/*
 * @(#)CompositeName.java	1.14 04/05/05
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.naming;

import java.util.Enumeration;
import java.util.Properties;

/**
 * This class represents a composite name -- a sequence of 
 * component names spanning multiple namespaces.
 * Each component is a string name from the namespace of a
 * naming system. If the component comes from a hierarchical
 * namespace, that component can be further parsed into
 * its atomic parts by using the CompoundName class.
 *<p>
 * The components of a composite name are numbered.  The indexes of a
 * composite name with N components range from 0 up to, but not including, N.
 * This range may be written as [0,N).
 * The most significant component is at index 0.
 * An empty composite name has no components.
 *<p> 
 * <h4>JNDI Composite Name Syntax</h4>
 * JNDI defines a standard string representation for composite names. This
 * representation is the concatenation of the components of a composite name
 * from left to right using the component separator (a forward 
 * slash character (/)) to separate each component. 
 * The JNDI syntax defines the following meta characters:
 * <ul>
 * <li>escape (backward slash \),
 * <li>quote characters  (single (') and double quotes (")), and
 * <li>component separator (forward slash character (/)).
 * </ul>
 * Any occurrence of a leading quote, an escape preceding any meta character,
 * an escape at the end of a component, or a component separator character 
 * in an unquoted component must be preceded by an escape character when 
 * that component is being composed into a composite name string.
 * Alternatively, to avoid adding escape characters as described,
 * the entire component can be quoted using matching single quotes
 * or matching double quotes. A single quote occurring within a double-quoted
 * component is not considered a meta character (and need not be escaped),
 * and vice versa.
 *<p>
 * When two composite names are compared, the case of the characters
 * is significant.
 *<p> 
 * A leading component separator (the composite name string begins with
 * a separator) denotes a leading empty component (a component consisting
 * of an empty string).
 * A trailing component separator (the composite name string ends with
 * a separator) denotes a trailing empty component.
 * Adjacent component separators denote an empty component.
 *<p>
 *<h4>Composite Name Examples</h4>
 *This table shows examples of some composite names. Each row shows
 *the string form of a composite name and its corresponding structural form
 *(<tt>CompositeName</tt>).
 *<p>
<table border="1" cellpadding=3 width="70%" summary="examples showing string form of composite name and its corresponding structural form (CompositeName)">

<tr>
<th>String Name</th>
<th>CompositeName</th>
</tr>

<tr>
<td>
""
</td>
<td>{} (the empty name == new CompositeName("") == new CompositeName())
</td>
</tr>

<tr>
<td>
"x"
</td>
<td>{"x"}
</td>
</tr>

<tr>
<td>
"x/y"
</td>
<td>{"x", "y"}</td>
</tr>

<tr>
<td>"x/"</td>
<td>{"x", ""}</td>
</tr>

<tr>
<td>"/x"</td>
<td>{"", "x"}</td>
</tr>

<tr>
<td>"/"</td>
<td>{""}</td>
</tr>

<tr>
<td>"//"</td>
<td>{"", ""}</td>
</tr>

<tr><td>"/x/"</td>
<td>{"", "x", ""}</td>
</tr>

<tr><td>"x//y"</td>
<td>{"x", "", "y"}</td>
</tr>
</table>  
 * <p>
 *<h4>Composition Examples</h4>
 * Here are some composition examples.  The right column shows composing
 * string composite names while the left column shows composing the
 * corresponding <tt>CompositeName</tt>s.  Notice that composing the
 * string forms of two composite names simply involves concatenating
 * their string forms together.  

<p> <table border="1" cellpadding=3 width="70%" summary="composition examples showing string names and composite names">

<tr>
<th>String Names</th>
<th>CompositeNames</th>
</tr>

<tr>
<td>
"x/y"		+ "/"	= x/y/
</td>
<td>
{"x", "y"}	+ {""}	= {"x", "y", ""}
</td>
</tr>

<tr>
<td>
""		+ "x"	= "x"
</td>
<td>
{}		+ {"x"}	= {"x"}
</td>
</tr>

<tr>
<td>
"/"		+ "x"	= "/x"
</td>
<td>
{""}		+ {"x"} = {"", "x"}
</td>
</tr>

<tr>
<td>
"x"   + ""	+ ""	= "x"
</td>
<td>
{"x"} + {}	+ {}	= {"x"}
</td>
</tr>

</table>
 *<p>
 *<h4>Multithreaded Access</h4>
 * A <tt>CompositeName</tt> instance is not synchronized against concurrent
 * multithreaded access. Multiple threads trying to access and modify a
 * <tt>CompositeName</tt> should lock the object.
 *
 * @author Rosanna Lee
 * @author Scott Seligman
 * @version 1.14 04/05/05
 * @since 1.3
 */


public class CompositeName implements Name {

    private transient NameImpl impl;
    /**
      * Constructs a new composite name instance using the components
      * specified by 'comps'. This protected method is intended to be
      * to be used by subclasses of CompositeName when they override
      * methods such as clone(), getPrefix(), getSuffix().
      *
      * @param comps A non-null enumeration containing the components for the new
      *              composite name. Each element is of class String.
      *               The enumeration will be consumed to extract its
      *               elements.
      */
    protected CompositeName(Enumeration<String> comps) {
	impl = new NameImpl(null, comps); // null means use default syntax
    }

    /**
      * Constructs a new composite name instance by parsing the string n
      * using the composite name syntax (left-to-right, slash separated).
      * The composite name syntax is described in detail in the class
      * description.
      *
      * @param	n	The non-null string to parse.
      * @exception InvalidNameException If n has invalid composite name syntax.
      */
    public CompositeName(String n) throws InvalidNameException {
	impl = new NameImpl(null, n);  // null means use default syntax
    }

    /**
      * Constructs a new empty composite name. Such a name returns true
      * when <code>isEmpty()</code> is invoked on it.
      */
    public CompositeName() {
	impl = new NameImpl(null);  // null means use default syntax
    }

    /**
      * Generates the string representation of this composite name.
      * The string representation consists of enumerating in order
      * each component of the composite name and separating
      * each component by a forward slash character. Quoting and
      * escape characters are applied where necessary according to
      * the JNDI syntax, which is described in the class description.
      * An empty component is represented by an empty string.
      *
      * The string representation thus generated can be passed to
      * the CompositeName constructor to create a new equivalent
      * composite name.
      *
      * @return	A non-null string representation of this composite name.
      */
    public String toString() {
	return impl.toString();
    }

    /**
      * Determines whether two composite names are equal.
      * If obj is null or not a composite name, false is returned.
      * Two composite names are equal if each component in one is equal
      * to the corresponding component in the other. This implies
      * both have the same number of components, and each component's
      * equals() test against the corresponding component in the other name
      * returns true.
      *
      * @param	obj	The possibly null object to compare against.
      * @return	true if obj is equal to this composite name, false otherwise.
      * @see #hashCode
      */
    public boolean equals(Object obj) {
	return (obj != null &&
		obj instanceof CompositeName &&
		impl.equals(((CompositeName)obj).impl));
    }

    /**
      * Computes the hash code of this composite name.
      * The hash code is the sum of the hash codes of individual components
      * of this composite name.
      * 
      * @return An int representing the hash code of this name.
      * @see #equals
      */
    public int hashCode() {
	return impl.hashCode();
    }


    /**
     * Compares this CompositeName 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 CompositeName, ClassCastException
     * is thrown.
     * <p>
     * See equals() for what it means for two composite names to be equal.
     * If two composite names are equal, 0 is returned.
     * <p>
     * Ordering of composite names follows the lexicographical rules for
     * string comparison, with the extension that this applies to all
     * the components in the composite name. The effect is as if all the
     * components were lined up in their specified ordered and the
     * lexicographical rules applied over the two line-ups.
     * If this composite name is "lexicographically" lesser than obj,
     * a negative number is returned.
     * If this composite name is "lexicographically" greater than obj,
     * a positive number is returned.
     * @param obj The non-null object 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 Object.
     * @exception ClassCastException if obj is not a CompositeName.
     */
    public int compareTo(Object obj) {
	if (!(obj instanceof CompositeName)) {
	    throw new ClassCastException("Not a CompositeName");
	}
	return impl.compareTo(((CompositeName)obj).impl);
    }

    /**
      * Generates a copy of this composite name.
      * Changes to the components of this composite name won't
      * affect the new copy and vice versa.
      *
      * @return A non-null copy of this composite name.
      */
    public Object clone() {
	return (new CompositeName(getAll()));
    }

    /**
      * Retrieves the number of components in this composite name.
      *
      * @return	The nonnegative number of components in this composite name.
      */
    public int size() {
	return (impl.size());
    }

    /**
      * Determines whether this composite name is empty. A composite name
      * is empty if it has zero components.
      *
      * @return true if this composite name is empty, false otherwise.
      */
    public boolean isEmpty() {
	return (impl.isEmpty());
    }

    /**
      * Retrieves the components of this composite name as an enumeration
      * of strings.
      * The effects of updates to this composite name on this enumeration
      * is undefined.
      *
      * @return	A non-null enumeration of the components of
      * 	this composite name. Each element of the enumeration is of
      *		class String.
      */
    public Enumeration<String> getAll() {
	return (impl.getAll());
    }

    /**
      * Retrieves a component of this composite name.
      *
      * @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 ArrayIndexOutOfBoundsException if posn is outside the
      * 	specified range.
      */
    public String get(int posn) {
	return (impl.get(posn));
    }

    /**
      * Creates a composite name whose components consist of a prefix of the
      * components in this composite name. Subsequent changes to
      * this composite name does not affect the name that is returned.
      *
      * @param	posn	The 0-based index of the component at which to stop.
      *			Must be in the range [0,size()].
      * @return	A composite name consisting of the components at indexes in
      *		the range [0,posn).
      * @exception ArrayIndexOutOfBoundsException
      *		If posn is outside the specified range.
      */
    public Name getPrefix(int posn) {
	Enumeration comps = impl.getPrefix(posn);
	return (new CompositeName(comps));
    }

    /**
      * Creates a composite name whose components consist of a suffix of the
      * components in this composite name. Subsequent changes to
      * this composite name does not affect the name that is returned.
      *
      * @param	posn	The 0-based index of the component at which to start.
      *			Must be in the range [0,size()].
      * @return	A composite name consisting of the components at indexes in
      *		the range [posn,size()).  If posn is equal to 
      * 	size(), an empty composite name is returned.
      * @exception ArrayIndexOutOfBoundsException
      *		If posn is outside the specified range.
      */
    public Name getSuffix(int posn) {
	Enumeration comps = impl.getSuffix(posn);
	return (new CompositeName(comps));
    }

    /**
      * Determines whether a composite name is a prefix of this composite name.
      * A composite name 'n' is a prefix if it is equal to
      * getPrefix(n.size())--in other words, this composite name
      * starts with 'n'. If 'n' is null or not a composite name, false is returned.
      *
      * @param	n	The possibly null name to check.
      * @return	true if n is a CompositeName and
      * 	is a prefix of this composite name, false otherwise.
      */
    public boolean startsWith(Name n) {
	if (n instanceof CompositeName) {
	    return (impl.startsWith(n.size(), n.getAll()));
	} else {
	    return false;
	}
    }

    /**
      * Determines whether a composite name is a suffix of this composite name.
      * A composite name 'n' is a suffix if it it is equal to
      * getSuffix(size()-n.size())--in other words, this
      * composite name ends with 'n'.
      * If n is null or not a composite name, false is returned.
      *
      * @param	n	The possibly null name to check.
      * @return	true if n is a CompositeName and
      * 	is a suffix of this composite name, false otherwise.
      */
    public boolean endsWith(Name n) {
	if (n instanceof CompositeName) {
	    return (impl.endsWith(n.size(), n.getAll()));
	} else {
	    return false;
	}
    }

    /**
      * Adds the components of a composite name -- in order -- to the end of
      * this composite name.
      *
      * @param suffix	The non-null components to add.
      * @return The updated CompositeName, not a new one. Cannot be null.
      * @exception InvalidNameException If suffix is not a composite name.
      */
    public Name addAll(Name suffix)
	throws InvalidNameException
    {
	if (suffix instanceof CompositeName) {
	    impl.addAll(suffix.getAll());
	    return this;
	} else {
	    throw new InvalidNameException("Not a composite name: " +
		suffix.toString());
	}
    }

    /**
      * Adds the components of a composite name -- in order -- at a specified
      * position within this composite name.
      * Components of this composite name at or after the index of the first
      * new component are shifted up (away from index 0)
      * to accommodate the new components.
      *
      * @param n 	The non-null components to add.
      * @param posn	The index in this name at which to add the new
      *			components.  Must be in the range [0,size()].
      * @return The updated CompositeName, not a new one. Cannot be null.
      * @exception InvalidNameException If n is not a composite name.
      * @exception ArrayIndexOutOfBoundsException
      *		If posn is outside the specified range.
      */
    public Name addAll(int posn, Name n)
	throws InvalidNameException
    {
	if (n instanceof CompositeName) {
	    impl.addAll(posn, n.getAll());
	    return this;
	} else {
	    throw new InvalidNameException("Not a composite name: " +
		n.toString());
	}
    }

    /**
      * Adds a single component to the end of this composite name.
      *
      * @param comp	The non-null component to add.
      * @return The updated CompositeName, not a new one. 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 {
	impl.add(comp);
	return this;
    }

    /**
      * Adds a single component at a specified position within this
      * composite name.
      * Components of this composite name at or after the index 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 CompositeName, not a new one. Cannot be null.
      * @exception ArrayIndexOutOfBoundsException
      *		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
    {
	impl.add(posn, comp);
	return this;
    }

    /**
      * Deletes a component from this composite name.
      * The component of this composite name at position 'posn' is removed,
      * and components at indices greater than 'posn'
      * are shifted down (towards index 0) by one.
      *
      * @param	posn	The index of the component to delete.
      *			Must be in the range [0,size()).
      * @return The component removed (a String).
      * @exception ArrayIndexOutOfBoundsException
      *		If posn is outside the specified range (includes case where
      *		composite name is empty).
      * @exception InvalidNameException If deleting the component
      *				would violate the name's syntax.
      */
    public Object remove(int posn) throws InvalidNameException{
	return impl.remove(posn);
    }

    /**
     * Overridden to avoid implementation dependency.
     * @serialData The number of components (an <tt>int</tt>) followed by
     * the individual components (each a <tt>String</tt>).
     */
    private void writeObject(java.io.ObjectOutputStream s)
	    throws java.io.IOException {
	s.writeInt(size());
	Enumeration comps = getAll();
	while (comps.hasMoreElements()) {
	    s.writeObject(comps.nextElement());
	}
    }

    /**
     * Overridden to avoid implementation dependency.
     */
    private void readObject(java.io.ObjectInputStream s)
	    throws java.io.IOException, ClassNotFoundException {
	impl = new NameImpl(null);  // null means use default syntax
	int n = s.readInt();	// number of components
	try {
	    while (--n >= 0) {
		add((String)s.readObject());
	    }
	} catch (InvalidNameException e) {
	    throw (new java.io.StreamCorruptedException("Invalid name"));
	}
    }

    /**
     * Use serialVersionUID from JNDI 1.1.1 for interoperability
     */
    private static final long serialVersionUID = 1667768148915813118L;

/*
    // %%% Test code for serialization.
    public static void main(String[] args) throws Exception {
	CompositeName c = new CompositeName("aaa/bbb");
	java.io.FileOutputStream f1 = new java.io.FileOutputStream("/tmp/ser");
	java.io.ObjectOutputStream s1 = new java.io.ObjectOutputStream(f1);
	s1.writeObject(c);
	s1.close();
	java.io.FileInputStream f2 = new java.io.FileInputStream("/tmp/ser");
	java.io.ObjectInputStream s2 = new java.io.ObjectInputStream(f2);
	c = (CompositeName)s2.readObject();

	System.out.println("Size: " + c.size());
	System.out.println("Size: " + c.snit);
    }
*/

/*
   %%% Testing code
    public static void main(String[] args) {
	try {
	    for (int i = 0; i < args.length; i++) {
		Name name;
		Enumeration e;
		System.out.println("Given name: " + args[i]);
		name = new CompositeName(args[i]);
		e = name.getComponents();
		while (e.hasMoreElements()) {
		    System.out.println("Element: " + e.nextElement());
		}
		System.out.println("Constructed name: " + name.toString());
	    }
	} catch (Exception ne) {
	    ne.printStackTrace();
	}
    }
*/
}
