/* Copyright (C) 2001 Free Software Foundation

   This file is part of libgcj.

This software is copyrighted work licensed under the terms of the
Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
details.  */

package javax.naming;

import java.io.Serializable;
import java.util.Enumeration;
import java.util.Properties;
import java.util.NoSuchElementException;
import java.util.Vector;

/**
 * @author Tom Tromey <tromey@redhat.com>
 * @date May 16, 2001
 *
 * FIXME: must write readObject and writeObject to conform to
 * serialization spec.
 *
 * FIXME: this class is underspecified.  For instance, the `flat'
 * direction is never described.  If it means that the CompoundName
 * can only have a single element, then the Enumeration-based
 * constructor ought to throw InvalidNameException.
 */
public class CompoundName implements Name, Cloneable, Serializable
{
  private CompoundName (Properties syntax)
  {
    elts = new Vector ();
    mySyntax = syntax;
    initializeSyntax ();
  }

  protected CompoundName (Enumeration comps, Properties syntax)
  {
    elts = new Vector ();
    mySyntax = syntax;
    initializeSyntax ();
    try
      {
	while (comps.hasMoreElements ())
	  elts.add (comps.nextElement ());
      }
    catch (NoSuchElementException ignore)
      {
      }
  }

  public CompoundName (String n, Properties syntax)
    throws InvalidNameException
  {
    elts = new Vector ();
    mySyntax = syntax;
    initializeSyntax ();

    StringBuffer new_element = new StringBuffer ();
    int i = 0;
    // QUOTE==null means no quoting right now.  When it is set it is
    // the value of the closing quote.
    String quote = null;
    while (i < n.length ())
      {
	String special = isSpecial (n, i);

	if (special == escape && escape != null)
	  {
	    if (n.length () == i + special.length ())
	      {
		// A trailing escape is treated as itself.
		new_element.append (special);
		i += special.length ();
	      }
	    else
	      {
		String eSpecial = isSpecial (n, i + special.length ());
		if (eSpecial != null)
		  {
		    // Treat the escape as an escape.
		    new_element.append (eSpecial);
		    i += special.length () + eSpecial.length ();
		  }
		else
		  {
		    // Treat the escape as itself.
		    new_element.append (special);
		    i += special.length ();
		  }
		continue;
	      }
	  }
	else if (quote != null)
	  {
	    // It is safe to use == here.
	    if (quote == special)
	      {
		// Quotes must surround a complete component.
		if (i + quote.length () < n.length ()
		    && ! n.startsWith (separator, i + quote.length ()))
		  throw new InvalidNameException ("close quote before end of component");
		elts.add (new_element.toString ());
		new_element.setLength (0);
		i += quote.length ();
		quote = null;
		continue;
	      }
	    // Otherwise, fall through.
	  }
	// Quotes are only special at the start of a component.
	else if (new_element.length () == 0 && special == beginQuote)
	  {
	    quote = endQuote;
	    i += special.length ();
	    continue;
	  }
	else if (new_element.length () == 0 && special == beginQuote2)
	  {
	    quote = endQuote2;
	    i += special.length ();
	    continue;
	  }
	else if (special == separator)
	  {
	    elts.add (new_element.toString ());
	    new_element.setLength (0);
	    i += special.length ();
	    continue;
	  }

	// Nothing in particular, so try the next character.
	new_element.append (n.charAt (i));
	++i;
      }

    if (new_element.length () != 0)
      elts.add (new_element.toString ());

    if (direction == RIGHT_TO_LEFT)
      {
	// Reverse the order of the elements.
	int len = elts.size ();
	for (i = 0; i < len / 2; ++i)
	  {
	    Object t = elts.set (i, elts.get (len - i - 1));
	    elts.set (len - i - 1, t);
	  }
      }

    // Error checking.
    if (quote != null)
      throw new InvalidNameException ("unterminated quote");
  }

  public Name add (int posn, String comp) throws InvalidNameException
  {
    elts.add (posn, comp);
    return this;
  }

  public Name add (String comp) throws InvalidNameException
  {
    elts.add (comp);
    return this;
  }

  public Name addAll (int posn, Name n) throws InvalidNameException
  {
    Enumeration e = n.getAll ();
    try
      {
	while (e.hasMoreElements ())
	  {
	    elts.add (posn, e.nextElement ());
	    ++posn;
	  }
      }
    catch (NoSuchElementException ignore)
      {
      }
    return this;
  }

  public Name addAll (Name suffix) throws InvalidNameException
  {
    Enumeration e = suffix.getAll ();
    try
      {
	while (e.hasMoreElements ())
	  elts.add (e.nextElement ());
      }
    catch (NoSuchElementException ignore)
      {
      }
    return this;
  }

  public Object clone ()
  {
    return new CompoundName (elts.elements (), mySyntax);
  }

  public int compareTo (Object obj)
  {
    if (obj == null || ! (obj instanceof CompoundName))
      throw new ClassCastException ("CompoundName.compareTo() expected CompoundName");
    CompoundName cn = (CompoundName) obj;
    int last = Math.min (cn.elts.size (), elts.size ());
    for (int i = 0; i < last; ++i)
      {
	String f = canonicalize ((String) elts.get (i));
	int comp = f.compareTo (canonicalize ((String) cn.elts.get (i)));
	if (comp != 0)
	  return comp;
      }
    return elts.size () - cn.elts.size ();
  }

  public boolean endsWith (Name n)
  {
    if (! (n instanceof CompoundName))
      return false;
    CompoundName cn = (CompoundName) n;
    if (cn.elts.size () > elts.size ())
      return false;
    int delta = elts.size () - cn.elts.size ();
    for (int i = 0; i < cn.elts.size (); ++i)
      {
	String f = canonicalize ((String) elts.get (i));
	if (! f.equals (canonicalize ((String) cn.elts.get (i))))
	  return false;
      }
    return true;
  }

  public boolean equals (Object obj)
  {
    if (! (obj instanceof CompoundName))
      return false;
    return compareTo (obj) == 0;
  }

  public String get (int posn)
  {
    return (String) elts.get (posn);
  }

  public Enumeration getAll ()
  {
    return elts.elements ();
  }

  public Name getPrefix (int posn)
  {
    CompoundName cn = new CompoundName (mySyntax);
    for (int i = 0; i < posn; ++i)
      cn.elts.add (elts.get (i));
    return cn;
  }

  public Name getSuffix (int posn)
  {
    if (posn > elts.size ())
      throw new ArrayIndexOutOfBoundsException (posn);
    CompoundName cn = new CompoundName (mySyntax);
    for (int i = posn; i < elts.size (); ++i)
      cn.elts.add (elts.get (i));
    return cn;
  }

  public int hashCode ()
  {
    int h = 0;
    for (int i = 0; i < elts.size (); ++i)
      h += canonicalize ((String) elts.get (i)).hashCode ();
    return h;
  }

  public boolean isEmpty ()
  {
    return elts.isEmpty ();
  }

  public Object remove (int posn) throws InvalidNameException
  {
    return elts.remove (posn);
  }

  public int size ()
  {
    return elts.size ();
  }

  public boolean startsWith (Name n)
  {
    if (! (n instanceof CompoundName))
      return false;
    CompoundName cn = (CompoundName) n;
    if (cn.elts.size () > elts.size ())
      return false;
    for (int i = 0; i < cn.elts.size (); ++i)
      {
	String f = canonicalize ((String) elts.get (i));
	if (! f.equals (canonicalize ((String) cn.elts.get (i))))
	  return false;
      }
    return true;
  }

  // If ELEMENT starts with some meta-sequence at OFFSET, then return
  // the string representing the meta-sequence.  Otherwise return
  // null.
  private String isSpecial (String element, int offset)
  {
    String special = null;
    if (separator != null && element.startsWith (separator, offset))
      special = separator;
    else if (escape != null && element.startsWith (escape, offset))
      special = escape;
    else if (beginQuote != null && element.startsWith (beginQuote, offset))
      special = beginQuote;
    else if (endQuote != null && element.startsWith (endQuote, offset))
      special = endQuote;
    else if (beginQuote2 != null
	     && element.startsWith (beginQuote2, offset))
      special = beginQuote2;
    else if (endQuote2 != null && element.startsWith (endQuote2, offset))
      special = endQuote2;

    return special;
  }

  public String toString ()
  {
    StringBuffer result = new StringBuffer ();
    int size = elts.size ();
    for (int i = 0; i < size; ++i)
      {
	// Find the appropriate element.  FIXME: not clear what FLAT
	// means.
	int offset = (direction == RIGHT_TO_LEFT) ? (size - i - 1) : i;
	String element = (String) elts.get (offset);
	if (i > 0
	    || (i == size - 1 && element.equals ("")))
	  result.append (separator);

	int k = 0;
	while (k < element.length ())
	  {
	    String special = isSpecial (element, k);
	    if (special != null)
	      {
		result.append (escape);
		result.append (special);
		k += special.length ();
	      }
	    else
	      {
		result.append (element.charAt (k));
		++k;
	      }
	  }
      }

    return result.toString ();
  }

  // This canonicalizes a String, based on the syntax, for comparison
  // or other similar purposes.
  private String canonicalize (String element)
  {
    String ret = element;

    if (ignoreCase)
      ret = ret.toLowerCase ();

    if (trimBlanks)
      {
	int first = 0;
	while (first < ret.length ()
	       && Character.isWhitespace (ret.charAt (first)))
	  ++first;

	int last = ret.length () - 1;
	while (last >= first
	       && Character.isWhitespace (ret.charAt (last)))
	  --last;

	ret = ret.substring (first, last);
      }

    return ret;
  }

  // This initializes all the syntax variables.  This seems easier
  // than re-querying the properties every time.  We're allowed to do
  // this because the spec says that subclasses should consider the
  // syntax as being read-only.
  private void initializeSyntax ()
  {
    String t = mySyntax.getProperty ("jndi.syntax.direction", "flat");
    if (t.equals ("right_to_left"))
      this.direction = RIGHT_TO_LEFT;
    else if (t.equals ("left_to_right"))
      this.direction = LEFT_TO_RIGHT;
    else
      {
	// If we don't recognize it, default to flat.
	this.direction = FLAT;
      }

    // This is required unless the direction is FLAT.  Unfortunately
    // there is no way to report this error.
    this.separator = mySyntax.getProperty ("jndi.syntax.separator", "");

    this.ignoreCase
      = Boolean.valueOf (mySyntax.getProperty ("jndi.syntax.ignorecase",
					       "false")).booleanValue ();
    this.escape = mySyntax.getProperty ("jndi.syntax.escape", null);
    this.beginQuote = mySyntax.getProperty ("jndi.syntax.beginquote", null);
    this.endQuote = mySyntax.getProperty ("jndi.syntax.endquote",
					  this.beginQuote);
    this.beginQuote2 = mySyntax.getProperty ("jndi.syntax.beginquote2",
					     null);
    this.endQuote2 = mySyntax.getProperty ("jndi.syntax.endquote2",
					   this.beginQuote2);
    this.trimBlanks
      = Boolean.valueOf (mySyntax.getProperty ("jndi.syntax.trimblanks",
					       "false")).booleanValue ();
  }

  // The spec specifies this but does not document it in any way (it
  // is a package-private class).  It is useless as far as I can tell.
  // So we ignore it.
  // protected transient NameImpl impl;
  protected transient Properties mySyntax;

  // The actual elements.
  private transient Vector elts;

  // The following are all used for syntax.
  private transient int direction;
  private transient String separator;
  private transient boolean ignoreCase;
  private transient String escape;
  private transient String beginQuote;
  private transient String endQuote;
  private transient String beginQuote2;
  private transient String endQuote2;
  private transient boolean trimBlanks;
  // We didn't need these for parsing, so they are gone.
  // private transient String avaSeparator;
  // private transient String typevalSeparator;

  private static final int RIGHT_TO_LEFT = -1;
  private static final int LEFT_TO_RIGHT = 1;
  private static final int FLAT = 0;
}