/**
 * $Id: MemoryDictionary.java,v 1.2 2006/09/24 10:06:38 wuttke Exp $
 * Created on 28.08.2005
 * @author mw
 * @version $Revision: 1.2 $
 */
package org.tinyradius.dictionary;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * A dictionary that keeps the values and names in hash maps
 * in the memory. The dictionary has to be filled using the
 * methods <code>addAttributeType</code> and
 * <code>addVendor</code>.
 * @see #addAttributeType(AttributeType)
 * @see #addVendor(int, String)
 * @see org.tinyradius.dictionary.Dictionary
 * @see org.tinyradius.dictionary.WritableDictionary
 */
public class MemoryDictionary 
implements WritableDictionary {

	/**
	 * Returns the AttributeType for the vendor -1 from the
	 * cache.
	 * @param typeCode attribute type code
	 * @return AttributeType or null
	 * @see org.tinyradius.dictionary.Dictionary#getAttributeTypeByCode(int)
	 */
	public AttributeType getAttributeTypeByCode(int typeCode) {
		return getAttributeTypeByCode(-1, typeCode);
	}
	
	/**
	 * Returns the specified AttributeType object.
	 * @param vendorCode vendor ID or -1 for "no vendor"
	 * @param typeCode attribute type code
	 * @return AttributeType or null
	 * @see org.tinyradius.dictionary.Dictionary#getAttributeTypeByCode(int, int)
	 */
	public AttributeType getAttributeTypeByCode(int vendorCode, int typeCode) {
		Map vendorAttributes = (Map)attributesByCode.get(new Integer(vendorCode));
		if (vendorAttributes == null)
			return null;
		else
			return (AttributeType)vendorAttributes.get(new Integer(typeCode));
	}
	
	/**
	 * Retrieves the attribute type with the given name.
	 * @param typeName name of the attribute type 
	 * @return AttributeType or null
	 * @see org.tinyradius.dictionary.Dictionary#getAttributeTypeByName(java.lang.String)
	 */
	public AttributeType getAttributeTypeByName(String typeName) {
		return (AttributeType)attributesByName.get(typeName);
	}
	
	/**
	 * Searches the vendor with the given name and returns its
	 * code. This method is seldomly used.
	 * @param vendorName vendor name
	 * @return vendor code or -1
	 * @see org.tinyradius.dictionary.Dictionary#getVendorId(java.lang.String)
	 */
	public int getVendorId(String vendorName) {
		for (Iterator i = vendorsByCode.entrySet().iterator(); i.hasNext();) {
			Map.Entry e = (Map.Entry)i.next();
			if (e.getValue().equals(vendorName))
				return ((Integer)e.getKey()).intValue();
		}
		return -1;
	}
	
	/**
	 * Retrieves the name of the vendor with the given code from
	 * the cache.
	 * @param vendorId vendor number
	 * @return vendor name or null
	 * @see org.tinyradius.dictionary.Dictionary#getVendorName(int)
	 */
	public String getVendorName(int vendorId) {
		return (String)vendorsByCode.get(new Integer(vendorId));
	}
	
	/**
	 * Adds the given vendor to the cache.
	 * @param vendorId vendor ID
	 * @param vendorName name of the vendor
	 * @exception IllegalArgumentException empty vendor name, invalid vendor ID
	 */
	public void addVendor(int vendorId, String vendorName) {
		if (vendorId < 0)
			throw new IllegalArgumentException("vendor ID must be positive");
		if (getVendorName(vendorId) != null)
			throw new IllegalArgumentException("duplicate vendor code");
		if (vendorName == null || vendorName.length() == 0)
			throw new IllegalArgumentException("vendor name empty");
		vendorsByCode.put(new Integer(vendorId), vendorName);
	}
	
	/**
	 * Adds an AttributeType object to the cache.
	 * @param attributeType AttributeType object
	 * @exception IllegalArgumentException duplicate attribute name/type code
	 */
	public void addAttributeType(AttributeType attributeType) {
		if (attributeType == null)
			throw new IllegalArgumentException("attribute type must not be null");
		
		Integer vendorId = new Integer(attributeType.getVendorId());
		Integer typeCode = new Integer(attributeType.getTypeCode());
		String attributeName = attributeType.getName();
		
		if (attributesByName.containsKey(attributeName))
			throw new IllegalArgumentException("duplicate attribute name: " + attributeName);
		
		Map vendorAttributes = (Map)attributesByCode.get(vendorId);
		if (vendorAttributes == null) {
			vendorAttributes = new HashMap();
			attributesByCode.put(vendorId, vendorAttributes);
		}
		if (vendorAttributes.containsKey(typeCode))
			throw new IllegalArgumentException("duplicate type code: " + typeCode);
		
		attributesByName.put(attributeName, attributeType);
		vendorAttributes.put(typeCode, attributeType);
	}
	
	private Map vendorsByCode = new HashMap();		// <Integer, String>
	private Map attributesByCode = new HashMap();	// <Integer, <Integer, AttributeType>>
	private Map attributesByName = new HashMap();	// <String, AttributeType>
	
}