//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20

// <flat_map>

// iterator erase(iterator position);
// iterator erase(const_iterator position);

#include <compare>
#include <concepts>
#include <deque>
#include <flat_map>
#include <functional>
#include <type_traits>
#include <utility>
#include <vector>

#include "MinSequenceContainer.h"
#include "../helpers.h"
#include "test_macros.h"
#include "min_allocator.h"

template <class KeyContainer, class ValueContainer>
constexpr void test() {
  using Key   = typename KeyContainer::value_type;
  using Value = typename ValueContainer::value_type;
  using M     = std::flat_map<Key, Value, std::less<Key>, KeyContainer, ValueContainer>;
  using P     = std::pair<Key, Value>;
  using I     = M::iterator;

  P ar[] = {
      P(1, 1.5),
      P(2, 2.5),
      P(3, 3.5),
      P(4, 4.5),
      P(5, 5.5),
      P(6, 6.5),
      P(7, 7.5),
      P(8, 8.5),
  };
  M m(ar, ar + sizeof(ar) / sizeof(ar[0]));
  assert(m.size() == 8);
  std::same_as<I> decltype(auto) i1 = m.erase(std::next(m.cbegin(), 3));
  assert(m.size() == 7);
  assert(i1 == std::next(m.begin(), 3));
  assert(m.begin()->first == 1);
  assert(m.begin()->second == 1.5);
  assert(std::next(m.begin())->first == 2);
  assert(std::next(m.begin())->second == 2.5);
  assert(std::next(m.begin(), 2)->first == 3);
  assert(std::next(m.begin(), 2)->second == 3.5);
  assert(std::next(m.begin(), 3)->first == 5);
  assert(std::next(m.begin(), 3)->second == 5.5);
  assert(std::next(m.begin(), 4)->first == 6);
  assert(std::next(m.begin(), 4)->second == 6.5);
  assert(std::next(m.begin(), 5)->first == 7);
  assert(std::next(m.begin(), 5)->second == 7.5);
  assert(std::next(m.begin(), 6)->first == 8);
  assert(std::next(m.begin(), 6)->second == 8.5);

  std::same_as<I> decltype(auto) i2 = m.erase(std::next(m.begin(), 0));
  assert(m.size() == 6);
  assert(i2 == m.begin());
  assert(m.begin()->first == 2);
  assert(m.begin()->second == 2.5);
  assert(std::next(m.begin())->first == 3);
  assert(std::next(m.begin())->second == 3.5);
  assert(std::next(m.begin(), 2)->first == 5);
  assert(std::next(m.begin(), 2)->second == 5.5);
  assert(std::next(m.begin(), 3)->first == 6);
  assert(std::next(m.begin(), 3)->second == 6.5);
  assert(std::next(m.begin(), 4)->first == 7);
  assert(std::next(m.begin(), 4)->second == 7.5);
  assert(std::next(m.begin(), 5)->first == 8);
  assert(std::next(m.begin(), 5)->second == 8.5);

  std::same_as<I> decltype(auto) i3 = m.erase(std::next(m.cbegin(), 5));
  assert(m.size() == 5);
  assert(i3 == m.end());
  assert(m.begin()->first == 2);
  assert(m.begin()->second == 2.5);
  assert(std::next(m.begin())->first == 3);
  assert(std::next(m.begin())->second == 3.5);
  assert(std::next(m.begin(), 2)->first == 5);
  assert(std::next(m.begin(), 2)->second == 5.5);
  assert(std::next(m.begin(), 3)->first == 6);
  assert(std::next(m.begin(), 3)->second == 6.5);
  assert(std::next(m.begin(), 4)->first == 7);
  assert(std::next(m.begin(), 4)->second == 7.5);

  std::same_as<I> decltype(auto) i4 = m.erase(std::next(m.begin(), 1));
  assert(m.size() == 4);
  assert(i4 == std::next(m.begin()));
  assert(m.begin()->first == 2);
  assert(m.begin()->second == 2.5);
  assert(std::next(m.begin())->first == 5);
  assert(std::next(m.begin())->second == 5.5);
  assert(std::next(m.begin(), 2)->first == 6);
  assert(std::next(m.begin(), 2)->second == 6.5);
  assert(std::next(m.begin(), 3)->first == 7);
  assert(std::next(m.begin(), 3)->second == 7.5);

  std::same_as<I> decltype(auto) i5 = m.erase(std::next(m.cbegin(), 2));
  assert(m.size() == 3);
  assert(i5 == std::next(m.begin(), 2));
  assert(m.begin()->first == 2);
  assert(m.begin()->second == 2.5);
  assert(std::next(m.begin())->first == 5);
  assert(std::next(m.begin())->second == 5.5);
  assert(std::next(m.begin(), 2)->first == 7);
  assert(std::next(m.begin(), 2)->second == 7.5);

  std::same_as<I> decltype(auto) i6 = m.erase(std::next(m.begin(), 2));
  assert(m.size() == 2);
  assert(i6 == std::next(m.begin(), 2));
  assert(m.begin()->first == 2);
  assert(m.begin()->second == 2.5);
  assert(std::next(m.begin())->first == 5);
  assert(std::next(m.begin())->second == 5.5);

  std::same_as<I> decltype(auto) i7 = m.erase(std::next(m.cbegin(), 0));
  assert(m.size() == 1);
  assert(i7 == std::next(m.begin(), 0));
  assert(m.begin()->first == 5);
  assert(m.begin()->second == 5.5);

  std::same_as<I> decltype(auto) i8 = m.erase(m.begin());
  assert(m.size() == 0);
  assert(i8 == m.begin());
  assert(i8 == m.end());
}

constexpr bool test() {
  test<std::vector<int>, std::vector<double>>();
#ifndef __cpp_lib_constexpr_deque
  if (!TEST_IS_CONSTANT_EVALUATED)
#endif
  {
    test<std::deque<int>, std::vector<double>>();
  }
  test<MinSequenceContainer<int>, MinSequenceContainer<double>>();
  test<std::vector<int, min_allocator<int>>, std::vector<double, min_allocator<double>>>();

  if (!TEST_IS_CONSTANT_EVALUATED) {
    auto erase_function = [](auto& m, auto) { m.erase(m.begin() + 2); };
    test_erase_exception_guarantee(erase_function);
  }

  return true;
}

int main(int, char**) {
  test();
#if TEST_STD_VER >= 26
  static_assert(test());
#endif

  return 0;
}