/* compress_lzma.cpp --

   This file is part of the UPX executable compressor.

   Copyright (C) 1996-2024 Markus Franz Xaver Johannes Oberhumer
   All Rights Reserved.

   UPX and the UCL library are free software; you can redistribute them
   and/or modify them under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of
   the License, or (at your option) any later version.

   This program 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 for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING.
   If not, write to the Free Software Foundation, Inc.,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

   Markus F.X.J. Oberhumer
   <markus@oberhumer.com>
 */

#include "../conf.h"
#include "compress.h"
#include "../util/membuffer.h"

#if (ACC_CC_CLANG)
#pragma clang diagnostic ignored "-Wshadow"
#endif
#if (ACC_CC_GNUC >= 0x040200)
#pragma GCC diagnostic ignored "-Wshadow"
#endif
#if (ACC_CC_MSC)
#pragma warning(disable : 4456) // -Wno-shadow
#endif

void lzma_compress_config_t::reset() noexcept {
    pos_bits.reset();
    lit_pos_bits.reset();
    lit_context_bits.reset();
    dict_size.reset();
    fast_mode = 2;
    num_fast_bytes.reset();
    match_finder_cycles = 0;

    max_num_probs = 0;
}

// INFO: the LZMA SDK is covered by a permissive license which allows
//   using unmodified LZMA source code in UPX and the UPX stubs.
//   See SPECIAL EXCEPTION below.
//
// Quoting from lzma-4.43/lzma.txt:
//
//   LICENSE
//   -------
//
//   LZMA SDK is available under any of the following licenses:
//
//   1) GNU Lesser General Public License (GNU LGPL)
//   2) Common Public License (CPL)
//   3) Simplified license for unmodified code (read SPECIAL EXCEPTION)
//   4) Proprietary license
//
//   It means that you can select one of these four options and follow rules
//   of that license.
//
//   1,2) GNU LGPL and CPL licenses are pretty similar and both these
//   licenses are classified as
//    - "Free software licenses" at http://www.gnu.org/
//    - "OSI-approved" at http://www.opensource.org/
//
//   3) SPECIAL EXCEPTION
//
//   Igor Pavlov, as the author of this code, expressly permits you
//   to statically or dynamically link your code (or bind by name)
//   to the files from LZMA SDK without subjecting your linked
//   code to the terms of the CPL or GNU LGPL.
//   Any modifications or additions to files from LZMA SDK, however,
//   are subject to the GNU LGPL or CPL terms.
//
//   SPECIAL EXCEPTION allows you to use LZMA SDK in applications with closed code,
//   while you keep LZMA SDK code unmodified.

/*************************************************************************
// compress defaults
**************************************************************************/

static bool prepare_result(lzma_compress_result_t *res, unsigned src_len, int method, int level,
                           const lzma_compress_config_t *lcconf) {
    // setup defaults
    res->pos_bits = 2;                // 0 .. 4
    res->lit_pos_bits = 0;            // 0 .. 4
    res->lit_context_bits = 3;        // 0 .. 8
    res->dict_size = 4 * 1024 * 1024; // 1 .. 2**30
    res->fast_mode = 2;               // 0 .. 2
    res->num_fast_bytes = 64;         // 5 .. 273
    res->match_finder_cycles = 0;
    // UPX overrides
    res->pos_bits = lzma_compress_config_t::pos_bits_t::default_value;
    res->lit_pos_bits = lzma_compress_config_t::lit_pos_bits_t::default_value;
    res->lit_context_bits = lzma_compress_config_t::lit_context_bits_t::default_value;
    res->dict_size = lzma_compress_config_t::dict_size_t::default_value;
    res->num_fast_bytes = lzma_compress_config_t::num_fast_bytes_t::default_value;
    // method overrides
    if (method >= 0x100) {
        res->pos_bits = (method >> 16) & 15;
        res->lit_pos_bits = (method >> 12) & 15;
        res->lit_context_bits = (method >> 8) & 15;
    }
#if 0
    // DEBUG - set sizes so that we use a maximum amount of stack.
    //  These settings cause res->num_probs == 3147574, i.e. we will
    //  need about 6 MiB of stack during runtime decompression.
    res->lit_pos_bits     = 4;
    res->lit_context_bits = 8;
#endif

    // TODO: tune these settings according to level
    switch (level) {
    case 1:
        res->dict_size = 256 * 1024;
        res->fast_mode = 0;
        res->num_fast_bytes = 8;
        break;
    case 2:
        res->dict_size = 256 * 1024;
        res->fast_mode = 0;
        break;
    case 3:
        break;
    case 4:
        break;
    case 5:
        break;
    case 6:
        break;
    case 7:
        break;
    case 8:
        break;
    case 9:
        res->dict_size = 8 * 1024 * 1024;
        break;
    case 10:
        res->dict_size = src_len;
        break;
    default:
        goto error;
    }

    // cconf overrides
    if (lcconf) {
        oassign(res->pos_bits, lcconf->pos_bits);
        oassign(res->lit_pos_bits, lcconf->lit_pos_bits);
        oassign(res->lit_context_bits, lcconf->lit_context_bits);
        oassign(res->dict_size, lcconf->dict_size);
        oassign(res->num_fast_bytes, lcconf->num_fast_bytes);
    }

    // limit dictionary size
    if (res->dict_size > src_len)
        res->dict_size = src_len;

    // limit num_probs
    if (lcconf && lcconf->max_num_probs) {
        for (;;) {
            unsigned n = 1846 + (768u << (res->lit_context_bits + res->lit_pos_bits));
            if (n <= lcconf->max_num_probs)
                break;
            if (res->lit_pos_bits > res->lit_context_bits) {
                if (res->lit_pos_bits == 0)
                    goto error;
                res->lit_pos_bits -= 1;
            } else {
                if (res->lit_context_bits == 0)
                    goto error;
                res->lit_context_bits -= 1;
            }
        }
    }

    lzma_compress_config_t::pos_bits_t::assertValue(res->pos_bits);
    lzma_compress_config_t::lit_pos_bits_t::assertValue(res->lit_pos_bits);
    lzma_compress_config_t::lit_context_bits_t::assertValue(res->lit_context_bits);
    lzma_compress_config_t::dict_size_t::assertValue(res->dict_size);
    lzma_compress_config_t::num_fast_bytes_t::assertValue(res->num_fast_bytes);

    res->num_probs = 1846 + (768u << (res->lit_context_bits + res->lit_pos_bits));
    NO_printf("\nlzma_compress config: %u %u %u %u %u\n", res->pos_bits, res->lit_pos_bits,
              res->lit_context_bits, res->dict_size, res->num_probs);
    return true;

error:
    return false;
}

/*************************************************************************
// compress - cruft because of pseudo-COM layer
**************************************************************************/

#if (ACC_CC_CLANG >= 0x080000)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
#elif (ACC_CC_GNUC >= 0x040700)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wzero-as-null-pointer-constant"
#endif

#undef MSDOS
#undef OS2
#undef _WIN32
#undef _WIN32_WCE
#undef COMPRESS_MF_MT
#undef _NO_EXCEPTIONS
#include <lzma-sdk/C/Common/MyInitGuid.h>
// #include <lzma-sdk/C/7zip/Compress/LZMA/LZMADecoder.h>
#include <lzma-sdk/C/7zip/Compress/LZMA/LZMAEncoder.h>

namespace MyLzma {

struct InStream final : public ISequentialInStream, public CMyUnknownImp {
    virtual ~InStream() {}
    MY_UNKNOWN_IMP
    const Byte *b_buf = nullptr;
    size_t b_size;
    size_t b_pos;
    void Init(const Byte *data, size_t size) {
        b_buf = data;
        b_size = size;
        b_pos = 0;
    }
    STDMETHOD(Read)(void *data, UInt32 size, UInt32 *processedSize) override;
};

STDMETHODIMP InStream::Read(void *data, UInt32 size, UInt32 *processedSize) {
    size_t remain = b_size - b_pos;
    if (size > remain)
        size = (UInt32) remain;
    memmove(data, b_buf + b_pos, size);
    b_pos += size;
    if (processedSize != nullptr)
        *processedSize = size;
    return S_OK;
}

struct OutStream final : public ISequentialOutStream, public CMyUnknownImp {
    virtual ~OutStream() {}
    MY_UNKNOWN_IMP
    Byte *b_buf = nullptr;
    size_t b_size;
    size_t b_pos;
    bool overflow;
    void Init(Byte *data, size_t size) {
        b_buf = data;
        b_size = size;
        b_pos = 0;
        overflow = false;
    }
    HRESULT WriteByte(Byte c) {
        if (b_pos >= b_size) {
            overflow = true;
            return E_FAIL;
        }
        b_buf[b_pos++] = c;
        return S_OK;
    }
    STDMETHOD(Write)(const void *data, UInt32 size, UInt32 *processedSize) override;
};

STDMETHODIMP OutStream::Write(const void *data, UInt32 size, UInt32 *processedSize) {
    size_t remain = b_size - b_pos;
    if (size > remain)
        size = (UInt32) remain, overflow = true;
    memmove(b_buf + b_pos, data, size);
    b_pos += size;
    if (processedSize != nullptr)
        *processedSize = size;
    return overflow ? E_FAIL : S_OK;
}

struct ProgressInfo final : public ICompressProgressInfo, public CMyUnknownImp {
    virtual ~ProgressInfo() {}
    MY_UNKNOWN_IMP
    STDMETHOD(SetRatioInfo)(const UInt64 *inSize, const UInt64 *outSize) override;
    upx_callback_t *cb = nullptr;
};

STDMETHODIMP ProgressInfo::SetRatioInfo(const UInt64 *inSize, const UInt64 *outSize) {
    if (cb && cb->nprogress)
        cb->nprogress(cb, (unsigned) *inSize, (unsigned) *outSize);
    return S_OK;
}

} // namespace MyLzma

#include <lzma-sdk/C/Common/Alloc.cpp>
#include <lzma-sdk/C/Common/CRC.cpp>
// #include <lzma-sdk/C/7zip/Common/InBuffer.cpp>
#include <lzma-sdk/C/7zip/Common/OutBuffer.cpp>
#include <lzma-sdk/C/7zip/Common/StreamUtils.cpp>
#include <lzma-sdk/C/7zip/Compress/LZ/LZInWindow.cpp>
// #include <lzma-sdk/C/7zip/Compress/LZ/LZOutWindow.cpp>
// #include <lzma-sdk/C/7zip/Compress/LZMA/LZMADecoder.cpp>
#include <lzma-sdk/C/7zip/Compress/LZMA/LZMAEncoder.cpp>
#include <lzma-sdk/C/7zip/Compress/RangeCoder/RangeCoderBit.cpp>
#undef RC_NORMALIZE

#if (ACC_CC_CLANG >= 0x080000)
#pragma clang diagnostic pop
#elif (ACC_CC_GNUC >= 0x040700)
#pragma GCC diagnostic pop
#endif

int upx_lzma_compress(const upx_bytep src, unsigned src_len, upx_bytep dst, unsigned *dst_len,
                      upx_callback_t *cb, int method, int level,
                      const upx_compress_config_t *cconf_parm, upx_compress_result_t *cresult) {
    assert(M_IS_LZMA(method));
    assert(level > 0);
    assert(cresult != nullptr);

    int r = UPX_E_ERROR;
    HRESULT rh;
    const lzma_compress_config_t *const lcconf = cconf_parm ? &cconf_parm->conf_lzma : nullptr;
    lzma_compress_result_t *const res = &cresult->result_lzma;
    res->reset();

    MyLzma::InStream is;
    is.AddRef();
    is.Init(src, src_len);
    MyLzma::OutStream os;
    os.AddRef();
    os.Init(dst, *dst_len);
    MyLzma::ProgressInfo progress;
    progress.AddRef();
    progress.cb = cb; // progress.Init()

    NCompress::NLZMA::CEncoder enc;
    constexpr unsigned NPROPS = 8;
    static const PROPID propIDs[NPROPS] = {
        NCoderPropID::kPosStateBits,      // 0  pb    _posStateBits(2)
        NCoderPropID::kLitPosBits,        // 1  lp    _numLiteralPosStateBits(0)
        NCoderPropID::kLitContextBits,    // 2  lc    _numLiteralContextBits(3)
        NCoderPropID::kDictionarySize,    // 3  ds
        NCoderPropID::kAlgorithm,         // 4  fm    _fastmode
        NCoderPropID::kNumFastBytes,      // 5  fb
        NCoderPropID::kMatchFinderCycles, // 6  mfc   _matchFinderCycles, _cutValue
        NCoderPropID::kMatchFinder        // 7  mf
    };
    PROPVARIANT pr[NPROPS];
    if (!prepare_result(res, src_len, method, level, lcconf))
        goto error;
    pr[0].vt = pr[1].vt = pr[2].vt = pr[3].vt = pr[4].vt = pr[5].vt = pr[6].vt = VT_UI4;
    pr[7].vt = VT_BSTR;
    pr[0].uintVal = res->pos_bits;
    pr[1].uintVal = res->lit_pos_bits;
    pr[2].uintVal = res->lit_context_bits;
    pr[3].uintVal = res->dict_size;
    pr[4].uintVal = res->fast_mode;
    pr[5].uintVal = res->num_fast_bytes;
    pr[6].uintVal = res->match_finder_cycles;
    static const wchar_t matchfinder[] = L"BT4";
    assert(NCompress::NLZMA::FindMatchFinder(matchfinder) >= 0);
    pr[7].bstrVal = ACC_PCAST(BSTR, ACC_UNCONST_CAST(wchar_t *, matchfinder));

    try {
        if (enc.SetCoderProperties(propIDs, pr, NPROPS) != S_OK)
            goto error;
        // encode properties in LZMA-style (5 bytes)
        if (enc.WriteCoderProperties(&os) != S_OK)
            goto error;
        if (os.overflow) {
            // r = UPX_E_OUTPUT_OVERRUN;
            r = UPX_E_NOT_COMPRESSIBLE;
            goto error;
        }
        assert(os.b_pos == 5);

        // reset and encode properties in UPX-style (2 bytes)
        os.b_pos = 0;
        // UPX extra stuff in first byte: 5 high bits convenience for stub decompressor
        unsigned t = res->lit_context_bits + res->lit_pos_bits;
        os.WriteByte(Byte((t << 3) | res->pos_bits));
        os.WriteByte(Byte((res->lit_pos_bits << 4) | res->lit_context_bits));

        // compress
        rh = enc.Code(&is, &os, nullptr, nullptr, &progress);

    } catch (...) {
        rh = E_OUTOFMEMORY;
    }

    assert(is.b_pos <= src_len);
    assert(os.b_pos <= *dst_len);
    if (rh == E_OUTOFMEMORY)
        r = UPX_E_OUT_OF_MEMORY;
    else if (os.overflow) {
        assert(os.b_pos == *dst_len);
        // r = UPX_E_OUTPUT_OVERRUN;
        r = UPX_E_NOT_COMPRESSIBLE;
    } else if (rh == S_OK) {
        assert(is.b_pos == src_len);
        r = UPX_E_OK;
    }

error:
    *dst_len = (unsigned) os.b_pos;
    NO_printf("\nlzma_compress: %d: %u %u %u %u %u, %u - > %u\n", r, res->pos_bits,
              res->lit_pos_bits, res->lit_context_bits, res->dict_size, res->num_probs, src_len,
              *dst_len);
    NO_printf("%u %u %u\n", is.__m_RefCount, os.__m_RefCount, progress.__m_RefCount);
    return r;
}

/*************************************************************************
// decompress
**************************************************************************/

#undef _LZMA_IN_CB
#undef _LZMA_OUT_READ
#undef _LZMA_PROB32
#undef _LZMA_LOC_OPT
#include <lzma-sdk/C/7zip/Compress/LZMA_C/LzmaDecode.h>
#include <lzma-sdk/C/7zip/Compress/LZMA_C/LzmaDecode.c>

int upx_lzma_decompress(const upx_bytep src, unsigned src_len, upx_bytep dst, unsigned *dst_len,
                        int method, const upx_compress_result_t *cresult) {
    assert(M_IS_LZMA(method));
    // see res->num_probs above
    COMPILE_TIME_ASSERT(sizeof(CProb) == 2)
    COMPILE_TIME_ASSERT(LZMA_BASE_SIZE == 1846)
    COMPILE_TIME_ASSERT(LZMA_LIT_SIZE == 768)

    CLzmaDecoderState s;
    mem_clear(&s);
    SizeT src_out = 0, dst_out = 0;
    int r = UPX_E_ERROR;
    int rh;

    // decode UPX-style properties (2 bytes)
    if (src_len < 3) {
        r = UPX_E_INPUT_OVERRUN;
        goto error;
    }
    s.Properties.pb = src[0] & 7;
    s.Properties.lp = (src[1] >> 4);
    s.Properties.lc = src[1] & 15;
    if (s.Properties.pb >= 5)
        goto error;
    if (s.Properties.lp >= 5)
        goto error;
    if (s.Properties.lc >= 9)
        goto error;
    // UPX extra stuff in first byte: 5 high bits convenience for stub decompressor
    if ((src[0] >> 3) != s.Properties.lc + s.Properties.lp)
        goto error;
    src += 2;
    src_len -= 2;

    if (cresult) {
        assert(cresult->debug.method == method);
        assert(cresult->result_lzma.pos_bits == (unsigned) s.Properties.pb);
        assert(cresult->result_lzma.lit_pos_bits == (unsigned) s.Properties.lp);
        assert(cresult->result_lzma.lit_context_bits == (unsigned) s.Properties.lc);
        assert(cresult->result_lzma.num_probs == (unsigned) LzmaGetNumProbs(&s.Properties));
        const lzma_compress_result_t *res = &cresult->result_lzma;
        NO_printf("\nlzma_decompress config: %u %u %u %u %u\n", res->pos_bits, res->lit_pos_bits,
                  res->lit_context_bits, res->dict_size, res->num_probs);
        UNUSED(res);
    }
    s.Probs = (CProb *) malloc(sizeof(CProb) * LzmaGetNumProbs(&s.Properties));
    if (!s.Probs) {
        r = UPX_E_OUT_OF_MEMORY;
        goto error;
    }
    rh = LzmaDecode(&s, src, src_len, &src_out, dst, *dst_len, &dst_out);
    assert(src_out <= src_len);
    assert(dst_out <= *dst_len);
    if (rh == 0) {
        r = UPX_E_OK;
        if (src_out != src_len)
            r = UPX_E_INPUT_NOT_CONSUMED;
    } else if (rh == LZMA_RESULT_INPUT_OVERRUN)
        r = UPX_E_INPUT_OVERRUN;
    else if (rh == LZMA_RESULT_OUTPUT_OVERRUN)
        r = UPX_E_OUTPUT_OVERRUN;

error:
    *dst_len = dst_out;
    free(s.Probs);
    return r;
}

/*************************************************************************
// test_overlap - see <ucl/ucl.h> for semantics
**************************************************************************/

int upx_lzma_test_overlap(const upx_bytep buf, const upx_bytep tbuf, unsigned src_off,
                          unsigned src_len, unsigned *dst_len, int method,
                          const upx_compress_result_t *cresult) {
    assert(M_IS_LZMA(method));

    MemBuffer b(src_off + src_len);
    memcpy(b + src_off, buf + src_off, src_len);
    unsigned saved_dst_len = *dst_len;
    int r = upx_lzma_decompress(raw_index_bytes(b, src_off, src_len), src_len,
                                raw_bytes(b, *dst_len), dst_len, method, cresult);
    if (r != UPX_E_OK)
        return r;
    if (*dst_len != saved_dst_len)
        return UPX_E_ERROR;
    // NOTE: there is a very tiny possibility that decompression has
    //   succeeded but the data is not restored correctly because of
    //   in-place buffer overlapping, so we use an extra memcmp().
    if (tbuf != nullptr && memcmp(tbuf, b, *dst_len) != 0)
        return UPX_E_ERROR;
    return UPX_E_OK;
}

/*************************************************************************
// misc
**************************************************************************/

int upx_lzma_init(void) { return 0; }

const char *upx_lzma_version_string(void) { return "4.43"; }

/*************************************************************************
// doctest checks
**************************************************************************/

TEST_CASE("upx_lzma_decompress") {
    const byte *c_data;
    byte d_buf[16];
    unsigned d_len;
    int r;

    c_data = (const byte *) "\x1a\x03\x00\x7f\xed\x3c\x00\x00\x00";
    d_len = 16;
    r = upx_lzma_decompress(c_data, 9, d_buf, &d_len, M_LZMA, nullptr);
    CHECK((r == 0 && d_len == 16));
    r = upx_lzma_decompress(c_data, 8, d_buf, &d_len, M_LZMA, nullptr);
    CHECK(r == UPX_E_INPUT_OVERRUN);
    d_len = 15;
    r = upx_lzma_decompress(c_data, 9, d_buf, &d_len, M_LZMA, nullptr);
    CHECK(r == UPX_E_OUTPUT_OVERRUN);
    UNUSED(r);
}

/* vim:set ts=4 sw=4 et: */
