/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (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.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.xerces.impl.xs.opti;

import org.w3c.dom.DOMException;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;

/**
 * @xerces.internal
 * 
 * @version $Id$
 */
final class SchemaDOMImplementation implements DOMImplementation {
    
    private static final SchemaDOMImplementation singleton = new SchemaDOMImplementation();
    
    /** NON-DOM: Obtain and return the single shared object */
    public static DOMImplementation getDOMImplementation() {
        return singleton;
    }
    
    private SchemaDOMImplementation() {}

    public Document createDocument(String namespaceURI, String qualifiedName, DocumentType doctype)
            throws DOMException {
        throw new DOMException(DOMException.NOT_SUPPORTED_ERR, "Method not supported");
    }

    public DocumentType createDocumentType(String qualifiedName, String publicId, String systemId)
            throws DOMException {
        throw new DOMException(DOMException.NOT_SUPPORTED_ERR, "Method not supported");
    }

    public Object getFeature(String feature, String version) {
        if (singleton.hasFeature(feature, version)) {
            return singleton;
        }
        return null;
    }

    public boolean hasFeature(String feature, String version) {
        final boolean anyVersion = version == null || version.length() == 0;
        return (feature.equalsIgnoreCase("Core") || feature.equalsIgnoreCase("XML")) && 
            (anyVersion || version.equals("1.0") || version.equals("2.0") || version.equals("3.0"));
    }

}
