#pragma once

#include "IXCUITextAtlasProvider.h"

#include <XCEngine/Rendering/RenderContext.h>
#include <XCEngine/Rendering/RenderSurface.h>
#include <XCEngine/RHI/RHIBuffer.h>
#include <XCEngine/RHI/RHICommandList.h>
#include <XCEngine/RHI/RHIDescriptorPool.h>
#include <XCEngine/RHI/RHIDescriptorSet.h>
#include <XCEngine/RHI/RHIEnums.h>
#include <XCEngine/RHI/RHIPipelineLayout.h>
#include <XCEngine/RHI/RHIPipelineState.h>
#include <XCEngine/RHI/RHIResourceView.h>
#include <XCEngine/RHI/RHISampler.h>
#include <XCEngine/RHI/RHITexture.h>
#include <XCEngine/UI/DrawData.h>

#include <cstddef>
#include <cstdint>
#include <vector>

namespace XCEngine {
namespace Editor {
namespace XCUIBackend {

class XCUIRHIRenderBackend {
public:
    struct OverlayStats {
        std::size_t drawListCount = 0;
        std::size_t commandCount = 0;
        std::size_t batchCount = 0;
        std::size_t colorBatchCount = 0;
        std::size_t texturedBatchCount = 0;
        std::size_t scissoredBatchCount = 0;
        std::size_t renderedCommandCount = 0;
        std::size_t skippedCommandCount = 0;
        std::size_t textureResolveCount = 0;
        std::size_t textureCacheHitCount = 0;
        std::size_t vertexCount = 0;
        std::size_t triangleCount = 0;
    };

    void SetTextAtlasProvider(const IXCUITextAtlasProvider* provider);
    const IXCUITextAtlasProvider* GetTextAtlasProvider() const { return m_textAtlasProvider; }
    void Shutdown();
    void ResetStats();
    bool Render(
        const ::XCEngine::Rendering::RenderContext& renderContext,
        const ::XCEngine::Rendering::RenderSurface& surface,
        const ::XCEngine::UI::UIDrawData& drawData);
    const OverlayStats& GetLastStats() const { return m_lastOverlayStats; }
    const OverlayStats& GetLastOverlayStats() const { return m_lastOverlayStats; }

private:
    using TextFontHandle = IXCUITextAtlasProvider::FontHandle;

    struct ExternalTextureBinding {
        std::uintptr_t handleKey = 0;
        ::XCEngine::RHI::RHIResourceView* shaderView = nullptr;
        ::XCEngine::RHI::RHIDescriptorSet* textureSet = nullptr;
    };

    bool EnsureInitialized(const ::XCEngine::Rendering::RenderContext& renderContext);
    bool CreateResources(const ::XCEngine::Rendering::RenderContext& renderContext);
    bool CreateOverlayResources();
    bool CreateTexturedOverlayResources();
    const IXCUITextAtlasProvider* ResolveActiveTextAtlasProvider(bool& outFontAtlasReady);
    bool EnsureOverlayVertexBufferCapacity(std::size_t requiredVertexCount);
    bool EnsureTexturedOverlayVertexBufferCapacity(std::size_t requiredVertexCount);
    bool EnsureFontAtlasResources(const IXCUITextAtlasProvider& atlasProvider);
    void ResetFontAtlasResources();
    ::XCEngine::RHI::RHIDescriptorSet* ResolveTextureSet(
        const ::XCEngine::UI::UITextureHandle& texture,
        bool* outCacheHit = nullptr);
    bool RenderCompiledDrawData(
        ::XCEngine::RHI::RHICommandList& commandList,
        ::XCEngine::RHI::RHIResourceView* renderTarget,
        const ::XCEngine::Rendering::RenderSurface& surface,
        const ::XCEngine::UI::UIDrawData& drawData,
        const IXCUITextAtlasProvider* atlasProvider,
        bool fontAtlasReady);
    void DestroyResources();

    const IXCUITextAtlasProvider* m_textAtlasProvider = nullptr;
    ::XCEngine::RHI::RHIDevice* m_device = nullptr;
    ::XCEngine::RHI::RHIType m_backendType = ::XCEngine::RHI::RHIType::D3D12;
    ::XCEngine::RHI::RHIPipelineLayout* m_overlayPipelineLayout = nullptr;
    ::XCEngine::RHI::RHIDescriptorPool* m_overlayConstantPool = nullptr;
    ::XCEngine::RHI::RHIDescriptorSet* m_overlayConstantSet = nullptr;
    ::XCEngine::RHI::RHIPipelineState* m_overlayPipelineState = nullptr;
    ::XCEngine::RHI::RHIPipelineLayout* m_texturedOverlayPipelineLayout = nullptr;
    ::XCEngine::RHI::RHIDescriptorPool* m_overlayTexturePool = nullptr;
    ::XCEngine::RHI::RHIDescriptorSet* m_overlayFontTextureSet = nullptr;
    ::XCEngine::RHI::RHIDescriptorPool* m_overlaySamplerPool = nullptr;
    ::XCEngine::RHI::RHIDescriptorSet* m_overlaySamplerSet = nullptr;
    ::XCEngine::RHI::RHIPipelineState* m_texturedOverlayPipelineState = nullptr;
    ::XCEngine::RHI::RHISampler* m_overlaySampler = nullptr;
    ::XCEngine::RHI::RHITexture* m_overlayFontTexture = nullptr;
    ::XCEngine::RHI::RHIResourceView* m_overlayFontTextureView = nullptr;
    ::XCEngine::UI::UITextureHandle m_overlayFontTextureHandle = {};
    ::XCEngine::RHI::RHIBuffer* m_overlayVertexBuffer = nullptr;
    ::XCEngine::RHI::RHIResourceView* m_overlayVertexBufferView = nullptr;
    ::XCEngine::RHI::RHIBuffer* m_texturedOverlayVertexBuffer = nullptr;
    ::XCEngine::RHI::RHIResourceView* m_texturedOverlayVertexBufferView = nullptr;
    std::uint64_t m_overlayVertexBufferCapacity = 0;
    std::uint64_t m_texturedOverlayVertexBufferCapacity = 0;
    TextFontHandle m_overlayFont = {};
    std::uintptr_t m_fontAtlasStorageKey = 0;
    std::uintptr_t m_fontAtlasPixelDataKey = 0;
    int m_fontAtlasWidth = 0;
    int m_fontAtlasHeight = 0;
    int m_fontAtlasStride = 0;
    std::vector<ExternalTextureBinding> m_externalTextureBindings = {};
    OverlayStats m_lastOverlayStats = {};
};

} // namespace XCUIBackend
} // namespace Editor
} // namespace XCEngine