/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.ant.core.xml;

import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.*;
import java.util.*;


/**
 * Validates and extracts attribute values from a set of element attributes.
 *
 * @author <a href="mailto:conor@apache.org">Conor MacNeill</a>
 */ 
public abstract class AttributeValidator {
    static public Map validateAttributes(String elementName, Attributes attributes, 
                                          Set validAttributes, Locator locator) 
        throws SAXParseException {
            
        return validateAttributes(elementName, attributes, null, validAttributes, locator);
    }

    static public Map validateAttributes(String elementName, Attributes attributes, Map aspects,
                                          Set validAttributes, Locator locator) 
        throws SAXParseException {
            
        Map attributeValues = new HashMap();    
        Set invalidAttributes = new HashSet();
        for (int i = 0; i < attributes.getLength(); ++i) {
            String attributeName = attributes.getQName(i);
            String attributeValue = attributes.getValue(i);
            if (validAttributes.contains(attributeName)) {
                attributeValues.put(attributeName, attributeValue);
            }
            else if (aspects != null && attributeName.indexOf(":") != -1) {
                aspects.put(attributeName, attributeValue);
            }
            else {
                invalidAttributes.add(attributeName);
            }
        }
        
        if (invalidAttributes.size() != 0) {
            StringBuffer message = new StringBuffer();
            boolean justOne = invalidAttributes.size() == 1;
            message.append(justOne ? "The attribute " : "The attributes ");
            for (Iterator i = invalidAttributes.iterator(); i.hasNext();) {
                String attributeName = (String)i.next();
                message.append(attributeName + " ");
            }
            message.append(justOne ? "is " : "are ");
            message.append("not valid for the <" + elementName + "> element.");
            
            throw new SAXParseException(message.toString(), locator);
        }
        
        return attributeValues;
    }

}
