// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "absl/container/flat_hash_set.h"

#include <vector>

#include "absl/container/internal/hash_generator_testing.h"
#include "absl/container/internal/unordered_set_constructor_test.h"
#include "absl/container/internal/unordered_set_lookup_test.h"
#include "absl/container/internal/unordered_set_members_test.h"
#include "absl/container/internal/unordered_set_modifiers_test.h"
#include "absl/log/check.h"
#include "absl/memory/memory.h"
#include "absl/strings/string_view.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
namespace {

using ::absl::container_internal::hash_internal::Enum;
using ::absl::container_internal::hash_internal::EnumClass;
using ::testing::IsEmpty;
using ::testing::Pointee;
using ::testing::UnorderedElementsAre;
using ::testing::UnorderedElementsAreArray;

// Check that absl::flat_hash_set works in a global constructor.
struct BeforeMain {
  BeforeMain() {
    absl::flat_hash_set<int> x;
    x.insert(1);
    CHECK(!x.contains(0)) << "x should not contain 0";
    CHECK(x.contains(1)) << "x should contain 1";
  }
};
const BeforeMain before_main;

template <class T>
using Set =
    absl::flat_hash_set<T, StatefulTestingHash, StatefulTestingEqual, Alloc<T>>;

using SetTypes =
    ::testing::Types<Set<int>, Set<std::string>, Set<Enum>, Set<EnumClass>>;

INSTANTIATE_TYPED_TEST_SUITE_P(FlatHashSet, ConstructorTest, SetTypes);
INSTANTIATE_TYPED_TEST_SUITE_P(FlatHashSet, LookupTest, SetTypes);
INSTANTIATE_TYPED_TEST_SUITE_P(FlatHashSet, MembersTest, SetTypes);
INSTANTIATE_TYPED_TEST_SUITE_P(FlatHashSet, ModifiersTest, SetTypes);

TEST(FlatHashSet, EmplaceString) {
  std::vector<std::string> v = {"a", "b"};
  absl::flat_hash_set<absl::string_view> hs(v.begin(), v.end());
  EXPECT_THAT(hs, UnorderedElementsAreArray(v));
}

TEST(FlatHashSet, BitfieldArgument) {
  union {
    int n : 1;
  };
  n = 0;
  absl::flat_hash_set<int> s = {n};
  s.insert(n);
  s.insert(s.end(), n);
  s.insert({n});
  s.erase(n);
  s.count(n);
  s.prefetch(n);
  s.find(n);
  s.contains(n);
  s.equal_range(n);
}

TEST(FlatHashSet, MergeExtractInsert) {
  struct Hash {
    size_t operator()(const std::unique_ptr<int>& p) const { return *p; }
  };
  struct Eq {
    bool operator()(const std::unique_ptr<int>& a,
                    const std::unique_ptr<int>& b) const {
      return *a == *b;
    }
  };
  absl::flat_hash_set<std::unique_ptr<int>, Hash, Eq> set1, set2;
  set1.insert(absl::make_unique<int>(7));
  set1.insert(absl::make_unique<int>(17));

  set2.insert(absl::make_unique<int>(7));
  set2.insert(absl::make_unique<int>(19));

  EXPECT_THAT(set1, UnorderedElementsAre(Pointee(7), Pointee(17)));
  EXPECT_THAT(set2, UnorderedElementsAre(Pointee(7), Pointee(19)));

  set1.merge(set2);

  EXPECT_THAT(set1, UnorderedElementsAre(Pointee(7), Pointee(17), Pointee(19)));
  EXPECT_THAT(set2, UnorderedElementsAre(Pointee(7)));

  auto node = set1.extract(absl::make_unique<int>(7));
  EXPECT_TRUE(node);
  EXPECT_THAT(node.value(), Pointee(7));
  EXPECT_THAT(set1, UnorderedElementsAre(Pointee(17), Pointee(19)));

  auto insert_result = set2.insert(std::move(node));
  EXPECT_FALSE(node);
  EXPECT_FALSE(insert_result.inserted);
  EXPECT_TRUE(insert_result.node);
  EXPECT_THAT(insert_result.node.value(), Pointee(7));
  EXPECT_EQ(**insert_result.position, 7);
  EXPECT_NE(insert_result.position->get(), insert_result.node.value().get());
  EXPECT_THAT(set2, UnorderedElementsAre(Pointee(7)));

  node = set1.extract(absl::make_unique<int>(17));
  EXPECT_TRUE(node);
  EXPECT_THAT(node.value(), Pointee(17));
  EXPECT_THAT(set1, UnorderedElementsAre(Pointee(19)));

  node.value() = absl::make_unique<int>(23);

  insert_result = set2.insert(std::move(node));
  EXPECT_FALSE(node);
  EXPECT_TRUE(insert_result.inserted);
  EXPECT_FALSE(insert_result.node);
  EXPECT_EQ(**insert_result.position, 23);
  EXPECT_THAT(set2, UnorderedElementsAre(Pointee(7), Pointee(23)));
}

bool IsEven(int k) { return k % 2 == 0; }

TEST(FlatHashSet, EraseIf) {
  // Erase all elements.
  {
    flat_hash_set<int> s = {1, 2, 3, 4, 5};
    EXPECT_EQ(erase_if(s, [](int) { return true; }), 5);
    EXPECT_THAT(s, IsEmpty());
  }
  // Erase no elements.
  {
    flat_hash_set<int> s = {1, 2, 3, 4, 5};
    EXPECT_EQ(erase_if(s, [](int) { return false; }), 0);
    EXPECT_THAT(s, UnorderedElementsAre(1, 2, 3, 4, 5));
  }
  // Erase specific elements.
  {
    flat_hash_set<int> s = {1, 2, 3, 4, 5};
    EXPECT_EQ(erase_if(s, [](int k) { return k % 2 == 1; }), 3);
    EXPECT_THAT(s, UnorderedElementsAre(2, 4));
  }
  // Predicate is function reference.
  {
    flat_hash_set<int> s = {1, 2, 3, 4, 5};
    EXPECT_EQ(erase_if(s, IsEven), 2);
    EXPECT_THAT(s, UnorderedElementsAre(1, 3, 5));
  }
  // Predicate is function pointer.
  {
    flat_hash_set<int> s = {1, 2, 3, 4, 5};
    EXPECT_EQ(erase_if(s, &IsEven), 2);
    EXPECT_THAT(s, UnorderedElementsAre(1, 3, 5));
  }
}

}  // namespace
}  // namespace container_internal
ABSL_NAMESPACE_END
}  // namespace absl
