/**

 * This fuzz target attempts to compress the fuzzed data with the simple

 * compression function with an output buffer that may be too small to

 * ensure that the compressor never crashes.

 */

#include <stddef.h>

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

#include "fuzz_helpers.h"

#include "fuzz_data_producer.h"

#include "lz4.h"

#include "lz4hc.h"

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)

{

    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);

    size_t const dstCapacitySeed = FUZZ_dataProducer_retrieve32(producer);

    size_t const levelSeed = FUZZ_dataProducer_retrieve32(producer);

    size = FUZZ_dataProducer_remainingBytes(producer);

    size_t const dstCapacity = FUZZ_getRange_from_uint32(dstCapacitySeed, 0, size);

    int const level = FUZZ_getRange_from_uint32(levelSeed, LZ4HC_CLEVEL_MIN, LZ4HC_CLEVEL_MAX);

    char* const dst = (char*)malloc(dstCapacity);

    char* const rt = (char*)malloc(size);

    FUZZ_ASSERT(dst);

    FUZZ_ASSERT(rt);

    /* If compression succeeds it must round trip correctly. */

    {

        int const dstSize = LZ4_compress_HC((const char*)data, dst, size,

                                            dstCapacity, level);

        if (dstSize > 0) {

            int const rtSize = LZ4_decompress_safe(dst, rt, dstSize, size);

            FUZZ_ASSERT_MSG(rtSize == size, "Incorrect regenerated size");

            FUZZ_ASSERT_MSG(!memcmp(data, rt, size), "Corruption!");

        }

    }

    if (dstCapacity > 0) {

        /* Compression succeeds and must round trip correctly. */

        void* state = malloc(LZ4_sizeofStateHC());

        FUZZ_ASSERT(state);

        int compressedSize = size;

        int const dstSize = LZ4_compress_HC_destSize(state, (const char*)data,

                                                     dst, &compressedSize,

                                                     dstCapacity, level);

        FUZZ_ASSERT(dstSize > 0);

        int const rtSize = LZ4_decompress_safe(dst, rt, dstSize, size);

        FUZZ_ASSERT_MSG(rtSize == compressedSize, "Incorrect regenerated size");

        FUZZ_ASSERT_MSG(!memcmp(data, rt, compressedSize), "Corruption!");

        free(state);

    }

    free(dst);

    free(rt);

    FUZZ_dataProducer_free(producer);

    return 0;

}