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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package com.sun.xml.internal.bind.v2.runtime.unmarshaller;

import java.io.ByteArrayInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import javax.activation.DataHandler;

import javax.activation.DataSource;

import javax.xml.stream.XMLStreamException;

import javax.xml.stream.XMLStreamWriter;

import com.sun.xml.internal.bind.DatatypeConverterImpl;

import com.sun.xml.internal.bind.v2.runtime.XMLSerializer;

import com.sun.xml.internal.bind.v2.runtime.output.Pcdata;

import com.sun.xml.internal.bind.v2.runtime.output.UTF8XmlOutput;

import com.sun.xml.internal.bind.v2.util.ByteArrayOutputStreamEx;

import com.sun.istack.internal.Nullable;

/**

 * Fed to unmarshaller when the 'text' data is actually

 * a virtual image of base64 encoding of the binary data

 * transferred on the wire.

 *

 * Used for the MTOM support.

 *

 * This object is mutable and the owner of this object can

 * reuse it with new data.

 *

 * Also used by the marshaller to write out the binary data

 * that could be possibly attached.

 *

 * @see XmlVisitor#text(CharSequence)

 * @see XMLSerializer#text(Pcdata,String)

 *

 * @author Kohsuke Kawaguchi, Martin Grebac

 */

public final class Base64Data extends Pcdata {

    // either dataHandler or (data,dataLen,mimeType?) must be present

    private DataHandler dataHandler;

    private byte[] data;

    /**

     * Length of the valid data in {@link #data}.

     */

    private int dataLen;

    /**

     * Optional MIME type of {@link #data}.

     *

     * Unused when {@link #dataHandler} is set.

     * Use {@link DataHandler#getContentType()} in that case.

     */

    private @Nullable

    String mimeType;

    /**

     * Fills in the data object by a portion of the byte[].

     *

     * @param len

     *      data[0] to data[len-1] are treated as the data.

     */

    public void set(byte[] data, int len, @Nullable String mimeType) {

        this.data = data;

        this.dataLen = len;

        this.dataHandler = null;

        this.mimeType = mimeType;

    }

    /**

     * Fills in the data object by the byte[] of the exact length.

     *

     * @param data

     *      this buffer may be owned directly by the unmarshaleld JAXB object.

     */

    public void set(byte[] data, @Nullable String mimeType) {

        set(data, data.length, mimeType);

    }

    /**

     * Fills in the data object by a {@link DataHandler}.

     */

    public void set(DataHandler data) {

        assert data != null;

        this.dataHandler = data;

        this.data = null;

    }

    /**

     * Gets the raw data.

     */

    public DataHandler getDataHandler() {

        if (dataHandler == null) {

            dataHandler = new DataHandler(new DataSource() {

                public String getContentType() {

                    return getMimeType();

                }

                public InputStream getInputStream() {

                    return new ByteArrayInputStream(data, 0, dataLen);

                }

                public String getName() {

                    return null;

                }

                public OutputStream getOutputStream() {

                    throw new UnsupportedOperationException();

                }

            });

        }

        return dataHandler;

    }

    /**

     * Gets the byte[] of the exact length.

     */

    public byte[] getExact() {

        get();

        if (dataLen != data.length) {

            byte[] buf = new byte[dataLen];

            System.arraycopy(data, 0, buf, 0, dataLen);

            data = buf;

        }

        return data;

    }

    /**

     * Gets the data as an {@link InputStream}.

     */

    public InputStream getInputStream() throws IOException {

        if (dataHandler != null) {

            return dataHandler.getInputStream();

        } else {

            return new ByteArrayInputStream(data, 0, dataLen);

        }

    }

    /**

     * Returns false if this object only has {@link DataHandler} and therefore

     * {@link #get()} operation is likely going to be expensive.

     */

    public boolean hasData() {

        return data != null;

    }

    /**

     * Gets the raw data. The size of the byte array maybe larger than the actual length.

     */

    public byte[] get() {

        if (data == null) {

            try {

                ByteArrayOutputStreamEx baos = new ByteArrayOutputStreamEx(1024);

                InputStream is = dataHandler.getDataSource().getInputStream();

                baos.readFrom(is);

                is.close();

                data = baos.getBuffer();

                dataLen = baos.size();

            } catch (IOException e) {

                // TODO: report the error to the unmarshaller

                dataLen = 0;    // recover by assuming length-0 data

            }

        }

        return data;

    }

    public int getDataLen() {

        return dataLen;

    }

    public String getMimeType() {

        if (mimeType == null) {

            return "application/octet-stream";

        }

        return mimeType;

    }

    /**

     * Gets the number of characters needed to represent

     * this binary data in the base64 encoding.

     */

    public int length() {

        // for each 3 bytes you use 4 chars

        // if the remainder is 1 or 2 there will be 4 more

        get();  // fill in the buffer if necessary

        return ((dataLen + 2) / 3) * 4;

    }

    /**

     * Encode this binary data in the base64 encoding

     * and returns the character at the specified position.

     */

    public char charAt(int index) {

        // we assume that the length() method is called before this method

        // (otherwise how would the caller know that the index is valid?)

        // so we assume that the byte[] is already populated

        int offset = index % 4;

        int base = (index / 4) * 3;

        byte b1, b2;

        switch (offset) {

            case 0:

                return DatatypeConverterImpl.encode(data[base] >> 2);

            case 1:

                if (base + 1 < dataLen) {

                    b1 = data[base + 1];

                } else {

                    b1 = 0;

                }

                return DatatypeConverterImpl.encode(

                        ((data[base] & 0x3) << 4)

                        | ((b1 >> 4) & 0xF));

            case 2:

                if (base + 1 < dataLen) {

                    b1 = data[base + 1];

                    if (base + 2 < dataLen) {

                        b2 = data[base + 2];

                    } else {

                        b2 = 0;

                    }

                    return DatatypeConverterImpl.encode(

                            ((b1 & 0xF) << 2)

                            | ((b2 >> 6) & 0x3));

                } else {

                    return '=';

                }

            case 3:

                if (base + 2 < dataLen) {

                    return DatatypeConverterImpl.encode(data[base + 2] & 0x3F);

                } else {

                    return '=';

                }

        }

        throw new IllegalStateException();

    }

    /**

     * Internally this is only used to split a text to a list,

     * which doesn't happen that much for base64.

     * So this method should be smaller than faster.

     */

    public CharSequence subSequence(int start, int end) {

        StringBuilder buf = new StringBuilder();

        get();  // fill in the buffer if we haven't done so

        for (int i = start; i < end; i++) {

            buf.append(charAt(i));

        }

        return buf;

    }

    /**

     * Returns the base64 encoded string of this data.

     */

    public String toString() {

        get();  // fill in the buffer

        return DatatypeConverterImpl._printBase64Binary(data, 0, dataLen);

    }

    @Override

    public void writeTo(char[] buf, int start) {

        get();

        DatatypeConverterImpl._printBase64Binary(data, 0, dataLen, buf, start);

    }

    public void writeTo(UTF8XmlOutput output) throws IOException {

        // TODO: this is inefficient if the data source is note byte[] but DataHandler

        get();

        output.text(data, dataLen);

    }

    public void writeTo(XMLStreamWriter output) throws IOException, XMLStreamException {

        get();

        DatatypeConverterImpl._printBase64Binary(data, 0, dataLen, output);

    }

}