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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
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 * This code 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
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package javax.naming.ldap;

import javax.naming.Name;
import javax.naming.InvalidNameException;

import java.util.Enumeration;
import java.util.Collection;
import java.util.ArrayList;
import java.util.List;
import java.util.Iterator;
import java.util.ListIterator;
import java.util.Collections;

import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;

This class represents a distinguished name as specified by
RFC 2253.
A distinguished name, or DN, is composed of an ordered list of
components called relative distinguished names, or RDNs.
Details of a DN's syntax are described in RFC 2253.

This class resolves a few ambiguities found in RFC 2253
as follows:

 RFC 2253 leaves the term "whitespace" undefined. The
     ASCII space character 0x20 (" ") is used in its place.
 Whitespace is allowed on either side of ',', ';', '=', and '+'.
     Such whitespace is accepted but not generated by this code,
     and is ignored when comparing names.
 AttributeValue strings containing '=' or non-leading '#'
     characters (unescaped) are accepted.

 String names passed to LdapName or returned by it use the full Unicode character set. They may also contain characters encoded into UTF-8 with each octet represented by a three-character substring such as "\\B4". They may not, however, contain characters encoded into UTF-8 with each octet represented by a single character in the string: the meaning would be ambiguous. 
 LdapName will properly parse all valid names, but does not attempt to detect all possible violations when parsing invalid names. It is "generous" in accepting invalid names. The "validity" of a name is determined ultimately when it is supplied to an LDAP server, which may accept or reject the name based on factors such as its schema information and interoperability considerations. 

When names are tested for equality, attribute types, both binary
and string values, are case-insensitive.
String values with different but equivalent usage of quoting,
escaping, or UTF8-hex-encoding are considered equal.  The order of
components in multi-valued RDNs (such as "ou=Sales+cn=Bob") is not
significant.

The components of a LDAP name, that is, RDNs, are numbered. The
indexes of a LDAP name with n RDNs range from 0 to n-1.
This range may be written as [0,n).
The right most RDN is at index 0, and the left most RDN is at
index n-1. For example, the distinguished name:
"CN=Steve Kille, O=Isode Limited, C=GB" is numbered in the following
sequence ranging from 0 to 2: {C=GB, O=Isode Limited, CN=Steve Kille}. An
empty LDAP name is represented by an empty RDN list.
 Concurrent multithreaded read-only access of an instance of LdapName need not be synchronized. 

Unless otherwise noted, the behavior of passing a null argument
to a constructor or method in this class will cause a
NullPointerException to be thrown.
Author:
Scott Seligman
Since:
1.5/**
 * This class represents a distinguished name as specified by
 * <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>.
 * A distinguished name, or DN, is composed of an ordered list of
 * components called <em>relative distinguished name</em>s, or RDNs.
 * Details of a DN's syntax are described in RFC 2253.
 *<p>
 * This class resolves a few ambiguities found in RFC 2253
 * as follows:
 * <ul>
 * <li> RFC 2253 leaves the term "whitespace" undefined. The
 *      ASCII space character 0x20 (" ") is used in its place.
 * <li> Whitespace is allowed on either side of ',', ';', '=', and '+'.
 *      Such whitespace is accepted but not generated by this code,
 *      and is ignored when comparing names.
 * <li> AttributeValue strings containing '=' or non-leading '#'
 *      characters (unescaped) are accepted.
 * </ul>
 *<p>
 * String names passed to {@code LdapName} or returned by it
 * use the full Unicode character set. They may also contain
 * characters encoded into UTF-8 with each octet represented by a
 * three-character substring such as "\\B4".
 * They may not, however, contain characters encoded into UTF-8 with
 * each octet represented by a single character in the string:  the
 * meaning would be ambiguous.
 *<p>
 * {@code LdapName} will properly parse all valid names, but
 * does not attempt to detect all possible violations when parsing
 * invalid names.  It is "generous" in accepting invalid names.
 * The "validity" of a name is determined ultimately when it
 * is supplied to an LDAP server, which may accept or
 * reject the name based on factors such as its schema information
 * and interoperability considerations.
 *<p>
 * When names are tested for equality, attribute types, both binary
 * and string values, are case-insensitive.
 * String values with different but equivalent usage of quoting,
 * escaping, or UTF8-hex-encoding are considered equal.  The order of
 * components in multi-valued RDNs (such as "ou=Sales+cn=Bob") is not
 * significant.
 * <p>
 * The components of a LDAP name, that is, RDNs, are numbered. The
 * indexes of a LDAP name with n RDNs range from 0 to n-1.
 * This range may be written as [0,n).
 * The right most RDN is at index 0, and the left most RDN is at
 * index n-1. For example, the distinguished name:
 * "CN=Steve Kille, O=Isode Limited, C=GB" is numbered in the following
 * sequence ranging from 0 to 2: {C=GB, O=Isode Limited, CN=Steve Kille}. An
 * empty LDAP name is represented by an empty RDN list.
 *<p>
 * Concurrent multithreaded read-only access of an instance of
 * {@code LdapName} need not be synchronized.
 *<p>
 * Unless otherwise noted, the behavior of passing a null argument
 * to a constructor or method in this class will cause a
 * NullPointerException to be thrown.
 *
 * @author Scott Seligman
 * @since 1.5
 */

public class LdapName implements Name {

    private transient List<Rdn> rdns;   // parsed name components
    private transient String unparsed;  // if non-null, the DN in unparsed form
    private static final long serialVersionUID = -1595520034788997356L;

    
Constructs an LDAP name from the given distinguished name.
Params:
name –  This is a non-null distinguished name formatted
according to the rules defined in
RFC 2253.
Throws:
InvalidNameException – if a syntax violation is detected.
See Also:
Rdn.escapeValue(Object value)/**
     * Constructs an LDAP name from the given distinguished name.
     *
     * @param name  This is a non-null distinguished name formatted
     * according to the rules defined in
     * <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>.
     *
     * @throws InvalidNameException if a syntax violation is detected.
     * @see Rdn#escapeValue(Object value)
     */
    public LdapName(String name) throws InvalidNameException {
        unparsed = name;
        parse();
    }

    
Constructs an LDAP name given its parsed RDN components.

The indexing of RDNs in the list follows the numbering of
RDNs described in the class description.
Params:
rdns – The non-null list of Rdns forming this LDAP name./**
     * Constructs an LDAP name given its parsed RDN components.
     * <p>
     * The indexing of RDNs in the list follows the numbering of
     * RDNs described in the class description.
     *
     * @param rdns The non-null list of {@code Rdn}s forming this LDAP name.
     */
    public LdapName(List<Rdn> rdns) {

        // if (rdns instanceof ArrayList<Rdn>) {
        //      this.rdns = rdns.clone();
        // } else if (rdns instanceof List<Rdn>) {
        //      this.rdns = new ArrayList<Rdn>(rdns);
        // } else {
        //      throw IllegalArgumentException(
        //              "Invalid entries, list entries must be of type Rdn");
        //  }

        this.rdns = new ArrayList<>(rdns.size());
        for (int i = 0; i < rdns.size(); i++) {
            Object obj = rdns.get(i);
            if (!(obj instanceof Rdn)) {
                throw new IllegalArgumentException("Entry:" + obj +
                        "  not a valid type;list entries must be of type Rdn");
            }
            this.rdns.add((Rdn)obj);
        }
    }

    /*
     * Constructs an LDAP name given its parsed components (the elements
     * of "rdns" in the range [beg,end)) and, optionally
     * (if "name" is not null), the unparsed DN.
     *
     */
    private LdapName(String name, List<Rdn> rdns, int beg, int end) {
        unparsed = name;
        // this.rdns = rdns.subList(beg, end);

        List<Rdn> sList = rdns.subList(beg, end);
        this.rdns = new ArrayList<>(sList);
    }

    
Retrieves the number of components in this LDAP name.
Returns:
The non-negative number of components in this LDAP name./**
     * Retrieves the number of components in this LDAP name.
     * @return The non-negative number of components in this LDAP name.
     */
    public int size() {
        return rdns.size();
    }

    
Determines whether this LDAP name is empty.
An empty name is one with zero components.
Returns:
true if this LDAP name is empty, false otherwise./**
     * Determines whether this LDAP name is empty.
     * An empty name is one with zero components.
     * @return true if this LDAP name is empty, false otherwise.
     */
    public boolean isEmpty() {
        return rdns.isEmpty();
    }

    
Retrieves the components of this name as an enumeration
of strings. The effect of updates to this name on this enumeration
is undefined. If the name has zero components, an empty (non-null)
enumeration is returned.
The order of the components returned by the enumeration is same as
the order in which the components are numbered as described in the
class description.
Returns:
A non-null enumeration of the components of this LDAP name.
Each element of the enumeration is of class String./**
     * Retrieves the components of this name as an enumeration
     * of strings. The effect of updates to this name on this enumeration
     * is undefined. If the name has zero components, an empty (non-null)
     * enumeration is returned.
     * The order of the components returned by the enumeration is same as
     * the order in which the components are numbered as described in the
     * class description.
     *
     * @return A non-null enumeration of the components of this LDAP name.
     * Each element of the enumeration is of class String.
     */
    public Enumeration<String> getAll() {
        final Iterator<Rdn> iter = rdns.iterator();

        return new Enumeration<String>() {
            public boolean hasMoreElements() {
                return iter.hasNext();
            }
            public String nextElement() {
                return iter.next().toString();
            }
        };
    }

    
Retrieves a component of this LDAP name as a string.
Params:
posn – The 0-based index of the component to retrieve.
             Must be in the range [0,size()).
Throws:
IndexOutOfBoundsException – if posn is outside the
         specified range.
Returns:
The non-null component at index posn./**
     * Retrieves a component of this LDAP name as a string.
     * @param  posn The 0-based index of the component to retrieve.
     *              Must be in the range [0,size()).
     * @return The non-null component at index posn.
     * @exception IndexOutOfBoundsException if posn is outside the
     *          specified range.
     */
    public String get(int posn) {
        return rdns.get(posn).toString();
    }

    
Retrieves an RDN of this LDAP name as an Rdn.
Params:
posn – The 0-based index of the RDN to retrieve.
         Must be in the range [0,size()).
Throws:
IndexOutOfBoundsException – if posn is outside the
           specified range.
Returns:
The non-null RDN at index posn./**
     * Retrieves an RDN of this LDAP name as an Rdn.
     * @param   posn The 0-based index of the RDN to retrieve.
     *          Must be in the range [0,size()).
     * @return The non-null RDN at index posn.
     * @exception IndexOutOfBoundsException if posn is outside the
     *            specified range.
     */
    public Rdn getRdn(int posn) {
        return rdns.get(posn);
    }

    
Creates a name whose components consist of a prefix of the
components of this LDAP name.
Subsequent changes to this name will not affect the name
that is returned and vice versa.
Params:
posn –     The 0-based index of the component at which to stop.
                 Must be in the range [0,size()].
Throws:
IndexOutOfBoundsException – 
             If posn is outside the specified range.
Returns:
 An instance of LdapName consisting of the components at indexes in the range [0,posn). If posn is zero, an empty LDAP name is returned./**
     * Creates a name whose components consist of a prefix of the
     * components of this LDAP name.
     * Subsequent changes to this name will not affect the name
     * that is returned and vice versa.
     * @param  posn     The 0-based index of the component at which to stop.
     *                  Must be in the range [0,size()].
     * @return  An instance of {@code LdapName} consisting of the
     *          components at indexes in the range [0,posn).
     *          If posn is zero, an empty LDAP name is returned.
     * @exception   IndexOutOfBoundsException
     *              If posn is outside the specified range.
     */
    public Name getPrefix(int posn) {
        try {
            return new LdapName(null, rdns, 0, posn);
        } catch (IllegalArgumentException e) {
            throw new IndexOutOfBoundsException(
                "Posn: " + posn + ", Size: "+ rdns.size());
        }
    }

    
Creates a name whose components consist of a suffix of the
components in this LDAP name.
Subsequent changes to this name do not affect the name that is
returned and vice versa.
Params:
posn –     The 0-based index of the component at which to start.
                 Must be in the range [0,size()].
Throws:
IndexOutOfBoundsException – 
         If posn is outside the specified range.
Returns:
 An instance of LdapName consisting of the components at indexes in the range [posn,size()). If posn is equal to size(), an empty LDAP name is returned./**
     * Creates a name whose components consist of a suffix of the
     * components in this LDAP name.
     * Subsequent changes to this name do not affect the name that is
     * returned and vice versa.
     *
     * @param  posn     The 0-based index of the component at which to start.
     *                  Must be in the range [0,size()].
     * @return  An instance of {@code LdapName} consisting of the
     *          components at indexes in the range [posn,size()).
     *          If posn is equal to size(), an empty LDAP name is
     *          returned.
     * @exception IndexOutOfBoundsException
     *          If posn is outside the specified range.
     */
    public Name getSuffix(int posn) {
        try {
            return new LdapName(null, rdns, posn, rdns.size());
        } catch (IllegalArgumentException e) {
            throw new IndexOutOfBoundsException(
                "Posn: " + posn + ", Size: "+ rdns.size());
        }
    }

    
Determines whether this LDAP name starts with a specified LDAP name prefix. A name n is a prefix if it is equal to getPrefix(n.size())--in other words this LDAP name starts with 'n'. If n is null or not a RFC2253 formatted name as described in the class description, false is returned. 
Params:
n – The LDAP name to check.
See Also:
getPrefix(int posn)
Returns:
 true if n is a prefix of this LDAP name, false otherwise./**
     * Determines whether this LDAP name starts with a specified LDAP name
     * prefix.
     * A name {@code n} is a prefix if it is equal to
     * {@code getPrefix(n.size())}--in other words this LDAP
     * name starts with 'n'. If n is null or not a RFC2253 formatted name
     * as described in the class description, false is returned.
     *
     * @param n The LDAP name to check.
     * @return  true if {@code n} is a prefix of this LDAP name,
     * false otherwise.
     * @see #getPrefix(int posn)
     */
    public boolean startsWith(Name n) {
        if (n == null) {
            return false;
        }
        int len1 = rdns.size();
        int len2 = n.size();
        return (len1 >= len2 &&
                matches(0, len2, n));
    }

    
Determines whether the specified RDN sequence forms a prefix of this
LDAP name.  Returns true if this LdapName is at least as long as rdns,
and for every position p in the range [0, rdns.size()) the component
getRdn(p) matches rdns.get(p). Returns false otherwise. If rdns is
null, false is returned.
Params:
rdns – The sequence of Rdns to check.
Returns:
 true if rdns form a prefix of this LDAP name, false otherwise./**
     * Determines whether the specified RDN sequence forms a prefix of this
     * LDAP name.  Returns true if this LdapName is at least as long as rdns,
     * and for every position p in the range [0, rdns.size()) the component
     * getRdn(p) matches rdns.get(p). Returns false otherwise. If rdns is
     * null, false is returned.
     *
     * @param rdns The sequence of {@code Rdn}s to check.
     * @return  true if {@code rdns} form a prefix of this LDAP name,
     *          false otherwise.
     */
    public boolean startsWith(List<Rdn> rdns) {
        if (rdns == null) {
            return false;
        }
        int len1 = this.rdns.size();
        int len2 = rdns.size();
        return (len1 >= len2 &&
                doesListMatch(0, len2, rdns));
    }

    
Determines whether this LDAP name ends with a specified LDAP name suffix. A name n is a suffix if it is equal to getSuffix(size()-n.size())--in other words this LDAP name ends with 'n'. If n is null or not a RFC2253 formatted name as described in the class description, false is returned. 
Params:
n – The LDAP name to check.
See Also:
getSuffix(int posn)
Returns:
true if n is a suffix of this name, false otherwise./**
     * Determines whether this LDAP name ends with a specified
     * LDAP name suffix.
     * A name {@code n} is a suffix if it is equal to
     * {@code getSuffix(size()-n.size())}--in other words this LDAP
     * name ends with 'n'. If n is null or not a RFC2253 formatted name
     * as described in the class description, false is returned.
     *
     * @param n The LDAP name to check.
     * @return true if {@code n} is a suffix of this name, false otherwise.
     * @see #getSuffix(int posn)
     */
    public boolean endsWith(Name n) {
        if (n == null) {
            return false;
        }
        int len1 = rdns.size();
        int len2 = n.size();
        return (len1 >= len2 &&
                matches(len1 - len2, len1, n));
    }

    
Determines whether the specified RDN sequence forms a suffix of this
LDAP name.  Returns true if this LdapName is at least as long as rdns,
and for every position p in the range [size() - rdns.size(), size())
the component getRdn(p) matches rdns.get(p). Returns false otherwise.
If rdns is null, false is returned.
Params:
rdns – The sequence of Rdns to check.
Returns:
 true if rdns form a suffix of this LDAP name, false otherwise./**
     * Determines whether the specified RDN sequence forms a suffix of this
     * LDAP name.  Returns true if this LdapName is at least as long as rdns,
     * and for every position p in the range [size() - rdns.size(), size())
     * the component getRdn(p) matches rdns.get(p). Returns false otherwise.
     * If rdns is null, false is returned.
     *
     * @param rdns The sequence of {@code Rdn}s to check.
     * @return  true if {@code rdns} form a suffix of this LDAP name,
     *          false otherwise.
     */
    public boolean endsWith(List<Rdn> rdns) {
        if (rdns == null) {
            return false;
        }
        int len1 = this.rdns.size();
        int len2 = rdns.size();
        return (len1 >= len2 &&
                doesListMatch(len1 - len2, len1, rdns));
    }

    private boolean doesListMatch(int beg, int end, List<Rdn> rdns) {
        for (int i = beg; i < end; i++) {
            if (!this.rdns.get(i).equals(rdns.get(i - beg))) {
                return false;
            }
        }
        return true;
    }

    /*
     * Helper method for startsWith() and endsWith().
     * Returns true if components [beg,end) match the components of "n".
     * If "n" is not an LdapName, each of its components is parsed as
     * the string form of an RDN.
     * The following must hold:  end - beg == n.size().
     */
    private boolean matches(int beg, int end, Name n) {
        if (n instanceof LdapName) {
            LdapName ln = (LdapName) n;
            return doesListMatch(beg, end, ln.rdns);
        } else {
            for (int i = beg; i < end; i++) {
                Rdn rdn;
                String rdnString = n.get(i - beg);
                try {
                    rdn = (new Rfc2253Parser(rdnString)).parseRdn();
                } catch (InvalidNameException e) {
                    return false;
                }
                if (!rdn.equals(rdns.get(i))) {
                    return false;
                }
            }
        }
        return true;
    }

    
Adds the components of a name -- in order -- to the end of this name.
Params:
suffix – The non-null components to add.
Throws:
InvalidNameException – if suffix is not a valid LDAP name, or if the addition of the components would violate the syntax rules of this LDAP name.
Returns:
 The updated name (not a new instance)./**
     * Adds the components of a name -- in order -- to the end of this name.
     *
     * @param   suffix The non-null components to add.
     * @return  The updated name (not a new instance).
     *
     * @throws  InvalidNameException if {@code suffix} is not a valid LDAP
     *          name, or if the addition of the components would violate the
     *          syntax rules of this LDAP name.
     */
    public Name addAll(Name suffix) throws InvalidNameException {
         return addAll(size(), suffix);
    }


    
Adds the RDNs of a name -- in order -- to the end of this name.
Params:
suffixRdns – The non-null suffix Rdns to add.
Returns:
 The updated name (not a new instance)./**
     * Adds the RDNs of a name -- in order -- to the end of this name.
     *
     * @param   suffixRdns The non-null suffix {@code Rdn}s to add.
     * @return  The updated name (not a new instance).
     */
    public Name addAll(List<Rdn> suffixRdns) {
        return addAll(size(), suffixRdns);
    }

    
Adds the components of a name -- in order -- at a specified position
within this name. Components of this LDAP name at or after the
index (if any) of the first new component are shifted up
(away from index 0) to accommodate the new components.
Params:
suffix –    The non-null components to add.
posn –      The index at which to add the new component.
                 Must be in the range [0,size()].
Throws:
InvalidNameException – if suffix is not a valid LDAP name, or if the addition of the components would violate the syntax rules of this LDAP name.
IndexOutOfBoundsException – 
         If posn is outside the specified range.
Returns:
 The updated name (not a new instance)./**
     * Adds the components of a name -- in order -- at a specified position
     * within this name. Components of this LDAP name at or after the
     * index (if any) of the first new component are shifted up
     * (away from index 0) to accommodate the new components.
     *
     * @param suffix    The non-null components to add.
     * @param posn      The index at which to add the new component.
     *                  Must be in the range [0,size()].
     *
     * @return  The updated name (not a new instance).
     *
     * @throws  InvalidNameException if {@code suffix} is not a valid LDAP
     *          name, or if the addition of the components would violate the
     *          syntax rules of this LDAP name.
     * @throws  IndexOutOfBoundsException
     *          If posn is outside the specified range.
     */
    public Name addAll(int posn, Name suffix)
        throws InvalidNameException {
        unparsed = null;        // no longer valid
        if (suffix instanceof LdapName) {
            LdapName s = (LdapName) suffix;
            rdns.addAll(posn, s.rdns);
        } else {
            Enumeration<String> comps = suffix.getAll();
            while (comps.hasMoreElements()) {
                rdns.add(posn++,
                    (new Rfc2253Parser(comps.nextElement()).
                    parseRdn()));
            }
        }
        return this;
    }

    
Adds the RDNs of a name -- in order -- at a specified position
within this name. RDNs of this LDAP name at or after the
index (if any) of the first new RDN are shifted up (away from index 0) to
accommodate the new RDNs.
Params:
suffixRdns –  The non-null suffix Rdns to add.
posn –              The index at which to add the suffix RDNs.
                         Must be in the range [0,size()].
Throws:
IndexOutOfBoundsException – 
         If posn is outside the specified range.
Returns:
 The updated name (not a new instance)./**
     * Adds the RDNs of a name -- in order -- at a specified position
     * within this name. RDNs of this LDAP name at or after the
     * index (if any) of the first new RDN are shifted up (away from index 0) to
     * accommodate the new RDNs.
     *
     * @param suffixRdns        The non-null suffix {@code Rdn}s to add.
     * @param posn              The index at which to add the suffix RDNs.
     *                          Must be in the range [0,size()].
     *
     * @return  The updated name (not a new instance).
     * @throws  IndexOutOfBoundsException
     *          If posn is outside the specified range.
     */
    public Name addAll(int posn, List<Rdn> suffixRdns) {
        unparsed = null;
        for (int i = 0; i < suffixRdns.size(); i++) {
            Object obj = suffixRdns.get(i);
            if (!(obj instanceof Rdn)) {
                throw new IllegalArgumentException("Entry:" + obj +
                "  not a valid type;suffix list entries must be of type Rdn");
            }
            rdns.add(i + posn, (Rdn)obj);
        }
        return this;
    }

    
Adds a single component to the end of this LDAP name.
Params:
comp –      The non-null component to add.
Throws:
InvalidNameException – If adding comp at end of the name
                 would violate the name's syntax.
Returns:
         The updated LdapName, not a new instance.
                 Cannot be null./**
     * Adds a single component to the end of this LDAP name.
     *
     * @param comp      The non-null component to add.
     * @return          The updated LdapName, not a new instance.
     *                  Cannot be null.
     * @exception       InvalidNameException If adding comp at end of the name
     *                  would violate the name's syntax.
     */
    public Name add(String comp) throws InvalidNameException {
        return add(size(), comp);
    }

    
Adds a single RDN to the end of this LDAP name.
Params:
comp –      The non-null RDN to add.
Returns:
         The updated LdapName, not a new instance.
                 Cannot be null./**
     * Adds a single RDN to the end of this LDAP name.
     *
     * @param comp      The non-null RDN to add.
     *
     * @return          The updated LdapName, not a new instance.
     *                  Cannot be null.
     */
    public Name add(Rdn comp) {
        return add(size(), comp);
    }

    
Adds a single component at a specified position within this
LDAP name.
Components of this LDAP name at or after the index (if any) of the new
component are shifted up by one (away from index 0) to accommodate
the new component.
Params:
comp –     The non-null component to add.
posn –     The index at which to add the new component.
                 Must be in the range [0,size()].
Throws:
IndexOutOfBoundsException – 
                 If posn is outside the specified range.
InvalidNameException – If adding comp at the
                 specified position would violate the name's syntax.
Returns:
         The updated LdapName, not a new instance.
                 Cannot be null./**
     * Adds a single component at a specified position within this
     * LDAP name.
     * Components of this LDAP name at or after the index (if any) of the new
     * component are shifted up by one (away from index 0) to accommodate
     * the new component.
     *
     * @param  comp     The non-null component to add.
     * @param  posn     The index at which to add the new component.
     *                  Must be in the range [0,size()].
     * @return          The updated LdapName, not a new instance.
     *                  Cannot be null.
     * @exception       IndexOutOfBoundsException
     *                  If posn is outside the specified range.
     * @exception       InvalidNameException If adding comp at the
     *                  specified position would violate the name's syntax.
     */
    public Name add(int posn, String comp) throws InvalidNameException {
        Rdn rdn = (new Rfc2253Parser(comp)).parseRdn();
        rdns.add(posn, rdn);
        unparsed = null;        // no longer valid
        return this;
    }

    
Adds a single RDN at a specified position within this
LDAP name.
RDNs of this LDAP name at or after the index (if any) of the new
RDN are shifted up by one (away from index 0) to accommodate
the new RDN.
Params:
comp –     The non-null RDN to add.
posn –     The index at which to add the new RDN.
                 Must be in the range [0,size()].
Throws:
IndexOutOfBoundsException – 
                 If posn is outside the specified range.
Returns:
         The updated LdapName, not a new instance.
                 Cannot be null./**
     * Adds a single RDN at a specified position within this
     * LDAP name.
     * RDNs of this LDAP name at or after the index (if any) of the new
     * RDN are shifted up by one (away from index 0) to accommodate
     * the new RDN.
     *
     * @param  comp     The non-null RDN to add.
     * @param  posn     The index at which to add the new RDN.
     *                  Must be in the range [0,size()].
     * @return          The updated LdapName, not a new instance.
     *                  Cannot be null.
     * @exception       IndexOutOfBoundsException
     *                  If posn is outside the specified range.
     */
    public Name add(int posn, Rdn comp) {
        if (comp == null) {
            throw new NullPointerException("Cannot set comp to null");
        }
        rdns.add(posn, comp);
        unparsed = null;        // no longer valid
        return this;
    }

    
Removes a component from this LDAP name.
The component of this name at the specified position is removed.
Components with indexes greater than this position (if any)
are shifted down (toward index 0) by one.
Params:
posn –      The index of the component to remove.
                 Must be in the range [0,size()).
Throws:
IndexOutOfBoundsException – 
                 if posn is outside the specified range.
InvalidNameException – if deleting the component
                 would violate the syntax rules of the name.
Returns:
         The component removed (a String)./**
     * Removes a component from this LDAP name.
     * The component of this name at the specified position is removed.
     * Components with indexes greater than this position (if any)
     * are shifted down (toward index 0) by one.
     *
     * @param posn      The index of the component to remove.
     *                  Must be in the range [0,size()).
     * @return          The component removed (a String).
     *
     * @throws          IndexOutOfBoundsException
     *                  if posn is outside the specified range.
     * @throws          InvalidNameException if deleting the component
     *                  would violate the syntax rules of the name.
     */
    public Object remove(int posn) throws InvalidNameException {
        unparsed = null;        // no longer valid
        return rdns.remove(posn).toString();
    }

    
Retrieves the list of relative distinguished names.
The contents of the list are unmodifiable.
The indexing of RDNs in the returned list follows the numbering of
RDNs as described in the class description.
If the name has zero components, an empty list is returned.
Returns:
 The name as a list of RDNs which are instances of the class Rdn./**
     * Retrieves the list of relative distinguished names.
     * The contents of the list are unmodifiable.
     * The indexing of RDNs in the returned list follows the numbering of
     * RDNs as described in the class description.
     * If the name has zero components, an empty list is returned.
     *
     * @return  The name as a list of RDNs which are instances of
     *          the class {@link Rdn Rdn}.
     */
    public List<Rdn> getRdns() {
        return Collections.unmodifiableList(rdns);
    }

    
Generates a new copy of this name.
Subsequent changes to the components of this name will not
affect the new copy, and vice versa.
Returns:
A copy of the this LDAP name./**
     * Generates a new copy of this name.
     * Subsequent changes to the components of this name will not
     * affect the new copy, and vice versa.
     *
     * @return A copy of the this LDAP name.
     */
    public Object clone() {
        return new LdapName(unparsed, rdns, 0, rdns.size());
    }

    
Returns a string representation of this LDAP name in a format
defined by RFC 2253
and described in the class description. If the name has zero
components an empty string is returned.
Returns:
The string representation of the LdapName./**
     * Returns a string representation of this LDAP name in a format
     * defined by <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>
     * and described in the class description. If the name has zero
     * components an empty string is returned.
     *
     * @return The string representation of the LdapName.
     */
    public String toString() {
        if (unparsed != null) {
            return unparsed;
        }
        StringBuilder builder = new StringBuilder();
        int size = rdns.size();
        if ((size - 1) >= 0) {
            builder.append(rdns.get(size - 1));
        }
        for (int next = size - 2; next >= 0; next--) {
            builder.append(',');
            builder.append(rdns.get(next));
        }
        unparsed = builder.toString();
        return unparsed;
    }

    
Determines whether two LDAP names are equal.
If obj is null or not an LDAP name, false is returned.
 Two LDAP names are equal if each RDN in one is equal to the corresponding RDN in the other. This implies both have the same number of RDNs, and each RDN's equals() test against the corresponding RDN in the other name returns true. See Rdn.equals(Object obj) for a definition of RDN equality. 
Params:
obj –      The possibly null object to compare against.
See Also:
hashCode
Returns:
         true if obj is equal to this LDAP name,
                 false otherwise./**
     * Determines whether two LDAP names are equal.
     * If obj is null or not an LDAP name, false is returned.
     * <p>
     * Two LDAP names are equal if each RDN in one is equal
     * to the corresponding RDN in the other. This implies
     * both have the same number of RDNs, and each RDN's
     * equals() test against the corresponding RDN in the other
     * name returns true. See {@link Rdn#equals(Object obj)}
     * for a definition of RDN equality.
     *
     * @param  obj      The possibly null object to compare against.
     * @return          true if obj is equal to this LDAP name,
     *                  false otherwise.
     * @see #hashCode
     */
    public boolean equals(Object obj) {
        // check possible shortcuts
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof LdapName)) {
            return false;
        }
        LdapName that = (LdapName) obj;
        if (rdns.size() != that.rdns.size()) {
            return false;
        }
        if (unparsed != null && unparsed.equalsIgnoreCase(
                that.unparsed)) {
            return true;
        }
        // Compare RDNs one by one for equality
        for (int i = 0; i < rdns.size(); i++) {
            // Compare a single pair of RDNs.
            Rdn rdn1 = rdns.get(i);
            Rdn rdn2 = that.rdns.get(i);
            if (!rdn1.equals(rdn2)) {
                return false;
            }
        }
        return true;
    }

    
Compares this LdapName with the specified Object for order.
Returns a negative integer, zero, or a positive integer as this
Name is less than, equal to, or greater than the given Object.

If obj is null or not an instance of LdapName, ClassCastException
is thrown.
 Ordering of LDAP names follows the lexicographical rules for string comparison, with the extension that this applies to all the RDNs in the LDAP name. All the RDNs are lined up in their specified order and compared lexicographically. See Rdn.compareTo(Object obj) for RDN comparison rules. 

If this LDAP name is lexicographically lesser than obj,
a negative number is returned.
If this LDAP name is lexicographically greater than obj,
a positive number is returned.
Params:
obj – The non-null LdapName instance to compare against.
Throws:
ClassCastException – if obj is null or not a LdapName.
Returns:
 A negative integer, zero, or a positive integer as this Name
         is less than, equal to, or greater than the given obj./**
     * Compares this LdapName with the specified Object for order.
     * Returns a negative integer, zero, or a positive integer as this
     * Name is less than, equal to, or greater than the given Object.
     * <p>
     * If obj is null or not an instance of LdapName, ClassCastException
     * is thrown.
     * <p>
     * Ordering of LDAP names follows the lexicographical rules for
     * string comparison, with the extension that this applies to all
     * the RDNs in the LDAP name. All the RDNs are lined up in their
     * specified order and compared lexicographically.
     * See {@link Rdn#compareTo(Object obj) Rdn.compareTo(Object obj)}
     * for RDN comparison rules.
     * <p>
     * If this LDAP name is lexicographically lesser than obj,
     * a negative number is returned.
     * If this LDAP name is lexicographically greater than obj,
     * a positive number is returned.
     * @param obj The non-null LdapName instance to compare against.
     *
     * @return  A negative integer, zero, or a positive integer as this Name
     *          is less than, equal to, or greater than the given obj.
     * @exception ClassCastException if obj is null or not a LdapName.
     */
    public int compareTo(Object obj) {

        if (!(obj instanceof LdapName)) {
            throw new ClassCastException("The obj is not a LdapName");
        }

        // check possible shortcuts
        if (obj == this) {
            return 0;
        }
        LdapName that = (LdapName) obj;

        if (unparsed != null && unparsed.equalsIgnoreCase(
                        that.unparsed)) {
            return 0;
        }

        // Compare RDNs one by one, lexicographically.
        int minSize = Math.min(rdns.size(), that.rdns.size());
        for (int i = 0; i < minSize; i++) {
            // Compare a single pair of RDNs.
            Rdn rdn1 = rdns.get(i);
            Rdn rdn2 = that.rdns.get(i);

            int diff = rdn1.compareTo(rdn2);
            if (diff != 0) {
                return diff;
            }
        }
        return (rdns.size() - that.rdns.size());        // longer DN wins
    }

    
Computes the hash code of this LDAP name.
The hash code is the sum of the hash codes of individual RDNs
of this  name.
See Also:
equals
Returns:
An int representing the hash code of this name./**
     * Computes the hash code of this LDAP name.
     * The hash code is the sum of the hash codes of individual RDNs
     * of this  name.
     *
     * @return An int representing the hash code of this name.
     * @see #equals
     */
    public int hashCode() {
        // Sum up the hash codes of the components.
        int hash = 0;

        // For each RDN...
        for (int i = 0; i < rdns.size(); i++) {
            Rdn rdn = rdns.get(i);
            hash += rdn.hashCode();
        }
        return hash;
    }

    
Serializes only the unparsed DN, for compactness and to avoid
any implementation dependency.
@serialData
     The DN string/**
     * Serializes only the unparsed DN, for compactness and to avoid
     * any implementation dependency.
     *
     * @serialData      The DN string
     */
    private void writeObject(ObjectOutputStream s)
            throws java.io.IOException {
        s.defaultWriteObject();
        s.writeObject(toString());
    }

    private void readObject(ObjectInputStream s)
            throws java.io.IOException, ClassNotFoundException {
        s.defaultReadObject();
        unparsed = (String)s.readObject();
        try {
            parse();
        } catch (InvalidNameException e) {
            // shouldn't happen
            throw new java.io.StreamCorruptedException(
                    "Invalid name: " + unparsed);
        }
    }

    private void parse() throws InvalidNameException {
        // rdns = (ArrayList<Rdn>) (new RFC2253Parser(unparsed)).getDN();

        rdns = new Rfc2253Parser(unparsed).parseDn();
    }
}