/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.util.zip;

import java.io.OutputStream;

import java.io.IOException;

import java.nio.charset.Charset;

import java.nio.charset.StandardCharsets;

import java.util.Vector;

import java.util.HashSet;

import static java.util.zip.ZipConstants64.*;

/**

 * This class implements an output stream filter for writing files in the

 * ZIP file format. Includes support for both compressed and uncompressed

 * entries.

 *

 * @author      David Connelly

 */

public

class ZipOutputStream extends DeflaterOutputStream implements ZipConstants {

    private static class XEntry {

        public final ZipEntry entry;

        public final long offset;

        public XEntry(ZipEntry entry, long offset) {

            this.entry = entry;

            this.offset = offset;

        }

    }

    private XEntry current;

    private Vector<XEntry> xentries = new Vector<>();

    private HashSet<String> names = new HashSet<>();

    private CRC32 crc = new CRC32();

    private long written = 0;

    private long locoff = 0;

    private byte[] comment;

    private int method = DEFLATED;

    private boolean finished;

    private boolean closed = false;

    private final ZipCoder zc;

    private static int version(ZipEntry e) throws ZipException {

        switch (e.method) {

        case DEFLATED: return 20;

        case STORED:   return 10;

        default: throw new ZipException("unsupported compression method");

        }

    }

    /**

     * Checks to make sure that this stream has not been closed.

     */

    private void ensureOpen() throws IOException {

        if (closed) {

            throw new IOException("Stream closed");

        }

    }

    /**

     * Compression method for uncompressed (STORED) entries.

     */

    public static final int STORED = ZipEntry.STORED;

    /**

     * Compression method for compressed (DEFLATED) entries.

     */

    public static final int DEFLATED = ZipEntry.DEFLATED;

    /**

     * Creates a new ZIP output stream.

     *

     * <p>The UTF-8 {@link java.nio.charset.Charset charset} is used

     * to encode the entry names and comments.

     *

     * @param out the actual output stream

     */

    public ZipOutputStream(OutputStream out) {

        this(out, StandardCharsets.UTF_8);

    }

    /**

     * Creates a new ZIP output stream.

     *

     * @param out the actual output stream

     *

     * @param charset the {@linkplain java.nio.charset.Charset charset}

     *                to be used to encode the entry names and comments

     *

     * @since 1.7

     */

    public ZipOutputStream(OutputStream out, Charset charset) {

        super(out, new Deflater(Deflater.DEFAULT_COMPRESSION, true));

        if (charset == null)

            throw new NullPointerException("charset is null");

        this.zc = ZipCoder.get(charset);

        usesDefaultDeflater = true;

    }

    /**

     * Sets the ZIP file comment.

     * @param comment the comment string

     * @exception IllegalArgumentException if the length of the specified

     *            ZIP file comment is greater than 0xFFFF bytes

     */

    public void setComment(String comment) {

        if (comment != null) {

            this.comment = zc.getBytes(comment);

            if (this.comment.length > 0xffff)

                throw new IllegalArgumentException("ZIP file comment too long.");

        }

    }

    /**

     * Sets the default compression method for subsequent entries. This

     * default will be used whenever the compression method is not specified

     * for an individual ZIP file entry, and is initially set to DEFLATED.

     * @param method the default compression method

     * @exception IllegalArgumentException if the specified compression method

     *            is invalid

     */

    public void setMethod(int method) {

        if (method != DEFLATED && method != STORED) {

            throw new IllegalArgumentException("invalid compression method");

        }

        this.method = method;

    }

    /**

     * Sets the compression level for subsequent entries which are DEFLATED.

     * The default setting is DEFAULT_COMPRESSION.

     * @param level the compression level (0-9)

     * @exception IllegalArgumentException if the compression level is invalid

     */

    public void setLevel(int level) {

        def.setLevel(level);

    }

    /**

     * Begins writing a new ZIP file entry and positions the stream to the

     * start of the entry data. Closes the current entry if still active.

     * The default compression method will be used if no compression method

     * was specified for the entry, and the current time will be used if

     * the entry has no set modification time.

     * @param e the ZIP entry to be written

     * @exception ZipException if a ZIP format error has occurred

     * @exception IOException if an I/O error has occurred

     */

    public void putNextEntry(ZipEntry e) throws IOException {

        ensureOpen();

        if (current != null) {

            closeEntry();       // close previous entry

        }

        if (e.time == -1) {

            e.setTime(System.currentTimeMillis());

        }

        if (e.method == -1) {

            e.method = method;  // use default method

        }

        // store size, compressed size, and crc-32 in LOC header

        e.flag = 0;

        switch (e.method) {

        case DEFLATED:

            // store size, compressed size, and crc-32 in data descriptor

            // immediately following the compressed entry data

            if (e.size  == -1 || e.csize == -1 || e.crc   == -1)

                e.flag = 8;

            break;

        case STORED:

            // compressed size, uncompressed size, and crc-32 must all be

            // set for entries using STORED compression method

            if (e.size == -1) {

                e.size = e.csize;

            } else if (e.csize == -1) {

                e.csize = e.size;

            } else if (e.size != e.csize) {

                throw new ZipException(

                    "STORED entry where compressed != uncompressed size");

            }

            if (e.size == -1 || e.crc == -1) {

                throw new ZipException(

                    "STORED entry missing size, compressed size, or crc-32");

            }

            break;

        default:

            throw new ZipException("unsupported compression method");

        }

        if (! names.add(e.name)) {

            throw new ZipException("duplicate entry: " + e.name);

        }

        if (zc.isUTF8())

            e.flag |= EFS;

        current = new XEntry(e, written);

        xentries.add(current);

        writeLOC(current);

    }

    /**

     * Closes the current ZIP entry and positions the stream for writing

     * the next entry.

     * @exception ZipException if a ZIP format error has occurred

     * @exception IOException if an I/O error has occurred

     */

    public void closeEntry() throws IOException {

        ensureOpen();

        if (current != null) {

            ZipEntry e = current.entry;

            switch (e.method) {

            case DEFLATED:

                def.finish();

                while (!def.finished()) {

                    deflate();

                }

                if ((e.flag & 8) == 0) {

                    // verify size, compressed size, and crc-32 settings

                    if (e.size != def.getBytesRead()) {

                        throw new ZipException(

                            "invalid entry size (expected " + e.size +

                            " but got " + def.getBytesRead() + " bytes)");

                    }

                    if (e.csize != def.getBytesWritten()) {

                        throw new ZipException(

                            "invalid entry compressed size (expected " +

                            e.csize + " but got " + def.getBytesWritten() + " bytes)");

                    }

                    if (e.crc != crc.getValue()) {

                        throw new ZipException(

                            "invalid entry CRC-32 (expected 0x" +

                            Long.toHexString(e.crc) + " but got 0x" +

                            Long.toHexString(crc.getValue()) + ")");

                    }

                } else {

                    e.size  = def.getBytesRead();

                    e.csize = def.getBytesWritten();

                    e.crc = crc.getValue();

                    writeEXT(e);

                }

                def.reset();

                written += e.csize;

                break;

            case STORED:

                // we already know that both e.size and e.csize are the same

                if (e.size != written - locoff) {

                    throw new ZipException(

                        "invalid entry size (expected " + e.size +

                        " but got " + (written - locoff) + " bytes)");

                }

                if (e.crc != crc.getValue()) {

                    throw new ZipException(

                         "invalid entry crc-32 (expected 0x" +

                         Long.toHexString(e.crc) + " but got 0x" +

                         Long.toHexString(crc.getValue()) + ")");

                }

                break;

            default:

                throw new ZipException("invalid compression method");

            }

            crc.reset();

            current = null;

        }

    }

    /**

     * Writes an array of bytes to the current ZIP entry data. This method

     * will block until all the bytes are written.

     * @param b the data to be written

     * @param off the start offset in the data

     * @param len the number of bytes that are written

     * @exception ZipException if a ZIP file error has occurred

     * @exception IOException if an I/O error has occurred

     */

    public synchronized void write(byte[] b, int off, int len)

        throws IOException

    {

        ensureOpen();

        if (off < 0 || len < 0 || off > b.length - len) {

            throw new IndexOutOfBoundsException();

        } else if (len == 0) {

            return;

        }

        if (current == null) {

            throw new ZipException("no current ZIP entry");

        }

        ZipEntry entry = current.entry;

        switch (entry.method) {

        case DEFLATED:

            super.write(b, off, len);

            break;

        case STORED:

            written += len;

            if (written - locoff > entry.size) {

                throw new ZipException(

                    "attempt to write past end of STORED entry");

            }

            out.write(b, off, len);

            break;

        default:

            throw new ZipException("invalid compression method");

        }

        crc.update(b, off, len);

    }

    /**

     * Finishes writing the contents of the ZIP output stream without closing

     * the underlying stream. Use this method when applying multiple filters

     * in succession to the same output stream.

     * @exception ZipException if a ZIP file error has occurred

     * @exception IOException if an I/O exception has occurred

     */

    public void finish() throws IOException {

        ensureOpen();

        if (finished) {

            return;

        }

        if (current != null) {

            closeEntry();

        }

        // write central directory

        long off = written;

        for (XEntry xentry : xentries)

            writeCEN(xentry);

        writeEND(off, written - off);

        finished = true;

    }

    /**

     * Closes the ZIP output stream as well as the stream being filtered.

     * @exception ZipException if a ZIP file error has occurred

     * @exception IOException if an I/O error has occurred

     */

    public void close() throws IOException {

        if (!closed) {

            super.close();

            closed = true;

        }

    }

    /*

     * Writes local file (LOC) header for specified entry.

     */

    private void writeLOC(XEntry xentry) throws IOException {

        ZipEntry e = xentry.entry;

        int flag = e.flag;

        int elen = (e.extra != null) ? e.extra.length : 0;

        boolean hasZip64 = false;

        writeInt(LOCSIG);               // LOC header signature

        if ((flag & 8) == 8) {

            writeShort(version(e));     // version needed to extract

            writeShort(flag);           // general purpose bit flag

            writeShort(e.method);       // compression method

            writeInt(e.time);           // last modification time

            // store size, uncompressed size, and crc-32 in data descriptor

            // immediately following compressed entry data

            writeInt(0);

            writeInt(0);

            writeInt(0);

        } else {

            if (e.csize >= ZIP64_MAGICVAL || e.size >= ZIP64_MAGICVAL) {

                hasZip64 = true;

                writeShort(45);         // ver 4.5 for zip64

            } else {

                writeShort(version(e)); // version needed to extract

            }

            writeShort(flag);           // general purpose bit flag

            writeShort(e.method);       // compression method

            writeInt(e.time);           // last modification time

            writeInt(e.crc);            // crc-32

            if (hasZip64) {

                writeInt(ZIP64_MAGICVAL);

                writeInt(ZIP64_MAGICVAL);

                elen += 20;        //headid(2) + size(2) + size(8) + csize(8)

            } else {

                writeInt(e.csize);  // compressed size

                writeInt(e.size);   // uncompressed size

            }

        }

        byte[] nameBytes = zc.getBytes(e.name);

        writeShort(nameBytes.length);

        writeShort(elen);

        writeBytes(nameBytes, 0, nameBytes.length);

        if (hasZip64) {

            writeShort(ZIP64_EXTID);

            writeShort(16);

            writeLong(e.size);

            writeLong(e.csize);

        }

        if (e.extra != null) {

            writeBytes(e.extra, 0, e.extra.length);

        }

        locoff = written;

    }

    /*

     * Writes extra data descriptor (EXT) for specified entry.

     */

    private void writeEXT(ZipEntry e) throws IOException {

        writeInt(EXTSIG);           // EXT header signature

        writeInt(e.crc);            // crc-32

        if (e.csize >= ZIP64_MAGICVAL || e.size >= ZIP64_MAGICVAL) {

            writeLong(e.csize);

            writeLong(e.size);

        } else {

            writeInt(e.csize);          // compressed size

            writeInt(e.size);           // uncompressed size

        }

    }

    /*

     * Write central directory (CEN) header for specified entry.

     * REMIND: add support for file attributes

     */

    private void writeCEN(XEntry xentry) throws IOException {

        ZipEntry e  = xentry.entry;

        int flag = e.flag;

        int version = version(e);

        long csize = e.csize;

        long size = e.size;

        long offset = xentry.offset;

        int e64len = 0;

        boolean hasZip64 = false;

        if (e.csize >= ZIP64_MAGICVAL) {

            csize = ZIP64_MAGICVAL;

            e64len += 8;              // csize(8)

            hasZip64 = true;

        }

        if (e.size >= ZIP64_MAGICVAL) {

            size = ZIP64_MAGICVAL;    // size(8)

            e64len += 8;

            hasZip64 = true;

        }

        if (xentry.offset >= ZIP64_MAGICVAL) {

            offset = ZIP64_MAGICVAL;

            e64len += 8;              // offset(8)

            hasZip64 = true;

        }

        writeInt(CENSIG);           // CEN header signature

        if (hasZip64) {

            writeShort(45);         // ver 4.5 for zip64

            writeShort(45);

        } else {

            writeShort(version);    // version made by

            writeShort(version);    // version needed to extract

        }

        writeShort(flag);           // general purpose bit flag

        writeShort(e.method);       // compression method

        writeInt(e.time);           // last modification time

        writeInt(e.crc);            // crc-32

        writeInt(csize);            // compressed size

        writeInt(size);             // uncompressed size

        byte[] nameBytes = zc.getBytes(e.name);

        writeShort(nameBytes.length);

        if (hasZip64) {

            // + headid(2) + datasize(2)

            writeShort(e64len + 4 + (e.extra != null ? e.extra.length : 0));

        } else {

            writeShort(e.extra != null ? e.extra.length : 0);

        }

        byte[] commentBytes;

        if (e.comment != null) {

            commentBytes = zc.getBytes(e.comment);

            writeShort(Math.min(commentBytes.length, 0xffff));

        } else {

            commentBytes = null;

            writeShort(0);

        }

        writeShort(0);              // starting disk number

        writeShort(0);              // internal file attributes (unused)

        writeInt(0);                // external file attributes (unused)

        writeInt(offset);           // relative offset of local header

        writeBytes(nameBytes, 0, nameBytes.length);

        if (hasZip64) {

            writeShort(ZIP64_EXTID);// Zip64 extra

            writeShort(e64len);

            if (size == ZIP64_MAGICVAL)

                writeLong(e.size);

            if (csize == ZIP64_MAGICVAL)

                writeLong(e.csize);

            if (offset == ZIP64_MAGICVAL)

                writeLong(xentry.offset);

        }

        if (e.extra != null) {

            writeBytes(e.extra, 0, e.extra.length);

        }