#include <gtest/gtest.h>

#include <XCEngine/Core/Asset/AssetRef.h>
#include <XCEngine/Rendering/GraphicsSettingsState.h>

#include <memory>
#include <utility>

using namespace XCEngine::Rendering;
namespace Resources = XCEngine::Resources;

namespace {

class DummyManagedRenderPipelineBridge final
    : public Pipelines::ManagedRenderPipelineBridge {
};

class GraphicsSettingsStateScope final {
public:
    GraphicsSettingsStateScope()
        : m_savedDescriptor(
            GetGraphicsSettingsState()
                .GetConfiguredRenderPipelineAssetDescriptor())
        , m_savedAssetRef(
            GetGraphicsSettingsState()
                .GetConfiguredRenderPipelineAssetRef())
        , m_savedBridge(
            GetGraphicsSettingsState().GetManagedRenderPipelineBridge()) {
    }

    ~GraphicsSettingsStateScope() {
        GraphicsSettingsState& state = GetGraphicsSettingsState();
        if (m_savedBridge != nullptr) {
            state.SetManagedRenderPipelineBridge(m_savedBridge);
        } else {
            state.ClearManagedRenderPipelineBridge();
        }

        if (m_savedAssetRef.IsValid()) {
            state.SetConfiguredRenderPipelineAssetSelection(
                m_savedAssetRef,
                m_savedDescriptor);
        } else if (m_savedDescriptor.IsValid() ||
                   m_savedDescriptor.managedAssetHandle != 0u) {
            state.SetConfiguredRenderPipelineAssetDescriptor(
                m_savedDescriptor);
        } else {
            state.ClearConfiguredRenderPipelineAssetDescriptor();
        }
    }

private:
    Pipelines::ManagedRenderPipelineAssetDescriptor m_savedDescriptor = {};
    Resources::AssetRef m_savedAssetRef = {};
    std::shared_ptr<const Pipelines::ManagedRenderPipelineBridge> m_savedBridge =
        nullptr;
};

Resources::AssetRef MakeRenderPipelineAssetRefForTest(
    uint64_t guidLow = 2u) {
    Resources::AssetRef assetRef = {};
    assetRef.assetGuid = Resources::AssetGUID(1u, guidLow);
    assetRef.localID = Resources::kMainAssetLocalID;
    assetRef.resourceType = Resources::ResourceType::RenderPipelineAsset;
    return assetRef;
}

} // namespace

TEST(GraphicsSettingsState_Test, StoresRenderPipelineAssetDescriptorAndBumpsEnvironmentGeneration) {
    GraphicsSettingsStateScope scope;
    GraphicsSettingsState& state = GetGraphicsSettingsState();
    state.ClearConfiguredRenderPipelineAssetDescriptor();

    const size_t generationBefore = state.GetEnvironmentGeneration();
    const Pipelines::ManagedRenderPipelineAssetDescriptor descriptor = {
        "XCEngine.GameScripts",
        "Gameplay",
        "ManagedUniversalRenderPipelineProbeAsset",
        42u
    };

    state.SetConfiguredRenderPipelineAssetDescriptor(descriptor);

    const Pipelines::ManagedRenderPipelineAssetDescriptor resolved =
        state.GetConfiguredRenderPipelineAssetDescriptor();
    EXPECT_EQ(resolved.assemblyName, descriptor.assemblyName);
    EXPECT_EQ(resolved.namespaceName, descriptor.namespaceName);
    EXPECT_EQ(resolved.className, descriptor.className);
    EXPECT_EQ(resolved.managedAssetHandle, descriptor.managedAssetHandle);
    EXPECT_FALSE(state.GetConfiguredRenderPipelineAssetRef().IsValid());
    EXPECT_GT(state.GetEnvironmentGeneration(), generationBefore);
}

TEST(
    GraphicsSettingsState_Test,
    StoresRenderPipelineAssetRefAsSelectionRootAndDescriptorAsRuntimeCache) {
    GraphicsSettingsStateScope scope;
    GraphicsSettingsState& state = GetGraphicsSettingsState();
    state.ClearConfiguredRenderPipelineAssetDescriptor();

    const Resources::AssetRef assetRef =
        MakeRenderPipelineAssetRefForTest();
    const Pipelines::ManagedRenderPipelineAssetDescriptor descriptor = {
        "XCEngine.RenderPipelines.Universal",
        "XCEngine.Rendering.Universal",
        "UniversalRenderPipelineAsset",
        0u
    };

    const size_t generationBefore = state.GetEnvironmentGeneration();
    state.SetConfiguredRenderPipelineAssetSelection(
        assetRef,
        descriptor);

    const Resources::AssetRef resolvedAssetRef =
        state.GetConfiguredRenderPipelineAssetRef();
    EXPECT_EQ(resolvedAssetRef.assetGuid, assetRef.assetGuid);
    EXPECT_EQ(resolvedAssetRef.localID, assetRef.localID);
    EXPECT_EQ(resolvedAssetRef.resourceType, assetRef.resourceType);

    const Pipelines::ManagedRenderPipelineAssetDescriptor resolvedDescriptor =
        state.GetConfiguredRenderPipelineAssetDescriptor();
    EXPECT_EQ(resolvedDescriptor.assemblyName, descriptor.assemblyName);
    EXPECT_EQ(resolvedDescriptor.namespaceName, descriptor.namespaceName);
    EXPECT_EQ(resolvedDescriptor.className, descriptor.className);
    EXPECT_TRUE(resolvedDescriptor.assetRef.IsValid());
    EXPECT_EQ(resolvedDescriptor.assetRef.assetGuid, assetRef.assetGuid);
    EXPECT_GT(state.GetEnvironmentGeneration(), generationBefore);
}

TEST(
    GraphicsSettingsState_Test,
    RuntimeDescriptorUpdatePreservesConfiguredRenderPipelineAssetRef) {
    GraphicsSettingsStateScope scope;
    GraphicsSettingsState& state = GetGraphicsSettingsState();
    state.ClearConfiguredRenderPipelineAssetDescriptor();

    const Resources::AssetRef assetRef =
        MakeRenderPipelineAssetRefForTest(3u);
    state.SetConfiguredRenderPipelineAssetRef(assetRef);

    Pipelines::ManagedRenderPipelineAssetDescriptor runtimeDescriptor = {
        "GameScripts",
        "Gameplay",
        "ProjectConfiguredRenderPipelineAsset",
        77u
    };
    state.UpdateConfiguredRenderPipelineAssetRuntimeDescriptor(
        runtimeDescriptor);

    const Resources::AssetRef resolvedAssetRef =
        state.GetConfiguredRenderPipelineAssetRef();
    EXPECT_EQ(resolvedAssetRef.assetGuid, assetRef.assetGuid);
    EXPECT_EQ(resolvedAssetRef.localID, assetRef.localID);
    EXPECT_EQ(resolvedAssetRef.resourceType, assetRef.resourceType);

    const Pipelines::ManagedRenderPipelineAssetDescriptor resolvedDescriptor =
        state.GetConfiguredRenderPipelineAssetDescriptor();
    EXPECT_EQ(resolvedDescriptor.managedAssetHandle, 77u);
    EXPECT_TRUE(resolvedDescriptor.assetRef.IsValid());
    EXPECT_EQ(resolvedDescriptor.assetRef.assetGuid, assetRef.assetGuid);
}

TEST(GraphicsSettingsState_Test, StoresManagedBridgeAndBumpsBridgeAndEnvironmentGenerations) {
    GraphicsSettingsStateScope scope;
    GraphicsSettingsState& state = GetGraphicsSettingsState();
    state.ClearManagedRenderPipelineBridge();

    const size_t environmentGenerationBefore =
        state.GetEnvironmentGeneration();
    const size_t bridgeGenerationBefore =
        state.GetManagedRenderPipelineBridgeGeneration();
    const auto bridge =
        std::make_shared<DummyManagedRenderPipelineBridge>();

    state.SetManagedRenderPipelineBridge(bridge);

    EXPECT_EQ(state.GetManagedRenderPipelineBridge(), bridge);
    EXPECT_GT(state.GetManagedRenderPipelineBridgeGeneration(),
              bridgeGenerationBefore);
    EXPECT_GT(state.GetEnvironmentGeneration(),
              environmentGenerationBefore);
}