//

// immer: immutable data structures for C++

// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente

//

// This software is distributed under the Boost Software License, Version 1.0.

// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt

//

#include "fuzzer_input.hpp"

#include <immer/algorithm.hpp>

#include <immer/set.hpp>

#include <array>

struct colliding_hash_t

{

    std::size_t operator()(std::size_t x) const { return x & ~15; }

};

extern "C" int LLVMFuzzerTestOneInput(const std::uint8_t* data,

                                      std::size_t size)

{

    constexpr auto var_count = 4;

    using set_t = immer::set<std::size_t, colliding_hash_t>;

    auto vars = std::array<set_t, var_count>{};

    auto is_valid_var = [&](auto idx) { return idx >= 0 && idx < var_count; };

    return fuzzer_input{data, size}.run([&](auto& in) {

        enum ops

        {

            op_insert,

            op_erase,

            op_insert_move,

            op_erase_move,

            op_iterate,

            op_diff

        };

        auto src = read<char>(in, is_valid_var);

        auto dst = read<char>(in, is_valid_var);

        switch (read<char>(in)) {

        case op_insert: {

            auto value = read<size_t>(in);

            vars[dst]  = vars[src].insert(value);

            break;

        }

        case op_erase: {

            auto value = read<size_t>(in);

            vars[dst]  = vars[src].erase(value);

            break;

        }

        case op_insert_move: {

            auto value = read<size_t>(in);

            vars[dst]  = std::move(vars[src]).insert(value);

            break;

        }

        case op_erase_move: {

            auto value = read<size_t>(in);

            vars[dst]  = vars[src].erase(value);

            break;

        }

        case op_iterate: {

            auto srcv = vars[src];

            for (const auto& v : srcv) {

                vars[dst] = vars[dst].insert(v);

            }

            break;

        }

        case op_diff: {

            auto&& a = vars[src];

            auto&& b = vars[dst];

            diff(

                a,

                b,

                [&](auto&& x) {

                    assert(!a.count(x));

                    assert(b.count(x));

                },

                [&](auto&& x) {

                    assert(a.count(x));

                    assert(!b.count(x));

                },

                [&](auto&& x, auto&& y) { assert(false); });

        }

        default:

            break;

        };

        return true;

    });

}