#include "fixtures/RHITestFixture.h"
#include "XCEngine/RHI/RHIShader.h"
#include <cstring>
#include <filesystem>

using namespace XCEngine::RHI;

namespace {

std::wstring ResolveShaderPath(const wchar_t* relativePath) {
    wchar_t exePath[MAX_PATH] = {};
    const DWORD length = GetModuleFileNameW(nullptr, exePath, MAX_PATH);
    std::filesystem::path rootPath = length > 0 ? std::filesystem::path(exePath).parent_path() : std::filesystem::current_path();
    for (int i = 0; i < 5; ++i) {
        rootPath = rootPath.parent_path();
    }
    return (rootPath / relativePath).wstring();
}

} // namespace

TEST_P(RHITestFixture, Shader_Compile_EmptyDesc_ReturnsNullptr) {
    ShaderCompileDesc desc = {};
    RHIShader* shader = GetDevice()->CreateShader(desc);
    EXPECT_EQ(shader, nullptr);
}

TEST_P(RHITestFixture, Shader_Compile_ValidVertexShader) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/quad.hlsl");
        desc.entryPoint = L"MainVS";
        desc.profile = L"vs_5_0";
    } else {
        desc.sourceLanguage = ShaderLanguage::GLSL;
        static const char* vs = "#version 430\nin vec4 aPosition;\nvoid main() { gl_Position = aPosition; }";
        desc.source.assign(vs, vs + strlen(vs));
        desc.profile = L"vs";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    if (shader != nullptr) {
        EXPECT_TRUE(shader->IsValid());
        EXPECT_EQ(shader->GetType(), ShaderType::Vertex);
        EXPECT_NE(shader->GetNativeHandle(), nullptr);
        shader->Shutdown();
        delete shader;
    }
}

TEST_P(RHITestFixture, Shader_Compile_ValidFragmentShader) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/quad.hlsl");
        desc.entryPoint = L"MainPS";
        desc.profile = L"ps_5_0";
    } else {
        desc.sourceLanguage = ShaderLanguage::GLSL;
        static const char* fs = "#version 430\nout vec4 c;\nvoid main() { c = vec4(1,0,0,1); }";
        desc.source.assign(fs, fs + strlen(fs));
        desc.profile = L"ps";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    if (shader != nullptr) {
        EXPECT_TRUE(shader->IsValid());
        EXPECT_EQ(shader->GetType(), ShaderType::Fragment);
        EXPECT_NE(shader->GetNativeHandle(), nullptr);
        shader->Shutdown();
        delete shader;
    }
}

TEST_P(RHITestFixture, Shader_GetType_VertexShader) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/quad.hlsl");
        desc.entryPoint = L"MainVS";
        desc.profile = L"vs_5_0";
    } else {
        desc.sourceLanguage = ShaderLanguage::GLSL;
        static const char* vs = "#version 430\nin vec4 aPosition;\nvoid main() { gl_Position = aPosition; }";
        desc.source.assign(vs, vs + strlen(vs));
        desc.profile = L"vs";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    if (shader != nullptr) {
        EXPECT_EQ(shader->GetType(), ShaderType::Vertex);
        shader->Shutdown();
        delete shader;
    }
}

TEST_P(RHITestFixture, Shader_GetType_FragmentShader) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/quad.hlsl");
        desc.entryPoint = L"MainPS";
        desc.profile = L"ps_5_0";
    } else {
        desc.sourceLanguage = ShaderLanguage::GLSL;
        static const char* fs = "#version 430\nout vec4 c;\nvoid main() { c = vec4(1,0,0,1); }";
        desc.source.assign(fs, fs + strlen(fs));
        desc.profile = L"ps";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    if (shader != nullptr) {
        EXPECT_EQ(shader->GetType(), ShaderType::Fragment);
        shader->Shutdown();
        delete shader;
    }
}

TEST_P(RHITestFixture, Shader_GetNativeHandle_ValidShader) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/quad.hlsl");
        desc.entryPoint = L"MainVS";
        desc.profile = L"vs_5_0";
    } else {
        desc.sourceLanguage = ShaderLanguage::GLSL;
        static const char* vs = "#version 430\nin vec4 aPosition;\nvoid main() { gl_Position = aPosition; }";
        desc.source.assign(vs, vs + strlen(vs));
        desc.profile = L"vs";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    if (shader != nullptr) {
        void* handle = shader->GetNativeHandle();
        EXPECT_NE(handle, nullptr);
        shader->Shutdown();
        delete shader;
    }
}

TEST_P(RHITestFixture, Shader_Shutdown_Invalidates) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/quad.hlsl");
        desc.entryPoint = L"MainVS";
        desc.profile = L"vs_5_0";
    } else {
        desc.sourceLanguage = ShaderLanguage::GLSL;
        static const char* vs = "#version 430\nin vec4 aPosition;\nvoid main() { gl_Position = aPosition; }";
        desc.source.assign(vs, vs + strlen(vs));
        desc.profile = L"vs";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    if (shader != nullptr) {
        EXPECT_TRUE(shader->IsValid());
        shader->Shutdown();
        EXPECT_FALSE(shader->IsValid());
        delete shader;
    }
}

TEST_P(RHITestFixture, Shader_Compile_FromFile_ReturnsValidShader) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/quad.hlsl");
        desc.entryPoint = L"MainVS";
        desc.profile = L"vs_5_0";
    } else if (GetBackendType() == RHIType::Vulkan) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/integration/triangle/Res/Shader/triangle_vulkan.vert");
        desc.entryPoint = L"main";
        desc.profile = L"vs";
    } else {
        desc.fileName = ResolveShaderPath(L"tests/RHI/OpenGL/integration/triangle/Res/Shader/triangle.vert");
        desc.entryPoint = L"main";
        desc.profile = L"vs_4_30";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    ASSERT_NE(shader, nullptr);
    EXPECT_TRUE(shader->IsValid());
    EXPECT_EQ(shader->GetType(), ShaderType::Vertex);
    shader->Shutdown();
    delete shader;
}

TEST_P(RHITestFixture, Shader_Compile_MissingFile_ReturnsNullptr) {
    ShaderCompileDesc desc = {};
    if (GetBackendType() == RHIType::D3D12) {
        desc.fileName = ResolveShaderPath(L"tests/RHI/D3D12/integration/quad/Res/Shader/does_not_exist.hlsl");
        desc.entryPoint = L"MainVS";
        desc.profile = L"vs_5_0";
    } else {
        desc.fileName = ResolveShaderPath(L"tests/RHI/OpenGL/integration/triangle/Res/Shader/does_not_exist.vert");
        desc.entryPoint = L"main";
        desc.profile = L"vs_4_30";
    }

    RHIShader* shader = GetDevice()->CreateShader(desc);
    EXPECT_EQ(shader, nullptr);
}