/*
    * Copyright (c) 2007, James Leigh All rights reserved.
    * 
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions are met:
    * 
    * - Redistributions of source code must retain the above copyright notice, this
    *   list of conditions and the following disclaimer.
    * - Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution. 
   * - Neither the name of the openrdf.org nor the names of its contributors may
   *   be used to endorse or promote products derived from this software without
   *   specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   * 
   */
  package org.openrdf.elmo.rolemapper;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  
  import org.openrdf.elmo.RdfTypeFactory;
  
  /**
   * Tracks recorded roles and maps them to their subject type.
   * 
   * @author James Leigh
   * 
   */
  public class HierarchicalRoleMapper<URI> {
  
  	private DirectMapper<URI> directMapper;
  
  	private TypeMapper<URI> typeMapper;
  
  	private SimpleRoleMapper<URI> simpleRoleMapper;
  
  	private Map<Class<?>, Set<Class<?>>> subclasses;
  
  	public HierarchicalRoleMapper(DirectMapper<URI> directMapper,
  			TypeMapper<URI> typeMapper, SimpleRoleMapper<URI> simpleRoleMapper) {
  		this.directMapper = directMapper;
  		this.typeMapper = typeMapper;
  		this.simpleRoleMapper = simpleRoleMapper;
  		subclasses = new HashMap<Class<?>, Set<Class<?>>>(256);
  	}
  
  	public void setRdfTypeFactory(RdfTypeFactory<URI> vf) {
  		simpleRoleMapper.setRdfTypeFactory(vf);
  	}
  
  	public Class<?>[] findBaseRoles() {
  		return simpleRoleMapper.findBaseRoles();
  	}
  
  	public Class<?>[] findRoles(URI type) {
  		return simpleRoleMapper.findRoles(type);
  	}
  
  	public Collection<Class<?>> findRoles(Collection<URI> types,
  			Collection<Class<?>> classes) {
  		return simpleRoleMapper.findRoles(types, classes);
  	}
  
  	public boolean isTypeRecorded(URI type) {
  		return simpleRoleMapper.isTypeRecorded(type);
  	}
  
  	public Collection<URI> findTypes(Class<?> javaClass,
  			Collection<URI> rdfTypes) {
  		return typeMapper.findTypes(javaClass, rdfTypes);
  	}
  
  	/**
  	 * Finds the rdf:Class<?> for this Java Class<?>.
  	 * 
  	 * @param javaClass
  	 * @return URI of the rdf:Class<?> for this Java Class<?> or null.
  	 */
  	public URI findType(Class<?> role) {
  		return typeMapper.findType(role);
  	}
  
 	public Collection<URI> findSubTypes(Class<?> role, Collection<URI> rdfTypes) {
 		findTypes(role, rdfTypes);
 		Set<Class<?>> subset = subclasses.get(role);
 		if (subset == null)
 			return rdfTypes;
 		for (Class<?> c : subset) {
 			findSubTypes(c, rdfTypes);
 		}
 		return rdfTypes;
 	}
 
 	public synchronized void recordRole(Class<?> role, URI type) {
 		assert type != null;
 		directMapper.recordRole(role, type);
 		recordClassHierarchy(role);
 		typeMapper.recordRole(role, type);
 
 		Set<Class<?>> superRoles = getSuperRoles(role);
 		Set<Class<?>> newRoles = new HashSet<Class<?>>(superRoles.size() + 1);
 		newRoles.addAll(superRoles);
 		newRoles.add(role);
 		newRoles = simpleRoleMapper.recordRoles(newRoles, type);
 		for (Class<?> r : directMapper.getDirectRoles(type)) {
 			addRolesInSubclasses(r, newRoles);
 		}
 	}
 
 	public void recordBaseRole(Class<?> role) {
 		URI type = simpleRoleMapper.getBaseType();
 		directMapper.recordRole(role, type);
 		recordClassHierarchy(role);
 		typeMapper.recordRole(role, type);
 		simpleRoleMapper.recordBaseRole(role);
 	}
 
 	/**
 	 * Record the class hierarchy of the role to looks subclasses of related
 	 * subject types.
 	 * 
 	 * @param role
 	 */
 	private void recordClassHierarchy(Class<?> role) {
 		for (Class<?> sup : role.getInterfaces()) {
 			Set<Class<?>> set = subclasses.get(sup);
 			if (set == null)
 				subclasses.put(sup, set = new HashSet<Class<?>>());
 			if (!set.contains(role)) {
 				set.add(role);
 				recordClassHierarchy(sup);
 			}
 		}
 	}
 
 	private Set<Class<?>> getSuperRoles(Class<?> role) {
 		Class[] interfaces = role.getInterfaces();
 		if (interfaces.length == 0)
 			return Collections.EMPTY_SET;
 		Set<Class<?>> superRoles = new HashSet<Class<?>>();
 		for (Class<?> sup : interfaces) {
 			Set<Class<?>> sr = getSuperRoles(sup);
 			addRelatedRoles(sr, sup, superRoles);
 		}
 		return superRoles;
 	}
 
 	private void addRolesInSubclasses(Class<?> role, Set<Class<?>> newRoles) {
 		Set<Class<?>> subset = subclasses.get(role);
 		if (subset == null)
 			return; // no subclasses
 		for (Class<?> sub : subset) {
 			Set<Class<?>> subRoles = new HashSet<Class<?>>();
 			subRoles = addRelatedRoles(newRoles, sub, subRoles);
 			addRolesInSubclasses(sub, subRoles);
 		}
 	}
 
 	private Set<Class<?>> addRelatedRoles(Set<Class<?>> existing,
 			Class<?> role, Set<Class<?>> roles) {
 		roles.addAll(existing);
 		Set<URI> set = directMapper.getDirectTypes(role);
 		if (set != null) {
 			for (URI uri : set) {
 				simpleRoleMapper.recordRoles(existing, uri);
 				for (Class<?> c : simpleRoleMapper.findRoles(uri)) {
 					roles.add(c);
 				}
 			}
 		}
 		return roles;
 	}
 }