// SPDX-License-Identifier: BSD-2-Clause
// author: Max Kellermann <max.kellermann@gmail.com>

#include "util/IntrusiveHashSet.hxx"

#include <gtest/gtest.h>

#include <string>

namespace {

struct IntItem final : IntrusiveHashSetHook<IntrusiveHookMode::TRACK> {
	int value;

	IntItem(int _value) noexcept:value(_value) {}

	struct Hash {
		constexpr std::size_t operator()(const IntItem &i) const noexcept {
			return i.value;
		}

		constexpr std::size_t operator()(int i) const noexcept {
			return i;
		}
	};

	struct Equal {
		constexpr bool operator()(const IntItem &a,
					  const IntItem &b) const noexcept {
			return a.value == b.value;
		}
	};
};

} // anonymous namespace

TEST(IntrusiveHashSet, Basic)
{
	IntItem a{1}, b{2}, c{3}, d{4}, e{5}, f{1};

	IntrusiveHashSet<IntItem, 3,
			 IntrusiveHashSetOperators<IntItem::Hash,
						   IntItem::Equal>> set;

	{
		auto [position, inserted] = set.insert_check(2);
		ASSERT_TRUE(inserted);
		set.insert_commit(position, b);
	}

	ASSERT_FALSE(set.insert_check(2).second);
	ASSERT_FALSE(set.insert_check(b).second);

	{
		auto [position, inserted] = set.insert_check(a);
		ASSERT_TRUE(inserted);
		set.insert_commit(position, a);
	}

	set.insert(c);

	ASSERT_EQ(set.size(), 3U);

	ASSERT_NE(set.find(c), set.end());
	ASSERT_EQ(set.find(c), set.iterator_to(c));
	ASSERT_NE(set.find(3), set.end());
	ASSERT_EQ(set.find(3), set.iterator_to(c));

	ASSERT_EQ(set.find(4), set.end());
	ASSERT_EQ(set.find(d), set.end());

	set.erase(set.iterator_to(c));

	ASSERT_EQ(set.size(), 2U);
	ASSERT_EQ(set.find(3), set.end());
	ASSERT_EQ(set.find(c), set.end());

	set.insert(c);
	set.insert(d);
	set.insert(e);

	ASSERT_EQ(set.size(), 5U);
	ASSERT_FALSE(set.insert_check(1).second);
	ASSERT_EQ(set.insert_check(1).first, set.iterator_to(a));
	ASSERT_FALSE(set.insert_check(f).second);
	ASSERT_EQ(set.insert_check(f).first, set.iterator_to(a));

	ASSERT_EQ(set.find(1), set.iterator_to(a));
	ASSERT_EQ(set.find(2), set.iterator_to(b));
	ASSERT_EQ(set.find(3), set.iterator_to(c));
	ASSERT_EQ(set.find(4), set.iterator_to(d));
	ASSERT_EQ(set.find(5), set.iterator_to(e));

	ASSERT_EQ(set.find(a), set.iterator_to(a));
	ASSERT_EQ(set.find(b), set.iterator_to(b));
	ASSERT_EQ(set.find(c), set.iterator_to(c));
	ASSERT_EQ(set.find(d), set.iterator_to(d));
	ASSERT_EQ(set.find(e), set.iterator_to(e));

	set.erase(set.find(1));

	{
		auto [position, inserted] = set.insert_check(f);
		ASSERT_TRUE(inserted);
		set.insert_commit(position, f);
	}

	ASSERT_EQ(set.find(a), set.iterator_to(f));
	ASSERT_EQ(set.find(f), set.iterator_to(f));
	ASSERT_EQ(set.find(1), set.iterator_to(f));

	set.clear_and_dispose([](auto *i){ i->value = -1; });

	ASSERT_EQ(a.value, 1);
	ASSERT_EQ(b.value, -1);
	ASSERT_EQ(c.value, -1);
	ASSERT_EQ(d.value, -1);
	ASSERT_EQ(e.value, -1);
	ASSERT_EQ(f.value, -1);
}

TEST(IntrusiveHashSet, Multi)
{
	IntItem a{1}, b{2}, c{3}, d{4}, e{5}, f{1};

	IntrusiveHashSet<IntItem, 3,
			 IntrusiveHashSetOperators<IntItem::Hash,
						   IntItem::Equal>> set;

	set.insert(a);
	set.insert(b);
	set.insert(c);
	set.insert(d);
	set.insert(e);
	set.insert(f);

	ASSERT_NE(set.find(f), set.end());
	ASSERT_TRUE(&*set.find(a) == &a || &*set.find(a) == &f);
	ASSERT_TRUE(&*set.find(f) == &a || &*set.find(f) == &f);

	ASSERT_EQ(set.remove_and_dispose_key(a, [](auto*){}), 2U);
	ASSERT_EQ(set.find(a), set.end());
	ASSERT_EQ(set.find(f), set.end());

	ASSERT_NE(set.find(b), set.end());
	ASSERT_EQ(&*set.find(b), &b);
	ASSERT_EQ(set.remove_and_dispose_key(b, [](auto*){}), 1U);
	ASSERT_EQ(set.find(b), set.end());
	ASSERT_EQ(set.remove_and_dispose_key(b, [](auto*){}), 0U);
	ASSERT_EQ(set.find(b), set.end());
}

TEST(IntrusiveHashSet, Tag)
{
	struct A {};
	struct B {};

	struct TaggedItem final
		: IntrusiveHashSetHook<IntrusiveHookMode::NORMAL, A>,
		  IntrusiveHashSetHook<IntrusiveHookMode::NORMAL, B> {
		int a, b;

		TaggedItem(int _a, int _b) noexcept
			:a(_a), b(_b) {}
	};

	struct GetA {
		int operator()(const TaggedItem &item) const noexcept {
			return item.a;
		}
	};

	struct GetB {
		int operator()(const TaggedItem &item) const noexcept {
			return item.b;
		}
	};

	TaggedItem one{1, 11}, two{2, 22};

	IntrusiveHashSet<TaggedItem, 3,
			 IntrusiveHashSetOperators<std::hash<int>,
						   std::equal_to<int>,
						   GetA>,
			 IntrusiveHashSetBaseHookTraits<TaggedItem, A>> a;

	IntrusiveHashSet<TaggedItem, 3,
			 IntrusiveHashSetOperators<std::hash<int>,
						   std::equal_to<int>,
						   GetB>,
			 IntrusiveHashSetBaseHookTraits<TaggedItem, B>> b;

	EXPECT_TRUE(a.empty());
	EXPECT_TRUE(b.empty());

	a.insert(one);
	a.insert(two);

	EXPECT_FALSE(a.empty());
	EXPECT_TRUE(b.empty());

	b.insert(one);

	EXPECT_FALSE(a.empty());
	EXPECT_FALSE(b.empty());

	a.clear();

	EXPECT_TRUE(a.empty());
	EXPECT_FALSE(b.empty());

	a.insert(two);
	a.insert(one);

	EXPECT_FALSE(a.empty());
	EXPECT_FALSE(b.empty());

	b.erase(b.iterator_to(one));

	EXPECT_FALSE(a.empty());
	EXPECT_TRUE(b.empty());
}