/*
 * 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.commons.compress.archivers.zip;

import java.util.zip.ZipException;

import static org.apache.commons.compress.archivers.zip.ZipConstants.DWORD;
import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD;

Holds size and other extended information for entries that use Zip64
features.
Currently Commons Compress doesn't support encrypting the
central directory so the note in APPNOTE.TXT about masking doesn't
apply.
The implementation relies on data being read from the local file
header and assumes that both size values are always present.
See Also:
PKWARE
 * APPNOTE.TXT, section 4.5.3
Since:
1.2
@NotThreadSafe
/**
 * Holds size and other extended information for entries that use Zip64
 * features.
 *
 * <p>Currently Commons Compress doesn't support encrypting the
 * central directory so the note in APPNOTE.TXT about masking doesn't
 * apply.</p>
 *
 * <p>The implementation relies on data being read from the local file
 * header and assumes that both size values are always present.</p>
 *
 * @see <a href="https://www.pkware.com/documents/casestudies/APPNOTE.TXT">PKWARE
 * APPNOTE.TXT, section 4.5.3</a>
 *
 * @since 1.2
 * @NotThreadSafe
 */
public class Zip64ExtendedInformationExtraField implements ZipExtraField {

    static final ZipShort HEADER_ID = new ZipShort(0x0001);

    private static final String LFH_MUST_HAVE_BOTH_SIZES_MSG =
        "Zip64 extended information must contain"
        + " both size values in the local file header.";
    private static final byte[] EMPTY = new byte[0];

    private ZipEightByteInteger size, compressedSize, relativeHeaderOffset;
    private ZipLong diskStart;

    
Stored in 
parseFromCentralDirectoryData so it can be reused when ZipFile calls 
reparseCentralDirectoryData. 
Not used for anything else
Since:
1.3/**
     * Stored in {@link #parseFromCentralDirectoryData
     * parseFromCentralDirectoryData} so it can be reused when ZipFile
     * calls {@link #reparseCentralDirectoryData
     * reparseCentralDirectoryData}.
     *
     * <p>Not used for anything else</p>
     *
     * @since 1.3
     */
    private byte[] rawCentralDirectoryData;

    
This constructor should only be used by the code that reads
archives inside of Commons Compress.
/**
     * This constructor should only be used by the code that reads
     * archives inside of Commons Compress.
     */
    public Zip64ExtendedInformationExtraField() { }

    
Creates an extra field based on the original and compressed size.
Params:
size – the entry's original size
compressedSize – the entry's compressed size
Throws:
IllegalArgumentException – if size or compressedSize is null/**
     * Creates an extra field based on the original and compressed size.
     *
     * @param size the entry's original size
     * @param compressedSize the entry's compressed size
     *
     * @throws IllegalArgumentException if size or compressedSize is null
     */
    public Zip64ExtendedInformationExtraField(final ZipEightByteInteger size,
                                              final ZipEightByteInteger compressedSize) {
        this(size, compressedSize, null, null);
    }

    
Creates an extra field based on all four possible values.
Params:
size – the entry's original size
compressedSize – the entry's compressed size
relativeHeaderOffset – the entry's offset
diskStart – the disk start
Throws:
IllegalArgumentException – if size or compressedSize is null/**
     * Creates an extra field based on all four possible values.
     *
     * @param size the entry's original size
     * @param compressedSize the entry's compressed size
     * @param relativeHeaderOffset the entry's offset
     * @param diskStart the disk start
     *
     * @throws IllegalArgumentException if size or compressedSize is null
     */
    public Zip64ExtendedInformationExtraField(final ZipEightByteInteger size,
                                              final ZipEightByteInteger compressedSize,
                                              final ZipEightByteInteger relativeHeaderOffset,
                                              final ZipLong diskStart) {
        this.size = size;
        this.compressedSize = compressedSize;
        this.relativeHeaderOffset = relativeHeaderOffset;
        this.diskStart = diskStart;
    }

    @Override
    public ZipShort getHeaderId() {
        return HEADER_ID;
    }

    @Override
    public ZipShort getLocalFileDataLength() {
        return new ZipShort(size != null ? 2 * DWORD : 0);
    }

    @Override
    public ZipShort getCentralDirectoryLength() {
        return new ZipShort((size != null ? DWORD : 0)
                            + (compressedSize != null ? DWORD : 0)
                            + (relativeHeaderOffset != null ? DWORD : 0)
                            + (diskStart != null ? WORD : 0));
    }

    @Override
    public byte[] getLocalFileDataData() {
        if (size != null || compressedSize != null) {
            if (size == null || compressedSize == null) {
                throw new IllegalArgumentException(LFH_MUST_HAVE_BOTH_SIZES_MSG);
            }
            final byte[] data = new byte[2 * DWORD];
            addSizes(data);
            return data;
        }
        return EMPTY;
    }

    @Override
    public byte[] getCentralDirectoryData() {
        final byte[] data = new byte[getCentralDirectoryLength().getValue()];
        int off = addSizes(data);
        if (relativeHeaderOffset != null) {
            System.arraycopy(relativeHeaderOffset.getBytes(), 0, data, off, DWORD);
            off += DWORD;
        }
        if (diskStart != null) {
            System.arraycopy(diskStart.getBytes(), 0, data, off, WORD);
            off += WORD; // NOSONAR - assignment as documentation
        }
        return data;
    }

    @Override
    public void parseFromLocalFileData(final byte[] buffer, int offset, final int length)
        throws ZipException {
        if (length == 0) {
            // no local file data at all, may happen if an archive
            // only holds a ZIP64 extended information extra field
            // inside the central directory but not inside the local
            // file header
            return;
        }
        if (length < 2 * DWORD) {
            throw new ZipException(LFH_MUST_HAVE_BOTH_SIZES_MSG);
        }
        size = new ZipEightByteInteger(buffer, offset);
        offset += DWORD;
        compressedSize = new ZipEightByteInteger(buffer, offset);
        offset += DWORD;
        int remaining = length - 2 * DWORD;
        if (remaining >= DWORD) {
            relativeHeaderOffset = new ZipEightByteInteger(buffer, offset);
            offset += DWORD;
            remaining -= DWORD;
        }
        if (remaining >= WORD) {
            diskStart = new ZipLong(buffer, offset);
            offset += WORD; // NOSONAR - assignment as documentation
            remaining -= WORD; // NOSONAR - assignment as documentation
        }
    }

    @Override
    public void parseFromCentralDirectoryData(final byte[] buffer, int offset,
                                              final int length)
        throws ZipException {
        // store for processing in reparseCentralDirectoryData
        rawCentralDirectoryData = new byte[length];
        System.arraycopy(buffer, offset, rawCentralDirectoryData, 0, length);

        // if there is no size information in here, we are screwed and
        // can only hope things will get resolved by LFH data later
        // But there are some cases that can be detected
        // * all data is there
        // * length == 24 -> both sizes and offset
        // * length % 8 == 4 -> at least we can identify the diskStart field
        if (length >= 3 * DWORD + WORD) {
            parseFromLocalFileData(buffer, offset, length);
        } else if (length == 3 * DWORD) {
            size = new ZipEightByteInteger(buffer, offset);
            offset += DWORD;
            compressedSize = new ZipEightByteInteger(buffer, offset);
            offset += DWORD;
            relativeHeaderOffset = new ZipEightByteInteger(buffer, offset);
        } else if (length % DWORD == WORD) {
            diskStart = new ZipLong(buffer, offset + length - WORD);
        }
    }

    
Parses the raw bytes read from the central directory extra
field with knowledge which fields are expected to be there.
All four fields inside the zip64 extended information extra
field are optional and must only be present if their corresponding
entry inside the central directory contains the correct magic
value.
Params:
hasUncompressedSize – flag to read from central directory
hasCompressedSize – flag to read from central directory
hasRelativeHeaderOffset – flag to read from central directory
hasDiskStart – flag to read from central directory
Throws:
ZipException – on error/**
     * Parses the raw bytes read from the central directory extra
     * field with knowledge which fields are expected to be there.
     *
     * <p>All four fields inside the zip64 extended information extra
     * field are optional and must only be present if their corresponding
     * entry inside the central directory contains the correct magic
     * value.</p>
     *
     * @param hasUncompressedSize flag to read from central directory
     * @param hasCompressedSize flag to read from central directory
     * @param hasRelativeHeaderOffset flag to read from central directory
     * @param hasDiskStart flag to read from central directory
     * @throws ZipException on error
     */
    public void reparseCentralDirectoryData(final boolean hasUncompressedSize,
                                            final boolean hasCompressedSize,
                                            final boolean hasRelativeHeaderOffset,
                                            final boolean hasDiskStart)
        throws ZipException {
        if (rawCentralDirectoryData != null) {
            final int expectedLength = (hasUncompressedSize ? DWORD : 0)
                + (hasCompressedSize ? DWORD : 0)
                + (hasRelativeHeaderOffset ? DWORD : 0)
                + (hasDiskStart ? WORD : 0);
            if (rawCentralDirectoryData.length < expectedLength) {
                throw new ZipException("Central directory zip64 extended"
                                       + " information extra field's length"
                                       + " doesn't match central directory"
                                       + " data.  Expected length "
                                       + expectedLength + " but is "
                                       + rawCentralDirectoryData.length);
            }
            int offset = 0;
            if (hasUncompressedSize) {
                size = new ZipEightByteInteger(rawCentralDirectoryData, offset);
                offset += DWORD;
            }
            if (hasCompressedSize) {
                compressedSize = new ZipEightByteInteger(rawCentralDirectoryData,
                                                         offset);
                offset += DWORD;
            }
            if (hasRelativeHeaderOffset) {
                relativeHeaderOffset =
                    new ZipEightByteInteger(rawCentralDirectoryData, offset);
                offset += DWORD;
            }
            if (hasDiskStart) {
                diskStart = new ZipLong(rawCentralDirectoryData, offset);
                offset += WORD; // NOSONAR - assignment as documentation
            }
        }
    }

    
The uncompressed size stored in this extra field.
Returns:
The uncompressed size stored in this extra field./**
     * The uncompressed size stored in this extra field.
     * @return The uncompressed size stored in this extra field.
     */
    public ZipEightByteInteger getSize() {
        return size;
    }

    
The uncompressed size stored in this extra field.
Params:
size – The uncompressed size stored in this extra field./**
     * The uncompressed size stored in this extra field.
     * @param size The uncompressed size stored in this extra field.
     */
    public void setSize(final ZipEightByteInteger size) {
        this.size = size;
    }

    
The compressed size stored in this extra field.
Returns:
The compressed size stored in this extra field./**
     * The compressed size stored in this extra field.
     * @return The compressed size stored in this extra field.
     */
    public ZipEightByteInteger getCompressedSize() {
        return compressedSize;
    }

    
The uncompressed size stored in this extra field.
Params:
compressedSize – The uncompressed size stored in this extra field./**
     * The uncompressed size stored in this extra field.
     * @param compressedSize The uncompressed size stored in this extra field.
     */
    public void setCompressedSize(final ZipEightByteInteger compressedSize) {
        this.compressedSize = compressedSize;
    }

    
The relative header offset stored in this extra field.
Returns:
The relative header offset stored in this extra field./**
     * The relative header offset stored in this extra field.
     * @return The relative header offset stored in this extra field.
     */
    public ZipEightByteInteger getRelativeHeaderOffset() {
        return relativeHeaderOffset;
    }

    
The relative header offset stored in this extra field.
Params:
rho – The relative header offset stored in this extra field./**
     * The relative header offset stored in this extra field.
     * @param rho The relative header offset stored in this extra field.
     */
    public void setRelativeHeaderOffset(final ZipEightByteInteger rho) {
        relativeHeaderOffset = rho;
    }

    
The disk start number stored in this extra field.
Returns:
The disk start number stored in this extra field./**
     * The disk start number stored in this extra field.
     * @return The disk start number stored in this extra field.
     */
    public ZipLong getDiskStartNumber() {
        return diskStart;
    }

    
The disk start number stored in this extra field.
Params:
ds – The disk start number stored in this extra field./**
     * The disk start number stored in this extra field.
     * @param ds The disk start number stored in this extra field.
     */
    public void setDiskStartNumber(final ZipLong ds) {
        diskStart = ds;
    }

    private int addSizes(final byte[] data) {
        int off = 0;
        if (size != null) {
            System.arraycopy(size.getBytes(), 0, data, 0, DWORD);
            off += DWORD;
        }
        if (compressedSize != null) {
            System.arraycopy(compressedSize.getBytes(), 0, data, off, DWORD);
            off += DWORD;
        }
        return off;
    }
}