/*
 * Copyright (C) 2018-present ScyllaDB
 */

/*
 * SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
 */

#define BOOST_TEST_MODULE core

#include <boost/test/unit_test.hpp>
#include "sstables/checksum_utils.hh"
#include "test/lib/make_random_string.hh"
#include <seastar/core/format.hh>

template<typename ReferenceImpl, typename Impl>
static
void test_combine() {
    auto check = [](size_t len2) {
        constexpr auto crc1 = 0x12381237;
        // len2==0 implies crc2==0. Newer zlib versions don't hold the
        // caller's hands anymore in this case, so make sure we don't
        // supply invalid input:
        const auto crc2 = len2 == 0 ? 0 : 0x73747474;
        auto c1 = Impl::checksum_combine(crc1, crc2, len2);
        auto c2 = ReferenceImpl::checksum_combine(crc1, crc2, len2);
        BOOST_REQUIRE_EQUAL(c1, c2);
    };

    check(0);
    check(1);
    check(2);
    check(3);
    check(8);
    check(255);
    check(256);
    check(1023);
    check(1024);
    check(1025);
    check(0xffff);
    check(0x10000);
    check(0xdeadbeef);
    check(0xffffffff);
    check(0x100000000);
    check(0x200000000);
    check(0x10000000001);
    check(0x7eadbeefcafebabe);
    check(0x7fffffffffffffff);
}

template<typename ReferenceImpl, typename Impl>
static
void test() {
    auto rolling = Impl::init_checksum();
    BOOST_REQUIRE_EQUAL(rolling, ReferenceImpl::init_checksum());

    for (auto size : {0, 1, 2, 10, 13, 16, 17, 22, 31, 1024, 2000, 80000}) {
        auto data = make_random_string(size);

        auto current = Impl::checksum(data.data(), data.size());
        auto ref_current = ReferenceImpl::checksum(data.data(), data.size());
        BOOST_REQUIRE_EQUAL(current, ref_current);

        auto new_rolling = Impl::checksum(rolling, data.data(), data.size());
        auto ref_new_rolling = ReferenceImpl::checksum(rolling, data.data(), data.size());
        BOOST_REQUIRE_EQUAL(new_rolling, ref_new_rolling);

        auto new_rolling_via_combine = Impl::checksum_combine(rolling, current, data.size());
        BOOST_REQUIRE_EQUAL(new_rolling, new_rolling_via_combine);

        rolling = new_rolling;
    }

    test_combine<ReferenceImpl, Impl>();
}

BOOST_AUTO_TEST_CASE(test_libdeflate_matches_zlib) {
    test<zlib_crc32_checksummer, libdeflate_crc32_checksummer>();
}

BOOST_AUTO_TEST_CASE(test_default_matches_zlib) {
    test<zlib_crc32_checksummer, crc32_utils>();
}