//

// 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/heap/gc_heap.hpp>

#include <immer/map.hpp>

#include <immer/refcount/no_refcount_policy.hpp>

#include <immer/algorithm.hpp>

#include <array>

using gc_memory = immer::memory_policy<immer::heap_policy<immer::gc_heap>,

                                       immer::no_refcount_policy,

                                       immer::default_lock_policy,

                                       immer::gc_transience_policy,

                                       false>;

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)

{

    auto guard = immer::gc_disable_guard{};

    constexpr auto var_count = 4;

    using map_t = immer::

        map<std::size_t, int, colliding_hash_t, std::equal_to<>, gc_memory>;

    auto vars = std::array<map_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_set,

            op_erase,

            op_set_move,

            op_erase_move,

            op_iterate,

            op_find,

            op_update,

            op_update_move,

            op_update_if_exists,

            op_update_if_exists_move,

            op_diff

        };

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

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

        switch (read<char>(in)) {

        case op_set: {

            auto value = read<size_t>(in);

            vars[dst]  = vars[src].set(value, 42);

            break;

        }

        case op_erase: {

            auto value = read<size_t>(in);

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

            break;

        }

        case op_set_move: {

            auto value = read<size_t>(in);

            vars[dst]  = std::move(vars[src]).set(value, 42);

            break;

        }

        case op_erase_move: {

            auto value = read<size_t>(in);

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

            break;

        }

        case op_iterate: {

            auto srcv = vars[src];

            for (const auto& v : srcv) {

                vars[dst] = vars[dst].set(v.first, v.second);

            }

            break;

        }

        case op_find: {

            auto value = read<size_t>(in);

            auto res   = vars[src].find(value);

            if (res != nullptr) {

                vars[dst] = vars[dst].set(*res, 42);

            }

            break;

        }

        case op_update: {

            auto key  = read<size_t>(in);

            vars[dst] = vars[src].update(key, [](int x) { return x + 1; });

            break;

        }

        case op_update_move: {

            auto key = read<size_t>(in);

            vars[dst] =

                std::move(vars[src]).update(key, [](int x) { return x + 1; });

            break;

        }

        case op_update_if_exists: {

            auto key = read<size_t>(in);

            vars[dst] =

                vars[src].update_if_exists(key, [](int x) { return x + 1; });

            break;

        }

        case op_update_if_exists_move: {

            auto key  = read<size_t>(in);

            vars[dst] = std::move(vars[src]).update_if_exists(

                key, [](int x) { return x + 1; });

            break;

        }

        case op_diff: {

            auto&& a = vars[src];

            auto&& b = vars[dst];

            diff(

                a,

                b,

                [&](auto&& x) {

                    assert(!a.count(x.first));

                    assert(b.count(x.first));

                },

                [&](auto&& x) {

                    assert(a.count(x.first));

                    assert(!b.count(x.first));

                },

                [&](auto&& x, auto&& y) {

                    assert(x.first == y.first);

                    assert(x.second != y.second);

                });

        }

        default:

            break;

        };

        return true;

    });

}