/*
 * 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.xmlgraphics.io;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URI;
import java.net.URL;

import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.URIResolver;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

public class URIResolverAdapter implements ResourceResolver {

    private final URIResolver resolver;

    public URIResolverAdapter(URIResolver resolver) {
        this.resolver = resolver;
    }

    public Resource getResource(URI uri) throws IOException {
        Source src;
        try {
            src = resolver.resolve(uri.toASCIIString(), null);
            if (src instanceof StreamSource) {
                return new Resource(((StreamSource) src).getInputStream());
            } else if (src instanceof DOMSource) {
                ByteArrayOutputStream outStream = new ByteArrayOutputStream();
                StreamResult xmlSource = new StreamResult(outStream);
                TransformerFactory.newInstance().newTransformer().transform(src, xmlSource);
                return new Resource(new ByteArrayInputStream(outStream.toByteArray()));
            }

            URL url = new URL(src.getSystemId());
            return new Resource(url.openStream());
        } catch (TransformerException e) {
            throw new RuntimeException(e);
        }
    }

    public OutputStream getOutputStream(URI uri) throws IOException {
        Source src;
        try {
            src = resolver.resolve(uri.toASCIIString(), null);
            if (src instanceof StreamResult) {
                return ((StreamResult) src).getOutputStream();
            }
        } catch (TransformerException e) {
            throw new RuntimeException(e);
        }
        return null;
    }
}