/*
 * Copyright (c) 2021 Huawei Device Co., Ltd.
 * Licensed 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.
 */
#include "log_compress.h"

#include <iostream>
#include <cstring>
#include <cstdlib>
#include <vector>

#include <securec.h>

namespace OHOS {
namespace HiviewDFX {
StringMap LogCompress::g_CompressTypes = StringMap({
        {COMPRESS_TYPE_NONE, "none"}, {COMPRESS_TYPE_ZLIB, "zlib"}, {COMPRESS_TYPE_ZSTD, "zstd"}
    }, COMPRESS_TYPE_ZLIB, "unknown");

std::string LogCompress::CompressType2Str(uint16_t compressType)
{
    return g_CompressTypes.GetValue(compressType);
}

uint16_t LogCompress::Str2CompressType(const std::string& str)
{
    return g_CompressTypes.GetKey(str);
}

int NoneCompress::Compress(const LogPersisterBuffer &inBuffer, LogPersisterBuffer &compressedBuffer)
{
    void *dest = compressedBuffer.content + compressedBuffer.offset;
    size_t destSize = MAX_PERSISTER_BUFFER_SIZE - compressedBuffer.offset;
    if (memcpy_s(dest, destSize, inBuffer.content, inBuffer.offset) != 0) {
        return -1;
    }
    compressedBuffer.offset += inBuffer.offset;
    return 0;
}

int ZlibCompress::Compress(const LogPersisterBuffer &inBuffer, LogPersisterBuffer &compressedBuffer)
{
    cStream.zalloc = Z_NULL;
    cStream.zfree = Z_NULL;
    cStream.opaque = Z_NULL;
    if (deflateInit2(&cStream, Z_DEFAULT_COMPRESSION, Z_DEFLATED, MAX_WBITS + 16, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
        return -1;
    }
    uint32_t zdlen = deflateBound(&cStream, inBuffer.offset);
    std::vector<char> zdataBuf(zdlen, 0);
    char* zdata = zdataBuf.data();
    if (zdata == nullptr) {
        std::cerr << "no enough memory!\n";
        return -1;
    }
    size_t const toRead = CHUNK;
    size_t src_pos = 0;
    size_t dst_pos = 0;
    size_t read = inBuffer.offset;
    int flush = 0;
    do {
        bool flag = read - src_pos < toRead;
        if (flag) {
            (void)memset_s(buffIn, CHUNK, 0, CHUNK);
            if (memmove_s(buffIn, CHUNK, inBuffer.content + src_pos, read - src_pos) != 0) {
                return -1;
            }
            cStream.avail_in = read - src_pos;
            src_pos += read - src_pos;
        } else {
            (void)memset_s(buffIn, CHUNK, 0, CHUNK);
            if (memmove_s(buffIn, CHUNK, inBuffer.content + src_pos, toRead) != 0) {
                return -1;
            }
            src_pos += toRead;
            cStream.avail_in = toRead;
        }
        flush = flag ? Z_FINISH : Z_NO_FLUSH;
        cStream.next_in = reinterpret_cast<Bytef*>(buffIn);
        /* run deflate() on input until output buffer not full, finish
           compression if all of source has been read in */
        do {
            cStream.avail_out = CHUNK;
            cStream.next_out = reinterpret_cast<Bytef*>(buffOut);
            if (deflate(&cStream, flush) == Z_STREAM_ERROR) {
                return -1;
            }
            unsigned have = CHUNK - cStream.avail_out;
            if (memmove_s(zdata + dst_pos, zdlen - dst_pos, buffOut, have) != 0) {
                return -1;
            }
            dst_pos += have;
            if (unlikely(zdlen < dst_pos)) { // zdataBuf is not long enough, shoudn't happen
                return -1;
            }
        } while (cStream.avail_out == 0);
    } while (flush != Z_FINISH);
    /* clean up and return */
    (void)deflateEnd(&cStream);
    if (memcpy_s(compressedBuffer.content + compressedBuffer.offset,
        MAX_PERSISTER_BUFFER_SIZE - compressedBuffer.offset, zdata, dst_pos) != 0) {
        return -1;
    }
    compressedBuffer.offset += dst_pos;
    return 0;
}

int ZstdCompress::Compress(const LogPersisterBuffer &inBuffer, LogPersisterBuffer &compressedBuffer)
{
#ifdef USING_ZSTD_COMPRESS
    uint32_t zdlen = ZSTD_CStreamOutSize();
    std::vector<char> zdataBuf(zdlen, 0);
    char* zdata = zdataBuf.data();
    if (zdata == nullptr) {
        std::cerr << "no enough memory!\n";
        return -1;
    }
    ZSTD_EndDirective mode;
    int compressionlevel = 1;
    cctx = ZSTD_createCCtx();
    if (cctx == nullptr) {
        std::cerr << "ZSTD_createCCtx() failed!\n";
        return -1;
    }
    ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, compressionlevel);
    size_t const toRead = CHUNK;
    auto src_pos = 0;
    auto dst_pos = 0;
    size_t read = inBuffer.offset;
    ZSTD_inBuffer input;
    do {
        bool flag = read - src_pos < toRead;
        if (flag) {
            (void)memset_s(buffIn, CHUNK, 0, CHUNK);
            if (memmove_s(buffIn, CHUNK, inBuffer.content + src_pos, read - src_pos) != 0) {
                return -1;
            }
            input = {buffIn, read - src_pos, 0};
            src_pos += read - src_pos;
        } else {
            (void)memset_s(buffIn, CHUNK, 0, CHUNK);
            if (memmove_s(buffIn, CHUNK, inBuffer.content + src_pos, toRead) != 0) {
                return -1;
            }
            input = {buffIn, toRead, 0};
            src_pos += toRead;
        }
        mode = flag ? ZSTD_e_end : ZSTD_e_continue;
        int finished;
        do {
            ZSTD_outBuffer output = {buffOut, CHUNK, 0};
            size_t const remaining = ZSTD_compressStream2(cctx, &output, &input, mode);
            if (memmove_s(zdata + dst_pos, zdlen, reinterpret_cast<Bytef*>(buffOut), output.pos) != 0) {
                return -1;
            }
            dst_pos += output.pos;
            finished = flag ? (remaining == 0) : (input.pos == input.size);
        } while (!finished);
    } while (mode != ZSTD_e_end);
    ZSTD_freeCCtx(cctx);
    if (memcpy_s(compressedBuffer.content + compressedBuffer.offset,
        MAX_PERSISTER_BUFFER_SIZE - compressedBuffer.offset, zdata, dst_pos) != 0) {
        return -1;
    }
    compressedBuffer.offset += dst_pos;
#endif // #ifdef USING_ZSTD_COMPRESS
    return 0;
}
} // namespace HiviewDFX
} // namespace OHOS