/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Rhino code, released
 * May 6, 1999.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1997-2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Igor Bukanov
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License Version 2 or later (the "GPL"), in which
 * case the provisions of the GPL are applicable instead of those above. If
 * you wish to allow use of your version of this file only under the terms of
 * the GPL and not to allow others to use your version of this file under the
 * MPL, indicate your decision by deleting the provisions above and replacing
 * them with the notice and other provisions required by the GPL. If you do
 * not delete the provisions above, a recipient may use your version of this
 * file under either the MPL or the GPL.
 *
 * ***** END LICENSE BLOCK ***** */

package org.mozilla.javascript.yst.xml;

import org.mozilla.javascript.yst.*;

public abstract class XMLLib
{
    private static final Object XML_LIB_KEY = new Object();
	
	/**
		An object which specifies an XMLLib implementation to be used at runtime.
	 
		This interface should be considered experimental.  It may be better
		(and certainly more flexible) to write an interface that returns an
		XMLLib object rather than a class name, for example.  But that would
		cause many more ripple effects in the code, all the way back to
		{@link ScriptRuntime}.
	 */
	public static abstract class Factory {
		public static Factory create(final String className) {
			return new Factory() {
				public String getImplementationClassName() {
					return className;
				}
			};
		}
		
		public abstract String getImplementationClassName();
	}

    public static XMLLib extractFromScopeOrNull(Scriptable scope)
    {
        ScriptableObject so = ScriptRuntime.getLibraryScopeOrNull(scope);
        if (so == null) {
            // If library is not yet initialized, return null
            return null;
        }

        // Ensure lazily initialization of real XML library instance
        // which is done on first access to XML property
        ScriptableObject.getProperty(so, "XML");

        return (XMLLib)so.getAssociatedValue(XML_LIB_KEY);
    }

    public static XMLLib extractFromScope(Scriptable scope)
    {
        XMLLib lib = extractFromScopeOrNull(scope);
        if (lib != null) {
            return lib;
        }
        String msg = ScriptRuntime.getMessage0("msg.XML.not.available");
        throw Context.reportRuntimeError(msg);
    }

    protected final XMLLib bindToScope(Scriptable scope)
    {
        ScriptableObject so = ScriptRuntime.getLibraryScopeOrNull(scope);
        if (so == null) {
            // standard library should be initialized at this point
            throw new IllegalStateException();
        }
        return (XMLLib)so.associateValue(XML_LIB_KEY, this);
    }

    public abstract boolean isXMLName(Context cx, Object name);

    public abstract Ref nameRef(Context cx, Object name,
                                Scriptable scope, int memberTypeFlags);

    public abstract Ref nameRef(Context cx, Object namespace, Object name,
                                Scriptable scope, int memberTypeFlags);

    /**
     * Escapes the reserved characters in a value of an attribute.
     *
     * @param value Unescaped text
     * @return The escaped text
     */
    public abstract String escapeAttributeValue(Object value);

    /**
     * Escapes the reserved characters in a value of a text node.
     *
     * @param value Unescaped text
     * @return The escaped text
     */
    public abstract String escapeTextValue(Object value);


    /**
     * Construct namespace for default xml statement.
     */
    public abstract Object toDefaultXmlNamespace(Context cx, Object uriValue);
}
