/*
 * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved.
 * 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.
 */

/**
 * Note: Lifted from uncrunch.c from jdk sources
 */
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <stdint.h>

#include <stdlib.h>
#include <assert.h>

#ifndef _MSC_VER
#include <strings.h>
#endif

#include "defines.h"
#include "bytes.h"
#include "utils.h"

#include "constants.h"
#include "unpack.h"

#include "zip.h"

#include "zlib.h"

inline uint32_t jar::get_crc32(uint32_t c, uchar *ptr, uint32_t len)
{
    return crc32(c, ptr, len);
}

// FIXME: this is bullshit. Do real endianness detection.
#ifdef sparc
#define SWAP_BYTES(a) ((((a) << 8) & 0xff00) | 0x00ff) & (((a) >> 8) | 0xff00)
#else
#define SWAP_BYTES(a) (a)
#endif

#define GET_INT_LO(a) SWAP_BYTES(a & 0xFFFF)

#define GET_INT_HI(a) SWAP_BYTES((a >> 16) & 0xFFFF);

void jar::init(unpacker *u_)
{
    BYTES_OF(*this).clear();
    u = u_;
    u->jarout = this;
}

// Write data to the ZIP output stream.
void jar::write_data(void *buff, int len)
{
    while (len > 0)
    {
        int rc = (int)fwrite(buff, 1, len, jarfp);
        if (rc <= 0)
        {
            fprintf(stderr, "Error: write on output file failed err=%d\n", errno);
            exit(1); // Called only from the native standalone unpacker
        }
        output_file_offset += rc;
        buff = ((char *)buff) + rc;
        len -= rc;
    }
}

void jar::add_to_jar_directory(const char *fname, bool store, int modtime, int len, int clen,
                               uint32_t crc)
{
    uint32_t fname_length = (uint32_t)strlen(fname);
    ushort header[23];
    if (modtime == 0)
        modtime = default_modtime;
    uint32_t dostime = get_dostime(modtime);

    header[0] = (ushort)SWAP_BYTES(0x4B50);
    header[1] = (ushort)SWAP_BYTES(0x0201);
    header[2] = (ushort)SWAP_BYTES(0xA);

    // required version
    header[3] = (ushort)SWAP_BYTES(0xA);

    // flags 02 = maximum  sub-compression flag
    header[4] = (store) ? 0x0 : SWAP_BYTES(0x2);

    // Compression method 8=deflate.
    header[5] = (store) ? 0x0 : SWAP_BYTES(0x08);

    // Last modified date and time.
    header[6] = (ushort)GET_INT_LO(dostime);
    header[7] = (ushort)GET_INT_HI(dostime);

    // CRC
    header[8] = (ushort)GET_INT_LO(crc);
    header[9] = (ushort)GET_INT_HI(crc);

    // Compressed length:
    header[10] = (ushort)GET_INT_LO(clen);
    header[11] = (ushort)GET_INT_HI(clen);

    // Uncompressed length.
    header[12] = (ushort)GET_INT_LO(len);
    header[13] = (ushort)GET_INT_HI(len);

    // Filename length
    header[14] = (ushort)SWAP_BYTES(fname_length);
    // So called "extra field" length.
    header[15] = 0;
    // So called "comment" length.
    header[16] = 0;
    // Disk number start
    header[17] = 0;
    // File flags => binary
    header[18] = 0;
    // More file flags
    header[19] = 0;
    header[20] = 0;
    // Offset within ZIP file.
    header[21] = (ushort)GET_INT_LO(output_file_offset);
    header[22] = (ushort)GET_INT_HI(output_file_offset);

    // Copy the whole thing into the central directory.
    central_directory.append(header, sizeof(header));

    // Copy the fname to the header.
    central_directory.append(fname, fname_length);

    central_directory_count++;
}

void jar::write_jar_header(const char *fname, bool store, int modtime, int len, int clen,
                           uint32_t crc)
{
    uint32_t fname_length = (uint32_t)strlen(fname);
    ushort header[15];
    if (modtime == 0)
        modtime = default_modtime;
    uint32_t dostime = get_dostime(modtime);

    // ZIP LOC magic.
    header[0] = (ushort)SWAP_BYTES(0x4B50);
    header[1] = (ushort)SWAP_BYTES(0x0403);

    // Version
    header[2] = (ushort)SWAP_BYTES(0xA);

    // flags 02 = maximum  sub-compression flag
    header[3] = (store) ? 0x0 : SWAP_BYTES(0x2);

    // Compression method = deflate
    header[4] = (store) ? 0x0 : SWAP_BYTES(0x08);

    // Last modified date and time.
    header[5] = (ushort)GET_INT_LO(dostime);
    header[6] = (ushort)GET_INT_HI(dostime);

    // CRC
    header[7] = (ushort)GET_INT_LO(crc);
    header[8] = (ushort)GET_INT_HI(crc);

    // Compressed length:
    header[9] = (ushort)GET_INT_LO(clen);
    header[10] = (ushort)GET_INT_HI(clen);

    // Uncompressed length.
    header[11] = (ushort)GET_INT_LO(len);
    header[12] = (ushort)GET_INT_HI(len);

    // Filename length
    header[13] = (ushort)SWAP_BYTES(fname_length);
    // So called "extra field" length.
    header[14] = 0;

    // Write the LOC header to the output file.
    write_data(header, (int)sizeof(header));

    // Copy the fname to the header.
    write_data((char *)fname, (int)fname_length);
}

void jar::write_central_directory()
{
    bytes mc;
    mc.set("PACK200");

    ushort header[11];

    // Create the End of Central Directory structure.
    header[0] = (ushort)SWAP_BYTES(0x4B50);
    header[1] = (ushort)SWAP_BYTES(0x0605);
    // disk numbers
    header[2] = 0;
    header[3] = 0;
    // Number of entries in central directory.
    header[4] = (ushort)SWAP_BYTES(central_directory_count);
    header[5] = (ushort)SWAP_BYTES(central_directory_count);
    // Size of the central directory}
    header[6] = (ushort)GET_INT_LO((int)central_directory.size());
    header[7] = (ushort)GET_INT_HI((int)central_directory.size());
    // Offset of central directory within disk.
    header[8] = (ushort)GET_INT_LO(output_file_offset);
    header[9] = (ushort)GET_INT_HI(output_file_offset);
    // zipfile comment length;
    header[10] = (ushort)SWAP_BYTES((int)mc.len);

    // Write the central directory.
    write_data(central_directory.b);

    // Write the End of Central Directory structure.
    write_data(header, (int)sizeof(header));

    // Write the comment.
    write_data(mc);
}

// Public API

// Open a Jar file and initialize.
void jar::openJarFile(const char *fname)
{
    if (!jarfp)
    {
        jarfp = fopen(fname, "wb");
        if (!jarfp)
        {
            fprintf(stderr, "Error: Could not open jar file: %s\n", fname);
            exit(3); // Called only from the native standalone unpacker
        }
    }
}

// Add a ZIP entry and copy the file data
void jar::addJarEntry(const char *fname, bool deflate_hint, int modtime, bytes &head,
                      bytes &tail)
{
    int len = (int)(head.len + tail.len);
    int clen = 0;

    uint32_t crc = get_crc32(0, Z_NULL, 0);
    if (head.len != 0)
        crc = get_crc32(crc, (uchar *)head.ptr, (uint32_t)head.len);
    if (tail.len != 0)
        crc = get_crc32(crc, (uchar *)tail.ptr, (uint32_t)tail.len);

    bool deflate = (deflate_hint && len > 0);

    if (deflate)
    {
        if (deflate_bytes(head, tail) == false)
        {
            deflate = false;
        }
    }
    clen = (int)((deflate) ? deflated.size() : len);
    add_to_jar_directory(fname, !deflate, modtime, len, clen, crc);
    write_jar_header(fname, !deflate, modtime, len, clen, crc);

    if (deflate)
    {
        write_data(deflated.b);
    }
    else
    {
        write_data(head);
        write_data(tail);
    }
}

// Add a ZIP entry for a directory name no data
void jar::addDirectoryToJarFile(const char *dir_name)
{
    bool store = true;
    add_to_jar_directory((const char *)dir_name, store, default_modtime, 0, 0, 0);
    write_jar_header((const char *)dir_name, store, default_modtime, 0, 0, 0);
}

// Write out the central directory and close the jar file.
void jar::closeJarFile(bool central)
{
    if (jarfp)
    {
        fflush(jarfp);
        if (central)
            write_central_directory();
        fflush(jarfp);
        fclose(jarfp);
    }
    reset();
}

/* Convert the date y/n/d and time h:m:s to a four byte DOS date and
 *  time (date in high two bytes, time in low two bytes allowing magnitude
 *  comparison).
 */
inline uint32_t jar::dostime(int y, int n, int d, int h, int m, int s)
{
    return y < 1980 ? dostime(1980, 1, 1, 0, 0, 0)
                    : (((uint32_t)y - 1980) << 25) | ((uint32_t)n << 21) | ((uint32_t)d << 16) |
                          ((uint32_t)h << 11) | ((uint32_t)m << 5) | ((uint32_t)s >> 1);
}
/*
#ifdef _REENTRANT // solaris
extern "C" struct tm *gmtime_r(const time_t *, struct tm *);
#else
#define gmtime_r(t, s) gmtime(t)
#endif
*/
/*
 * Return the Unix time in DOS format
 */
uint32_t jar::get_dostime(int modtime)
{
    // see defines.h
    if (modtime != 0 && modtime == modtime_cache)
        return dostime_cache;
    if (modtime != 0 && default_modtime == 0)
        default_modtime = modtime; // catch a reasonable default
    time_t t = modtime;
    struct tm sbuf;
    (void)memset((void *)&sbuf, 0, sizeof(sbuf));
    struct tm *s = gmtime_r(&t, &sbuf);
    modtime_cache = modtime;
    dostime_cache =
        dostime(s->tm_year + 1900, s->tm_mon + 1, s->tm_mday, s->tm_hour, s->tm_min, s->tm_sec);
    // printf("modtime %d => %d\n", modtime_cache, dostime_cache);
    return dostime_cache;
}

/* Returns true on success, and will set the clen to the compressed
   length, the caller should verify if true and clen less than the
   input data
*/
bool jar::deflate_bytes(bytes &head, bytes &tail)
{
    int len = (int)(head.len + tail.len);

    z_stream zs;
    BYTES_OF(zs).clear();

    // NOTE: the window size should always be -MAX_WBITS normally -15.
    // unzip/zipup.c and java/Deflater.c

    int error =
        deflateInit2(&zs, Z_BEST_COMPRESSION, Z_DEFLATED, -MAX_WBITS, 8, Z_DEFAULT_STRATEGY);
    if (error != Z_OK)
    {
        /*
        switch (error)
        {
        case Z_MEM_ERROR:
            PRINTCR((2, "Error: deflate error : Out of memory \n"));
            break;
        case Z_STREAM_ERROR:
            PRINTCR((2, "Error: deflate error : Invalid compression level \n"));
            break;
        case Z_VERSION_ERROR:
            PRINTCR((2, "Error: deflate error : Invalid version\n"));
            break;
        default:
            PRINTCR((2, "Error: Internal deflate error error = %d\n", error));
        }
        */
        return false;
    }

    deflated.empty();
    zs.next_out = (uchar *)deflated.grow(len + (len / 2));
    zs.avail_out = (int)deflated.size();

    zs.next_in = (uchar *)head.ptr;
    zs.avail_in = (int)head.len;

    bytes *first = &head;
    bytes *last = &tail;
    if (last->len == 0)
    {
        first = nullptr;
        last = &head;
    }
    else if (first->len == 0)
    {
        first = nullptr;
    }

    if (first != nullptr && error == Z_OK)
    {
        zs.next_in = (uchar *)first->ptr;
        zs.avail_in = (int)first->len;
        error = deflate(&zs, Z_NO_FLUSH);
    }
    if (error == Z_OK)
    {
        zs.next_in = (uchar *)last->ptr;
        zs.avail_in = (int)last->len;
        error = deflate(&zs, Z_FINISH);
    }
    if (error == Z_STREAM_END)
    {
        if (len > (int)zs.total_out)
        {
            deflated.b.len = zs.total_out;
            deflateEnd(&zs);
            return true;
        }
        deflateEnd(&zs);
        return false;
    }

    deflateEnd(&zs);
    return false;
}

// Callback for fetching data from a GZIP input stream
static int64_t read_input_via_gzip(unpacker *u, void *buf, int64_t minlen, int64_t maxlen)
{
    assert(minlen <= maxlen); // don't talk nonsense
    int64_t numread = 0;
    char *bufptr = (char *)buf;
    char *inbuf = u->gzin->inbuf;
    size_t inbuflen = sizeof(u->gzin->inbuf);
    read_input_fn_t read_gzin_fn = u->gzin->read_input_fn;
    z_stream &zs = *(z_stream *)u->gzin->zstream;
    while (numread < minlen)
    {
        int readlen = (1 << 16); // pretty arbitrary
        if (readlen > (maxlen - numread))
            readlen = (int)(maxlen - numread);
        zs.next_out = (uchar *)bufptr;
        zs.avail_out = readlen;
        if (zs.avail_in == 0)
        {
            zs.avail_in = (int)read_gzin_fn(u, inbuf, 1, inbuflen);
            zs.next_in = (uchar *)inbuf;
        }
        int error = inflate(&zs, Z_NO_FLUSH);
        if (error != Z_OK && error != Z_STREAM_END)
        {
            unpack_abort("error inflating input");
            break;
        }
        int nr = readlen - zs.avail_out;
        numread += nr;
        bufptr += nr;
        assert(numread <= maxlen);
        if (error == Z_STREAM_END)
        {
            enum
            {
                TRAILER_LEN = 8
            };
            // skip 8-byte trailer
            if (zs.avail_in >= TRAILER_LEN)
            {
                zs.avail_in -= TRAILER_LEN;
            }
            else
            {
                // Bug: 5023768,we read past the TRAILER_LEN to see if there is
                // any extraneous data, as we dont support concatenated .gz
                // files just yet.
                int extra = (int)read_gzin_fn(u, inbuf, 1, inbuflen);
                zs.avail_in += extra - TRAILER_LEN;
            }
            // %%% should check final CRC and length here
            // %%% should check for concatenated *.gz files here
            if (zs.avail_in > 0)
                unpack_abort("garbage after end of deflated input stream");
            // pop this filter off:
            u->gzin->free();
            break;
        }
    }

    // fprintf(u->errstrm, "readInputFn(%d,%d) => %d (gunzip)\n",
    //        (int)minlen, (int)maxlen, (int)numread);
    return numread;
}

void gunzip::init(unpacker *u_)
{
    BYTES_OF(*this).clear();
    u = u_;
    assert(u->gzin == nullptr); // once only, please
    read_input_fn = u->read_input_fn;
    zstream = NEW(z_stream, 1);
    u->gzin = this;
    u->read_input_fn = read_input_via_gzip;
}

void gunzip::start(int magic)
{
    assert((magic & GZIP_MAGIC_MASK) == GZIP_MAGIC);
    int gz_flg = (magic & 0xFF); // keep "flg", discard other 3 bytes
    enum
    {
        FHCRC = (1 << 1),
        FEXTRA = (1 << 2),
        FNAME = (1 << 3),
        FCOMMENT = (1 << 4)
    };
    char gz_mtime[4];
    char gz_xfl[1];
    char gz_os[1];
    char gz_extra_len[2];
    char gz_hcrc[2];
    char gz_ignore;
    // do not save extra, name, comment
    read_fixed_field(gz_mtime, sizeof(gz_mtime));
    read_fixed_field(gz_xfl, sizeof(gz_xfl));
    read_fixed_field(gz_os, sizeof(gz_os));
    if (gz_flg & FEXTRA)
    {
        read_fixed_field(gz_extra_len, sizeof(gz_extra_len));
        int extra_len = gz_extra_len[0] & 0xFF;
        extra_len += (gz_extra_len[1] & 0xFF) << 8;
        for (; extra_len > 0; extra_len--)
        {
            read_fixed_field(&gz_ignore, 1);
        }
    }
    int null_terms = 0;
    if (gz_flg & FNAME)
        null_terms++;
    if (gz_flg & FCOMMENT)
        null_terms++;
    for (; null_terms; null_terms--)
    {
        for (;;)
        {
            gz_ignore = 0;
            read_fixed_field(&gz_ignore, 1);
            if (gz_ignore == 0)
                break;
        }
    }
    if (gz_flg & FHCRC)
        read_fixed_field(gz_hcrc, sizeof(gz_hcrc));

    // now the input stream is ready to read into the inflater
    int error = inflateInit2((z_stream *)zstream, -MAX_WBITS);
    if (error != Z_OK)
    {
        unpack_abort("cannot create input");
    }
}

void gunzip::free()
{
    assert(u->gzin == this);
    u->gzin = nullptr;
    u->read_input_fn = this->read_input_fn;
    inflateEnd((z_stream *)zstream);
    ::free(zstream);
    zstream = nullptr;
    ::free(this);
}

void gunzip::read_fixed_field(char *buf, size_t buflen)
{
    int64_t nr = read_input_fn(u, buf, buflen, buflen);
    if ((size_t)nr != buflen)
        unpack_abort("short stream header");
}