#include "zbuild.h"

#include <assert.h>

#ifdef ZLIB_COMPAT

#  include "zlib.h"

#else

#  include "zlib-ng.h"

#endif

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t dataLen) {

    uint32_t crc0 = PREFIX(crc32)(0L, NULL, 0);

    uint32_t crc1 = crc0;

    uint32_t crc2 = crc0;

    uint32_t adler0 = PREFIX(adler32)(0L, NULL, 0);

    uint32_t adler1 = adler0;

    uint32_t adler2 = adler0;

    uint32_t combine1, combine2;

    /* Checksum with a buffer of size equal to the first byte in the input. */

    uint32_t buffSize = data[0];

    uint32_t offset = 0;

    uint32_t op;

    /* Discard inputs larger than 1Mb. */

    static size_t kMaxSize = 1024 * 1024;

    if (dataLen < 1 || dataLen > kMaxSize)

        return 0;

    /* Make sure the buffer has at least a byte. */

    if (buffSize == 0)

        ++buffSize;

    /* CRC32 */

    op = PREFIX(crc32_combine_gen)(buffSize);

    for (offset = 0; offset + buffSize <= dataLen; offset += buffSize) {

        uint32_t crc3 = PREFIX(crc32_z)(crc0, data + offset, buffSize);

        uint32_t crc4 = PREFIX(crc32_combine_op)(crc1, crc3, op);

        crc1 = PREFIX(crc32_z)(crc1, data + offset, buffSize);

        assert(crc1 == crc4);

        Z_UNUSED(crc1);

        Z_UNUSED(crc4);

    }

    crc1 = PREFIX(crc32_z)(crc1, data + offset, dataLen % buffSize);

    crc2 = PREFIX(crc32_z)(crc2, data, dataLen);

    assert(crc1 == crc2);

    Z_UNUSED(crc1);

    Z_UNUSED(crc2);

    combine1 = PREFIX(crc32_combine)(crc1, crc2, (z_off_t)dataLen);

    combine2 = PREFIX(crc32_combine)(crc1, crc1, (z_off_t)dataLen);

    assert(combine1 == combine2);

    /* Fast CRC32 combine. */

    op = PREFIX(crc32_combine_gen)((z_off_t)dataLen);

    combine1 = PREFIX(crc32_combine_op)(crc1, crc2, op);

    combine2 = PREFIX(crc32_combine_op)(crc2, crc1, op);

    assert(combine1 == combine2);

    combine1 = PREFIX(crc32_combine)(crc1, crc2, (z_off_t)dataLen);

    combine2 = PREFIX(crc32_combine_op)(crc2, crc1, op);

    assert(combine1 == combine2);

    /* Adler32 */

    for (offset = 0; offset + buffSize <= dataLen; offset += buffSize)

        adler1 = PREFIX(adler32_z)(adler1, data + offset, buffSize);

    adler1 = PREFIX(adler32_z)(adler1, data + offset, dataLen % buffSize);

    adler2 = PREFIX(adler32_z)(adler2, data, dataLen);

    assert(adler1 == adler2);

    Z_UNUSED(adler1);

    Z_UNUSED(adler2);

    combine1 = PREFIX(adler32_combine)(adler1, adler2, (z_off_t)dataLen);

    combine2 = PREFIX(adler32_combine)(adler1, adler1, (z_off_t)dataLen);

    assert(combine1 == combine2);

    Z_UNUSED(combine1);

    Z_UNUSED(combine2);

    /* This function must return 0. */

    return 0;

}