/*
    * Copyright 2005-2008 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.springframework.ldap.core;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  
  import org.apache.commons.lang.StringUtils;
  import org.springframework.ldap.BadLdapGrammarException;
  import org.springframework.ldap.support.ListComparator;
  
  /**
   * Datatype for a LDAP name, a part of a path.
   * 
   * The name: uid=adam.skogman Key: uid Value: adam.skogman
   * 
   * @author Adam Skogman
   * @author Mattias Hellborg Arthursson
   */
  public class LdapRdn implements Serializable, Comparable {
  	private static final long serialVersionUID = 5681397547245228750L;
  
  	private List components = new LinkedList();
  
  	/**
  	 * Default constructor. Create an empty, uninitialized LdapRdn.
  	 */
  	public LdapRdn() {
  	}
  
  	/**
  	 * Parse the supplied string and construct this instance accordingly.
  	 * 
  	 * @param string the string to parse.
  	 */
  	public LdapRdn(String string) {
  		DnParser parser = DefaultDnParserFactory.createDnParser(string);
  		LdapRdn rdn;
  		try {
  			rdn = parser.rdn();
  		}
  		catch (ParseException e) {
  			throw new BadLdapGrammarException("Failed to parse Rdn", e);
  		}
  		catch (TokenMgrError e) {
  			throw new BadLdapGrammarException("Failed to parse Rdn", e);
  		}
  		this.components = rdn.components;
  	}
  
  	/**
  	 * Construct an LdapRdn using the supplied key and value.
  	 * 
  	 * @param key the attribute name.
  	 * @param value the attribute value.
  	 */
  	public LdapRdn(String key, String value) {
  		components.add(new LdapRdnComponent(key, value));
  	}
  
  	/**
  	 * Add an LdapRdnComponent to this LdapRdn.
  	 * 
  	 * @param rdnComponent the LdapRdnComponent to add.s
  	 */
  	public void addComponent(LdapRdnComponent rdnComponent) {
  		components.add(rdnComponent);
  	}
  
  	/**
  	 * Gets all components in this LdapRdn.
  	 * 
  	 * @return the List of all LdapRdnComponents composing this LdapRdn.
  	 */
  	public List getComponents() {
  		return components;
  	}
  
  	/**
  	 * Gets the first LdapRdnComponent of this LdapRdn.
 	 * 
 	 * @return The first LdapRdnComponent of this LdapRdn.
 	 * @throws IndexOutOfBoundsException if there are no components in this Rdn.
 	 */
 	public LdapRdnComponent getComponent() {
 		return (LdapRdnComponent) components.get(0);
 	}
 
 	/**
 	 * Get the LdapRdnComponent at index <code>idx</code>.
 	 * 
 	 * @param idx the 0-based index of the component to get.
 	 * @return the LdapRdnComponent at index <code>idx</code>.
 	 * @throws IndexOutOfBoundsException if there are no components in this Rdn.
 	 */
 	public LdapRdnComponent getComponent(int idx) {
 		return (LdapRdnComponent) components.get(idx);
 	}
 
 	/**
 	 * Get a properly rfc2253-encoded String representation of this LdapRdn.
 	 * 
 	 * @return an escaped String corresponding to this LdapRdn.
 	 * @throws IndexOutOfBoundsException if there are no components in this Rdn.
 	 */
 	public String getLdapEncoded() {
 		if (components.size() == 0) {
 			throw new IndexOutOfBoundsException("No components in Rdn.");
 		}
 		StringBuffer sb = new StringBuffer(100);
 		for (Iterator iter = components.iterator(); iter.hasNext();) {
 			LdapRdnComponent component = (LdapRdnComponent) iter.next();
 			sb.append(component.encodeLdap());
 			if (iter.hasNext()) {
 				sb.append("+");
 			}
 		}
 
 		return sb.toString();
 	}
 
 	/**
 	 * Get a String representation of this LdapRdn for use in urls.
 	 * 
 	 * @return a String representation of this LdapRdn for use in urls.
 	 */
 	public String encodeUrl() {
 		StringBuffer sb = new StringBuffer(100);
 		for (Iterator iter = components.iterator(); iter.hasNext();) {
 			LdapRdnComponent component = (LdapRdnComponent) iter.next();
 			sb.append(component.encodeUrl());
 			if (iter.hasNext()) {
 				sb.append("+");
 			}
 		}
 
 		return sb.toString();
 	}
 
 	/**
 	 * Compare this LdapRdn to another object.
 	 * 
 	 * @param obj the object to compare to.
 	 * @throws ClassCastException if the supplied object is not an LdapRdn
 	 * instance.
 	 */
 	public int compareTo(Object obj) {
 		LdapRdn that = (LdapRdn) obj;
 		Comparator comparator = new ListComparator();
 		return comparator.compare(this.components, that.components);
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see java.lang.Object#equals(java.lang.Object)
 	 */
 	public boolean equals(Object obj) {
 		if (obj == null || obj.getClass() != this.getClass()) {
 			return false;
 		}
 
 		LdapRdn that = (LdapRdn) obj;
 		return this.getComponents().equals(that.getComponents());
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see java.lang.Object#hashCode()
 	 */
 	public int hashCode() {
 		return this.getClass().hashCode() ^ getComponents().hashCode();
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see java.lang.Object#toString()
 	 */
 	public String toString() {
 		return getLdapEncoded();
 	}
 
 	/**
 	 * Get the value of this LdapRdn. Note that if this Rdn is multi-value the
 	 * first value will be returned. E.g. for the Rdn
 	 * <code>cn=john doe+sn=doe</code>, the return value would be
 	 * <code>john doe</code>.
 	 * 
 	 * @return the (first) value of this LdapRdn.
 	 * @throws IndexOutOfBoundsException if there are no components in this Rdn.
 	 */
 	public String getValue() {
 		return getComponent().getValue();
 	}
 
 	/**
 	 * Get the key of this LdapRdn. Note that if this Rdn is multi-value the
 	 * first key will be returned. E.g. for the Rdn
 	 * <code>cn=john doe+sn=doe</code>, the return value would be
 	 * <code>cn</code>.
 	 * 
 	 * @return the (first) key of this LdapRdn.
 	 * @throws IndexOutOfBoundsException if there are no components in this Rdn.
 	 */
 	public String getKey() {
 		return getComponent().getKey();
 	}
 
 	/**
 	 * Get the value of the LdapComponent with the specified key (Attribute
 	 * name).
 	 * 
 	 * @param key the key
 	 * @return the value.
 	 * @throws IllegalArgumentException if there is no component with the
 	 * specified key.
 	 */
 	public String getValue(String key) {
 		for (Iterator iter = components.iterator(); iter.hasNext();) {
 			LdapRdnComponent component = (LdapRdnComponent) iter.next();
 			if (StringUtils.equals(component.getKey(), key)) {
 				return component.getValue();
 			}
 		}
 
 		throw new IllegalArgumentException("No RdnComponent with the key " + key);
 	}
 
 	/**
 	 * Create an immutable copy of this instance. It will not be possible to add
 	 * or remove components or modify the keys and values of these components.
 	 * 
 	 * @return an immutable copy of this instance.
 	 * @since 1.3
 	 */
 	public LdapRdn immutableLdapRdn() {
 		List listWithImmutableRdns = new ArrayList(components.size());
 		for (Iterator iterator = components.iterator(); iterator.hasNext();) {
 			LdapRdnComponent rdnComponent = (LdapRdnComponent) iterator.next();
 			listWithImmutableRdns.add(rdnComponent.immutableLdapRdnComponent());
 		}
 		List unmodifiableListOfImmutableRdns = Collections.unmodifiableList(listWithImmutableRdns);
 		LdapRdn immutableRdn = new LdapRdn();
 		immutableRdn.components = unmodifiableListOfImmutableRdns;
 		return immutableRdn;
 	}
 }