/*
 * 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.sanselan.formats.jpeg.xmp;

import java.io.UnsupportedEncodingException;

import org.apache.sanselan.ImageReadException;
import org.apache.sanselan.common.BinaryFileParser;
import org.apache.sanselan.formats.jpeg.JpegConstants;

public class JpegXmpParser extends BinaryFileParser implements JpegConstants
{

    public JpegXmpParser()
    {
        setByteOrder(BYTE_ORDER_NETWORK);
    }


    public boolean isXmpJpegSegment(byte segmentData[])
    {
        int index = 0;

        if (segmentData.length < XMP_IDENTIFIER.length)
            return false;
        for (; index < XMP_IDENTIFIER.length; index++)
            if (segmentData[index] < XMP_IDENTIFIER[index])
                return false;

        return true;
    }

    public String parseXmpJpegSegment(byte segmentData[])
            throws ImageReadException
    {
        int index = 0;

        if (segmentData.length < XMP_IDENTIFIER.length)
            throw new ImageReadException("Invalid JPEG XMP Segment.");
        for (; index < XMP_IDENTIFIER.length; index++)
            if (segmentData[index] < XMP_IDENTIFIER[index])
                throw new ImageReadException("Invalid JPEG XMP Segment.");

        try
        {
            // segment data is UTF-8 encoded xml.
            String xml = new String(segmentData, index, segmentData.length
                    - index, "utf-8");
            return xml;
        } catch (UnsupportedEncodingException e)
        {
            throw new ImageReadException("Invalid JPEG XMP Segment.");
        }
    }

}