// Copyright 2006-2009 Daniel James.
// 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)

// The code for erasing elements from containers with equivalent keys is very
// hairy with several tricky edge cases - so explicitly test each one.

// clang-format off
#include "../helpers/prefix.hpp"
#include <boost/unordered_map.hpp>
#include "../helpers/postfix.hpp"
// clang-format on

#include "../helpers/test.hpp"
#include "../helpers/list.hpp"
#include "../helpers/invariants.hpp"
#include "../helpers/helpers.hpp"
#include <set>
#include <iterator>
#include "../objects/test.hpp"

#if BOOST_WORKAROUND(BOOST_MSVC, < 1400)
#pragma warning(disable : 4267) // conversion from 'size_t' to 'unsigned int',
                                // possible loss of data.
#endif

struct write_pair_type
{
  template <class X1, class X2>
  void operator()(std::pair<X1, X2> const& x) const
  {
    BOOST_LIGHTWEIGHT_TEST_OSTREAM << "(" << x.first << "," << x.second << ")";
  }
} write_pair;

template <class Container> void write_container(Container const& x)
{
  std::for_each(x.begin(), x.end(), write_pair);
  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "\n";
}

// Make everything collide - for testing erase in a single bucket.
struct collision_hash
{
  std::size_t operator()(int) const { return 0; }
};

// For testing erase in 2 buckets.
struct collision2_hash
{
  std::size_t operator()(int x) const
  {
    return static_cast<std::size_t>(x & 1);
  }
};

// For testing erase in lots of buckets.
struct collision3_hash
{
  std::size_t operator()(int x) const { return static_cast<std::size_t>(x); }
};

typedef boost::unordered_multimap<int, int, collision_hash, std::equal_to<int>,
  test::allocator1<std::pair<int const, int> > >
  collide_map;
typedef boost::unordered_multimap<int, int, collision2_hash, std::equal_to<int>,
  test::allocator2<std::pair<int const, int> > >
  collide_map2;
typedef boost::unordered_multimap<int, int, collision3_hash, std::equal_to<int>,
  test::allocator2<std::pair<int const, int> > >
  collide_map3;
typedef collide_map::value_type collide_value;
typedef test::list<collide_value> collide_list;

UNORDERED_AUTO_TEST (empty_range_tests) {
  collide_map x;
  x.erase(x.begin(), x.end());
  x.erase(x.begin(), x.begin());
  x.erase(x.end(), x.end());
  test::check_equivalent_keys(x);
}

UNORDERED_AUTO_TEST (single_item_tests) {
  collide_list init;
  init.push_back(collide_value(1, 1));

  collide_map x(init.begin(), init.end());
  x.erase(x.begin(), x.begin());
  BOOST_TEST(x.count(1) == 1 && x.size() == 1);
  test::check_equivalent_keys(x);
  x.erase(x.end(), x.end());
  BOOST_TEST(x.count(1) == 1 && x.size() == 1);
  test::check_equivalent_keys(x);
  x.erase(x.begin(), x.end());
  BOOST_TEST(x.count(1) == 0 && x.size() == 0);
  test::check_equivalent_keys(x);
}

UNORDERED_AUTO_TEST (two_equivalent_item_tests) {
  collide_list init;
  init.push_back(collide_value(1, 1));
  init.push_back(collide_value(1, 2));

  {
    collide_map x(init.begin(), init.end());
    x.erase(x.begin(), x.end());
    BOOST_TEST(x.count(1) == 0 && x.size() == 0);
    test::check_equivalent_keys(x);
  }

  {
    collide_map x(init.begin(), init.end());
    int value = test::next(x.begin())->second;
    x.erase(x.begin(), test::next(x.begin()));
    BOOST_TEST(x.count(1) == 1 && x.size() == 1 && x.begin()->first == 1 &&
               x.begin()->second == value);
    test::check_equivalent_keys(x);
  }

  {
    collide_map x(init.begin(), init.end());
    int value = x.begin()->second;
    x.erase(test::next(x.begin()), x.end());
    BOOST_TEST(x.count(1) == 1 && x.size() == 1 && x.begin()->first == 1 &&
               x.begin()->second == value);
    test::check_equivalent_keys(x);
  }
}

// More automated tests...

template <class Range1, class Range2>
bool compare(Range1 const& x, Range2 const& y)
{
  collide_list a(x.begin(), x.end());
  collide_list b(y.begin(), y.end());
  a.sort();
  b.sort();
  return a == b;
}

template <class Container>
bool general_erase_range_test(Container& x, std::size_t start, std::size_t end)
{
  collide_list l(x.begin(), x.end());

  l.erase(test::next(l.begin(), start), test::next(l.begin(), end));
  x.erase(test::next(x.begin(), start), test::next(x.begin(), end));

  test::check_equivalent_keys(x);
  return compare(l, x);
}

template <class Container> void erase_subrange_tests(Container const& x)
{
  for (std::size_t length = 0; length < x.size(); ++length) {
    for (std::size_t position = 0; position < x.size() - length; ++position) {
      Container y(x);
      collide_list init(y.begin(), y.end());
      if (!general_erase_range_test(y, position, position + length)) {
        BOOST_ERROR("general_erase_range_test failed.");
        BOOST_LIGHTWEIGHT_TEST_OSTREAM << "Erase: [" << position << ","
                                       << position + length << ")\n";
        write_container(init);
        write_container(y);
      }
    }
  }
}

template <class Container>
void x_by_y_erase_range_tests(Container*, int values, int duplicates)
{
  Container y;

  for (int i = 0; i < values; ++i) {
    for (int j = 0; j < duplicates; ++j) {
      y.insert(collide_value(i, j));
    }
  }

  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "Values: " << values
                                 << ", Duplicates: " << duplicates << "\n";
  erase_subrange_tests(y);
}

template <class Container>
void exhaustive_erase_tests(Container* x, int num_values, int num_duplicated)
{
  for (int i = 0; i < num_values; ++i) {
    for (int j = 0; j < num_duplicated; ++j) {
      x_by_y_erase_range_tests(x, i, j);
    }
  }
}

UNORDERED_AUTO_TEST (exhaustive_collide_tests) {
  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "exhaustive_collide_tests:\n";
  collide_map m;
  exhaustive_erase_tests((collide_map*)0, 4, 4);
  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "\n";
}

UNORDERED_AUTO_TEST (exhaustive_collide2_tests) {
  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "exhaustive_collide2_tests:\n";
  exhaustive_erase_tests((collide_map2*)0, 8, 4);
  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "\n";
}

UNORDERED_AUTO_TEST (exhaustive_collide3_tests) {
  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "exhaustive_collide3_tests:\n";
  exhaustive_erase_tests((collide_map3*)0, 8, 4);
  BOOST_LIGHTWEIGHT_TEST_OSTREAM << "\n";
}

RUN_TESTS()