#include "ProductProjectPanel.h"

#include "Icons/ProductBuiltInIcons.h"
#include "Panels/ProductTreeViewStyle.h"

#include <XCEditor/Collections/UIEditorTreeView.h>
#include <XCEditor/Foundation/UIEditorTheme.h>

#include <algorithm>
#include <cmath>
#include <cstdint>
#include <string_view>
#include <utility>

#include <windows.h>

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

namespace {

using ::XCEngine::UI::Editor::UIEditorTextMeasureRequest;
using ::XCEngine::UI::Editor::UIEditorTextMeasurer;
using ::XCEngine::UI::UIColor;
using ::XCEngine::UI::UIDrawList;
using ::XCEngine::UI::UIInputEvent;
using ::XCEngine::UI::UIInputEventType;
using ::XCEngine::UI::UIPoint;
using ::XCEngine::UI::UIRect;
using Widgets::AppendUIEditorTreeViewBackground;
using Widgets::AppendUIEditorTreeViewForeground;

constexpr std::string_view kProjectPanelId = "project";
constexpr std::size_t kInvalidLayoutIndex = static_cast<std::size_t>(-1);

constexpr float kBrowserHeaderHeight = 24.0f;
constexpr float kNavigationMinWidth = 180.0f;
constexpr float kBrowserMinWidth = 260.0f;
constexpr float kHeaderHorizontalPadding = 10.0f;
constexpr float kHeaderBottomBorderThickness = 1.0f;
constexpr float kBreadcrumbItemPaddingX = 4.0f;
constexpr float kBreadcrumbItemPaddingY = 1.0f;
constexpr float kBreadcrumbSpacing = 3.0f;
constexpr float kTreeTopPadding = 0.0f;
constexpr float kGridInsetX = 16.0f;
constexpr float kGridInsetY = 12.0f;
constexpr float kGridTileWidth = 92.0f;
constexpr float kGridTileHeight = 92.0f;
constexpr float kGridTileGapX = 12.0f;
constexpr float kGridTileGapY = 12.0f;
constexpr float kGridPreviewWidth = 68.0f;
constexpr float kGridPreviewHeight = 54.0f;
constexpr float kHeaderFontSize = 12.0f;
constexpr float kTileLabelFontSize = 11.0f;

constexpr UIColor kSurfaceColor(0.200f, 0.200f, 0.200f, 1.0f);
constexpr UIColor kPaneColor(0.205f, 0.205f, 0.205f, 1.0f);
constexpr UIColor kHeaderColor(0.215f, 0.215f, 0.215f, 1.0f);
constexpr UIColor kTextPrimary(0.830f, 0.830f, 0.830f, 1.0f);
constexpr UIColor kTextStrong(0.910f, 0.910f, 0.910f, 1.0f);
constexpr UIColor kTextMuted(0.560f, 0.560f, 0.560f, 1.0f);
constexpr UIColor kTileHoverColor(0.245f, 0.245f, 0.245f, 1.0f);
constexpr UIColor kTileSelectedColor(0.300f, 0.300f, 0.300f, 1.0f);
constexpr UIColor kTilePreviewFillColor(0.700f, 0.700f, 0.700f, 1.0f);
constexpr UIColor kTilePreviewShadeColor(0.610f, 0.610f, 0.610f, 1.0f);
constexpr UIColor kTilePreviewOutlineColor(0.860f, 0.860f, 0.860f, 0.35f);

bool ContainsPoint(const UIRect& rect, const UIPoint& point) {
    return point.x >= rect.x &&
        point.x <= rect.x + rect.width &&
        point.y >= rect.y &&
        point.y <= rect.y + rect.height;
}

float ClampNonNegative(float value) {
    return (std::max)(value, 0.0f);
}

float ResolveTextTop(float rectY, float rectHeight, float fontSize) {
    const float lineHeight = fontSize * 1.6f;
    return rectY + std::floor((rectHeight - lineHeight) * 0.5f);
}

float MeasureTextWidth(
    const UIEditorTextMeasurer* textMeasurer,
    std::string_view text,
    float fontSize) {
    if (text.empty()) {
        return 0.0f;
    }

    if (textMeasurer != nullptr) {
        const float measuredWidth =
            textMeasurer->MeasureTextWidth(UIEditorTextMeasureRequest{ text, fontSize });
        if (measuredWidth > 0.0f) {
            return measuredWidth;
        }
    }

    return static_cast<float>(text.size()) * fontSize * 0.56f;
}

std::vector<UIInputEvent> FilterProjectPanelInputEvents(
    const UIRect& bounds,
    const std::vector<UIInputEvent>& inputEvents,
    bool allowInteraction,
    bool panelActive,
    bool captureActive) {
    if (!allowInteraction && !captureActive) {
        return {};
    }

    std::vector<UIInputEvent> filteredEvents = {};
    filteredEvents.reserve(inputEvents.size());
    for (const UIInputEvent& event : inputEvents) {
        switch (event.type) {
        case UIInputEventType::PointerMove:
        case UIInputEventType::PointerButtonDown:
        case UIInputEventType::PointerButtonUp:
        case UIInputEventType::PointerWheel:
            if (captureActive || ContainsPoint(bounds, event.position)) {
                filteredEvents.push_back(event);
            }
            break;
        case UIInputEventType::PointerLeave:
            filteredEvents.push_back(event);
            break;
        case UIInputEventType::FocusGained:
        case UIInputEventType::FocusLost:
            if (panelActive || captureActive) {
                filteredEvents.push_back(event);
            }
            break;
        case UIInputEventType::KeyDown:
        case UIInputEventType::KeyUp:
        case UIInputEventType::Character:
            if (panelActive) {
                filteredEvents.push_back(event);
            }
            break;
        default:
            break;
        }
    }

    return filteredEvents;
}

std::vector<UIInputEvent> FilterTreeInputEvents(
    const std::vector<UIInputEvent>& inputEvents,
    bool suppressPointerInput) {
    if (!suppressPointerInput) {
        return inputEvents;
    }

    std::vector<UIInputEvent> filteredEvents = {};
    filteredEvents.reserve(inputEvents.size());
    for (const UIInputEvent& event : inputEvents) {
        switch (event.type) {
        case UIInputEventType::PointerMove:
        case UIInputEventType::PointerButtonDown:
        case UIInputEventType::PointerButtonUp:
        case UIInputEventType::PointerWheel:
        case UIInputEventType::PointerEnter:
            break;
        default:
            filteredEvents.push_back(event);
            break;
        }
    }
    return filteredEvents;
}

::XCEngine::UI::UITextureHandle ResolveFolderIcon(const ProductBuiltInIcons* icons) {
    return icons != nullptr
        ? icons->Resolve(ProductBuiltInIconKind::Folder)
        : ::XCEngine::UI::UITextureHandle {};
}

float ClampNavigationWidth(float value, float totalWidth) {
    const float maxWidth =
        (std::max)(
            kNavigationMinWidth,
            totalWidth - kBrowserMinWidth - ResolveUIEditorDockHostMetrics().splitterMetrics.thickness);
    return std::clamp(value, kNavigationMinWidth, maxWidth);
}

void AppendTilePreview(
    UIDrawList& drawList,
    const UIRect& previewRect,
    bool directory) {
    if (directory) {
        const UIRect tabRect(
            previewRect.x + 8.0f,
            previewRect.y + 7.0f,
            22.0f,
            7.0f);
        const UIRect bodyRect(
            previewRect.x + 4.0f,
            previewRect.y + 13.0f,
            previewRect.width - 8.0f,
            previewRect.height - 18.0f);
        drawList.AddFilledRect(tabRect, kTilePreviewShadeColor, 1.0f);
        drawList.AddFilledRect(bodyRect, kTilePreviewFillColor, 1.0f);
        drawList.AddRectOutline(bodyRect, kTilePreviewOutlineColor, 1.0f, 1.0f);
        return;
    }

    const UIRect sheetRect(
        previewRect.x + 10.0f,
        previewRect.y + 4.0f,
        previewRect.width - 20.0f,
        previewRect.height - 8.0f);
    const UIRect accentRect(
        sheetRect.x,
        sheetRect.y,
        sheetRect.width,
        7.0f);
    drawList.AddFilledRect(sheetRect, kTilePreviewFillColor, 1.0f);
    drawList.AddFilledRect(accentRect, kTilePreviewShadeColor, 1.0f);
    drawList.AddRectOutline(sheetRect, kTilePreviewOutlineColor, 1.0f, 1.0f);
}

} // namespace

void ProductProjectPanel::Initialize(const std::filesystem::path& repoRoot) {
    m_browserModel.Initialize(repoRoot);
    SyncCurrentFolderSelection();
}

void ProductProjectPanel::SetBuiltInIcons(const ProductBuiltInIcons* icons) {
    m_icons = icons;
    m_browserModel.SetFolderIcon(ResolveFolderIcon(m_icons));
    SyncCurrentFolderSelection();
}

void ProductProjectPanel::SetTextMeasurer(const UIEditorTextMeasurer* textMeasurer) {
    m_textMeasurer = textMeasurer;
}

ProductProjectPanel::CursorKind ProductProjectPanel::GetCursorKind() const {
    return (m_splitterHovered || m_splitterDragging) ? CursorKind::ResizeEW : CursorKind::Arrow;
}

bool ProductProjectPanel::WantsHostPointerCapture() const {
    return m_requestPointerCapture;
}

bool ProductProjectPanel::WantsHostPointerRelease() const {
    return m_requestPointerRelease;
}

bool ProductProjectPanel::HasActivePointerCapture() const {
    return m_splitterDragging;
}

const std::vector<ProductProjectPanel::Event>& ProductProjectPanel::GetFrameEvents() const {
    return m_frameEvents;
}

const ProductProjectPanel::FolderEntry* ProductProjectPanel::FindFolderEntry(
    std::string_view itemId) const {
    return m_browserModel.FindFolderEntry(itemId);
}

const ProductProjectPanel::AssetEntry* ProductProjectPanel::FindAssetEntry(
    std::string_view itemId) const {
    return m_browserModel.FindAssetEntry(itemId);
}

const UIEditorPanelContentHostPanelState* ProductProjectPanel::FindMountedProjectPanel(
    const UIEditorPanelContentHostFrame& contentHostFrame) const {
    for (const UIEditorPanelContentHostPanelState& panelState : contentHostFrame.panelStates) {
        if (panelState.panelId == kProjectPanelId && panelState.mounted) {
            return &panelState;
        }
    }

    return nullptr;
}

ProductProjectPanel::Layout ProductProjectPanel::BuildLayout(const UIRect& bounds) const {
    Layout layout = {};
    const auto& assetEntries = m_browserModel.GetAssetEntries();
    const std::vector<ProductProjectPanel::BrowserModel::BreadcrumbSegment> breadcrumbSegments =
        m_browserModel.BuildBreadcrumbSegments();
    const float dividerThickness = ResolveUIEditorDockHostMetrics().splitterMetrics.thickness;
    layout.bounds = UIRect(
        bounds.x,
        bounds.y,
        ClampNonNegative(bounds.width),
        ClampNonNegative(bounds.height));

    const float leftWidth = ClampNavigationWidth(m_navigationWidth, layout.bounds.width);
    layout.leftPaneRect = UIRect(
        layout.bounds.x,
        layout.bounds.y,
        leftWidth,
        layout.bounds.height);
    layout.dividerRect = UIRect(
        layout.leftPaneRect.x + layout.leftPaneRect.width,
        layout.bounds.y,
        dividerThickness,
        layout.bounds.height);
    layout.rightPaneRect = UIRect(
        layout.dividerRect.x + layout.dividerRect.width,
        layout.bounds.y,
        ClampNonNegative(layout.bounds.width - layout.leftPaneRect.width - layout.dividerRect.width),
        layout.bounds.height);

    layout.treeRect = UIRect(
        layout.leftPaneRect.x,
        layout.leftPaneRect.y + kTreeTopPadding,
        layout.leftPaneRect.width,
        ClampNonNegative(layout.leftPaneRect.height - kTreeTopPadding));

    layout.browserHeaderRect = UIRect(
        layout.rightPaneRect.x,
        layout.rightPaneRect.y,
        layout.rightPaneRect.width,
        (std::min)(kBrowserHeaderHeight, layout.rightPaneRect.height));
    layout.browserBodyRect = UIRect(
        layout.rightPaneRect.x,
        layout.browserHeaderRect.y + layout.browserHeaderRect.height,
        layout.rightPaneRect.width,
        ClampNonNegative(layout.rightPaneRect.height - layout.browserHeaderRect.height));
    layout.gridRect = UIRect(
        layout.browserBodyRect.x + kGridInsetX,
        layout.browserBodyRect.y + kGridInsetY,
        ClampNonNegative(layout.browserBodyRect.width - kGridInsetX * 2.0f),
        ClampNonNegative(layout.browserBodyRect.height - kGridInsetY * 2.0f));

    const float breadcrumbRowHeight = kHeaderFontSize + kBreadcrumbItemPaddingY * 2.0f;
    const float breadcrumbY =
        layout.browserHeaderRect.y + std::floor((layout.browserHeaderRect.height - breadcrumbRowHeight) * 0.5f);
    const float headerRight =
        layout.browserHeaderRect.x + layout.browserHeaderRect.width - kHeaderHorizontalPadding;
    float nextItemX = layout.browserHeaderRect.x + kHeaderHorizontalPadding;
    for (std::size_t index = 0u; index < breadcrumbSegments.size(); ++index) {
        if (index > 0u) {
            const float separatorWidth =
                MeasureTextWidth(m_textMeasurer, ">", kHeaderFontSize);
            if (nextItemX < headerRight && separatorWidth > 0.0f) {
                layout.breadcrumbItems.push_back({
                    ">",
                    {},
                    UIRect(
                        nextItemX,
                        breadcrumbY,
                        ClampNonNegative((std::min)(separatorWidth, headerRight - nextItemX)),
                        breadcrumbRowHeight),
                    true,
                    false,
                    false
                });
            }
            nextItemX += separatorWidth + kBreadcrumbSpacing;
        }

        const ProductProjectPanel::BrowserModel::BreadcrumbSegment& segment = breadcrumbSegments[index];
        const float labelWidth =
            MeasureTextWidth(m_textMeasurer, segment.label, kHeaderFontSize);
        const float itemWidth = labelWidth + kBreadcrumbItemPaddingX * 2.0f;
        const float availableWidth = headerRight - nextItemX;
        if (availableWidth <= 0.0f) {
            break;
        }

        layout.breadcrumbItems.push_back({
            segment.label,
            segment.targetFolderId,
            UIRect(
                nextItemX,
                breadcrumbY,
                ClampNonNegative((std::min)(itemWidth, availableWidth)),
                breadcrumbRowHeight),
            false,
            !segment.current,
            segment.current
        });
        nextItemX += itemWidth + kBreadcrumbSpacing;
    }

    const float effectiveTileWidth = kGridTileWidth + kGridTileGapX;
    int columnCount = effectiveTileWidth > 0.0f
        ? static_cast<int>((layout.gridRect.width + kGridTileGapX) / effectiveTileWidth)
        : 1;
    if (columnCount < 1) {
        columnCount = 1;
    }

    layout.assetTiles.reserve(assetEntries.size());
    for (std::size_t index = 0; index < assetEntries.size(); ++index) {
        const int column = static_cast<int>(index % static_cast<std::size_t>(columnCount));
        const int row = static_cast<int>(index / static_cast<std::size_t>(columnCount));
        const float tileX = layout.gridRect.x + static_cast<float>(column) * (kGridTileWidth + kGridTileGapX);
        const float tileY = layout.gridRect.y + static_cast<float>(row) * (kGridTileHeight + kGridTileGapY);

        AssetTileLayout tile = {};
        tile.itemIndex = index;
        tile.tileRect = UIRect(tileX, tileY, kGridTileWidth, kGridTileHeight);
        tile.previewRect = UIRect(
            tile.tileRect.x + (tile.tileRect.width - kGridPreviewWidth) * 0.5f,
            tile.tileRect.y + 6.0f,
            kGridPreviewWidth,
            kGridPreviewHeight);
        tile.labelRect = UIRect(
            tile.tileRect.x + 4.0f,
            tile.previewRect.y + tile.previewRect.height + 8.0f,
            tile.tileRect.width - 8.0f,
            18.0f);
        layout.assetTiles.push_back(tile);
    }

    return layout;
}

std::size_t ProductProjectPanel::HitTestBreadcrumbItem(const UIPoint& point) const {
    for (std::size_t index = 0u; index < m_layout.breadcrumbItems.size(); ++index) {
        const BreadcrumbItemLayout& item = m_layout.breadcrumbItems[index];
        if (!item.separator && ContainsPoint(item.rect, point)) {
            return index;
        }
    }

    return kInvalidLayoutIndex;
}

std::size_t ProductProjectPanel::HitTestAssetTile(const UIPoint& point) const {
    for (const AssetTileLayout& tile : m_layout.assetTiles) {
        if (ContainsPoint(tile.tileRect, point)) {
            return tile.itemIndex;
        }
    }

    return kInvalidLayoutIndex;
}

void ProductProjectPanel::SyncCurrentFolderSelection() {
    const std::string& currentFolderId = m_browserModel.GetCurrentFolderId();
    if (currentFolderId.empty()) {
        m_folderSelection.ClearSelection();
        return;
    }

    const std::vector<std::string> ancestorFolderIds =
        m_browserModel.CollectCurrentFolderAncestorIds();
    for (const std::string& ancestorFolderId : ancestorFolderIds) {
        m_folderExpansion.Expand(ancestorFolderId);
    }
    m_folderSelection.SetSelection(currentFolderId);
}

bool ProductProjectPanel::NavigateToFolder(std::string_view itemId, EventSource source) {
    if (!m_browserModel.NavigateToFolder(itemId)) {
        return false;
    }

    SyncCurrentFolderSelection();
    m_assetSelection.ClearSelection();
    m_hoveredAssetItemId.clear();
    m_lastPrimaryClickedAssetId.clear();
    EmitEvent(EventKind::FolderNavigated, source, FindFolderEntry(m_browserModel.GetCurrentFolderId()));
    return true;
}

void ProductProjectPanel::EmitEvent(
    EventKind kind,
    EventSource source,
    const FolderEntry* folder) {
    if (kind == EventKind::None || folder == nullptr) {
        return;
    }

    Event event = {};
    event.kind = kind;
    event.source = source;
    event.itemId = folder->itemId;
    event.absolutePath = folder->absolutePath;
    event.displayName = folder->label;
    event.directory = true;
    m_frameEvents.push_back(std::move(event));
}

void ProductProjectPanel::EmitEvent(
    EventKind kind,
    EventSource source,
    const AssetEntry* asset) {
    if (kind == EventKind::None) {
        return;
    }

    Event event = {};
    event.kind = kind;
    event.source = source;
    if (asset != nullptr) {
        event.itemId = asset->itemId;
        event.absolutePath = asset->absolutePath;
        event.displayName = asset->displayName;
        event.directory = asset->directory;
    }
    m_frameEvents.push_back(std::move(event));
}

void ProductProjectPanel::EmitSelectionClearedEvent(EventSource source) {
    Event event = {};
    event.kind = EventKind::AssetSelectionCleared;
    event.source = source;
    m_frameEvents.push_back(std::move(event));
}

void ProductProjectPanel::ResetTransientFrames() {
    m_treeFrame = {};
    m_frameEvents.clear();
    m_layout = {};
    m_hoveredAssetItemId.clear();
    m_hoveredBreadcrumbIndex = kInvalidLayoutIndex;
    m_pressedBreadcrumbIndex = kInvalidLayoutIndex;
    m_splitterHovered = false;
    m_splitterDragging = false;
}

void ProductProjectPanel::Update(
    const UIEditorPanelContentHostFrame& contentHostFrame,
    const std::vector<UIInputEvent>& inputEvents,
    bool allowInteraction,
    bool panelActive) {
    m_requestPointerCapture = false;
    m_requestPointerRelease = false;
    m_frameEvents.clear();

    const UIEditorPanelContentHostPanelState* panelState =
        FindMountedProjectPanel(contentHostFrame);
    if (panelState == nullptr) {
        if (m_splitterDragging) {
            m_requestPointerRelease = true;
        }
        m_visible = false;
        ResetTransientFrames();
        return;
    }

    if (m_browserModel.GetTreeItems().empty()) {
        m_browserModel.Refresh();
        SyncCurrentFolderSelection();
    }

    m_visible = true;
    const std::vector<UIInputEvent> filteredEvents =
        FilterProjectPanelInputEvents(
            panelState->bounds,
            inputEvents,
            allowInteraction,
            panelActive,
            m_splitterDragging);

    m_navigationWidth = ClampNavigationWidth(m_navigationWidth, panelState->bounds.width);
    m_layout = BuildLayout(panelState->bounds);
    const Widgets::UIEditorTreeViewMetrics treeMetrics = BuildProductTreeViewMetrics();
    const std::vector<UIInputEvent> treeEvents =
        FilterTreeInputEvents(filteredEvents, m_splitterDragging);
    m_treeFrame = UpdateUIEditorTreeViewInteraction(
        m_treeInteractionState,
        m_folderSelection,
        m_folderExpansion,
        m_layout.treeRect,
        m_browserModel.GetTreeItems(),
        treeEvents,
        treeMetrics);

    if (m_treeFrame.result.selectionChanged &&
        !m_treeFrame.result.selectedItemId.empty() &&
        m_treeFrame.result.selectedItemId != m_browserModel.GetCurrentFolderId()) {
        NavigateToFolder(m_treeFrame.result.selectedItemId, EventSource::Tree);
        m_layout = BuildLayout(panelState->bounds);
    }

    for (const UIInputEvent& event : filteredEvents) {
        switch (event.type) {
        case UIInputEventType::FocusLost:
            m_hoveredAssetItemId.clear();
            m_hoveredBreadcrumbIndex = kInvalidLayoutIndex;
            m_pressedBreadcrumbIndex = kInvalidLayoutIndex;
            m_splitterHovered = false;
            if (m_splitterDragging) {
                m_splitterDragging = false;
                m_requestPointerRelease = true;
            }
            break;

        case UIInputEventType::PointerMove: {
            if (m_splitterDragging) {
                m_navigationWidth =
                    ClampNavigationWidth(event.position.x - panelState->bounds.x, panelState->bounds.width);
                m_layout = BuildLayout(panelState->bounds);
            }

            m_splitterHovered =
                m_splitterDragging || ContainsPoint(m_layout.dividerRect, event.position);
            m_hoveredBreadcrumbIndex = HitTestBreadcrumbItem(event.position);
            const std::size_t hoveredAssetIndex = HitTestAssetTile(event.position);
            const auto& assetEntries = m_browserModel.GetAssetEntries();
            m_hoveredAssetItemId =
                hoveredAssetIndex < assetEntries.size()
                    ? assetEntries[hoveredAssetIndex].itemId
                    : std::string();
            break;
        }

        case UIInputEventType::PointerLeave:
            if (!m_splitterDragging) {
                m_splitterHovered = false;
            }
            m_hoveredBreadcrumbIndex = kInvalidLayoutIndex;
            m_hoveredAssetItemId.clear();
            break;

        case UIInputEventType::PointerButtonDown:
            if (event.pointerButton == ::XCEngine::UI::UIPointerButton::Left) {
                if (ContainsPoint(m_layout.dividerRect, event.position)) {
                    m_splitterDragging = true;
                    m_splitterHovered = true;
                    m_pressedBreadcrumbIndex = kInvalidLayoutIndex;
                    m_requestPointerCapture = true;
                    break;
                }

                m_pressedBreadcrumbIndex = HitTestBreadcrumbItem(event.position);

                if (!ContainsPoint(m_layout.gridRect, event.position)) {
                    break;
                }

                const auto& assetEntries = m_browserModel.GetAssetEntries();
                const std::size_t hitIndex = HitTestAssetTile(event.position);
                if (hitIndex >= assetEntries.size()) {
                    if (m_assetSelection.HasSelection()) {
                        m_assetSelection.ClearSelection();
                        EmitSelectionClearedEvent(EventSource::Background);
                    }
                    break;
                }

                const AssetEntry& assetEntry = assetEntries[hitIndex];
                const bool alreadySelected = m_assetSelection.IsSelected(assetEntry.itemId);
                const bool selectionChanged = m_assetSelection.SetSelection(assetEntry.itemId);
                if (selectionChanged) {
                    EmitEvent(EventKind::AssetSelected, EventSource::GridPrimary, &assetEntry);
                }

                const std::uint64_t nowMs = GetTickCount64();
                const std::uint64_t doubleClickThresholdMs =
                    static_cast<std::uint64_t>(GetDoubleClickTime());
                const bool doubleClicked =
                    alreadySelected &&
                    m_lastPrimaryClickedAssetId == assetEntry.itemId &&
                    nowMs >= m_lastPrimaryClickTimeMs &&
                    nowMs - m_lastPrimaryClickTimeMs <= doubleClickThresholdMs;

                m_lastPrimaryClickedAssetId = assetEntry.itemId;
                m_lastPrimaryClickTimeMs = nowMs;
                if (!doubleClicked) {
                    break;
                }

                if (assetEntry.directory) {
                    NavigateToFolder(assetEntry.itemId, EventSource::GridDoubleClick);
                    m_layout = BuildLayout(panelState->bounds);
                    m_hoveredAssetItemId.clear();
                } else {
                    EmitEvent(EventKind::AssetOpened, EventSource::GridDoubleClick, &assetEntry);
                }
                break;
            }

            if (event.pointerButton == ::XCEngine::UI::UIPointerButton::Right &&
                ContainsPoint(m_layout.gridRect, event.position)) {
                const auto& assetEntries = m_browserModel.GetAssetEntries();
                const std::size_t hitIndex = HitTestAssetTile(event.position);
                if (hitIndex >= assetEntries.size()) {
                    EmitEvent(
                        EventKind::ContextMenuRequested,
                        EventSource::Background,
                        static_cast<const AssetEntry*>(nullptr));
                    break;
                }

                const AssetEntry& assetEntry = assetEntries[hitIndex];
                if (!m_assetSelection.IsSelected(assetEntry.itemId)) {
                    m_assetSelection.SetSelection(assetEntry.itemId);
                    EmitEvent(EventKind::AssetSelected, EventSource::GridSecondary, &assetEntry);
                }
                EmitEvent(EventKind::ContextMenuRequested, EventSource::GridSecondary, &assetEntry);
            }
            break;

        case UIInputEventType::PointerButtonUp:
            if (event.pointerButton != ::XCEngine::UI::UIPointerButton::Left) {
                break;
            }

            if (m_splitterDragging) {
                m_splitterDragging = false;
                m_splitterHovered = ContainsPoint(m_layout.dividerRect, event.position);
                m_requestPointerRelease = true;
                break;
            }

            {
                const std::size_t releasedBreadcrumbIndex =
                    HitTestBreadcrumbItem(event.position);
                if (m_pressedBreadcrumbIndex != kInvalidLayoutIndex &&
                    m_pressedBreadcrumbIndex == releasedBreadcrumbIndex &&
                    releasedBreadcrumbIndex < m_layout.breadcrumbItems.size()) {
                    const BreadcrumbItemLayout& item =
                        m_layout.breadcrumbItems[releasedBreadcrumbIndex];
                    if (item.clickable) {
                        NavigateToFolder(item.targetFolderId, EventSource::Breadcrumb);
                        m_layout = BuildLayout(panelState->bounds);
                    }
                }
                m_pressedBreadcrumbIndex = kInvalidLayoutIndex;
            }
            break;

        default:
            break;
        }
    }
}

void ProductProjectPanel::Append(UIDrawList& drawList) const {
    if (!m_visible || m_layout.bounds.width <= 0.0f || m_layout.bounds.height <= 0.0f) {
        return;
    }

    const auto& assetEntries = m_browserModel.GetAssetEntries();

    drawList.AddFilledRect(m_layout.bounds, kSurfaceColor);
    drawList.AddFilledRect(m_layout.leftPaneRect, kPaneColor);
    drawList.AddFilledRect(m_layout.rightPaneRect, kPaneColor);
    drawList.AddFilledRect(
        m_layout.dividerRect,
        ResolveUIEditorDockHostPalette().splitterColor);

    drawList.AddFilledRect(m_layout.browserHeaderRect, kHeaderColor);
    drawList.AddFilledRect(
        UIRect(
            m_layout.browserHeaderRect.x,
            m_layout.browserHeaderRect.y + m_layout.browserHeaderRect.height - kHeaderBottomBorderThickness,
            m_layout.browserHeaderRect.width,
            kHeaderBottomBorderThickness),
        ResolveUIEditorDockHostPalette().splitterColor);

    const Widgets::UIEditorTreeViewPalette treePalette = BuildProductTreeViewPalette();
    const Widgets::UIEditorTreeViewMetrics treeMetrics = BuildProductTreeViewMetrics();
    AppendUIEditorTreeViewBackground(
        drawList,
        m_treeFrame.layout,
        m_browserModel.GetTreeItems(),
        m_folderSelection,
        m_treeInteractionState.treeViewState,
        treePalette,
        treeMetrics);
    AppendUIEditorTreeViewForeground(
        drawList,
        m_treeFrame.layout,
        m_browserModel.GetTreeItems(),
        treePalette,
        treeMetrics);

    drawList.PushClipRect(m_layout.browserHeaderRect);
    for (std::size_t index = 0u; index < m_layout.breadcrumbItems.size(); ++index) {
        const BreadcrumbItemLayout& item = m_layout.breadcrumbItems[index];
        const UIColor textColor =
            item.separator
                ? kTextMuted
                : (index == m_hoveredBreadcrumbIndex && item.clickable
                    ? kTextStrong
                    : (item.current ? kTextPrimary : kTextMuted));
        const float textWidth = MeasureTextWidth(m_textMeasurer, item.label, kHeaderFontSize);
        const float textX = item.separator
            ? item.rect.x
            : item.rect.x + (item.rect.width - textWidth) * 0.5f;
        drawList.AddText(
            UIPoint(textX, ResolveTextTop(item.rect.y, item.rect.height, kHeaderFontSize)),
            item.label,
            textColor,
            kHeaderFontSize);
    }
    drawList.PopClipRect();

    for (const AssetTileLayout& tile : m_layout.assetTiles) {
        if (tile.itemIndex >= assetEntries.size()) {
            continue;
        }

        const AssetEntry& assetEntry = assetEntries[tile.itemIndex];
        const bool selected = m_assetSelection.IsSelected(assetEntry.itemId);
        const bool hovered = m_hoveredAssetItemId == assetEntry.itemId;

        if (selected || hovered) {
            drawList.AddFilledRect(
                tile.tileRect,
                selected ? kTileSelectedColor : kTileHoverColor);
        }

        AppendTilePreview(drawList, tile.previewRect, assetEntry.directory);

        drawList.PushClipRect(tile.labelRect);
        const float textWidth =
            MeasureTextWidth(m_textMeasurer, assetEntry.displayName, kTileLabelFontSize);
        drawList.AddText(
            UIPoint(
                tile.labelRect.x + (tile.labelRect.width - textWidth) * 0.5f,
                ResolveTextTop(tile.labelRect.y, tile.labelRect.height, kTileLabelFontSize)),
            assetEntry.displayName,
            kTextPrimary,
            kTileLabelFontSize);
        drawList.PopClipRect();
    }

    if (assetEntries.empty()) {
        const UIRect messageRect(
            m_layout.gridRect.x,
            m_layout.gridRect.y,
            m_layout.gridRect.width,
            18.0f);
        drawList.AddText(
            UIPoint(messageRect.x, ResolveTextTop(messageRect.y, messageRect.height, kHeaderFontSize)),
            "Current folder is empty.",
            kTextMuted,
            kHeaderFontSize);
    }
}

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