter = dynamicFilter.replace(PACKAGENAME_FILTER_COMPONENT + filterPackageName, PACKAGENAME_FILTER_COMPONENT + dynamicPkgName);
			}
		} else if (dynamicPkgName.equals(filterPackageName)) {
			specificPackageFilter = dynamicFilter;
		}

		if (specificPackageFilter != null) {
			Map<String, String> dynamicDirectives = new HashMap<>(directives);
			dynamicDirectives.put(PackageNamespace.REQUIREMENT_FILTER_DIRECTIVE, specificPackageFilter);
			return new DynamicModuleRequirement(host, dynamicDirectives);
		}
		return null;
	}

	class DynamicModuleRequirement extends ModuleRequirement {

		DynamicModuleRequirement(ModuleRevision host, Map<String, String> directives) {
			super(ModuleRequirement.this.getNamespace(), directives, ModuleRequirement.this.getAttributes(), host);
		}

		ModuleRequirement getOriginal() {
			return ModuleRequirement.this;
		}
	}

}