#include "Platform/Win32/EditorWindowRuntimeController.h"

#include "Bootstrap/EditorResources.h"
#include "Composition/EditorContext.h"
#include "Platform/Win32/EditorWindowSupport.h"
#include "Support/EmbeddedPngLoader.h"

#include <algorithm>
#include <chrono>
#include <cstdio>
#include <cmath>
#include <utility>

namespace XCEngine::UI::Editor::App {

using App::LoadEmbeddedPngTexture;
using namespace EditorWindowSupport;

namespace {

constexpr float kFrameTimeSmoothingFactor = 0.12f;
constexpr float kFrameStatsDisplayRefreshIntervalSeconds = 0.25f;

}

EditorWindowRuntimeController::EditorWindowRuntimeController(
    UIEditorWorkspaceController workspaceController)
    : m_workspaceController(std::move(workspaceController)) {
}

EditorWindowRuntimeController::~EditorWindowRuntimeController() = default;

bool EditorWindowRuntimeController::IsReady() const {
    return m_ready;
}

const UIEditorWorkspaceController& EditorWindowRuntimeController::GetWorkspaceController() const {
    return m_workspaceController;
}

UIEditorWorkspaceController& EditorWindowRuntimeController::GetMutableWorkspaceController() {
    return m_workspaceController;
}

void EditorWindowRuntimeController::ReplaceWorkspaceController(
    UIEditorWorkspaceController workspaceController) {
    m_workspaceController = std::move(workspaceController);
}

const EditorShellRuntime& EditorWindowRuntimeController::GetShellRuntime() const {
    return m_shellRuntime;
}

EditorShellRuntime& EditorWindowRuntimeController::GetShellRuntime() {
    return m_shellRuntime;
}

const UIEditorShellInteractionFrame& EditorWindowRuntimeController::GetShellFrame() const {
    return m_shellRuntime.GetShellFrame();
}

const UIEditorShellInteractionState& EditorWindowRuntimeController::GetShellInteractionState()
    const {
    return m_shellRuntime.GetShellInteractionState();
}

void EditorWindowRuntimeController::SetExternalDockHostDropPreview(
    const Widgets::UIEditorDockHostDropPreviewState& preview) {
    m_shellRuntime.SetExternalDockHostDropPreview(preview);
}

void EditorWindowRuntimeController::ClearExternalDockHostDropPreview() {
    m_shellRuntime.ClearExternalDockHostDropPreview();
}

void EditorWindowRuntimeController::SetDpiScale(float dpiScale) {
    m_dpiScale = dpiScale > 0.0f ? dpiScale : 1.0f;
    m_renderer.SetDpiScale(dpiScale);
    m_textSystem.SetDpiScale(m_dpiScale);
    m_uiRenderer.SetDpiScale(m_dpiScale);
}

::XCEngine::UI::Editor::UIEditorTextMeasurer& EditorWindowRuntimeController::GetTextMeasurer() {
    return m_textSystem;
}

const ::XCEngine::UI::Editor::UIEditorTextMeasurer&
EditorWindowRuntimeController::GetTextMeasurer() const {
    return m_textSystem;
}

const ::XCEngine::UI::UITextureHandle& EditorWindowRuntimeController::GetTitleBarLogoIcon() const {
    return m_titleBarLogoIcon;
}

bool EditorWindowRuntimeController::Initialize(
    HWND hwnd,
    const std::filesystem::path& repoRoot,
    EditorContext& editorContext,
    const std::filesystem::path& captureRoot,
    bool autoCaptureOnStartup) {
    if (hwnd == nullptr) {
        LogRuntimeTrace("app", "window initialize skipped: hwnd is null");
        return false;
    }

    RECT clientRect = {};
    GetClientRect(hwnd, &clientRect);
    const int clientWidth = (std::max)(clientRect.right - clientRect.left, 1L);
    const int clientHeight = (std::max)(clientRect.bottom - clientRect.top, 1L);
    if (!m_windowRenderer.Initialize(hwnd, clientWidth, clientHeight)) {
        LogRuntimeTrace("app", "d3d12 window renderer initialization failed");
        return false;
    }

    if (!m_textureHost.Initialize(m_windowRenderer)) {
        LogRuntimeTrace("app", "d3d12 ui texture host initialization failed");
        m_windowRenderer.Shutdown();
        return false;
    }

    if (!m_textSystem.Initialize()) {
        LogRuntimeTrace("app", "d3d12 ui text system initialization failed");
        m_textureHost.Shutdown();
        m_windowRenderer.Shutdown();
        return false;
    }
    m_textSystem.SetDpiScale(m_dpiScale);

    if (!m_uiRenderer.Initialize(m_windowRenderer, m_textureHost, m_textSystem)) {
        LogRuntimeTrace("app", "d3d12 ui renderer initialization failed");
        m_textSystem.Shutdown();
        m_textureHost.Shutdown();
        m_windowRenderer.Shutdown();
        return false;
    }
    m_uiRenderer.SetDpiScale(m_dpiScale);

    const Host::D3D12WindowRenderLoopAttachResult attachResult =
        m_windowRenderLoop.Attach(m_uiRenderer, m_windowRenderer);
    if (!attachResult.warning.empty()) {
        LogRuntimeTrace("app", attachResult.warning);
    }

    editorContext.AttachTextMeasurer(m_textSystem);
    m_shellRuntime.Initialize(repoRoot, m_textureHost, m_textSystem);
    m_shellRuntime.AttachViewportWindowRenderer(m_windowRenderer);
    m_shellRuntime.SetViewportSurfacePresentationEnabled(
        attachResult.hasViewportSurfacePresentation);

    std::string titleBarLogoError = {};
    if (!LoadEmbeddedPngTexture(
            m_textureHost,
            IDR_PNG_LOGO_ICON,
            m_titleBarLogoIcon,
            titleBarLogoError)) {
        LogRuntimeTrace("icons", "titlebar logo_icon.png: " + titleBarLogoError);
    }
    if (!m_shellRuntime.GetBuiltInIconError().empty()) {
        LogRuntimeTrace("icons", m_shellRuntime.GetBuiltInIconError());
    }

    LogRuntimeTrace(
        "app",
        "shell runtime initialized: " +
            editorContext.DescribeWorkspaceState(
                m_workspaceController,
                m_shellRuntime.GetShellInteractionState()));
    ResetFrameTiming();
    m_ready = true;

    m_autoScreenshot.Initialize(captureRoot);
    if (autoCaptureOnStartup && IsAutoCaptureOnStartupEnabled()) {
        m_autoScreenshot.RequestCapture("startup");
        editorContext.SetStatus("Capture", "Startup capture requested.");
    }

    return true;
}

void EditorWindowRuntimeController::Shutdown() {
    m_ready = false;
    ResetFrameTiming();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=WaitForGpuIdle");
    m_windowRenderer.WaitForGpuIdle();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=AutoScreenshot");
    m_autoScreenshot.Shutdown();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=ShellRuntime");
    m_shellRuntime.Shutdown();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=RenderLoopDetach");
    m_windowRenderLoop.Detach();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=UiRenderer");
    m_uiRenderer.Shutdown();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=TextSystem");
    m_textSystem.Shutdown();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=TitleBarLogo");
    m_textureHost.ReleaseTexture(m_titleBarLogoIcon);
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=TextureHost");
    m_textureHost.Shutdown();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=WindowRenderer");
    m_windowRenderer.Shutdown();
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown stage=NativeRenderer");
    m_renderer.Shutdown();
    m_dpiScale = 1.0f;
    LogRuntimeTrace("window-close", "EditorWindowRuntimeController::Shutdown end");
}

void EditorWindowRuntimeController::ResetInteractionState() {
    m_shellRuntime.ResetInteractionState();
    ResetFrameTiming();
}

bool EditorWindowRuntimeController::ApplyResize(UINT width, UINT height) {
    if (!m_ready || width == 0u || height == 0u) {
        return false;
    }

    const Host::D3D12WindowRenderLoopResizeResult resizeResult =
        m_windowRenderLoop.ApplyResize(width, height);
    m_shellRuntime.SetViewportSurfacePresentationEnabled(
        resizeResult.hasViewportSurfacePresentation);

    if (!resizeResult.windowRendererWarning.empty()) {
        LogRuntimeTrace("present", resizeResult.windowRendererWarning);
    }

    return resizeResult.hasViewportSurfacePresentation;
}

Host::D3D12WindowRenderLoopFrameContext EditorWindowRuntimeController::BeginFrame() {
    UpdateFrameTiming();
    return m_windowRenderLoop.BeginFrame();
}

Host::D3D12WindowRenderLoopPresentResult EditorWindowRuntimeController::Present(
    const ::XCEngine::UI::UIDrawData& drawData) const {
    return m_windowRenderLoop.Present(drawData);
}

void EditorWindowRuntimeController::CaptureIfRequested(
    const ::XCEngine::UI::UIDrawData& drawData,
    UINT pixelWidth,
    UINT pixelHeight,
    bool framePresented) {
    m_autoScreenshot.CaptureIfRequested(
        m_renderer,
        m_windowRenderer,
        drawData,
        pixelWidth,
        pixelHeight,
        framePresented);
}

void EditorWindowRuntimeController::RequestManualScreenshot(std::string reason) {
    m_autoScreenshot.RequestCapture(std::move(reason));
}

std::string EditorWindowRuntimeController::BuildCaptureStatusText() const {
    if (m_autoScreenshot.HasPendingCapture()) {
        return "Shot pending...";
    }

    if (!m_autoScreenshot.GetLastCaptureError().empty()) {
        return TruncateText(m_autoScreenshot.GetLastCaptureError(), 38u);
    }

    if (!m_autoScreenshot.GetLastCaptureSummary().empty()) {
        return TruncateText(m_autoScreenshot.GetLastCaptureSummary(), 38u);
    }

    return {};
}

std::string EditorWindowRuntimeController::BuildFrameRateText() const {
    return m_frameRateText;
}

void EditorWindowRuntimeController::ResetFrameTiming() {
    m_lastFrameTime = {};
    m_hasLastFrameTime = false;
    m_smoothedDeltaTimeSeconds = 0.0f;
    m_frameStatsDisplayAccumulatorSeconds = 0.0f;
    m_displayFps = 0.0f;
    m_displayFrameTimeMs = 0.0f;
    m_frameRateText.clear();
}

void EditorWindowRuntimeController::UpdateFrameTiming() {
    const auto now = std::chrono::steady_clock::now();
    if (!m_hasLastFrameTime) {
        m_lastFrameTime = now;
        m_hasLastFrameTime = true;
        return;
    }

    const float deltaTime = std::chrono::duration<float>(now - m_lastFrameTime).count();
    m_lastFrameTime = now;
    if (deltaTime <= 0.0f) {
        return;
    }

    if (m_smoothedDeltaTimeSeconds <= 0.0f) {
        m_smoothedDeltaTimeSeconds = deltaTime;
    } else {
        m_smoothedDeltaTimeSeconds +=
            (deltaTime - m_smoothedDeltaTimeSeconds) * kFrameTimeSmoothingFactor;
    }

    m_displayFrameTimeMs = m_smoothedDeltaTimeSeconds * 1000.0f;
    m_displayFps = m_smoothedDeltaTimeSeconds > 0.0f
        ? 1.0f / m_smoothedDeltaTimeSeconds
        : 0.0f;

    m_frameStatsDisplayAccumulatorSeconds += deltaTime;
    if (m_frameRateText.empty() ||
        m_frameStatsDisplayAccumulatorSeconds >= kFrameStatsDisplayRefreshIntervalSeconds) {
        RefreshDisplayedFrameStats();
        m_frameStatsDisplayAccumulatorSeconds = 0.0f;
    }
}

void EditorWindowRuntimeController::RefreshDisplayedFrameStats() {
    if (m_displayFps <= 0.0f || m_displayFrameTimeMs <= 0.0f) {
        m_frameRateText.clear();
        return;
    }

    const int roundedFps = (std::max)(0, static_cast<int>(std::lround(m_displayFps)));
    const int roundedFrameTimeMs =
        (std::max)(0, static_cast<int>(std::lround(m_displayFrameTimeMs)));

    char buffer[48] = {};
    std::snprintf(
        buffer,
        sizeof(buffer),
        "FPS %3d | %2d ms",
        roundedFps,
        roundedFrameTimeMs);
    m_frameRateText = buffer;
}

} // namespace XCEngine::UI::Editor::App