// Copyright (c) 2020-2021 The Bitcoin Core developers

// Distributed under the MIT software license, see the accompanying

// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <crypto/muhash.h>

#include <test/fuzz/FuzzedDataProvider.h>

#include <test/fuzz/fuzz.h>

#include <test/fuzz/util.h>

#include <vector>

FUZZ_TARGET(muhash)

{

    FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};

    std::vector<uint8_t> data{ConsumeRandomLengthByteVector(fuzzed_data_provider)};

    std::vector<uint8_t> data2{ConsumeRandomLengthByteVector(fuzzed_data_provider)};

    MuHash3072 muhash;

    muhash.Insert(data);

    muhash.Insert(data2);

    constexpr uint256 initial_state_hash{"dd5ad2a105c2d29495f577245c357409002329b9f4d6182c0af3dc2f462555c8"};

    uint256 out;

    uint256 out2;

    CallOneOf(

        fuzzed_data_provider,

        [&] {

            // Test that MuHash result is consistent independent of order of operations

            muhash.Finalize(out);

            muhash = MuHash3072();

            muhash.Insert(data2);

            muhash.Insert(data);

            muhash.Finalize(out2);

        },

        [&] {

            // Test that multiplication with the initial state never changes the finalized result

            muhash.Finalize(out);

            MuHash3072 muhash3;

            muhash3 *= muhash;

            muhash3.Finalize(out2);

        },

        [&] {

            // Test that dividing a MuHash by itself brings it back to it's initial state

            // See note about clang + self-assignment in test/uint256_tests.cpp

            #if defined(__clang__)

            #    pragma clang diagnostic push

            #    pragma clang diagnostic ignored "-Wself-assign-overloaded"

            #endif

            muhash /= muhash;

            #if defined(__clang__)

            #    pragma clang diagnostic pop

            #endif

            muhash.Finalize(out);

            out2 = initial_state_hash;

        },

        [&] {

            // Test that removing all added elements brings the object back to it's initial state

            muhash.Remove(data);

            muhash.Remove(data2);

            muhash.Finalize(out);

            out2 = initial_state_hash;

        });

    assert(out == out2);

}