#pragma once

#include <XCEngine/Input/InputTypes.h>

#include "XCUIBackend/XCUIEditorCommandRouter.h"
#include "XCUIBackend/NativeXCUIPanelCanvasHost.h"
#include "XCUIBackend/XCUIHostedPreviewPresenter.h"
#include "XCUIBackend/XCUIInputBridge.h"
#include "XCUIBackend/XCUILayoutLabRuntime.h"
#include "XCUIBackend/XCUIRHIRenderBackend.h"
#include "XCUIBackend/XCUIShellChromeState.h"
#include "XCUIBackend/XCUIStandaloneTextAtlasProvider.h"
#include "XCUIBackend/UITextureRegistration.h"
#include "Platform/D3D12WindowRenderer.h"
#include "Rendering/MainWindowNativeBackdropRenderer.h"

#include <chrono>
#include <cstdint>
#include <functional>
#include <initializer_list>
#include <memory>
#include <string>
#include <string_view>
#include <vector>
#include <windows.h>

namespace XCEngine {
namespace Editor {
namespace XCUIBackend {

class IWindowUICompositor;

} // namespace XCUIBackend
} // namespace Editor

namespace NewEditor {

class XCUIDemoPanel;
class XCUILayoutLabPanel;

class Application {
public:
    Application();
    ~Application();

    using ShellChromeState = ::XCEngine::Editor::XCUIBackend::XCUIShellChromeState;
    using ShellPanelId = ::XCEngine::Editor::XCUIBackend::XCUIShellPanelId;
    using ShellViewToggleId = ::XCEngine::Editor::XCUIBackend::XCUIShellViewToggleId;
    using ShellHostedPreviewMode = ::XCEngine::Editor::XCUIBackend::XCUIShellHostedPreviewMode;
    using ShellPanelChromeState = ::XCEngine::Editor::XCUIBackend::XCUIShellPanelChromeState;
    using ShellViewToggleState = ::XCEngine::Editor::XCUIBackend::XCUIShellViewToggleState;
    enum class WindowHostMode : std::uint8_t {
        NativeXCUI = 0,
        CompatibilityHost
    };

    struct ShellCommandIds {
        static constexpr const char* ToggleXCUIDemoPanel =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::ToggleXCUIDemoPanel;
        static constexpr const char* ToggleXCUILayoutLabPanel =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::ToggleXCUILayoutLabPanel;
        static constexpr const char* ToggleNativeBackdrop =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::ToggleNativeBackdrop;
        static constexpr const char* TogglePulseAccent =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::TogglePulseAccent;
        static constexpr const char* ToggleNativeXCUIOverlay =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::ToggleNativeXCUIOverlay;
        static constexpr const char* ToggleHostedPreviewHud =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::ToggleHostedPreviewHud;
        static constexpr const char* ToggleNativeDemoPanelPreview =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::ToggleNativeDemoPanelPreview;
        static constexpr const char* ToggleNativeLayoutLabPreview =
            ::XCEngine::Editor::XCUIBackend::XCUIShellChromeCommandIds::ToggleNativeLayoutLabPreview;
    };

    struct ShellCommandBindings {
        std::function<bool()> getXCUIDemoPanelVisible = {};
        std::function<void(bool)> setXCUIDemoPanelVisible = {};
        std::function<bool()> getXCUILayoutLabPanelVisible = {};
        std::function<void(bool)> setXCUILayoutLabPanelVisible = {};
        std::function<bool()> getNativeBackdropVisible = {};
        std::function<void(bool)> setNativeBackdropVisible = {};
        std::function<bool()> getPulseAccentEnabled = {};
        std::function<void(bool)> setPulseAccentEnabled = {};
        std::function<bool()> getNativeXCUIOverlayVisible = {};
        std::function<void(bool)> setNativeXCUIOverlayVisible = {};
        std::function<bool()> getHostedPreviewHudVisible = {};
        std::function<void(bool)> setHostedPreviewHudVisible = {};
        std::function<bool()> getNativeDemoPanelPreviewEnabled = {};
        std::function<void(bool)> setNativeDemoPanelPreviewEnabled = {};
        std::function<bool()> getNativeLayoutLabPreviewEnabled = {};
        std::function<void(bool)> setNativeLayoutLabPreviewEnabled = {};
        std::function<void()> onHostedPreviewModeChanged = {};
    };

    enum class NativeHostedPreviewSurfaceState : std::uint8_t {
        Disabled = 0,
        AwaitingSubmit,
        Warming,
        Live
    };

    struct NativeHostedPreviewConsumption {
        NativeHostedPreviewSurfaceState surfaceState = NativeHostedPreviewSurfaceState::Disabled;
        bool queueRuntimeFrame = false;
        bool appendRuntimeDrawDataToShell = true;
        bool showSurfaceImage = false;
        bool drawRuntimeDebugRects = true;
        std::string_view placeholderTitle = {};
        std::string_view placeholderSubtitle = {};
    };

    static ::XCEngine::Editor::XCUIBackend::XCUIEditorCommandInputSnapshot BuildShellShortcutSnapshot(
        const ::XCEngine::Editor::XCUIBackend::XCUIInputBridgeFrameDelta& frameDelta) {
        ::XCEngine::Editor::XCUIBackend::XCUIEditorCommandInputSnapshot snapshot = {};
        snapshot.modifiers = frameDelta.state.modifiers;
        snapshot.windowFocused = frameDelta.state.windowFocused;
        snapshot.wantCaptureKeyboard = frameDelta.state.wantCaptureKeyboard;
        snapshot.wantTextInput = frameDelta.state.wantTextInput;

        snapshot.keys.reserve(
            frameDelta.keyboard.pressedKeys.size() +
            frameDelta.keyboard.repeatedKeys.size());

        const auto appendKeyState =
            [&snapshot](std::int32_t keyCode, bool repeat) {
                for (auto& existing : snapshot.keys) {
                    if (existing.keyCode != keyCode) {
                        continue;
                    }

                    existing.down = true;
                    existing.repeat = existing.repeat || repeat;
                    return;
                }

                ::XCEngine::Editor::XCUIBackend::XCUIEditorCommandKeyState keyState = {};
                keyState.keyCode = keyCode;
                keyState.down = true;
                keyState.repeat = repeat;
                snapshot.keys.push_back(keyState);
            };

        for (std::int32_t keyCode : frameDelta.keyboard.pressedKeys) {
            appendKeyState(keyCode, false);
        }
        for (std::int32_t keyCode : frameDelta.keyboard.repeatedKeys) {
            appendKeyState(keyCode, true);
        }

        return snapshot;
    }

    static void RegisterShellViewCommands(
        ::XCEngine::Editor::XCUIBackend::XCUIEditorCommandRouter& router,
        const ShellCommandBindings& bindings) {
        using ::XCEngine::Editor::XCUIBackend::XCUIEditorCommandAccelerator;
        using ::XCEngine::Editor::XCUIBackend::XCUIEditorCommandDefinition;
        using ::XCEngine::Input::KeyCode;
        using ModifierState = ::XCEngine::UI::UIInputModifiers;

        const auto bindToggleCommand =
            [&router](
                const char* commandId,
                const std::function<bool()>& getter,
                const std::function<void(bool)>& setter,
                std::initializer_list<XCUIEditorCommandAccelerator> accelerators,
                const std::function<void()>& afterToggle = {}) {
                if (!getter || !setter) {
                    return;
                }

                XCUIEditorCommandDefinition definition = {};
                definition.commandId = commandId;
                definition.isEnabled = [getter, setter]() {
                    return static_cast<bool>(getter) && static_cast<bool>(setter);
                };
                definition.invoke = [getter, setter, afterToggle]() {
                    const bool nextValue = !getter();
                    setter(nextValue);
                    if (afterToggle) {
                        afterToggle();
                    }
                };
                definition.accelerators.assign(accelerators.begin(), accelerators.end());
                router.RegisterCommand(definition);
            };

        const ModifierState ctrlOnly = { false, true, false, false };
        const ModifierState ctrlShift = { true, true, false, false };
        const ModifierState ctrlAlt = { false, true, true, false };

        bindToggleCommand(
            ShellCommandIds::ToggleXCUIDemoPanel,
            bindings.getXCUIDemoPanelVisible,
            bindings.setXCUIDemoPanelVisible,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::One),
                ctrlOnly,
                true,
                false } });
        bindToggleCommand(
            ShellCommandIds::ToggleXCUILayoutLabPanel,
            bindings.getXCUILayoutLabPanelVisible,
            bindings.setXCUILayoutLabPanelVisible,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::Two),
                ctrlOnly,
                true,
                false } });
        bindToggleCommand(
            ShellCommandIds::ToggleNativeBackdrop,
            bindings.getNativeBackdropVisible,
            bindings.setNativeBackdropVisible,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::B),
                ctrlShift,
                true,
                false } });
        bindToggleCommand(
            ShellCommandIds::TogglePulseAccent,
            bindings.getPulseAccentEnabled,
            bindings.setPulseAccentEnabled,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::P),
                ctrlShift,
                true,
                false } });
        bindToggleCommand(
            ShellCommandIds::ToggleNativeXCUIOverlay,
            bindings.getNativeXCUIOverlayVisible,
            bindings.setNativeXCUIOverlayVisible,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::O),
                ctrlShift,
                true,
                false } });
        bindToggleCommand(
            ShellCommandIds::ToggleHostedPreviewHud,
            bindings.getHostedPreviewHudVisible,
            bindings.setHostedPreviewHudVisible,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::H),
                ctrlShift,
                true,
                false } });
        bindToggleCommand(
            ShellCommandIds::ToggleNativeDemoPanelPreview,
            bindings.getNativeDemoPanelPreviewEnabled,
            bindings.setNativeDemoPanelPreviewEnabled,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::One),
                ctrlAlt,
                true,
                false } },
            bindings.onHostedPreviewModeChanged);
        bindToggleCommand(
            ShellCommandIds::ToggleNativeLayoutLabPreview,
            bindings.getNativeLayoutLabPreviewEnabled,
            bindings.setNativeLayoutLabPreviewEnabled,
            { XCUIEditorCommandAccelerator{
                static_cast<std::int32_t>(KeyCode::Two),
                ctrlAlt,
                true,
                false } },
            bindings.onHostedPreviewModeChanged);
    }

    static void BeginHostedPreviewFrameLifecycle(
        ::XCEngine::Editor::XCUIBackend::XCUIHostedPreviewQueue& previewQueue,
        ::XCEngine::Editor::XCUIBackend::XCUIHostedPreviewSurfaceRegistry& surfaceRegistry) {
        previewQueue.BeginFrame();
        surfaceRegistry.BeginFrame();
    }

    static bool HasHostedPreviewTextureRegistration(
        const ::XCEngine::Editor::XCUIBackend::UITextureRegistration& registration) {
        return registration.texture.IsValid() ||
            registration.cpuHandle.ptr != 0u ||
            registration.gpuHandle.ptr != 0u;
    }

    static bool HasHostedPreviewPublishedTexture(
        const ::XCEngine::Editor::XCUIBackend::UITextureRegistration& registration) {
        return registration.texture.IsValid();
    }

    static NativeHostedPreviewConsumption ResolveNativeHostedPreviewConsumption(
        bool nativeHostedPreview,
        bool hasHostedSurfaceDescriptor,
        bool showHostedSurfaceImage,
        std::string_view pendingTitle = {},
        std::string_view pendingSubtitle = {}) {
        NativeHostedPreviewConsumption consumption = {};
        if (!nativeHostedPreview) {
            return consumption;
        }

        consumption.queueRuntimeFrame = true;
        consumption.appendRuntimeDrawDataToShell = false;
        consumption.showSurfaceImage = showHostedSurfaceImage;
        consumption.drawRuntimeDebugRects = showHostedSurfaceImage;
        consumption.surfaceState = showHostedSurfaceImage
            ? NativeHostedPreviewSurfaceState::Live
            : (hasHostedSurfaceDescriptor
                ? NativeHostedPreviewSurfaceState::Warming
                : NativeHostedPreviewSurfaceState::AwaitingSubmit);
        if (!showHostedSurfaceImage) {
            consumption.placeholderTitle = pendingTitle;
            consumption.placeholderSubtitle = pendingSubtitle;
        }

        return consumption;
    }

    static std::string ComposeNativeHostedPreviewStatusLine(
        const NativeHostedPreviewConsumption& consumption,
        std::string_view status) {
        switch (consumption.surfaceState) {
        case NativeHostedPreviewSurfaceState::AwaitingSubmit:
            return std::string("Native surface awaiting submit | ") + std::string(status);
        case NativeHostedPreviewSurfaceState::Warming:
            return std::string("Native surface warming | ") + std::string(status);
        case NativeHostedPreviewSurfaceState::Live:
            return std::string("Native surface live | ") + std::string(status);
        case NativeHostedPreviewSurfaceState::Disabled:
        default:
            return std::string(status);
        }
    }

    int Run(HINSTANCE instance, int nCmdShow);

private:
    struct HostedPreviewPanelDiagnostics {
        std::string debugName = {};
        std::string debugSource = {};
        bool visible = false;
        bool hostedPreviewEnabled = false;
        bool nativeRequested = false;
        bool nativePresenterBound = false;
        bool descriptorAvailable = false;
        bool surfaceImageAvailable = false;
        bool surfaceAllocated = false;
        bool surfaceReady = false;
        bool presentedThisFrame = false;
        bool queuedToNativePassThisFrame = false;
        std::uint32_t surfaceWidth = 0;
        std::uint32_t surfaceHeight = 0;
        float logicalWidth = 0.0f;
        float logicalHeight = 0.0f;
        std::size_t queuedFrameIndex = 0;
        std::size_t submittedDrawListCount = 0;
        std::size_t submittedCommandCount = 0;
        std::size_t flushedDrawListCount = 0;
        std::size_t flushedCommandCount = 0;
    };

    struct HostedPreviewOffscreenSurface {
        std::string debugName = {};
        std::uint32_t width = 0;
        std::uint32_t height = 0;
        ::XCEngine::RHI::RHITexture* colorTexture = nullptr;
        ::XCEngine::RHI::RHIResourceView* colorView = nullptr;
        ::XCEngine::Editor::XCUIBackend::UITextureRegistration textureRegistration = {};
        ::XCEngine::RHI::ResourceStates colorState = ::XCEngine::RHI::ResourceStates::Common;

        bool IsReady() const {
            return !debugName.empty() &&
                colorTexture != nullptr &&
                colorView != nullptr &&
                Application::HasHostedPreviewPublishedTexture(textureRegistration) &&
                width > 0u &&
                height > 0u;
        }
    };

    static LRESULT CALLBACK StaticWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
    LRESULT WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);

    bool CreateMainWindow(HINSTANCE instance, int nCmdShow);
    bool InitializeRenderer();
    void InitializeWindowCompositor();
    void InitializeNativeShell();
    void ShutdownWindowCompositor();
    void ShutdownRenderer();
    void DestroyHostedPreviewSurfaces();
    void SyncShellChromePanelStateFromPanels();
    void SyncHostedPreviewSurfaces();
    std::unique_ptr<::XCEngine::Editor::XCUIBackend::IXCUIHostedPreviewPresenter> CreateHostedPreviewPresenter(
        bool nativePreview);
    void ConfigureHostedPreviewPresenters();
    const ShellPanelChromeState* TryGetShellPanelState(ShellPanelId panelId) const;
    bool IsShellViewToggleEnabled(ShellViewToggleId toggleId) const;
    void SetShellViewToggleEnabled(ShellViewToggleId toggleId, bool enabled);
    bool IsNativeHostedPreviewEnabled(ShellPanelId panelId) const;
    HostedPreviewPanelDiagnostics BuildHostedPreviewPanelDiagnostics(
        const char* debugName,
        const char* fallbackDebugSource,
        bool visible,
        bool hostedPreviewEnabled,
        bool nativeRequested,
        bool nativePresenterBound,
        const ::XCEngine::Editor::XCUIBackend::XCUIHostedPreviewStats& previewStats) const;
    HostedPreviewOffscreenSurface* FindHostedPreviewSurface(const std::string& debugName);
    const HostedPreviewOffscreenSurface* FindHostedPreviewSurface(const std::string& debugName) const;
    HostedPreviewOffscreenSurface& FindOrAddHostedPreviewSurface(const std::string& debugName);
    bool EnsureHostedPreviewSurface(
        HostedPreviewOffscreenSurface& previewSurface,
        std::uint32_t width,
        std::uint32_t height);
    bool RenderHostedPreviewOffscreenSurface(
        HostedPreviewOffscreenSurface& previewSurface,
        const ::XCEngine::Rendering::RenderContext& renderContext,
        const ::XCEngine::UI::UIDrawData& drawData);
    void ResetCompatibilityHostPanels();
    void ConfigureShellCommandRouter();
    ::XCEngine::Editor::XCUIBackend::XCUIInputBridgeFrameDelta DispatchShellShortcuts(
        const ::XCEngine::Editor::XCUIBackend::XCUIInputBridgeFrameSnapshot& snapshot);
    bool IsNativeWindowHostEnabled() const;
    void InitializePanelsForActiveWindowHost();
    void InitializeCompatibilityHostPanels();
    void RenderCompatibilityHostUiFrame();
    ::XCEngine::UI::UIDrawData BuildNativeShellDrawData(
        const ::XCEngine::Editor::XCUIBackend::XCUIInputBridgeFrameSnapshot& shellSnapshot,
        const ::XCEngine::Editor::XCUIBackend::XCUIInputBridgeFrameDelta& shellFrameDelta);
    void FrameCompatibilityHost();
    void FrameNativeXCUIHost();
    void RenderShellChrome();
    void RenderHostedPreviewHud();
    void RenderQueuedHostedPreviews(
        const ::XCEngine::Rendering::RenderContext& renderContext,
        const ::XCEngine::Rendering::RenderSurface& surface);
    void Frame();

    HWND m_hwnd = nullptr;
    ::XCEngine::Editor::Platform::D3D12WindowRenderer m_windowRenderer;
    std::unique_ptr<::XCEngine::Editor::XCUIBackend::IWindowUICompositor> m_windowCompositor;
    std::unique_ptr<XCUIDemoPanel> m_demoPanel;
    std::unique_ptr<XCUILayoutLabPanel> m_layoutLabPanel;
    ::XCEngine::Editor::XCUIBackend::XCUIWin32InputSource m_xcuiInputSource;
    ::XCEngine::Editor::XCUIBackend::XCUIInputBridge m_shellInputBridge;
    ::XCEngine::Editor::XCUIBackend::XCUIEditorCommandRouter m_shellCommandRouter;
    ::XCEngine::Editor::XCUIBackend::XCUIHostedPreviewQueue m_hostedPreviewQueue;
    ::XCEngine::Editor::XCUIBackend::XCUIHostedPreviewSurfaceRegistry m_hostedPreviewSurfaceRegistry;
    ::XCEngine::Editor::XCUIBackend::XCUIStandaloneTextAtlasProvider m_hostedPreviewTextAtlasProvider;
    ::XCEngine::Editor::XCUIBackend::XCUIRHIRenderBackend m_hostedPreviewRenderBackend;
    ShellChromeState m_shellChromeState = {};
    std::vector<HostedPreviewOffscreenSurface> m_hostedPreviewSurfaces = {};
    WindowHostMode m_windowHostMode = WindowHostMode::NativeXCUI;
    ::XCEngine::Editor::XCUIBackend::NativeXCUIPanelCanvasHost m_nativeDemoCanvasHost;
    ::XCEngine::Editor::XCUIBackend::NativeXCUIPanelCanvasHost m_nativeLayoutCanvasHost;
    ShellPanelId m_nativeActivePanel = ShellPanelId::XCUIDemo;
    bool m_legacyHostDemoWindowVisible = false;
    ::XCEngine::Editor::XCUIBackend::XCUILayoutLabRuntime m_nativeOverlayRuntime;
    MainWindowNativeBackdropRenderer m_nativeBackdropRenderer;
    bool m_running = false;
    bool m_renderReady = false;
    std::chrono::steady_clock::time_point m_startTime = {};
};

} // namespace NewEditor
} // namespace XCEngine