package org.javaldap.server.schema;

/*
The JavaLDAP Server
Copyright (C) 2000  Clayton Donley (donley@linc-dev.com) - All Rights Reserved

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

/**
 * Class for Checking Schema
 * @author: Clayton Donley
 */

import java.util.Hashtable;
import java.util.Vector;
import java.util.Enumeration;
import org.javaldap.server.Entry;
import org.javaldap.server.syntax.DirectoryString;
import org.javaldap.server.util.ServerConfig;

public class SchemaChecker {
	private static Hashtable attributeTypes = null;
	private static Hashtable objectClasses = null;
	private static Hashtable fullOCTable = null;
	private static SchemaChecker instance;
	private static boolean schemaCheckOn = true;
	private static DirectoryString objClassAttr = new DirectoryString("objectclass");

	/**
	 * SchemaChecker constructor comment.
	 */
	private SchemaChecker() {
		super();
		objectClasses = new Hashtable();
		attributeTypes = new Hashtable();
		fullOCTable = new Hashtable();

		if (ServerConfig.getInstance().get(ServerConfig.JAVALDAP_SCHEMACHECK).equals("0")) {
			this.schemaCheckOn = false;
		}
	}
	public void addAttributeType(AttributeType attributeType) {
		attributeTypes.put(attributeType.getName(),attributeType);
	}
	public void addObjectClass(ObjectClass objectClass) {
		objectClasses.put(objectClass.getName(),objectClass);
	}
	public void checkEntry(Entry entry) throws org.javaldap.server.util.DirectorySchemaViolation {
		if (isSchemaCheckOn() == false) {
			return;
		}
		Vector objectClass = (Vector)entry.get(objClassAttr);
		if (objectClass == null) {
			throw new org.javaldap.server.util.DirectorySchemaViolation("Missing Object Class");
		}
		Vector missingAttr = new Vector();
		Vector invalidAttr = new Vector();
		Enumeration ocEnum = objectClass.elements();
		while (ocEnum.hasMoreElements()) {
			ObjectClass oc = getObjectClass((DirectoryString)ocEnum.nextElement());
			Vector must = null;
			if (oc != null) {
				must = oc.getMust();
			}
			if (must != null) {
				Enumeration mustEnum = must.elements();
				while (mustEnum.hasMoreElements()) {
					DirectoryString aMust = (DirectoryString)mustEnum.nextElement();
					if (!entry.containsKey(aMust) || ((Vector)entry.get(aMust)).isEmpty()) {
						missingAttr.addElement(aMust);
					}
				}
			}
			while (oc != null && oc.getSuperior() != null && !objectClass.contains(oc.getSuperior())) {
				DirectoryString aSup = oc.getSuperior();
				objectClass.addElement(aSup);
				oc = getObjectClass(aSup);
			}
		}

		ocEnum = objectClass.elements();
		boolean firstOC = true;

		while (ocEnum.hasMoreElements()) {
			ObjectClass oc = getObjectClass((DirectoryString)ocEnum.nextElement());
			Vector tmpInvalidAttr = null;
			Enumeration attrEnum = null;
			if (firstOC) {
				attrEnum = entry.keys();
				firstOC = false;
			} else {
				tmpInvalidAttr = (Vector)invalidAttr.clone();
				attrEnum = tmpInvalidAttr.elements();
			}
			while (attrEnum.hasMoreElements()) {
				DirectoryString attr = (DirectoryString)attrEnum.nextElement();
				if (oc != null && (oc.getMust().contains(attr) || oc.getMay().contains(attr))) {
					if (invalidAttr.contains(attr)) {
						invalidAttr.removeElement(attr);
					}
				} else {
					if (!invalidAttr.contains(attr)) {
						invalidAttr.addElement(attr);
					}
				}
			}
		}
		if (!invalidAttr.isEmpty() || !missingAttr.isEmpty()) {
			throw new org.javaldap.server.util.DirectorySchemaViolation("Missing Attributes: " + missingAttr.toString() + ", Not Allowed Attributes: " + invalidAttr.toString());
		}
	}
	private AttributeType getAttributeType(DirectoryString attributeType) {
		return (AttributeType)this.attributeTypes.get(attributeType);
	}
	public static SchemaChecker getInstance() {
		if (instance == null) {
			instance = new SchemaChecker();
		}
		return instance;
	}
	private ObjectClass getObjectClass(DirectoryString objectClass) {
		return (ObjectClass)this.objectClasses.get(objectClass);
	}
	public Hashtable getObjectClasses() {
		return this.objectClasses;
	}
	public boolean isSchemaCheckOn() {
		return this.schemaCheckOn;
	}
	public void removeAttributeType(DirectoryString name) {
		attributeTypes.remove(name);
	}
	public void removeObjectClass(DirectoryString name) {
		objectClasses.remove(name);
	}
	public void setSchemaCheckOn(boolean schemaCheckOn) {
		this.schemaCheckOn = schemaCheckOn;
	}
}