/**************************************************************************
 *
 * Copyright 2011 Jose Fonseca
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 **************************************************************************/


#include <assert.h>
#include <string.h>
#include <getopt.h>

#include <iostream>
#include <memory>

#include "cli.hpp"

#include <brotli/encode.h>
#include <zlib.h>  // for crc32

#include "trace_file.hpp"
#include "trace_ostream.hpp"


static const char *synopsis = "Repack a trace file with different compression.";

static void
usage(void)
{
    std::cout
        << "usage: apitrace repack [options] <in-trace-file> <out-trace-file>\n"
        << synopsis << "\n"
        << "\n"
        << "Snappy compression allows for faster replay and smaller memory footprint,\n"
        << "at the expense of a slightly smaller compression ratio than zlib\n"
        << "\n"
        << "    -b,--brotli[=QUALITY]  Use Brotli compression (quality " << BROTLI_MIN_QUALITY << "-" << BROTLI_MAX_QUALITY << ", default " << BROTLI_DEFAULT_QUALITY << ")\n"
        << "    -s,--snappy            Use Snappy compression (default format; recommended for qapitrace)\n"
        << "    -z,--zlib              Use ZLib compression\n"
        << "\n";
}

const static char *
shortOptions = "hbsz";

const static struct option
longOptions[] = {
    {"help", no_argument, 0, 'h'},
    {"brotli", optional_argument, 0, 'b'},
    {"snappy", no_argument, 0, 's'},
    {"zlib", no_argument, 0, 'z'},
    {0, 0, 0, 0}
};

enum Format {
    FORMAT_SNAPPY = 0,
    FORMAT_ZLIB,
    FORMAT_BROTLI,
};


static int
repack_generic(trace::File *inFile, trace::OutStream *outFile)
{
    const size_t size = 8192;
    char *buf = new char[size];
    size_t read;

    while ((read = inFile->read(buf, size)) != 0) {
        outFile->write(buf, read);
    }

    delete [] buf;

    return EXIT_SUCCESS;
}


static int
repack_brotli(trace::File *inFile, const char *outFileName, int quality)
{
    BrotliEncoderState *s = BrotliEncoderCreateInstance(nullptr, nullptr, nullptr);
    if (!s) {
        return EXIT_FAILURE;
    }

    // Brotli default quality is 11.  There used to be problems using quality
    // higher than 9:
    //
    // - Some traces cause compression to be extremely slow.  Possibly the same
    //   issue as https://github.com/google/brotli/issues/330
    // - Some traces get lower compression ratio with 11 than 9.  Possibly the
    //   same issue as https://github.com/google/brotli/issues/222
    //
    // but not any more.
    BrotliEncoderSetParameter(s, BROTLI_PARAM_QUALITY, quality);

    // The larger the window, the higher the compression ratio and
    // decompression speeds, so choose the maximum.
    BrotliEncoderSetParameter(s, BROTLI_PARAM_LGWIN, 24);

    FILE *fout = fopen(outFileName, "wb");
    if (!fout) {
        return EXIT_FAILURE;
    }

    uLong inCrc = crc32(0L, Z_NULL, 0);
    static const size_t kFileBufferSize = 1 << 16;
    uint8_t *input = (uint8_t *)malloc(kFileBufferSize * 2);
    uint8_t *output = input + kFileBufferSize;
    size_t available_in = 0;
    const uint8_t *next_in = nullptr;
    size_t available_out = kFileBufferSize;
    uint8_t *next_out = output;
    bool is_eof = false;
    do {
        if (available_in == 0 && !is_eof) {
            available_in = inFile->read(input, kFileBufferSize);
            next_in = input;
            if (available_in == 0) {
                is_eof = true;
            } else {
                crc32(inCrc, reinterpret_cast<const Bytef *>(input), available_in);
            }
        }

        if (!BrotliEncoderCompressStream(s,
                                         is_eof ? BROTLI_OPERATION_FINISH : BROTLI_OPERATION_PROCESS,
                                         &available_in, &next_in,
                                         &available_out, &next_out, nullptr)) {
            std::cerr << "error: failed to compress data\n";
            return EXIT_FAILURE;
        }

        if (available_out != kFileBufferSize) {
            size_t out_size = kFileBufferSize - available_out;
            fwrite(output, 1, out_size, fout);
            if (ferror(fout)) {
                std::cerr << "error: failed to write to " << outFileName << "\n";
                return EXIT_FAILURE;
            }
            available_out = kFileBufferSize;
            next_out = output;
        }
    } while(!BrotliEncoderIsFinished(s));

    fclose(fout);

    BrotliEncoderDestroyInstance(s);

    // Do a CRC check
    std::unique_ptr<trace::File> outFileIn(trace::File::createBrotli());
    if (!outFileIn->open(outFileName)) {
        std::cerr << "error: failed to open " << outFileName << " for reading\n";
        return EXIT_FAILURE;
    }
    uLong outCrc = crc32(0L, Z_NULL, 0);
    do {
        available_in = inFile->read(input, kFileBufferSize);
        crc32(inCrc, reinterpret_cast<const Bytef *>(input), available_in);
    } while (available_in > 0);
    if (inCrc != outCrc) {
        std::cerr << "error: CRC mismatch reading " << outFileName << "\n";
        return EXIT_FAILURE;
    }

    free(input);

    return EXIT_SUCCESS;
}

static int
repack(const char *inFileName, const char *outFileName, Format format, int quality)
{
    int ret = EXIT_FAILURE;

    trace::File *inFile = trace::File::createForRead(inFileName);
    if (!inFile) {
        return 1;
    }

    trace::OutStream *outFile = nullptr;
    if (format == FORMAT_SNAPPY) {
        outFile = trace::createSnappyStream(outFileName);
    } else if (format == FORMAT_BROTLI) {
        ret = repack_brotli(inFile, outFileName, quality);
        delete inFile;
        return ret;
    } else if (format == FORMAT_ZLIB) {
        outFile = trace::createZLibStream(outFileName);
    }
    if (outFile) {
        ret = repack_generic(inFile, outFile);
        delete outFile;
    }

    delete inFile;

    return ret;
}

static int
command(int argc, char *argv[])
{
    Format format = FORMAT_SNAPPY;
    int opt;
    int quality = BROTLI_DEFAULT_QUALITY;
    while ((opt = getopt_long(argc, argv, shortOptions, longOptions, NULL)) != -1) {
        switch (opt) {
        case 'h':
            usage();
            return 0;
        case 'b':
            format = FORMAT_BROTLI;
            if (optarg) {
                quality = atoi(optarg);
                if (quality < BROTLI_MIN_QUALITY || quality > BROTLI_MAX_QUALITY) {
                    std::cerr << "error: brotli quality must be between " << BROTLI_MIN_QUALITY << " and " << BROTLI_MAX_QUALITY << std::endl;
                    return 1;
                }
            }
            break;
        case 's':
            format = FORMAT_SNAPPY;
            break;
        case 'z':
            format = FORMAT_ZLIB;
            break;
        default:
            std::cerr << "error: unexpected option `" << (char)opt << "`\n";
            usage();
            return 1;
        }
    }

    if (argc != optind + 2) {
        std::cerr << "error: insufficient number of arguments\n";
        usage();
        return 1;
    }

    return repack(argv[optind], argv[optind + 1], format, quality);
}

const Command repack_command = {
    "repack",
    synopsis,
    usage,
    command
};