/**
* @file		test_math.cpp
* @brief	math 模块单元测试（Math 命名空间）
*
*
* @version	1.0
* @author	CodeBuddy
* @date		26-09-03
*
* @note		
*/
#include <gtest/gtest.h>

#include "math/dl_math.h"
#include "math/dl_random.h"
#include "math/dl_texture_pack.h"

TEST(MathTest, Pow)
{
	EXPECT_EQ(dl::Math::Pow(2, 10), 1024);
	EXPECT_EQ(dl::Math::Pow64(2, 10), 1024ull);
	EXPECT_EQ(dl::Math::Pow32(2, 10), 1024u);
}

TEST(MathTest, SubU)
{
	EXPECT_EQ(dl::Math::SubU(5u, 3u), 2u);
	EXPECT_EQ(dl::Math::SubU(3u, 5u), 0u);
}

TEST(MathTest, DisU)
{
	EXPECT_EQ(dl::Math::DisU(3u, 5u), 2u);
	EXPECT_EQ(dl::Math::DisU(5u, 3u), 2u);
}

TEST(MathTest, IsPow2)
{
	EXPECT_TRUE(dl::Math::IsPow2(8));
	EXPECT_TRUE(dl::Math::IsPow2(1));
	EXPECT_FALSE(dl::Math::IsPow2(0));
	EXPECT_FALSE(dl::Math::IsPow2(6));
}

TEST(MathTest, AlignPow2)
{
	EXPECT_EQ(dl::Math::AlignPow2(5u, 4u), 8u);
	EXPECT_EQ(dl::Math::AlignPow2(8u, 4u), 8u);
	EXPECT_EQ(dl::Math::AlignPow2(1u, 4u), 4u);
	// 非 2 的幂返回 0
	EXPECT_EQ(dl::Math::AlignPow2(5u, 3u), 0u);
}

TEST(MathTest, DistancePow2)
{
	dl::Position a{ 0.0f, 0.0f };
	dl::Position b{ 3.0f, 4.0f };
	EXPECT_FLOAT_EQ(dl::Math::DistancePow2(a, b), 25.0f);
	EXPECT_FLOAT_EQ(dl::Math::Distance(b - a), 5.0f);
}

TEST(MathTest, DotProduct)
{
	dl::Position a{ 1.0f, 2.0f };
	dl::Position b{ 3.0f, 4.0f };
	EXPECT_FLOAT_EQ(dl::Math::DotProduct(a, b), 11.0f); // 1*3 + 2*4
}

TEST(MathTest, CrossProduct)
{
	dl::Position2 a{ 1.0f, 0.0f };
	dl::Position2 b{ 0.0f, 1.0f };
	EXPECT_FLOAT_EQ(dl::Math::CrossProduct(a, b), 1.0f);
}

TEST(MathTest, IsLeapYear)
{
	EXPECT_TRUE(dl::Math::IsLeapYear(2000));
	EXPECT_TRUE(dl::Math::IsLeapYear(2024));
	EXPECT_FALSE(dl::Math::IsLeapYear(1900));
	EXPECT_FALSE(dl::Math::IsLeapYear(2023));
}

TEST(MathTest, GetMouthDayNum)
{
	EXPECT_EQ(dl::Math::GetMouthDayNum(2024, 2), 29);  // 闰年二月
	EXPECT_EQ(dl::Math::GetMouthDayNum(2023, 2), 28);  // 平年二月
	EXPECT_EQ(dl::Math::GetMouthDayNum(2024, 1), 31);
	EXPECT_EQ(dl::Math::GetMouthDayNum(2024, 4), 30);
}

//------------------------------算法------------------------------
TEST(MathTest, Clamp)
{
	EXPECT_EQ(dl::clamp(5, 1, 3), 3);   // 上界
	EXPECT_EQ(dl::clamp(0, 1, 3), 1);   // 下界
	EXPECT_EQ(dl::clamp(2, 1, 3), 2);   // 中间
	EXPECT_FLOAT_EQ(dl::clamp(1.5f, 0.0f, 1.0f), 1.0f);
	EXPECT_FLOAT_EQ(dl::clamp(-0.5f, 0.0f, 1.0f), 0.0f);
}

TEST(MathTest, Saturate)
{
	EXPECT_FLOAT_EQ(dl::saturate(0.5f), 0.5f);
	EXPECT_FLOAT_EQ(dl::saturate(2.0f), 1.0f);
	EXPECT_FLOAT_EQ(dl::saturate(-1.0f), 0.0f);
	EXPECT_TRUE(dl::is_saturate(0.5f));
	EXPECT_FALSE(dl::is_saturate(1.5f));
}

TEST(MathTest, Sign)
{
	EXPECT_EQ(dl::sign(5), 1);
	EXPECT_EQ(dl::sign(-5), -1);
	EXPECT_EQ(dl::sign(0), 0);
}

TEST(MathTest, Cross3)
{
	dl::Position3 a{ 1.0f, 0.0f, 0.0f };
	dl::Position3 b{ 0.0f, 1.0f, 0.0f };
	auto c = dl::cross(a, b);
	EXPECT_FLOAT_EQ(c[0], 0.0f);
	EXPECT_FLOAT_EQ(c[1], 0.0f);
	EXPECT_FLOAT_EQ(c[2], 1.0f);
}

TEST(MathTest, InsertPerNum)
{
	EXPECT_EQ(dl::insert_per_num(std::string("1234567890"), ',', 3), "123,456,789,0");
	EXPECT_EQ(dl::r_insert_per_num(std::string("123456789"), ',', 3), "123,456,789");
}

TEST(MathTest, MakeSequence)
{
	std::vector<int> v;
	dl::make_sequence<std::vector<int>, int>(v, { {0, 3}, {5, 7} });
	ASSERT_EQ(v.size(), 5u);
	EXPECT_EQ(v[0], 0);
	EXPECT_EQ(v[1], 1);
	EXPECT_EQ(v[2], 2);
	EXPECT_EQ(v[3], 5);
	EXPECT_EQ(v[4], 6);
}

//------------------------------Random------------------------------
TEST(RandomTest, SetSeed)
{
	dl::Random::SetSeed(42);
	int a = dl::Random::Int(0, 100);
	dl::Random::SetSeed(42);
	int b = dl::Random::Int(0, 100);
	EXPECT_EQ(a, b);  // 同种子结果一致
}

TEST(RandomTest, IntRange)
{
	dl::Random::SetSeed(1);
	for (int i = 0; i < 100; ++i)
	{
		int v = dl::Random::Int(10, 20);
		EXPECT_GE(v, 10);
		EXPECT_LE(v, 20);
	}
}

TEST(RandomTest, FloatRange)
{
	dl::Random::SetSeed(1);
	for (int i = 0; i < 100; ++i)
	{
		float v = dl::Random::Float(0.0f, 1.0f);
		EXPECT_GE(v, 0.0f);
		EXPECT_LT(v, 1.0f);
	}
}

TEST(RandomTest, Percent)
{
	dl::Random::SetSeed(1);
	EXPECT_TRUE(dl::Random::Percent(100));
	EXPECT_FALSE(dl::Random::Percent(0));
}

TEST(RandomTest, Select)
{
	std::vector<int> v = { 1, 2, 3, 4, 5 };
	dl::Random::SetSeed(1);
	int sel = dl::Random::Select(v);
	EXPECT_GE(sel, 1);
	EXPECT_LE(sel, 5);
}

//------------------------------TexturePack------------------------------
TEST(TexturePackTest, Dynamic)
{
	dl::TexturePack::Dynamic<2> pack;
	pack.Reset({ 100, 100 });

	dl::RectU r1;
	EXPECT_TRUE(pack.Add({ 30, 30 }, r1));
	EXPECT_EQ(r1[0], 0u);
	EXPECT_EQ(r1[1], 0u);
	EXPECT_EQ(r1[2], 30u);
	EXPECT_EQ(r1[3], 30u);

	dl::RectU r2;
	EXPECT_TRUE(pack.Add({ 30, 30 }, r2));
	EXPECT_EQ(r2[0], 30u);  // 同一行，x 偏移
	EXPECT_EQ(r2[1], 0u);

	dl::RectU r3;
	EXPECT_TRUE(pack.Add({ 30, 30 }, r3));
	EXPECT_EQ(r3[0], 60u);
	EXPECT_EQ(r3[1], 0u);

	dl::RectU r4;
	EXPECT_TRUE(pack.Add({ 30, 30 }, r4));
	EXPECT_EQ(r4[0], 0u);   // 换行
	EXPECT_EQ(r4[1], 30u);
}

TEST(TexturePackTest, Static)
{
	dl::TexturePack::Static pack;
	pack.SetSize({ 100, 100 });

	std::list<dl::Size> boxes = { {50, 50}, {50, 50}, {100, 50} };
	std::vector<dl::PointU> results;
	pack.Calc(boxes,
		[](const dl::Size& s) { return s; },
		[&](const dl::Size& s, const dl::PointU& lt) { results.push_back(lt); });

	// 3 个箱子总面积 10000 = 100*100，能全部放下
	EXPECT_TRUE(boxes.empty());
	EXPECT_EQ(results.size(), 3u);
}