// Copyright (C) 2023 Christian Mazakas
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#include "helpers.hpp"

#include <boost/unordered/concurrent_flat_map.hpp>

test::seed_t initialize_seed{996130204};

using test::default_generator;
using test::limited_range;
using test::sequential;

template <class T> struct pocs_allocator
{
  using propagate_on_container_swap = std::true_type;

  int x_ = -1;

  using value_type = T;

  pocs_allocator() = default;
  pocs_allocator(pocs_allocator const&) = default;
  pocs_allocator(pocs_allocator&&) = default;

  pocs_allocator(int const x) : x_{x} {}

  pocs_allocator& operator=(pocs_allocator const& rhs)
  {
    if (this != &rhs) {
      x_ = rhs.x_;
    }
    return *this;
  }

  template <class U> pocs_allocator(pocs_allocator<U> const& rhs) : x_{rhs.x_}
  {
  }

  T* allocate(std::size_t n)
  {
    return static_cast<T*>(::operator new(n * sizeof(T)));
  }

  void deallocate(T* p, std::size_t) { ::operator delete(p); }

  bool operator==(pocs_allocator const& rhs) const { return x_ == rhs.x_; }
  bool operator!=(pocs_allocator const& rhs) const { return x_ != rhs.x_; }

  friend void swap(pocs_allocator& lhs, pocs_allocator& rhs) noexcept
  {
    std::swap(lhs.x_, rhs.x_);
  }
};

using hasher = stateful_hash;
using key_equal = stateful_key_equal;
using allocator_type = stateful_allocator<std::pair<raii const, raii> >;

using map_type = boost::unordered::concurrent_flat_map<raii, raii, hasher,
  key_equal, allocator_type>;

using map_value_type = typename map_type::value_type;

using pocs_allocator_type = pocs_allocator<std::pair<const raii, raii> >;

using pocs_map_type = boost::unordered::concurrent_flat_map<raii, raii, hasher,
  key_equal, pocs_allocator_type>;

template <class T> struct is_nothrow_member_swappable
{
  static bool const value =
    noexcept(std::declval<T&>().swap(std::declval<T&>()));
};

BOOST_STATIC_ASSERT(is_nothrow_member_swappable<
  boost::unordered::concurrent_flat_map<int, int, std::hash<int>,
    std::equal_to<int>, std::allocator<std::pair<int const, int> > > >::value);

BOOST_STATIC_ASSERT(is_nothrow_member_swappable<pocs_map_type>::value);

BOOST_STATIC_ASSERT(!is_nothrow_member_swappable<map_type>::value);

namespace {
  template <class X, class G>
  void swap_tests(X*, G gen, test::random_generator rg)
  {
    using allocator = typename X::allocator_type;

    bool const pocs =
      boost::allocator_propagate_on_container_swap<allocator>::type::value;

    auto vals1 = make_random_values(1024 * 8, [&] { return gen(rg); });
    auto vals2 = make_random_values(1024 * 4, [&] { return gen(rg); });

    auto ref_map1 =
      boost::unordered_flat_map<raii, raii>(vals1.begin(), vals1.end());

    auto ref_map2 =
      boost::unordered_flat_map<raii, raii>(vals2.begin(), vals2.end());

    {
      raii::reset_counts();

      X x1(vals1.begin(), vals1.end(), vals1.size(), hasher(1), key_equal(2),
        allocator(3));

      X x2(vals2.begin(), vals2.end(), vals2.size(), hasher(2), key_equal(1),
        pocs ? allocator(4) : allocator(3));

      if (pocs) {
        BOOST_TEST(x1.get_allocator() != x2.get_allocator());
      } else {
        BOOST_TEST(x1.get_allocator() == x2.get_allocator());
      }

      auto const old_cc = +raii::copy_constructor;
      auto const old_mc = +raii::move_constructor;

      thread_runner(vals1, [&x1, &x2](boost::span<map_value_type> s) {
        (void)s;

        x1.swap(x2);
        x2.swap(x1);
      });

      BOOST_TEST_EQ(raii::copy_constructor, old_cc);
      BOOST_TEST_EQ(raii::move_constructor, old_mc);

      if (pocs) {
        if (x1.get_allocator() == allocator(3)) {
          BOOST_TEST(x2.get_allocator() == allocator(4));
        } else {
          BOOST_TEST(x1.get_allocator() == allocator(4));
          BOOST_TEST(x2.get_allocator() == allocator(3));
        }
      } else {
        BOOST_TEST(x1.get_allocator() == allocator(3));
        BOOST_TEST(x1.get_allocator() == x2.get_allocator());
      }

      if (x1.size() == ref_map1.size()) {
        test_matches_reference(x1, ref_map1);
        test_matches_reference(x2, ref_map2);

        BOOST_TEST_EQ(x1.hash_function(), hasher(1));
        BOOST_TEST_EQ(x1.key_eq(), key_equal(2));

        BOOST_TEST_EQ(x2.hash_function(), hasher(2));
        BOOST_TEST_EQ(x2.key_eq(), key_equal(1));
      } else {
        test_matches_reference(x2, ref_map1);
        test_matches_reference(x1, ref_map2);

        BOOST_TEST_EQ(x1.hash_function(), hasher(2));
        BOOST_TEST_EQ(x1.key_eq(), key_equal(1));

        BOOST_TEST_EQ(x2.hash_function(), hasher(1));
        BOOST_TEST_EQ(x2.key_eq(), key_equal(2));
      }
    }
    check_raii_counts();
  }

  template <class G> void insert_and_swap(G gen, test::random_generator rg)
  {
    auto vals1 = make_random_values(1024 * 8, [&] { return gen(rg); });
    auto vals2 = make_random_values(1024 * 4, [&] { return gen(rg); });

    {
      raii::reset_counts();

      map_type x1(vals1.size(), hasher(1), key_equal(2), allocator_type(3));
      map_type x2(vals2.size(), hasher(2), key_equal(1), allocator_type(3));

      std::thread t1, t2, t3;
      boost::latch l(2);

      std::mutex m;
      std::condition_variable cv;
      std::atomic_bool done1{false}, done2{false};
      std::atomic<unsigned> num_swaps{0};

      t1 = std::thread([&x1, &vals1, &l, &done1, &cv] {
        l.arrive_and_wait();

        for (std::size_t idx = 0; idx < vals1.size(); ++idx) {
          auto const& val = vals1[idx];
          x1.insert(val);
          if (idx % 100 == 0) {
            cv.notify_all();
          }
        }

        done1 = true;
      });

      t2 = std::thread([&x2, &vals2, &l, &done2] {
        l.arrive_and_wait();

        for (auto const& val : vals2) {
          x2.insert(val);
        }

        done2 = true;
      });

      t3 = std::thread([&x1, &x2, &m, &cv, &done1, &done2, &num_swaps] {
        do {
          {
            std::unique_lock<std::mutex> lk(m);
            cv.wait(lk, [] { return true; });
          }
          x1.swap(x2);
          ++num_swaps;
        } while (!done1 || !done2);
      });

      t1.join();
      t2.join();
      t3.join();

      BOOST_TEST_GT(num_swaps, 0u);

      BOOST_TEST_NOT(x1.empty());
      BOOST_TEST_NOT(x2.empty());

      if (x1.hash_function() == hasher(1)) {
        BOOST_TEST_EQ(x1.key_eq(), key_equal(2));

        BOOST_TEST_EQ(x2.hash_function(), hasher(2));
        BOOST_TEST_EQ(x2.key_eq(), key_equal(1));
      } else {
        BOOST_TEST_EQ(x1.hash_function(), hasher(2));
        BOOST_TEST_EQ(x1.key_eq(), key_equal(1));

        BOOST_TEST_EQ(x2.hash_function(), hasher(1));
        BOOST_TEST_EQ(x2.key_eq(), key_equal(2));
      }
    }

    check_raii_counts();
  }

  map_type* map;
  pocs_map_type* pocs_map;

} // namespace

// clang-format off
UNORDERED_TEST(
  swap_tests,
  ((map)(pocs_map))
  ((value_type_generator))
  ((default_generator)(sequential)(limited_range)))

UNORDERED_TEST(insert_and_swap,
  ((value_type_generator))
  ((default_generator)(sequential)(limited_range)))
// clang-format on

RUN_TESTS()