#include <gtest/gtest.h>
#include <XCEngine/Resources/Material/Material.h>
#include <XCEngine/Resources/Shader/Shader.h>
#include <XCEngine/Resources/Texture/Texture.h>
#include <XCEngine/Core/Asset/ResourceTypes.h>
#include <XCEngine/Core/Math/Vector2.h>
#include <XCEngine/Core/Math/Vector3.h>
#include <XCEngine/Core/Math/Vector4.h>

using namespace XCEngine::Resources;
using namespace XCEngine::Math;

namespace {

Shader* CreateMaterialSchemaShader() {
    auto* shader = new Shader();

    ShaderPropertyDesc baseColor = {};
    baseColor.name = "_BaseColor";
    baseColor.displayName = "Base Color";
    baseColor.type = ShaderPropertyType::Color;
    baseColor.defaultValue = "(1.0,0.5,0.25,1.0)";
    baseColor.semantic = "BaseColor";
    shader->AddProperty(baseColor);

    ShaderPropertyDesc metallic = {};
    metallic.name = "_Metallic";
    metallic.displayName = "Metallic";
    metallic.type = ShaderPropertyType::Float;
    metallic.defaultValue = "0.7";
    shader->AddProperty(metallic);

    ShaderPropertyDesc baseMap = {};
    baseMap.name = "_MainTex";
    baseMap.displayName = "Base Map";
    baseMap.type = ShaderPropertyType::Texture2D;
    baseMap.defaultValue = "white";
    baseMap.semantic = "BaseColorTexture";
    shader->AddProperty(baseMap);

    return shader;
}

TEST(Material, DefaultConstructor) {
    Material material;
    EXPECT_EQ(material.GetType(), ResourceType::Material);
    EXPECT_FALSE(material.IsValid());
    EXPECT_EQ(material.GetMemorySize(), 0u);
}

TEST(Material, GetType) {
    Material material;
    EXPECT_EQ(material.GetType(), ResourceType::Material);
}

TEST(Material, SetGetShader) {
    Material material;
    Shader* shader = new Shader();
    
    ResourceHandle<Shader> handle(shader);
    material.SetShader(handle);
    
    EXPECT_EQ(material.GetShader(), shader);
}

TEST(Material, DefaultRenderMetadata) {
    Material material;
    EXPECT_EQ(material.GetRenderQueue(), static_cast<XCEngine::Core::int32>(MaterialRenderQueue::Geometry));
    EXPECT_EQ(material.GetRenderState().cullMode, MaterialCullMode::None);
    EXPECT_FALSE(material.GetRenderState().blendEnable);
    EXPECT_TRUE(material.GetRenderState().depthTestEnable);
    EXPECT_TRUE(material.GetRenderState().depthWriteEnable);
    EXPECT_EQ(material.GetRenderState().depthFunc, MaterialComparisonFunc::Less);
    EXPECT_TRUE(material.GetShaderPass().Empty());
    EXPECT_EQ(material.GetTagCount(), 0u);
}

TEST(Material, SetGetRenderQueue) {
    Material material;

    material.SetRenderQueue(MaterialRenderQueue::Transparent);
    EXPECT_EQ(material.GetRenderQueue(), static_cast<XCEngine::Core::int32>(MaterialRenderQueue::Transparent));

    material.SetRenderQueue(2600);
    EXPECT_EQ(material.GetRenderQueue(), 2600);
}

TEST(Material, SetGetRenderState) {
    Material material;

    MaterialRenderState renderState;
    renderState.cullMode = MaterialCullMode::Back;
    renderState.blendEnable = true;
    renderState.srcBlend = MaterialBlendFactor::SrcAlpha;
    renderState.dstBlend = MaterialBlendFactor::InvSrcAlpha;
    renderState.srcBlendAlpha = MaterialBlendFactor::One;
    renderState.dstBlendAlpha = MaterialBlendFactor::InvSrcAlpha;
    renderState.blendOp = MaterialBlendOp::Add;
    renderState.blendOpAlpha = MaterialBlendOp::Add;
    renderState.depthTestEnable = true;
    renderState.depthWriteEnable = false;
    renderState.depthFunc = MaterialComparisonFunc::LessEqual;
    renderState.colorWriteMask = 0x7;

    material.SetRenderState(renderState);

    const MaterialRenderState& result = material.GetRenderState();
    EXPECT_EQ(result.cullMode, MaterialCullMode::Back);
    EXPECT_TRUE(result.blendEnable);
    EXPECT_EQ(result.srcBlend, MaterialBlendFactor::SrcAlpha);
    EXPECT_EQ(result.dstBlend, MaterialBlendFactor::InvSrcAlpha);
    EXPECT_EQ(result.srcBlendAlpha, MaterialBlendFactor::One);
    EXPECT_EQ(result.dstBlendAlpha, MaterialBlendFactor::InvSrcAlpha);
    EXPECT_EQ(result.blendOp, MaterialBlendOp::Add);
    EXPECT_EQ(result.blendOpAlpha, MaterialBlendOp::Add);
    EXPECT_TRUE(result.depthTestEnable);
    EXPECT_FALSE(result.depthWriteEnable);
    EXPECT_EQ(result.depthFunc, MaterialComparisonFunc::LessEqual);
    EXPECT_EQ(result.colorWriteMask, 0x7);
}

TEST(Material, SetGetShaderPass) {
    Material material;

    material.SetShaderPass("ForwardLit");
    EXPECT_EQ(material.GetShaderPass(), "ForwardLit");
}

TEST(Material, SetGetTags) {
    Material material;

    material.SetTag("LightMode", "ForwardBase");
    material.SetTag("RenderType", "Opaque");

    EXPECT_TRUE(material.HasTag("LightMode"));
    EXPECT_EQ(material.GetTag("LightMode"), "ForwardBase");
    EXPECT_EQ(material.GetTag("RenderType"), "Opaque");
    EXPECT_EQ(material.GetTagCount(), 2u);
}

TEST(Material, SetTagReplacesExistingValue) {
    Material material;

    material.SetTag("LightMode", "ForwardBase");
    material.SetTag("LightMode", "ShadowCaster");

    EXPECT_EQ(material.GetTagCount(), 1u);
    EXPECT_EQ(material.GetTag("LightMode"), "ShadowCaster");
}

TEST(Material, RemoveTag) {
    Material material;

    material.SetTag("LightMode", "ForwardBase");
    EXPECT_TRUE(material.HasTag("LightMode"));

    material.RemoveTag("LightMode");
    EXPECT_FALSE(material.HasTag("LightMode"));
    EXPECT_TRUE(material.GetTag("LightMode").Empty());
}

TEST(Material, ClearTags) {
    Material material;

    material.SetTag("LightMode", "ForwardBase");
    material.SetTag("RenderType", "Opaque");
    ASSERT_EQ(material.GetTagCount(), 2u);

    material.ClearTags();
    EXPECT_EQ(material.GetTagCount(), 0u);
    EXPECT_FALSE(material.HasTag("LightMode"));
    EXPECT_FALSE(material.HasTag("RenderType"));
}

TEST(Material, SetGetFloat) {
    Material material;
    
    material.SetFloat("uTime", 1.5f);
    EXPECT_FLOAT_EQ(material.GetFloat("uTime"), 1.5f);
}

TEST(Material, SetGetFloat2) {
    Material material;
    
    Vector2 value(1.0f, 2.0f);
    material.SetFloat2("uUV", value);
    
    Vector2 result = material.GetFloat2("uUV");
    EXPECT_FLOAT_EQ(result.x, 1.0f);
    EXPECT_FLOAT_EQ(result.y, 2.0f);
}

TEST(Material, SetGetFloat3) {
    Material material;
    
    Vector3 value(1.0f, 2.0f, 3.0f);
    material.SetFloat3("uPosition", value);
    
    Vector3 result = material.GetFloat3("uPosition");
    EXPECT_FLOAT_EQ(result.x, 1.0f);
    EXPECT_FLOAT_EQ(result.y, 2.0f);
    EXPECT_FLOAT_EQ(result.z, 3.0f);
}

TEST(Material, SetGetFloat4) {
    Material material;
    
    Vector4 value(1.0f, 2.0f, 3.0f, 4.0f);
    material.SetFloat4("uColor", value);
    
    Vector4 result = material.GetFloat4("uColor");
    EXPECT_FLOAT_EQ(result.x, 1.0f);
    EXPECT_FLOAT_EQ(result.y, 2.0f);
    EXPECT_FLOAT_EQ(result.z, 3.0f);
    EXPECT_FLOAT_EQ(result.w, 4.0f);
}

TEST(Material, SetGetInt) {
    Material material;
    
    material.SetInt("uIndex", 42);
    EXPECT_EQ(material.GetInt("uIndex"), 42);
}

TEST(Material, SetGetBool) {
    Material material;
    
    material.SetBool("uEnabled", true);
    EXPECT_TRUE(material.GetBool("uEnabled"));
    
    material.SetBool("uEnabled", false);
    EXPECT_FALSE(material.GetBool("uEnabled"));
}

TEST(Material, SetGetTexture) {
    Material material;
    Texture* texture = new Texture();
    
    ResourceHandle<Texture> handle(texture);
    material.SetTexture("uDiffuse", handle);
    
    EXPECT_EQ(material.GetTexture("uDiffuse").Get(), texture);
}

TEST(Material, SetTextureReplacesExistingBinding) {
    Material material;
    Texture* firstTexture = new Texture();
    Texture* secondTexture = new Texture();

    material.SetTexture("uDiffuse", ResourceHandle<Texture>(firstTexture));
    material.SetTexture("uDiffuse", ResourceHandle<Texture>(secondTexture));

    EXPECT_EQ(material.GetTextureBindingCount(), 1u);
    EXPECT_EQ(material.GetTexture("uDiffuse").Get(), secondTexture);
}

TEST(Material, SetTextureAssetRefStoresStableBindingMetadata) {
    Material material;

    AssetRef textureRef;
    textureRef.assetGuid = AssetGUID(1, 2);
    textureRef.localID = kMainAssetLocalID;
    textureRef.resourceType = ResourceType::Texture;

    material.SetTextureAssetRef("uDiffuse", textureRef, "Assets/diffuse.bmp");

    ASSERT_EQ(material.GetTextureBindingCount(), 1u);
    EXPECT_TRUE(material.HasProperty("uDiffuse"));
    EXPECT_EQ(material.GetTextureBindingName(0), "uDiffuse");
    EXPECT_EQ(material.GetTextureBindingPath(0), "Assets/diffuse.bmp");

    const AssetRef storedRef = material.GetTextureBindingAssetRef(0);
    EXPECT_EQ(storedRef.assetGuid, textureRef.assetGuid);
    EXPECT_EQ(storedRef.localID, textureRef.localID);
    EXPECT_EQ(storedRef.resourceType, textureRef.resourceType);
    EXPECT_FALSE(material.GetTextureBindingLoadedTexture(0).IsValid());
}

TEST(Material, ChangeVersionIncrementsWhenMaterialMutates) {
    Material material;
    const XCEngine::Core::uint64 initialVersion = material.GetChangeVersion();

    material.SetFloat("uTime", 1.0f);
    const XCEngine::Core::uint64 afterFloatVersion = material.GetChangeVersion();
    EXPECT_GT(afterFloatVersion, initialVersion);

    material.SetTexture("uDiffuse", ResourceHandle<Texture>(new Texture()));
    EXPECT_GT(material.GetChangeVersion(), afterFloatVersion);
}

TEST(Material, UpdateConstantBufferPacksNumericPropertiesIntoStableSlots) {
    Material material;
    material.SetFloat("alpha", 3.5f);
    material.SetFloat4("beta", Vector4(1.0f, 2.0f, 3.0f, 4.0f));
    material.SetInt("gamma", 7);

    const auto& constantLayout = material.GetConstantLayout();
    ASSERT_EQ(constantLayout.Size(), 3u);
    EXPECT_EQ(constantLayout[0].name, "alpha");
    EXPECT_EQ(constantLayout[0].offset, 0u);
    EXPECT_EQ(constantLayout[0].size, 4u);
    EXPECT_EQ(constantLayout[0].alignedSize, 16u);
    EXPECT_EQ(constantLayout[1].name, "beta");
    EXPECT_EQ(constantLayout[1].offset, 16u);
    EXPECT_EQ(constantLayout[1].size, 16u);
    EXPECT_EQ(constantLayout[2].name, "gamma");
    EXPECT_EQ(constantLayout[2].offset, 32u);
    EXPECT_EQ(constantLayout[2].size, 4u);

    const MaterialConstantFieldDesc* betaField = material.FindConstantField("beta");
    ASSERT_NE(betaField, nullptr);
    EXPECT_EQ(betaField->offset, 16u);
    EXPECT_EQ(betaField->alignedSize, 16u);

    const auto& constantBufferData = material.GetConstantBufferData();
    ASSERT_EQ(constantBufferData.Size(), 48u);

    const float* alphaSlot = reinterpret_cast<const float*>(constantBufferData.Data());
    EXPECT_FLOAT_EQ(alphaSlot[0], 3.5f);
    EXPECT_FLOAT_EQ(alphaSlot[1], 0.0f);
    EXPECT_FLOAT_EQ(alphaSlot[2], 0.0f);
    EXPECT_FLOAT_EQ(alphaSlot[3], 0.0f);

    const float* betaSlot = reinterpret_cast<const float*>(constantBufferData.Data() + 16);
    EXPECT_FLOAT_EQ(betaSlot[0], 1.0f);
    EXPECT_FLOAT_EQ(betaSlot[1], 2.0f);
    EXPECT_FLOAT_EQ(betaSlot[2], 3.0f);
    EXPECT_FLOAT_EQ(betaSlot[3], 4.0f);

    const XCEngine::Core::int32* gammaSlot =
        reinterpret_cast<const XCEngine::Core::int32*>(constantBufferData.Data() + 32);
    EXPECT_EQ(gammaSlot[0], 7);
    EXPECT_EQ(gammaSlot[1], 0);
    EXPECT_EQ(gammaSlot[2], 0);
    EXPECT_EQ(gammaSlot[3], 0);
}

TEST(Material, RemoveTexturePropertyAlsoRemovesTextureBinding) {
    Material material;
    Texture* texture = new Texture();

    material.SetTexture("uDiffuse", ResourceHandle<Texture>(texture));
    ASSERT_EQ(material.GetTextureBindingCount(), 1u);

    material.RemoveProperty("uDiffuse");

    EXPECT_FALSE(material.HasProperty("uDiffuse"));
    EXPECT_EQ(material.GetTextureBindingCount(), 0u);
    EXPECT_EQ(material.GetTexture("uDiffuse").Get(), nullptr);
}

TEST(Material, ReplacingTexturePropertyWithScalarRemovesTextureBinding) {
    Material material;
    Texture* texture = new Texture();

    material.SetTexture("uMain", ResourceHandle<Texture>(texture));
    ASSERT_EQ(material.GetTextureBindingCount(), 1u);

    material.SetFloat("uMain", 2.0f);

    EXPECT_EQ(material.GetTextureBindingCount(), 0u);
    EXPECT_EQ(material.GetTexture("uMain").Get(), nullptr);
    EXPECT_FLOAT_EQ(material.GetFloat("uMain"), 2.0f);
}

TEST(Material, HasProperty) {
    Material material;
    
    EXPECT_FALSE(material.HasProperty("uTime"));
    
    material.SetFloat("uTime", 1.0f);
    EXPECT_TRUE(material.HasProperty("uTime"));
}

TEST(Material, RemoveProperty) {
    Material material;
    
    material.SetFloat("uTime", 1.0f);
    EXPECT_TRUE(material.HasProperty("uTime"));
    
    material.RemoveProperty("uTime");
    EXPECT_FALSE(material.HasProperty("uTime"));
}

TEST(Material, ClearAllProperties) {
    Material material;
    
    material.SetFloat("uTime", 1.0f);
    material.SetFloat3("uPosition", Vector3(1.0f, 2.0f, 3.0f));
    material.SetInt("uIndex", 1);
    
    EXPECT_TRUE(material.HasProperty("uTime"));
    EXPECT_TRUE(material.HasProperty("uPosition"));
    EXPECT_TRUE(material.HasProperty("uIndex"));
    
    material.ClearAllProperties();
    
    EXPECT_FALSE(material.HasProperty("uTime"));
    EXPECT_FALSE(material.HasProperty("uPosition"));
    EXPECT_FALSE(material.HasProperty("uIndex"));
}

TEST(Material, SetShaderSeedsDefaultsAndRemovePropertyRestoresShaderDefault) {
    Material material;
    Shader* shader = CreateMaterialSchemaShader();

    material.SetShader(ResourceHandle<Shader>(shader));

    EXPECT_TRUE(material.HasProperty("_BaseColor"));
    EXPECT_TRUE(material.HasProperty("_Metallic"));
    EXPECT_TRUE(material.HasProperty("_MainTex"));
    EXPECT_EQ(material.GetFloat4("_BaseColor"), Vector4(1.0f, 0.5f, 0.25f, 1.0f));
    EXPECT_FLOAT_EQ(material.GetFloat("_Metallic"), 0.7f);
    EXPECT_EQ(material.GetTextureBindingCount(), 0u);

    material.SetFloat4("_BaseColor", Vector4(0.2f, 0.3f, 0.4f, 0.5f));
    EXPECT_EQ(material.GetFloat4("_BaseColor"), Vector4(0.2f, 0.3f, 0.4f, 0.5f));

    material.RemoveProperty("_BaseColor");
    EXPECT_EQ(material.GetFloat4("_BaseColor"), Vector4(1.0f, 0.5f, 0.25f, 1.0f));
}

TEST(Material, ClearAllPropertiesWithShaderRestoresSchemaDefaults) {
    Material material;
    Shader* shader = CreateMaterialSchemaShader();

    material.SetShader(ResourceHandle<Shader>(shader));
    material.SetFloat("_Metallic", 0.15f);
    material.SetTexture("_MainTex", ResourceHandle<Texture>(new Texture()));
    ASSERT_EQ(material.GetTextureBindingCount(), 1u);

    material.ClearAllProperties();

    EXPECT_TRUE(material.HasProperty("_BaseColor"));
    EXPECT_TRUE(material.HasProperty("_Metallic"));
    EXPECT_TRUE(material.HasProperty("_MainTex"));
    EXPECT_EQ(material.GetFloat4("_BaseColor"), Vector4(1.0f, 0.5f, 0.25f, 1.0f));
    EXPECT_FLOAT_EQ(material.GetFloat("_Metallic"), 0.7f);
    EXPECT_EQ(material.GetTextureBindingCount(), 0u);
}

TEST(Material, ShaderSchemaRejectsUnknownAndTypeMismatchedAssignments) {
    Material material;
    Shader* shader = CreateMaterialSchemaShader();

    material.SetShader(ResourceHandle<Shader>(shader));
    const Vector4 defaultBaseColor = material.GetFloat4("_BaseColor");
    const float defaultMetallic = material.GetFloat("_Metallic");

    material.SetFloat("_BaseColor", 0.1f);
    material.SetFloat4("_Metallic", Vector4(1.0f, 2.0f, 3.0f, 4.0f));
    material.SetFloat("UnknownProperty", 5.0f);

    EXPECT_EQ(material.GetFloat4("_BaseColor"), defaultBaseColor);
    EXPECT_FLOAT_EQ(material.GetFloat("_Metallic"), defaultMetallic);
    EXPECT_FALSE(material.HasProperty("UnknownProperty"));
}

TEST(Material, SwitchingShaderResyncsPropertiesAgainstNewSchema) {
    Material material;

    auto* shaderA = new Shader();
    ShaderPropertyDesc sharedA = {};
    sharedA.name = "Shared";
    sharedA.type = ShaderPropertyType::Float;
    sharedA.defaultValue = "1.0";
    shaderA->AddProperty(sharedA);
    ShaderPropertyDesc onlyA = {};
    onlyA.name = "OnlyA";
    onlyA.type = ShaderPropertyType::Float;
    onlyA.defaultValue = "2.0";
    shaderA->AddProperty(onlyA);

    auto* shaderB = new Shader();
    ShaderPropertyDesc sharedB = {};
    sharedB.name = "Shared";
    sharedB.type = ShaderPropertyType::Float;
    sharedB.defaultValue = "4.0";
    shaderB->AddProperty(sharedB);
    ShaderPropertyDesc onlyB = {};
    onlyB.name = "OnlyB";
    onlyB.type = ShaderPropertyType::Color;
    onlyB.defaultValue = "(0.1,0.2,0.3,0.4)";
    shaderB->AddProperty(onlyB);

    material.SetFloat("Legacy", 9.0f);
    material.SetShader(ResourceHandle<Shader>(shaderA));
    material.SetFloat("Shared", 5.0f);
    material.SetFloat("OnlyA", 8.0f);

    material.SetShader(ResourceHandle<Shader>(shaderB));

    EXPECT_FALSE(material.HasProperty("Legacy"));
    EXPECT_FALSE(material.HasProperty("OnlyA"));
    EXPECT_TRUE(material.HasProperty("Shared"));
    EXPECT_TRUE(material.HasProperty("OnlyB"));
    EXPECT_FLOAT_EQ(material.GetFloat("Shared"), 5.0f);
    EXPECT_EQ(material.GetFloat4("OnlyB"), Vector4(0.1f, 0.2f, 0.3f, 0.4f));
}

TEST(Material, UpdateConstantBufferFollowsShaderSchemaOrderInsteadOfAlphabeticalOrder) {
    Material material;

    auto* shader = new Shader();
    ShaderPropertyDesc beta = {};
    beta.name = "beta";
    beta.type = ShaderPropertyType::Float;
    beta.defaultValue = "0.0";
    shader->AddProperty(beta);

    ShaderPropertyDesc alpha = {};
    alpha.name = "alpha";
    alpha.type = ShaderPropertyType::Float;
    alpha.defaultValue = "0.0";
    shader->AddProperty(alpha);

    material.SetShader(ResourceHandle<Shader>(shader));
    material.SetFloat("alpha", 10.0f);
    material.SetFloat("beta", 20.0f);

    const auto& constantLayout = material.GetConstantLayout();
    ASSERT_EQ(constantLayout.Size(), 2u);
    EXPECT_EQ(constantLayout[0].name, "beta");
    EXPECT_EQ(constantLayout[0].offset, 0u);
    EXPECT_EQ(constantLayout[1].name, "alpha");
    EXPECT_EQ(constantLayout[1].offset, 16u);

    const auto& constantBufferData = material.GetConstantBufferData();
    ASSERT_EQ(constantBufferData.Size(), 32u);

    const float* firstSlot = reinterpret_cast<const float*>(constantBufferData.Data());
    const float* secondSlot = reinterpret_cast<const float*>(constantBufferData.Data() + 16);
    EXPECT_FLOAT_EQ(firstSlot[0], 20.0f);
    EXPECT_FLOAT_EQ(secondSlot[0], 10.0f);
}

} // namespace