#include <gtest/gtest.h>

#include "Viewport/ViewportHostSurfaceUtils.h"

namespace {

using XCEngine::Editor::BuildViewportRenderSurface;
using XCEngine::Editor::BuildViewportTextureDesc;
using XCEngine::Editor::BuildViewportTextureViewDesc;
using XCEngine::Editor::CanReuseViewportResources;
using XCEngine::Editor::ClampViewportPixelCoordinate;
using XCEngine::Editor::EditorViewportKind;
using XCEngine::Editor::ViewportHostResourceReuseQuery;
using XCEngine::Editor::ViewportRequiresObjectIdResources;
using XCEngine::RHI::Format;
using XCEngine::RHI::RHIResourceView;
using XCEngine::RHI::ResourceStates;
using XCEngine::RHI::ResourceViewDimension;
using XCEngine::RHI::ResourceViewType;

class DummyResourceView final : public RHIResourceView {
public:
    void Shutdown() override {
    }

    void* GetNativeHandle() override {
        return nullptr;
    }

    bool IsValid() const override {
        return true;
    }

    ResourceViewType GetViewType() const override {
        return ResourceViewType::RenderTarget;
    }

    ResourceViewDimension GetDimension() const override {
        return ResourceViewDimension::Texture2D;
    }

    Format GetFormat() const override {
        return Format::R8G8B8A8_UNorm;
    }
};

TEST(ViewportHostSurfaceUtilsTest, ClampViewportPixelCoordinateClampsAndFloors) {
    EXPECT_EQ(ClampViewportPixelCoordinate(-3.0f, 1280), 0u);
    EXPECT_EQ(ClampViewportPixelCoordinate(0.99f, 1280), 0u);
    EXPECT_EQ(ClampViewportPixelCoordinate(10.8f, 1280), 10u);
    EXPECT_EQ(ClampViewportPixelCoordinate(5000.0f, 1280), 1279u);
    EXPECT_EQ(ClampViewportPixelCoordinate(12.0f, 0), 0u);
}

TEST(ViewportHostSurfaceUtilsTest, ViewportReuseRequiresObjectIdOnlyForSceneViewport) {
    ViewportHostResourceReuseQuery gameQuery = {};
    gameQuery.kind = EditorViewportKind::Game;
    gameQuery.width = 1280;
    gameQuery.height = 720;
    gameQuery.requestedWidth = 1280;
    gameQuery.requestedHeight = 720;
    gameQuery.resources.hasColorTexture = true;
    gameQuery.resources.hasColorView = true;
    gameQuery.resources.hasDepthTexture = true;
    gameQuery.resources.hasDepthView = true;
    gameQuery.resources.hasTextureDescriptor = true;

    EXPECT_FALSE(ViewportRequiresObjectIdResources(EditorViewportKind::Game));
    EXPECT_TRUE(CanReuseViewportResources(gameQuery));

    ViewportHostResourceReuseQuery sceneQuery = gameQuery;
    sceneQuery.kind = EditorViewportKind::Scene;
    EXPECT_TRUE(ViewportRequiresObjectIdResources(EditorViewportKind::Scene));
    EXPECT_FALSE(CanReuseViewportResources(sceneQuery));

    sceneQuery.resources.hasDepthShaderView = true;
    sceneQuery.resources.hasObjectIdTexture = true;
    sceneQuery.resources.hasObjectIdDepthTexture = true;
    sceneQuery.resources.hasObjectIdDepthView = true;
    sceneQuery.resources.hasObjectIdView = true;
    sceneQuery.resources.hasObjectIdShaderView = true;
    sceneQuery.resources.hasSelectionMaskTexture = true;
    sceneQuery.resources.hasSelectionMaskView = true;
    sceneQuery.resources.hasSelectionMaskShaderView = true;
    EXPECT_TRUE(CanReuseViewportResources(sceneQuery));
}

TEST(ViewportHostSurfaceUtilsTest, ViewportReuseRejectsMismatchedOrMissingResources) {
    ViewportHostResourceReuseQuery query = {};
    query.kind = EditorViewportKind::Scene;
    query.width = 1280;
    query.height = 720;
    query.requestedWidth = 1280;
    query.requestedHeight = 720;
    query.resources.hasColorTexture = true;
    query.resources.hasColorView = true;
    query.resources.hasDepthTexture = true;
    query.resources.hasDepthView = true;
    query.resources.hasDepthShaderView = true;
    query.resources.hasObjectIdTexture = true;
    query.resources.hasObjectIdDepthTexture = true;
    query.resources.hasObjectIdDepthView = true;
    query.resources.hasObjectIdView = true;
    query.resources.hasObjectIdShaderView = true;
    query.resources.hasSelectionMaskTexture = true;
    query.resources.hasSelectionMaskView = true;
    query.resources.hasSelectionMaskShaderView = true;
    query.resources.hasTextureDescriptor = true;

    EXPECT_TRUE(CanReuseViewportResources(query));

    query.requestedWidth = 0;
    EXPECT_FALSE(CanReuseViewportResources(query));

    query.requestedWidth = 1280;
    query.width = 1024;
    EXPECT_FALSE(CanReuseViewportResources(query));

    query.width = 1280;
    query.resources.hasTextureDescriptor = false;
    EXPECT_FALSE(CanReuseViewportResources(query));
}

TEST(ViewportHostSurfaceUtilsTest, BuildViewportTextureDescriptorsUseExpectedDefaults) {
    const auto textureDesc = BuildViewportTextureDesc(640, 360, Format::D24_UNorm_S8_UInt);
    EXPECT_EQ(textureDesc.width, 640u);
    EXPECT_EQ(textureDesc.height, 360u);
    EXPECT_EQ(textureDesc.depth, 1u);
    EXPECT_EQ(textureDesc.mipLevels, 1u);
    EXPECT_EQ(textureDesc.arraySize, 1u);
    EXPECT_EQ(textureDesc.format, static_cast<uint32_t>(Format::D24_UNorm_S8_UInt));
    EXPECT_EQ(textureDesc.textureType, static_cast<uint32_t>(XCEngine::RHI::TextureType::Texture2D));
    EXPECT_EQ(textureDesc.sampleCount, 1u);
    EXPECT_EQ(textureDesc.sampleQuality, 0u);
    EXPECT_EQ(textureDesc.flags, 0u);

    const auto viewDesc = BuildViewportTextureViewDesc(Format::R8G8B8A8_UNorm);
    EXPECT_EQ(viewDesc.format, static_cast<uint32_t>(Format::R8G8B8A8_UNorm));
    EXPECT_EQ(viewDesc.dimension, ResourceViewDimension::Texture2D);
}

TEST(ViewportHostSurfaceUtilsTest, BuildViewportRenderSurfaceCarriesAttachmentsAndStates) {
    DummyResourceView colorView;
    DummyResourceView depthView;

    const auto surface = BuildViewportRenderSurface(
        800,
        600,
        &colorView,
        &depthView,
        ResourceStates::Common,
        ResourceStates::PixelShaderResource);

    ASSERT_EQ(surface.GetWidth(), 800u);
    ASSERT_EQ(surface.GetHeight(), 600u);
    ASSERT_EQ(surface.GetColorAttachments().size(), 1u);
    EXPECT_EQ(surface.GetColorAttachments()[0], &colorView);
    EXPECT_EQ(surface.GetDepthAttachment(), &depthView);
    EXPECT_EQ(surface.GetColorStateBefore(), ResourceStates::Common);
    EXPECT_EQ(surface.GetColorStateAfter(), ResourceStates::PixelShaderResource);
}

} // namespace