/*
 * 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.
 */

#include "gzip_compressor.h"

using namespace common;

namespace storage {

GzipCompressor::GzipCompressor() : compressed_buf() { zstream_valid_ = false; }

GzipCompressor::~GzipCompressor() { end_zstream(); }

int GzipCompressor::reset() {
    int ret = E_OK;
    if (RET_FAIL(end_zstream())) {
    } else if (RET_FAIL(init_zstream())) {
    }
    return ret;
}

int GzipCompressor::init_zstream() {
    if (zstream_valid_) {
        return E_OK;
    }
    compress_stream_.zalloc = (alloc_func)0;  // Z_NULL
    compress_stream_.zfree = (free_func)0;
    compress_stream_.opaque = (voidpf)0;
    compress_stream_.next_in = 0;
    compress_stream_.avail_in = 0;
    compress_stream_.next_out = 0;
    compress_stream_.avail_out = 0;

    memset(compressed_buf, 0, DEFLATE_BUFFER_SIZE);

    if (deflateInit2(&compress_stream_, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 31,
                     8, Z_DEFAULT_STRATEGY) != Z_OK) {
        // log_err("gzip deflateInit2 failed");
        return E_COMPRESS_ERR;
    }
    zstream_valid_ = true;
    return E_OK;
}

int GzipCompressor::end_zstream() {
    if (!zstream_valid_) {
        return E_OK;
    }
    if (deflateEnd(&compress_stream_) != Z_OK) {
        // log_err("deflateEnd failed");
        return E_COMPRESS_ERR;
    }
    zstream_valid_ = false;
    return E_OK;
}

int GzipCompressor::compress_into_bytestream(char* uncompressed_buf,
                                             uint32_t uncompressed_buf_len,
                                             ByteStream& out) {
    int ret = Z_OK;

    compress_stream_.next_in = (Bytef*)uncompressed_buf;
    compress_stream_.avail_in = uncompressed_buf_len;
    compress_stream_.next_out = (Bytef*)compressed_buf;
    compress_stream_.avail_out = DEFLATE_BUFFER_SIZE;

    if (uncompressed_buf == nullptr || uncompressed_buf_len == 0) {  // no more
        if (compress_stream_.next_out) {
            while (ret != Z_STREAM_END) {
                ret = deflate(&compress_stream_, Z_FINISH);
                if (ret != Z_OK && ret != Z_STREAM_END) {
                    // log_err("deflate failed");
                    return E_COMPRESS_ERR;
                }
                out.write_buf(compressed_buf,
                              DEFLATE_BUFFER_SIZE - compress_stream_.avail_out);
                compress_stream_.next_out = (Bytef*)compressed_buf;
                compress_stream_.avail_out = DEFLATE_BUFFER_SIZE;
            }
        }
        return E_OK;
    }

    for (;;) {
        ret = deflate(&compress_stream_, Z_NO_FLUSH);
        if (ret != Z_OK) {
            // log_err("deflate failed");
            return E_COMPRESS_ERR;
        }

        if (compress_stream_.avail_in == 0) {  // current input data are all
            out.write_buf(compressed_buf,
                          DEFLATE_BUFFER_SIZE - compress_stream_.avail_out);
            compress_stream_.next_out = (Bytef*)compressed_buf;
            compress_stream_.avail_out = DEFLATE_BUFFER_SIZE;
            break;
        } else if (compress_stream_.avail_out ==
                   0) {  // no more space for output
            out.write_buf(compressed_buf, DEFLATE_BUFFER_SIZE);
            compress_stream_.next_out = (Bytef*)compressed_buf;
            compress_stream_.avail_out = DEFLATE_BUFFER_SIZE;
        }
    }

    return E_OK;
}

int GzipCompressor::compress(char* uncompressed_buf,
                             uint32_t uncompressed_buf_len,
                             char*& compressed_buf,
                             uint32_t& compressed_buf_len) {
    int ret = E_OK;
    ByteStream out(DEFLATE_BUFFER_SIZE, MOD_COMPRESSOR_OBJ);
    if (RET_FAIL(compress_into_bytestream(uncompressed_buf,
                                          uncompressed_buf_len, out))) {
        return ret;
    }
    if (RET_FAIL(compress_into_bytestream(nullptr, 0, out))) {
        return ret;
    }
    compressed_buf = get_bytes_from_bytestream(out);
    compressed_buf_len = out.total_size();
    out.destroy();
    return ret;
}

GzipDeCompressor::GzipDeCompressor() : decompressed_buf() {
    zstream_valid_ = false;
}

GzipDeCompressor::~GzipDeCompressor() { end_zstream(); }

int GzipDeCompressor::init_zstream() {
    if (zstream_valid_) {
        return E_OK;
    }
    decompress_stream_.zalloc = (alloc_func)0;  // Z_NULL
    decompress_stream_.zfree = (free_func)0;
    decompress_stream_.opaque = (voidpf)0;
    decompress_stream_.next_in = 0;
    decompress_stream_.avail_in = 0;
    decompress_stream_.next_out = 0;
    decompress_stream_.avail_out = 0;

    memset(decompressed_buf, 0, INFLATE_BUFFER_SIZE);

    if (inflateInit2(&decompress_stream_, 31) != Z_OK) {
        // log_err("inflateInit2 failed");
        return E_COMPRESS_ERR;
    }
    zstream_valid_ = true;
    return E_OK;
}

int GzipDeCompressor::end_zstream() {
    if (!zstream_valid_) {
        return E_OK;
    }
    if (inflateEnd(&decompress_stream_) != Z_OK) {
        // log_err("inflateEnd failed");
        return E_COMPRESS_ERR;
    }
    zstream_valid_ = false;
    return E_OK;
}

int GzipDeCompressor::reset() {
    int ret = E_OK;
    if (RET_FAIL(end_zstream())) {
    } else if (RET_FAIL(init_zstream())) {
    }
    return ret;
}

int GzipDeCompressor::decompress_into_bytestream(char* compressed_buf,
                                                 uint32_t compressed_buf_len,
                                                 ByteStream& out) {
    int ret = Z_OK;

    decompress_stream_.next_in = (Bytef*)compressed_buf;
    decompress_stream_.avail_in = compressed_buf_len;
    decompress_stream_.next_out = (Bytef*)decompressed_buf;
    decompress_stream_.avail_out = INFLATE_BUFFER_SIZE;

    if (compressed_buf == nullptr || compressed_buf_len == 0) {
        if (decompress_stream_.next_out) {
            while (ret != Z_STREAM_END) {
                ret = inflate(&decompress_stream_, Z_FINISH);
                if (ret != Z_OK && ret != Z_STREAM_END) {
                    // log_err("inflate failed");
                    return E_COMPRESS_ERR;
                }
                out.write_buf(
                    decompressed_buf,
                    INFLATE_BUFFER_SIZE - decompress_stream_.avail_out);
                decompress_stream_.next_out = (Bytef*)decompressed_buf;
                decompress_stream_.avail_out = INFLATE_BUFFER_SIZE;
            }
        }
        return E_OK;
    }

    for (;;) {
        ret = inflate(&decompress_stream_, Z_NO_FLUSH);
        if (ret == Z_STREAM_END) {
            out.write_buf(decompressed_buf,
                          INFLATE_BUFFER_SIZE - decompress_stream_.avail_out);
            break;
        }
        if (ret != Z_OK) {
            // log_err("inflate failed");
            return E_COMPRESS_ERR;
        }
        if (decompress_stream_.avail_in == 0) {
            out.write_buf(decompressed_buf,
                          INFLATE_BUFFER_SIZE - decompress_stream_.avail_out);
            decompress_stream_.next_out = (Bytef*)decompressed_buf;
            decompress_stream_.avail_out = INFLATE_BUFFER_SIZE;
            break;
        } else if (decompress_stream_.avail_out == 0) {
            out.write_buf(decompressed_buf, INFLATE_BUFFER_SIZE);
            decompress_stream_.next_out = (Bytef*)decompressed_buf;
            decompress_stream_.avail_out = INFLATE_BUFFER_SIZE;
        }
    }

    return E_OK;
}

int GzipDeCompressor::uncompress(char* compressed_buf,
                                 uint32_t compressed_buf_len,
                                 char*& uncompressed_buf,
                                 uint32_t& uncompressed_buf_len) {
    int ret = E_OK;
    ByteStream out(INFLATE_BUFFER_SIZE, MOD_COMPRESSOR_OBJ);
    if (RET_FAIL(decompress_into_bytestream(compressed_buf, compressed_buf_len,
                                            out))) {
        return ret;
    }
    if (RET_FAIL(decompress_into_bytestream(nullptr, 0, out))) {
        return ret;
    }
    uncompressed_buf = get_bytes_from_bytestream(out);
    uncompressed_buf_len = out.total_size();
    //   uncompressed_buf[uncompressed_buf_len] = '\0';
    out.destroy();
    return ret;
}

}  // end namespace storage