#include <gtest/gtest.h>

#include "Viewport/ViewportHostRenderFlowUtils.h"

#include <memory>
#include <string>

namespace {

using XCEngine::Editor::ApplySceneViewportRenderRequestSetup;
using XCEngine::Editor::ApplyViewportFailureStatus;
using XCEngine::Editor::BuildGameViewportRenderFailurePolicy;
using XCEngine::Editor::BuildSceneViewportRenderFailurePolicy;
using XCEngine::Editor::BuildViewportRenderTargetUnavailablePolicy;
using XCEngine::Editor::GameViewportRenderFailure;
using XCEngine::Editor::MarkGameViewportRenderSuccess;
using XCEngine::Editor::MarkSceneViewportRenderSuccess;
using XCEngine::Editor::SceneViewportRenderFailure;
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;
    }
};

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, ApplySceneRenderRequestSetupAttachesOptionalPassesAndObjectIdSurface) {
    DummyResourceView depthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView objectIdView(ResourceViewType::RenderTarget);

    ViewportRenderTargets targets = {};
    targets.width = 800;
    targets.height = 600;
    targets.depthView = &depthView;
    targets.objectIdView = &objectIdView;
    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(), &depthView);

    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, MarkSceneRenderSuccessMovesTargetsToShaderResourceState) {
    DummyResourceView depthView(ResourceViewType::DepthStencil, Format::D24_UNorm_S8_UInt);
    DummyResourceView objectIdView(ResourceViewType::RenderTarget);

    ViewportRenderTargets targets = {};
    targets.width = 640;
    targets.height = 360;
    targets.depthView = &depthView;
    targets.objectIdView = &objectIdView;
    targets.colorState = ResourceStates::Common;
    targets.objectIdState = 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_TRUE(targets.hasValidObjectIdFrame);

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

    MarkSceneViewportRenderSuccess(noObjectIdTargets, noObjectIdRequest);
    EXPECT_EQ(noObjectIdTargets.colorState, ResourceStates::PixelShaderResource);
    EXPECT_EQ(noObjectIdTargets.objectIdState, 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