#include <gtest/gtest.h>

#include "Viewport/SceneViewportEditorOverlayData.h"
#include "Viewport/SceneViewportRenderPlan.h"
#include "Viewport/ViewportHostRenderFlowUtils.h"

#include <memory>
#include <string>

namespace {

using XCEngine::Editor::ApplySceneViewportRenderRequestSetup;
using XCEngine::Editor::ApplySceneViewportRenderPlan;
using XCEngine::Editor::ApplyViewportFailureStatus;
using XCEngine::Editor::BuildGameViewportRenderFailurePolicy;
using XCEngine::Editor::BuildSceneViewportGridPassData;
using XCEngine::Editor::BuildSceneViewportRenderPlan;
using XCEngine::Editor::BuildSceneViewportRenderFailurePolicy;
using XCEngine::Editor::BuildSceneViewportSelectionOutlineStyle;
using XCEngine::Editor::BuildViewportRenderTargetUnavailablePolicy;
using XCEngine::Editor::GameViewportRenderFailure;
using XCEngine::Editor::MarkGameViewportRenderSuccess;
using XCEngine::Editor::MarkSceneViewportRenderSuccess;
using XCEngine::Editor::SceneViewportOverlayFrameData;
using XCEngine::Editor::SceneViewportOverlayLinePrimitive;
using XCEngine::Editor::SceneViewportRenderFailure;
using XCEngine::Editor::SceneViewportOverlayData;
using XCEngine::Editor::SceneViewportGridPassData;
using XCEngine::Editor::SceneViewportRenderPlan;
using XCEngine::Editor::SceneViewportSelectionOutlineStyle;
using XCEngine::Editor::ViewportRenderTargets;
using XCEngine::RHI::Format;
using XCEngine::RHI::RHIResourceView;
using XCEngine::RHI::ResourceStates;
using XCEngine::RHI::ResourceViewDimension;
using XCEngine::RHI::ResourceViewType;
using XCEngine::Rendering::RenderPass;
using XCEngine::Rendering::RenderPassContext;
using XCEngine::Rendering::RenderPassSequence;
using XCEngine::Rendering::RenderSurface;

class DummyResourceView final : public RHIResourceView {
public:
    explicit DummyResourceView(
        ResourceViewType viewType = ResourceViewType::RenderTarget,
        Format format = Format::R8G8B8A8_UNorm)
        : m_viewType(viewType)
        , m_format(format) {
    }

    void Shutdown() override {
    }

    void* GetNativeHandle() override {
        return nullptr;
    }

    bool IsValid() const override {
        return true;
    }

    ResourceViewType GetViewType() const override {
        return m_viewType;
    }

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

    Format GetFormat() const override {
        return m_format;
    }

private:
    ResourceViewType m_viewType = ResourceViewType::RenderTarget;
    Format m_format = Format::R8G8B8A8_UNorm;
};

class NoopRenderPass final : public RenderPass {
public:
    const char* GetName() const override {
        return "NoopRenderPass";
    }

    bool Execute(const RenderPassContext&) override {
        return true;
    }
};

SceneViewportOverlayData CreateValidOverlay() {
    SceneViewportOverlayData overlay = {};
    overlay.valid = true;
    overlay.cameraPosition = XCEngine::Math::Vector3(1.0f, 2.0f, 3.0f);
    overlay.cameraForward = XCEngine::Math::Vector3::Forward();
    overlay.cameraRight = XCEngine::Math::Vector3::Right();
    overlay.cameraUp = XCEngine::Math::Vector3::Up();
    overlay.verticalFovDegrees = 70.0f;
    overlay.nearClipPlane = 0.1f;
    overlay.farClipPlane = 500.0f;
    overlay.orbitDistance = 9.0f;
    return overlay;
}

SceneViewportOverlayFrameData CreateOverlayFrameDataWithLine(
    const SceneViewportOverlayData& overlay,
    const XCEngine::Math::Vector3& start,
    const XCEngine::Math::Vector3& end) {
    SceneViewportOverlayFrameData frameData = {};
    frameData.overlay = overlay;

    SceneViewportOverlayLinePrimitive& line = frameData.worldLines.emplace_back();
    line.startWorld = start;
    line.endWorld = end;
    line.color = XCEngine::Math::Color::White();
    return frameData;
}

TEST(ViewportRenderFlowUtilsTest, BuildFailurePoliciesExposeExpectedStatusAndClearBehavior) {
    const auto targetUnavailable = BuildViewportRenderTargetUnavailablePolicy();
    EXPECT_STREQ(targetUnavailable.statusText, "Viewport render target is unavailable");
    EXPECT_FALSE(targetUnavailable.shouldClear);
    EXPECT_TRUE(targetUnavailable.invalidateObjectIdFrame);

    const auto missingSceneCamera =
        BuildSceneViewportRenderFailurePolicy(SceneViewportRenderFailure::MissingSceneViewCamera);
    EXPECT_STREQ(missingSceneCamera.statusText, "Scene view camera is unavailable");
    EXPECT_TRUE(missingSceneCamera.shouldClear);
    EXPECT_FLOAT_EQ(missingSceneCamera.clearColor.r, 0.18f);
    EXPECT_FLOAT_EQ(missingSceneCamera.clearColor.g, 0.07f);
    EXPECT_FLOAT_EQ(missingSceneCamera.clearColor.b, 0.07f);
    EXPECT_FALSE(missingSceneCamera.setStatusIfEmpty);

    const auto sceneRendererFailed =
        BuildSceneViewportRenderFailurePolicy(SceneViewportRenderFailure::SceneRendererFailed);
    EXPECT_STREQ(sceneRendererFailed.statusText, "Scene renderer failed");
    EXPECT_TRUE(sceneRendererFailed.shouldClear);
    EXPECT_TRUE(sceneRendererFailed.setStatusIfEmpty);

    const auto noGameCamera =
        BuildGameViewportRenderFailurePolicy(GameViewportRenderFailure::NoCameraInScene);
    EXPECT_STREQ(noGameCamera.statusText, "No camera in scene");
    EXPECT_TRUE(noGameCamera.shouldClear);
    EXPECT_FLOAT_EQ(noGameCamera.clearColor.r, 0.10f);
    EXPECT_FLOAT_EQ(noGameCamera.clearColor.g, 0.09f);
    EXPECT_FLOAT_EQ(noGameCamera.clearColor.b, 0.08f);
}

TEST(ViewportRenderFlowUtilsTest, ApplyViewportFailureStatusRespectsSetIfEmptyBehavior) {
    std::string statusText;
    ApplyViewportFailureStatus(
        statusText,
        BuildSceneViewportRenderFailurePolicy(SceneViewportRenderFailure::SceneRendererFailed));
    EXPECT_EQ(statusText, "Scene renderer failed");

    statusText = "Scene object id shader view is unavailable";
    ApplyViewportFailureStatus(
        statusText,
        BuildSceneViewportRenderFailurePolicy(SceneViewportRenderFailure::SceneRendererFailed));
    EXPECT_EQ(statusText, "Scene object id shader view is unavailable");

    ApplyViewportFailureStatus(
        statusText,
        BuildGameViewportRenderFailurePolicy(GameViewportRenderFailure::NoActiveScene));
    EXPECT_EQ(statusText, "No active scene");
}

TEST(ViewportRenderFlowUtilsTest, BuildSceneViewportGridPassDataCopiesSceneCameraState) {
    const SceneViewportOverlayData overlay = CreateValidOverlay();
    const auto gridPassData = BuildSceneViewportGridPassData(overlay);

    EXPECT_TRUE(gridPassData.valid);
    EXPECT_FLOAT_EQ(gridPassData.cameraPosition.x, overlay.cameraPosition.x);
    EXPECT_FLOAT_EQ(gridPassData.cameraPosition.y, overlay.cameraPosition.y);
    EXPECT_FLOAT_EQ(gridPassData.cameraPosition.z, overlay.cameraPosition.z);
    EXPECT_FLOAT_EQ(gridPassData.verticalFovDegrees, overlay.verticalFovDegrees);
    EXPECT_FLOAT_EQ(gridPassData.orbitDistance, overlay.orbitDistance);
}

TEST(ViewportRenderFlowUtilsTest, BuildSceneViewportSelectionOutlineStyleAppliesSceneDefaults) {
    const auto style = BuildSceneViewportSelectionOutlineStyle(false);
    const auto debugStyle = BuildSceneViewportSelectionOutlineStyle(true);

    EXPECT_FLOAT_EQ(style.outlineColor.r, 1.0f);
    EXPECT_FLOAT_EQ(style.outlineColor.g, 0.4f);
    EXPECT_FLOAT_EQ(style.outlineColor.b, 0.0f);
    EXPECT_FLOAT_EQ(style.outlineWidthPixels, 2.0f);
    EXPECT_FALSE(style.debugSelectionMask);
    EXPECT_TRUE(debugStyle.debugSelectionMask);
}

TEST(ViewportRenderFlowUtilsTest, ApplySceneRenderRequestSetupAttachesOptionalPassesAndObjectIdSurface) {
    DummyResourceView depthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView objectIdDepthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView objectIdView(ResourceViewType::RenderTarget);
    DummyResourceView objectIdShaderView(ResourceViewType::ShaderResource);

    ViewportRenderTargets targets = {};
    targets.width = 800;
    targets.height = 600;
    targets.depthView = &depthView;
    targets.objectIdDepthView = &objectIdDepthView;
    targets.objectIdView = &objectIdView;
    targets.objectIdShaderView = &objectIdShaderView;
    targets.objectIdState = ResourceStates::Common;

    RenderPassSequence postPasses;
    postPasses.AddPass(std::make_unique<NoopRenderPass>());

    XCEngine::Rendering::CameraRenderRequest request = {};
    request.surface = RenderSurface(800, 600);
    request.surface.SetRenderArea(XCEngine::Math::RectInt(64, 32, 320, 240));

    ApplySceneViewportRenderRequestSetup(
        targets,
        &postPasses,
        request);

    EXPECT_EQ(request.postScenePasses, &postPasses);
    EXPECT_TRUE(request.objectId.IsRequested());
    ASSERT_EQ(request.objectId.surface.GetColorAttachments().size(), 1u);
    EXPECT_EQ(request.objectId.surface.GetColorAttachments()[0], &objectIdView);
    EXPECT_EQ(request.objectId.surface.GetDepthAttachment(), &objectIdDepthView);

    const auto requestArea = request.surface.GetRenderArea();
    const auto objectIdArea = request.objectId.surface.GetRenderArea();
    EXPECT_EQ(objectIdArea.x, requestArea.x);
    EXPECT_EQ(objectIdArea.y, requestArea.y);
    EXPECT_EQ(objectIdArea.width, requestArea.width);
    EXPECT_EQ(objectIdArea.height, requestArea.height);
}

TEST(ViewportRenderFlowUtilsTest, ApplySceneRenderRequestSetupSkipsUnavailableOptionalAttachments) {
    ViewportRenderTargets targets = {};
    targets.width = 800;
    targets.height = 600;

    RenderPassSequence postPasses;

    XCEngine::Rendering::CameraRenderRequest request = {};
    request.postScenePasses = reinterpret_cast<RenderPassSequence*>(static_cast<uintptr_t>(0x1));
    request.objectId.surface = RenderSurface(1, 1);
    request.objectId.surface.SetColorAttachment(
        reinterpret_cast<RHIResourceView*>(static_cast<uintptr_t>(0x2)));

    ApplySceneViewportRenderRequestSetup(targets, &postPasses, request);

    EXPECT_EQ(request.postScenePasses, nullptr);
    EXPECT_FALSE(request.objectId.IsRequested());
}

TEST(ViewportRenderFlowUtilsTest, BuildSceneViewportRenderPlanCollectsPostSceneAndOverlayPasses) {
    DummyResourceView depthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView depthShaderView(ResourceViewType::ShaderResource, Format::D24_UNorm_S8_UInt);
    DummyResourceView selectionMaskView(ResourceViewType::RenderTarget);
    DummyResourceView selectionMaskShaderView(ResourceViewType::ShaderResource);

    DummyResourceView objectIdShaderView(ResourceViewType::ShaderResource);

    ViewportRenderTargets targets = {};
    targets.depthView = &depthView;
    targets.depthShaderView = &depthShaderView;
    targets.selectionMaskView = &selectionMaskView;
    targets.selectionMaskShaderView = &selectionMaskShaderView;
    targets.objectIdShaderView = &objectIdShaderView;

    const SceneViewportOverlayData overlay = CreateValidOverlay();
    const SceneViewportOverlayFrameData editorOverlayFrameData =
        CreateOverlayFrameDataWithLine(
            overlay,
            XCEngine::Math::Vector3::Zero(),
            XCEngine::Math::Vector3::Right());

    size_t factoryCallCount = 0u;
    size_t combinedWorldLineCount = 0u;
    size_t gridPassFactoryCallCount = 0u;
    size_t selectionOutlinePassFactoryCallCount = 0u;
    const auto result = BuildSceneViewportRenderPlan(
        targets,
        overlay,
        { 7u, 11u },
        editorOverlayFrameData,
        [&gridPassFactoryCallCount](const SceneViewportGridPassData& data) {
            ++gridPassFactoryCallCount;
            EXPECT_TRUE(data.valid);
            return std::make_unique<NoopRenderPass>();
        },
        [&selectionOutlinePassFactoryCallCount](
            ViewportRenderTargets* outlineTargets,
            const std::vector<uint64_t>& selectedObjectIds,
            const SceneViewportSelectionOutlineStyle& style) {
            ++selectionOutlinePassFactoryCallCount;
            EXPECT_NE(outlineTargets, nullptr);
            if (outlineTargets == nullptr) {
                return std::unique_ptr<NoopRenderPass>();
            }
            EXPECT_NE(outlineTargets->selectionMaskShaderView, nullptr);
            EXPECT_NE(outlineTargets->depthShaderView, nullptr);
            EXPECT_EQ(selectedObjectIds.size(), 2u);
            EXPECT_FLOAT_EQ(style.outlineWidthPixels, 2.0f);
            return std::make_unique<NoopRenderPass>();
        },
        [&factoryCallCount, &combinedWorldLineCount](const SceneViewportOverlayFrameData& frameData) {
            ++factoryCallCount;
            combinedWorldLineCount = frameData.worldLines.size();
            return std::make_unique<NoopRenderPass>();
        },
        false);

    EXPECT_EQ(result.plan.postScenePasses.GetPassCount(), 2u);
    EXPECT_EQ(result.plan.overlayPasses.GetPassCount(), 1u);
    EXPECT_EQ(factoryCallCount, 1u);
    EXPECT_EQ(gridPassFactoryCallCount, 1u);
    EXPECT_EQ(selectionOutlinePassFactoryCallCount, 1u);
    EXPECT_EQ(combinedWorldLineCount, 1u);
    EXPECT_EQ(result.warningStatusText, nullptr);
}

TEST(ViewportRenderFlowUtilsTest, BuildSceneViewportRenderPlanSkipsRhiOverlayPassWhenFrameContainsOnlySceneIcons) {
    const SceneViewportOverlayData overlay = CreateValidOverlay();
    ViewportRenderTargets targets = {};

    SceneViewportOverlayFrameData editorOverlayFrameData = {};
    editorOverlayFrameData.overlay = overlay;
    auto& sprite = editorOverlayFrameData.worldSprites.emplace_back();
    sprite.worldPosition = XCEngine::Math::Vector3::Zero();
    sprite.sizePixels = XCEngine::Math::Vector2(32.0f, 32.0f);

    size_t overlayFactoryCallCount = 0u;
    const auto result = BuildSceneViewportRenderPlan(
        targets,
        overlay,
        {},
        editorOverlayFrameData,
        [](const SceneViewportGridPassData&) {
            return std::make_unique<NoopRenderPass>();
        },
        [](
            ViewportRenderTargets*,
            const std::vector<uint64_t>&,
            const SceneViewportSelectionOutlineStyle&) {
            return std::make_unique<NoopRenderPass>();
        },
        [&overlayFactoryCallCount](const SceneViewportOverlayFrameData&) {
            ++overlayFactoryCallCount;
            return std::make_unique<NoopRenderPass>();
        },
        false);

    EXPECT_EQ(result.plan.postScenePasses.GetPassCount(), 1u);
    EXPECT_EQ(result.plan.overlayPasses.GetPassCount(), 0u);
    EXPECT_EQ(overlayFactoryCallCount, 0u);
}

TEST(ViewportRenderFlowUtilsTest, BuildSceneViewportRenderPlanWarnsWhenSelectionOutlineCannotAccessObjectIdTexture) {
    const SceneViewportOverlayData overlay = CreateValidOverlay();

    ViewportRenderTargets targets = {};
    const auto result = BuildSceneViewportRenderPlan(
        targets,
        overlay,
        { 42u },
        {},
        [](const SceneViewportGridPassData&) {
            return std::make_unique<NoopRenderPass>();
        },
        [](
            ViewportRenderTargets*,
            const std::vector<uint64_t>&,
            const SceneViewportSelectionOutlineStyle&) {
            return std::make_unique<NoopRenderPass>();
        },
        [](const SceneViewportOverlayFrameData&) {
            return std::make_unique<NoopRenderPass>();
        },
        false);

    EXPECT_EQ(result.plan.postScenePasses.GetPassCount(), 1u);
    EXPECT_STREQ(result.warningStatusText, "Scene selection outline resources are unavailable");
}

TEST(ViewportRenderFlowUtilsTest, ApplySceneViewportRenderPlanAttachesPlannedPassesAndClearState) {
    DummyResourceView depthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView objectIdDepthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView objectIdView(ResourceViewType::RenderTarget);
    DummyResourceView objectIdShaderView(ResourceViewType::ShaderResource);

    ViewportRenderTargets targets = {};
    targets.width = 800;
    targets.height = 600;
    targets.depthView = &depthView;
    targets.objectIdDepthView = &objectIdDepthView;
    targets.objectIdView = &objectIdView;
    targets.objectIdShaderView = &objectIdShaderView;

    SceneViewportRenderPlan plan = {};
    plan.postScenePasses.AddPass(std::make_unique<NoopRenderPass>());
    plan.overlayPasses.AddPass(std::make_unique<NoopRenderPass>());
    plan.clearColorOverride = XCEngine::Math::Color(0.1f, 0.2f, 0.3f, 1.0f);

    XCEngine::Rendering::CameraRenderRequest request = {};
    request.surface = RenderSurface(800, 600);
    request.surface.SetRenderArea(XCEngine::Math::RectInt(10, 20, 300, 200));

    ApplySceneViewportRenderPlan(targets, plan, request);

    EXPECT_EQ(request.postScenePasses, &plan.postScenePasses);
    EXPECT_EQ(request.overlayPasses, &plan.overlayPasses);
    EXPECT_TRUE(request.objectId.IsRequested());
    EXPECT_TRUE(request.hasClearColorOverride);
    EXPECT_FLOAT_EQ(request.clearColorOverride.r, 0.1f);
    EXPECT_FLOAT_EQ(request.clearColorOverride.g, 0.2f);
    EXPECT_FLOAT_EQ(request.clearColorOverride.b, 0.3f);
}

TEST(ViewportRenderFlowUtilsTest, MarkSceneRenderSuccessMovesTargetsToShaderResourceState) {
    DummyResourceView depthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView objectIdView(ResourceViewType::RenderTarget);
    DummyResourceView objectIdDepthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView selectionMaskView(ResourceViewType::RenderTarget);

    ViewportRenderTargets targets = {};
    targets.width = 640;
    targets.height = 360;
    targets.depthView = &depthView;
    targets.objectIdDepthView = &objectIdDepthView;
    targets.objectIdView = &objectIdView;
    targets.selectionMaskView = &selectionMaskView;
    targets.colorState = ResourceStates::Common;
    targets.objectIdState = ResourceStates::Common;
    targets.selectionMaskState = ResourceStates::Common;

    XCEngine::Rendering::CameraRenderRequest request = {};
    request.surface = RenderSurface(640, 360);
    ApplySceneViewportRenderRequestSetup(targets, nullptr, request);

    MarkSceneViewportRenderSuccess(targets, request);
    EXPECT_EQ(targets.colorState, ResourceStates::PixelShaderResource);
    EXPECT_EQ(targets.objectIdState, ResourceStates::PixelShaderResource);
    EXPECT_EQ(targets.selectionMaskState, ResourceStates::PixelShaderResource);
    EXPECT_TRUE(targets.hasValidObjectIdFrame);

    ViewportRenderTargets noObjectIdTargets = {};
    noObjectIdTargets.colorState = ResourceStates::Common;
    noObjectIdTargets.objectIdState = ResourceStates::Common;
    noObjectIdTargets.selectionMaskState = ResourceStates::Common;
    XCEngine::Rendering::CameraRenderRequest noObjectIdRequest = {};

    MarkSceneViewportRenderSuccess(noObjectIdTargets, noObjectIdRequest);
    EXPECT_EQ(noObjectIdTargets.colorState, ResourceStates::PixelShaderResource);
    EXPECT_EQ(noObjectIdTargets.objectIdState, ResourceStates::PixelShaderResource);
    EXPECT_EQ(noObjectIdTargets.selectionMaskState, ResourceStates::PixelShaderResource);
    EXPECT_FALSE(noObjectIdTargets.hasValidObjectIdFrame);
}

TEST(ViewportRenderFlowUtilsTest, MarkGameRenderSuccessClearsObjectIdFrameAndUpdatesColorState) {
    ViewportRenderTargets targets = {};
    targets.colorState = ResourceStates::Common;
    targets.hasValidObjectIdFrame = true;

    MarkGameViewportRenderSuccess(targets);

    EXPECT_EQ(targets.colorState, ResourceStates::PixelShaderResource);
    EXPECT_FALSE(targets.hasValidObjectIdFrame);
}

} // namespace