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

import java.security.AllPermission;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.eclipse.osgi.internal.framework.FilterImpl;
import org.osgi.framework.AdminPermission;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleException;
import org.osgi.framework.Constants;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.Version;
import org.osgi.framework.namespace.HostNamespace;
import org.osgi.framework.wiring.BundleRevision;
import org.osgi.resource.Namespace;

A builder for creating module ModuleRevision objects. A builder can only be used by the module container to build revisions when 
installing or updating a module. 
 The builder provides the instructions to the container for creating a ModuleRevision. They are not thread-safe; in the absence of external synchronization, they do not support concurrent access by multiple threads. 
Since:
3.10/**
 * A builder for creating module {@link ModuleRevision} objects.  A builder can only be used by 
 * the module {@link ModuleContainer container} to build revisions when 
 * {@link ModuleContainer#install(Module, String, ModuleRevisionBuilder, Object) 
 * installing} or {@link ModuleContainer#update(Module, ModuleRevisionBuilder, Object) updating} a module.
 * <p>
 * The builder provides the instructions to the container for creating a {@link ModuleRevision}.
 * They are not thread-safe; in the absence of external synchronization, they do not support concurrent access by multiple threads.
 * @since 3.10
 */
public final class ModuleRevisionBuilder {
	private final static Class<?> SINGLETON_MAP_CLASS = Collections.singletonMap(null, null).getClass();
	private final static Class<?> UNMODIFIABLE_MAP_CLASS = Collections.unmodifiableMap(Collections.emptyMap()).getClass();

	
Provides information about a capability or requirement
/**
	 * Provides information about a capability or requirement
	 */
	public static class GenericInfo {
		final String namespace;
		final Map<String, String> directives;
		final Map<String, Object> attributes;

		GenericInfo(String namespace, Map<String, String> directives, Map<String, Object> attributes) {
			this.namespace = namespace;
			this.directives = directives;
			this.attributes = attributes;
		}

		
Returns the namespace of this generic info
Returns:
the namespace/**
		 * Returns the namespace of this generic info
		 * @return the namespace
		 */
		public String getNamespace() {
			return namespace;
		}

		
Returns the directives of this generic info
Returns:
the directives/**
		 * Returns the directives of this generic info
		 * @return the directives
		 */
		public Map<String, String> getDirectives() {
			return directives;
		}

		
Returns the attributes of this generic info
Returns:
the attributes/**
		 * Returns the attributes of this generic info
		 * @return the attributes
		 */
		public Map<String, Object> getAttributes() {
			return attributes;
		}
	}

	private String symbolicName = null;
	private Version version = Version.emptyVersion;
	private int types = 0;
	private final List<GenericInfo> capabilityInfos = new ArrayList<>();
	private final List<GenericInfo> requirementInfos = new ArrayList<>();
	private long id = -1;

	
Constructs a new module builder
/**
	 * Constructs a new module builder
	 */
	public ModuleRevisionBuilder() {
		// nothing
	}

	
Sets the symbolic name for the builder
Params:
symbolicName – the symbolic name/**
	 * Sets the symbolic name for the builder
	 * @param symbolicName the symbolic name
	 */
	public void setSymbolicName(String symbolicName) {
		this.symbolicName = symbolicName;
	}

	
Sets the module version for the builder.
Params:
version – the version/**
	 * Sets the module version for the builder.
	 * @param version the version
	 */
	public void setVersion(Version version) {
		this.version = version;
	}

	
Sets the module types for the builder.
Params:
types – the module types/**
	 * Sets the module types for the builder.
	 * @param types the module types
	 */
	public void setTypes(int types) {
		this.types = types;
	}

	
Sets the module ID for the builder.
 This module ID will be used if this builder is used to install a module. If the ID is not set then a module ID will be generated by the module container at install time. If a module already exists with the specified ID then an error will occur when attempting to install a new module with this builder. 
 Note that the system module with location Constants.SYSTEM_BUNDLE_LOCATION always gets module ID of zero. The builder for the system module is not asked to provide the module ID for the system module at install time. 
Params:
id – the module ID to use.  Must be >= 1.
Since:
3.13/**
	 * Sets the module ID for the builder.
	 * <p>
	 * This module ID will be used if this builder is used to
	 * {@link ModuleContainer#install(Module, String, ModuleRevisionBuilder, Object) install}
	 * a module.  If the ID is not set then a module ID will be generated by the module
	 * container at install time. If a module already exists with the specified ID
	 * then an error will occur when attempting to install a new module with this
	 * builder.
	 * <p>
	 * Note that the system module with location {@link Constants#SYSTEM_BUNDLE_LOCATION}
	 * always gets module ID of zero.  The builder for the system module is not
	 * asked to provide the module ID for the system module at install time.
	 * @param id the module ID to use.  Must be >= 1.
	 * @since 3.13
	 */
	public void setId(long id) {
		if (id < 1) {
			throw new IllegalArgumentException("ID must be >=1."); //$NON-NLS-1$
		}
		this.id = id;
	}

	void setInternalId(long id) {
		this.id = id;
	}

	
Adds a capability to this builder using the specified namespace, directives and attributes
Params:
namespace – the namespace of the capability
directives – the directives of the capability
attributes – the attributes of the capability/**
	 * Adds a capability to this builder using the specified namespace, directives and attributes
	 * @param namespace the namespace of the capability
	 * @param directives the directives of the capability
	 * @param attributes the attributes of the capability
	 */
	public void addCapability(String namespace, Map<String, String> directives, Map<String, Object> attributes) {
		addGenericInfo(capabilityInfos, namespace, directives, attributes);
	}

	
Returns a snapshot of the capabilities for this builder
Returns:
the capabilities/**
	 * Returns a snapshot of the capabilities for this builder
	 * @return the capabilities
	 */
	public List<GenericInfo> getCapabilities() {
		return new ArrayList<>(capabilityInfos);
	}

	
Adds a requirement to this builder using the specified namespace, directives and attributes
Params:
namespace – the namespace of the requirement
directives – the directives of the requirement
attributes – the attributes of the requirement/**
	 * Adds a requirement to this builder using the specified namespace, directives and attributes
	 * @param namespace the namespace of the requirement
	 * @param directives the directives of the requirement
	 * @param attributes the attributes of the requirement
	 */
	public void addRequirement(String namespace, Map<String, String> directives, Map<String, Object> attributes) {
		addGenericInfo(requirementInfos, namespace, directives, attributes);
	}

	
Returns a snapshot of the requirements for this builder
Returns:
the requirements/**
	 * Returns a snapshot of the requirements for this builder
	 * @return the requirements
	 */
	public List<GenericInfo> getRequirements() {
		return new ArrayList<>(requirementInfos);
	}

	
Returns the symbolic name for this builder.
Returns:
the symbolic name for this builder./**
	 * Returns the symbolic name for this builder.
	 * @return the symbolic name for this builder.
	 */
	public String getSymbolicName() {
		return symbolicName;
	}

	
Returns the module version for this builder.
Returns:
the module version for this builder./**
	 * Returns the module version for this builder.
	 * @return the module version for this builder.
	 */
	public Version getVersion() {
		return version;
	}

	
Returns the module type for this builder.
Returns:
the module type for this builder./**
	 * Returns the module type for this builder.
	 * @return the module type for this builder.
	 */
	public int getTypes() {
		return types;
	}

	
Returns the module id for this builder. A value of -1 indicates that the module ID will be generated by the module container at install time. 
Returns:
the module id for this builder.
Since:
3.13/**
	 * Returns the module id for this builder. A value of -1
	 * indicates that the module ID will be generated by the
	 * module container at {@link ModuleContainer#install(Module, String, ModuleRevisionBuilder, Object) install}
	 * time.
	 * @return the module id for this builder.
	 * @since 3.13
	 */
	public long getId() {
		return id;
	}

	
Used by the container to build a new revision for a module. This builder is used to build a new current revision for the specified module. 
Params:
module – the module to build a new revision for
revisionInfo – the revision info for the new revision, may be null
Returns:
the new new current revision./**
	 * Used by the container to build a new revision for a module.
	 * This builder is used to build a new {@link Module#getCurrentRevision() current}
	 * revision for the specified module.
	 * @param module the module to build a new revision for
	 * @param revisionInfo the revision info for the new revision, may be {@code null}
	 * @return the new new {@link Module#getCurrentRevision() current} revision.
	 */
	ModuleRevision addRevision(Module module, Object revisionInfo) {
		ModuleRevisions revisions = module.getRevisions();
		ModuleRevision revision = new ModuleRevision(symbolicName, version, types, capabilityInfos, requirementInfos, revisions, revisionInfo);

		revisions.addRevision(revision);
		module.getContainer().getAdaptor().associateRevision(revision, revisionInfo);

		try {
			checkFrameworkExtensionPermission(module, revision);
			module.getContainer().checkAdminPermission(module.getBundle(), AdminPermission.LIFECYCLE);
		} catch (SecurityException e) {
			revisions.removeRevision(revision);
			throw e;
		}
		return revision;
	}

	private void checkFrameworkExtensionPermission(Module module, ModuleRevision revision) {
		if (System.getSecurityManager() == null) {
			return;
		}
		if ((revision.getTypes() & BundleRevision.TYPE_FRAGMENT) != 0) {
			Collection<?> systemNames = Collections.emptyList();
			Module systemModule = module.getContainer().getModule(0);
			if (systemModule != null) {
				ModuleRevision systemRevision = systemModule.getCurrentRevision();
				List<ModuleCapability> hostCapabilities = systemRevision.getModuleCapabilities(HostNamespace.HOST_NAMESPACE);
				for (ModuleCapability hostCapability : hostCapabilities) {
					Object hostNames = hostCapability.getAttributes().get(HostNamespace.HOST_NAMESPACE);
					if (hostNames instanceof Collection) {
						systemNames = (Collection<?>) hostNames;
					} else if (hostNames instanceof String) {
						systemNames = Arrays.asList(hostNames);
					}
				}
			}
			List<ModuleRequirement> hostRequirements = revision.getModuleRequirements(HostNamespace.HOST_NAMESPACE);
			for (ModuleRequirement hostRequirement : hostRequirements) {
				FilterImpl f = null;
				String filterSpec = hostRequirement.getDirectives().get(Namespace.REQUIREMENT_FILTER_DIRECTIVE);
				if (filterSpec != null) {
					try {
						f = FilterImpl.newInstance(filterSpec);
						String hostName = f.getPrimaryKeyValue(HostNamespace.HOST_NAMESPACE);
						if (hostName != null) {
							if (systemNames.contains(hostName)) {
								Bundle b = module.getBundle();
								if (b != null && !b.hasPermission(new AllPermission())) {
									SecurityException se = new SecurityException("Must have AllPermission granted to install an extension bundle"); //$NON-NLS-1$
									// TODO this is such a hack: making the cause a bundle exception so we can throw the right one later
									BundleException be = new BundleException(se.getMessage(), BundleException.SECURITY_ERROR, se);
									se.initCause(be);
									throw se;
								}
								module.getContainer().checkAdminPermission(module.getBundle(), AdminPermission.EXTENSIONLIFECYCLE);
							}
						}
					} catch (InvalidSyntaxException e) {
						continue;
					}
				}
			}
		}
	}

	private static void addGenericInfo(List<GenericInfo> infos, String namespace, Map<String, String> directives, Map<String, Object> attributes) {
		if (infos == null) {
			infos = new ArrayList<>();
		}
		infos.add(new GenericInfo(namespace, copyUnmodifiableMap(directives), copyUnmodifiableMap(attributes)));
	}

	private static <K, V> Map<K, V> copyUnmodifiableMap(Map<K, V> map) {
		int size = map.size();
		if (size == 0) {
			return Collections.emptyMap();
		}
		if (size == 1) {
			Map.Entry<K, V> entry = map.entrySet().iterator().next();
			return Collections.singletonMap(entry.getKey(), entry.getValue());
		}
		return Collections.unmodifiableMap(new HashMap<>(map));
	}

	void basicAddCapability(String namespace, Map<String, String> directives, Map<String, Object> attributes) {
		basicAddGenericInfo(capabilityInfos, namespace, directives, attributes);
	}

	void basicAddRequirement(String namespace, Map<String, String> directives, Map<String, Object> attributes) {
		basicAddGenericInfo(requirementInfos, namespace, directives, attributes);
	}

	private static void basicAddGenericInfo(List<GenericInfo> infos, String namespace, Map<String, String> directives, Map<String, Object> attributes) {
		infos.add(new GenericInfo(namespace, unmodifiableMap(directives), unmodifiableMap(attributes)));
	}

	@SuppressWarnings("unchecked")
	static <K, V> Map<K, V> unmodifiableMap(Map<? extends K, ? extends V> map) {
		int size = map.size();
		if (size == 0) {
			return Collections.emptyMap();
		}
		if (size == 1) {
			if (map.getClass() != SINGLETON_MAP_CLASS) {
				Map.Entry<? extends K, ? extends V> entry = map.entrySet().iterator().next();
				map = Collections.<K, V> singletonMap(entry.getKey(), entry.getValue());
			}
		} else {
			if (map.getClass() != UNMODIFIABLE_MAP_CLASS) {
				map = Collections.unmodifiableMap(map);
			}
		}
		return (Map<K, V>) map;
	}

	void clear() {
		capabilityInfos.clear();
		requirementInfos.clear();
		id = -1;
		symbolicName = null;
		version = Version.emptyVersion;
		types = 0;
	}
}