#include <XCEditor/Fields/UIEditorPropertyGridInteraction.h>

#include <XCEditor/Fields/UIEditorFieldStyle.h>
#include <XCEditor/Fields/UIEditorColorFieldInteraction.h>
#include <XCEditor/Menu/UIEditorMenuPopup.h>
#include <XCEditor/Fields/UIEditorNumberField.h>

#include <XCEngine/Input/InputTypes.h>
#include <XCEngine/UI/Widgets/UIPopupOverlayModel.h>

#include <algorithm>
#include <utility>

namespace XCEngine::UI::Editor {

namespace {

using ::XCEngine::Input::KeyCode;
using ::XCEngine::UI::Text::HandleKeyDown;
using ::XCEngine::UI::Text::InsertCharacter;
using ::XCEngine::UI::UIInputEvent;
using ::XCEngine::UI::UIInputEventType;
using ::XCEngine::UI::UIPointerButton;
using ::XCEngine::UI::UISize;
using ::XCEngine::UI::Editor::BuildUIEditorPropertyGridColorFieldMetrics;
using ::XCEngine::UI::Editor::UIEditorColorFieldInteractionFrame;
using ::XCEngine::UI::Editor::UIEditorColorFieldInteractionState;
using ::XCEngine::UI::Editor::UpdateUIEditorColorFieldInteraction;
using ::XCEngine::UI::Widgets::ResolvePopupPlacementRect;
using ::XCEngine::UI::Widgets::UIPopupPlacement;
using Widgets::BuildUIEditorPropertyGridLayout;
using Widgets::FindUIEditorPropertyGridFieldLocation;
using Widgets::FindUIEditorPropertyGridVisibleFieldIndex;
using Widgets::HitTestUIEditorPropertyGrid;
using Widgets::IsUIEditorPropertyGridPointInside;
using Widgets::ResolveUIEditorPropertyGridFieldValueText;
using Widgets::UIEditorPropertyGridField;
using Widgets::UIEditorPropertyGridFieldKind;
using Widgets::UIEditorPropertyGridHitTarget;
using Widgets::UIEditorPropertyGridHitTargetKind;
using Widgets::UIEditorPropertyGridInvalidIndex;
using Widgets::UIEditorPropertyGridLayout;
using Widgets::UIEditorPropertyGridSection;
using Widgets::UIEditorPropertyGridColorFieldVisualState;
using Widgets::UIEditorMenuPopupHitTarget;
using Widgets::UIEditorMenuPopupHitTargetKind;
using Widgets::UIEditorMenuPopupInvalidIndex;
using Widgets::UIEditorMenuPopupItem;
using Widgets::UIEditorMenuPopupLayout;
using Widgets::UIEditorColorFieldHitTargetKind;
using Widgets::UIEditorColorFieldSpec;
using ::XCEngine::UI::Editor::UIEditorMenuItemKind;

bool ShouldUsePointerPosition(const UIInputEvent& event) {
    switch (event.type) {
    case UIInputEventType::PointerMove:
    case UIInputEventType::PointerEnter:
    case UIInputEventType::PointerButtonDown:
    case UIInputEventType::PointerButtonUp:
        return true;
    default:
        return false;
    }
}

bool HasSystemModifiers(const ::XCEngine::UI::UIInputModifiers& modifiers) {
    return modifiers.control || modifiers.alt || modifiers.super;
}

bool ApplyKeyboardNavigation(
    UIEditorPropertyGridInteractionState& state,
    std::int32_t keyCode) {
    switch (static_cast<KeyCode>(keyCode)) {
    case KeyCode::Up:
        return state.keyboardNavigation.MovePrevious();
    case KeyCode::Down:
        return state.keyboardNavigation.MoveNext();
    case KeyCode::Home:
        return state.keyboardNavigation.MoveHome();
    case KeyCode::End:
        return state.keyboardNavigation.MoveEnd();
    default:
        return false;
    }
}

void ClearHoverState(UIEditorPropertyGridInteractionState& state) {
    state.propertyGridState.hoveredSectionId.clear();
    state.propertyGridState.hoveredFieldId.clear();
    state.propertyGridState.hoveredHitTarget = UIEditorPropertyGridHitTargetKind::None;
}

void ClearPopupState(UIEditorPropertyGridInteractionState& state) {
    state.propertyGridState.popupFieldId.clear();
    state.propertyGridState.popupHighlightedIndex = UIEditorPropertyGridInvalidIndex;
    state.pressedPopupIndex = UIEditorPropertyGridInvalidIndex;
}

bool IsInlineEditable(const UIEditorPropertyGridField& field) {
    return field.kind == UIEditorPropertyGridFieldKind::Text ||
        field.kind == UIEditorPropertyGridFieldKind::Number;
}

bool IsNumberEditCharacter(const UIEditorPropertyGridField& field, std::uint32_t character) {
    if (field.kind != UIEditorPropertyGridFieldKind::Number) {
        return true;
    }

    if (character >= static_cast<std::uint32_t>('0') &&
        character <= static_cast<std::uint32_t>('9')) {
        return true;
    }

    if (character == static_cast<std::uint32_t>('-') ||
        character == static_cast<std::uint32_t>('+')) {
        return true;
    }

    return !field.numberValue.integerMode && character == static_cast<std::uint32_t>('.');
}

UIEditorColorFieldSpec BuildColorFieldSpec(const UIEditorPropertyGridField& field) {
    UIEditorColorFieldSpec spec = {};
    spec.fieldId = field.fieldId;
    spec.label = field.label;
    spec.value = field.colorValue.value;
    spec.showAlpha = field.colorValue.showAlpha;
    spec.readOnly = field.readOnly;
    return spec;
}

UIEditorPropertyGridField* FindMutableField(
    std::vector<UIEditorPropertyGridSection>& sections,
    std::string_view fieldId) {
    const auto location = FindUIEditorPropertyGridFieldLocation(sections, fieldId);
    if (!location.IsValid() ||
        location.sectionIndex >= sections.size() ||
        location.fieldIndex >= sections[location.sectionIndex].fields.size()) {
        return nullptr;
    }

    return &sections[location.sectionIndex].fields[location.fieldIndex];
}

const UIEditorPropertyGridField* FindField(
    const std::vector<UIEditorPropertyGridSection>& sections,
    std::string_view fieldId) {
    const auto location = FindUIEditorPropertyGridFieldLocation(sections, fieldId);
    if (!location.IsValid() ||
        location.sectionIndex >= sections.size() ||
        location.fieldIndex >= sections[location.sectionIndex].fields.size()) {
        return nullptr;
    }

    return &sections[location.sectionIndex].fields[location.fieldIndex];
}

void SetChangedValueResult(
    const UIEditorPropertyGridField& field,
    UIEditorPropertyGridInteractionResult& result) {
    result.fieldValueChanged = true;
    result.changedFieldId = field.fieldId;
    result.changedValue = ResolveUIEditorPropertyGridFieldValueText(field);
}

void MergeInteractionResult(
    UIEditorPropertyGridInteractionResult& accumulated,
    const UIEditorPropertyGridInteractionResult& current) {
    accumulated.consumed = accumulated.consumed || current.consumed;
    accumulated.sectionToggled = accumulated.sectionToggled || current.sectionToggled;
    accumulated.selectionChanged = accumulated.selectionChanged || current.selectionChanged;
    accumulated.keyboardNavigated = accumulated.keyboardNavigated || current.keyboardNavigated;
    accumulated.editStarted = accumulated.editStarted || current.editStarted;
    accumulated.editValueChanged = accumulated.editValueChanged || current.editValueChanged;
    accumulated.editCommitted = accumulated.editCommitted || current.editCommitted;
    accumulated.editCommitRejected = accumulated.editCommitRejected || current.editCommitRejected;
    accumulated.editCanceled = accumulated.editCanceled || current.editCanceled;
    accumulated.popupOpened = accumulated.popupOpened || current.popupOpened;
    accumulated.popupClosed = accumulated.popupClosed || current.popupClosed;
    accumulated.fieldValueChanged = accumulated.fieldValueChanged || current.fieldValueChanged;
    accumulated.secondaryClicked = accumulated.secondaryClicked || current.secondaryClicked;

    if (current.hitTarget.kind != UIEditorPropertyGridHitTargetKind::None) {
        accumulated.hitTarget = current.hitTarget;
    }
    if (!current.toggledSectionId.empty()) {
        accumulated.toggledSectionId = current.toggledSectionId;
    }
    if (!current.selectedFieldId.empty()) {
        accumulated.selectedFieldId = current.selectedFieldId;
    }
    if (!current.activeFieldId.empty()) {
        accumulated.activeFieldId = current.activeFieldId;
    }
    if (!current.committedFieldId.empty()) {
        accumulated.committedFieldId = current.committedFieldId;
    }
    if (!current.committedValue.empty()) {
        accumulated.committedValue = current.committedValue;
    }
    if (!current.changedFieldId.empty()) {
        accumulated.changedFieldId = current.changedFieldId;
    }
    if (!current.changedValue.empty()) {
        accumulated.changedValue = current.changedValue;
    }
}

UIEditorPropertyGridColorFieldVisualState* FindMutableColorFieldVisualState(
    UIEditorPropertyGridInteractionState& state,
    std::string_view fieldId) {
    for (UIEditorPropertyGridColorFieldVisualState& entry : state.propertyGridState.colorFieldStates) {
        if (entry.fieldId == fieldId) {
            return &entry;
        }
    }

    return nullptr;
}

const UIEditorPropertyGridColorFieldVisualState* FindColorFieldVisualState(
    const UIEditorPropertyGridInteractionState& state,
    std::string_view fieldId) {
    for (const UIEditorPropertyGridColorFieldVisualState& entry : state.propertyGridState.colorFieldStates) {
        if (entry.fieldId == fieldId) {
            return &entry;
        }
    }

    return nullptr;
}

UIEditorColorFieldInteractionState BuildColorFieldInteractionState(
    const UIEditorPropertyGridInteractionState& state,
    std::string_view fieldId) {
    UIEditorColorFieldInteractionState interactionState = {};
    if (const UIEditorPropertyGridColorFieldVisualState* entry =
            FindColorFieldVisualState(state, fieldId);
        entry != nullptr) {
        interactionState.colorFieldState = entry->state;
    }

    interactionState.pointerPosition = state.pointerPosition;
    interactionState.hasPointerPosition = state.hasPointerPosition;
    return interactionState;
}

void StoreColorFieldVisualState(
    UIEditorPropertyGridInteractionState& state,
    std::string_view fieldId,
    const UIEditorColorFieldInteractionState& interactionState) {
    if (UIEditorPropertyGridColorFieldVisualState* entry =
            FindMutableColorFieldVisualState(state, fieldId);
        entry != nullptr) {
        entry->state = interactionState.colorFieldState;
        return;
    }

    UIEditorPropertyGridColorFieldVisualState entry = {};
    entry.fieldId = std::string(fieldId);
    entry.state = interactionState.colorFieldState;
    state.propertyGridState.colorFieldStates.push_back(std::move(entry));
}

void PruneColorFieldVisualStates(
    UIEditorPropertyGridInteractionState& state,
    const UIEditorPropertyGridLayout& layout,
    const std::vector<UIEditorPropertyGridSection>& sections) {
    const auto isVisibleColorFieldId = [&layout, &sections](std::string_view fieldId) {
        const std::size_t visibleFieldIndex =
            FindUIEditorPropertyGridVisibleFieldIndex(layout, fieldId, sections);
        if (visibleFieldIndex == UIEditorPropertyGridInvalidIndex ||
            visibleFieldIndex >= layout.visibleFieldSectionIndices.size() ||
            visibleFieldIndex >= layout.visibleFieldIndices.size()) {
            return false;
        }

        const std::size_t sectionIndex = layout.visibleFieldSectionIndices[visibleFieldIndex];
        const std::size_t fieldIndex = layout.visibleFieldIndices[visibleFieldIndex];
        return sectionIndex < sections.size() &&
            fieldIndex < sections[sectionIndex].fields.size() &&
            sections[sectionIndex].fields[fieldIndex].kind == UIEditorPropertyGridFieldKind::Color;
    };

    state.propertyGridState.colorFieldStates.erase(
        std::remove_if(
            state.propertyGridState.colorFieldStates.begin(),
            state.propertyGridState.colorFieldStates.end(),
            [&isVisibleColorFieldId](const UIEditorPropertyGridColorFieldVisualState& entry) {
                return !isVisibleColorFieldId(entry.fieldId);
            }),
        state.propertyGridState.colorFieldStates.end());
}

void CloseOtherColorFieldPopups(
    UIEditorPropertyGridInteractionState& state,
    std::string_view keepFieldId) {
    for (UIEditorPropertyGridColorFieldVisualState& entry : state.propertyGridState.colorFieldStates) {
        if (entry.fieldId == keepFieldId) {
            continue;
        }

        entry.state.popupOpen = false;
        entry.state.activeTarget = UIEditorColorFieldHitTargetKind::None;
    }
}

std::vector<UIEditorMenuPopupItem> BuildPopupItems(
    const UIEditorPropertyGridField& field) {
    std::vector<UIEditorMenuPopupItem> items = {};
    if (field.kind != UIEditorPropertyGridFieldKind::Enum) {
        return items;
    }

    items.reserve(field.enumValue.options.size());
    const std::size_t selectedIndex =
        field.enumValue.options.empty()
            ? 0u
            : (std::min)(field.enumValue.selectedIndex, field.enumValue.options.size() - 1u);
    for (std::size_t index = 0u; index < field.enumValue.options.size(); ++index) {
        UIEditorMenuPopupItem item = {};
        item.itemId = field.fieldId + "." + std::to_string(index);
        item.kind = UIEditorMenuItemKind::Command;
        item.label = field.enumValue.options[index];
        item.enabled = !field.readOnly;
        item.checked = index == selectedIndex;
        items.push_back(std::move(item));
    }

    return items;
}

::XCEngine::UI::UIRect ResolvePopupViewportRect(
    const ::XCEngine::UI::UIRect& bounds) {
    return ::XCEngine::UI::UIRect(bounds.x - 4096.0f, bounds.y - 4096.0f, 8192.0f, 8192.0f);
}

bool BuildPopupLayout(
    const UIEditorPropertyGridInteractionState& state,
    const UIEditorPropertyGridLayout& layout,
    const std::vector<UIEditorPropertyGridSection>& sections,
    const Widgets::UIEditorMenuPopupMetrics& popupMetrics,
    UIEditorMenuPopupLayout& popupLayout,
    std::vector<UIEditorMenuPopupItem>& popupItems) {
    if (state.propertyGridState.popupFieldId.empty()) {
        return false;
    }

    const std::size_t visibleFieldIndex =
        FindUIEditorPropertyGridVisibleFieldIndex(
            layout,
            state.propertyGridState.popupFieldId,
            sections);
    if (visibleFieldIndex == UIEditorPropertyGridInvalidIndex ||
        visibleFieldIndex >= layout.visibleFieldSectionIndices.size() ||
        visibleFieldIndex >= layout.visibleFieldIndices.size()) {
        return false;
    }

    const std::size_t sectionIndex = layout.visibleFieldSectionIndices[visibleFieldIndex];
    const std::size_t fieldIndex = layout.visibleFieldIndices[visibleFieldIndex];
    if (sectionIndex >= sections.size() ||
        fieldIndex >= sections[sectionIndex].fields.size()) {
        return false;
    }

    const UIEditorPropertyGridField& field = sections[sectionIndex].fields[fieldIndex];
    popupItems = BuildPopupItems(field);
    if (popupItems.empty()) {
        return false;
    }

    const float popupWidth = (std::max)(
        layout.fieldValueRects[visibleFieldIndex].width,
        Widgets::ResolveUIEditorMenuPopupDesiredWidth(popupItems, popupMetrics));
    const float popupHeight = Widgets::MeasureUIEditorMenuPopupHeight(popupItems, popupMetrics);
    const auto placement = ResolvePopupPlacementRect(
        layout.fieldValueRects[visibleFieldIndex],
        UISize(popupWidth, popupHeight),
        ResolvePopupViewportRect(layout.bounds),
        UIPopupPlacement::BottomStart);
    popupLayout = Widgets::BuildUIEditorMenuPopupLayout(placement.rect, popupItems, popupMetrics);
    return true;
}

UIEditorMenuPopupHitTarget ResolvePopupHit(
    const UIEditorPropertyGridInteractionState& state,
    const UIEditorPropertyGridLayout& layout,
    const std::vector<UIEditorPropertyGridSection>& sections,
    const Widgets::UIEditorMenuPopupMetrics& popupMetrics) {
    if (!state.hasPointerPosition) {
        return {};
    }

    UIEditorMenuPopupLayout popupLayout = {};
    std::vector<UIEditorMenuPopupItem> popupItems = {};
    if (!BuildPopupLayout(state, layout, sections, popupMetrics, popupLayout, popupItems)) {
        return {};
    }

    return Widgets::HitTestUIEditorMenuPopup(popupLayout, popupItems, state.pointerPosition);
}

void SyncHoverTarget(
    UIEditorPropertyGridInteractionState& state,
    const UIEditorPropertyGridLayout& layout,
    const std::vector<UIEditorPropertyGridSection>& sections,
    const Widgets::UIEditorMenuPopupMetrics& popupMetrics) {
    ClearHoverState(state);
    if (!state.hasPointerPosition) {
        return;
    }

    const UIEditorMenuPopupHitTarget popupHit = ResolvePopupHit(state, layout, sections, popupMetrics);
    if (popupHit.kind == UIEditorMenuPopupHitTargetKind::Item) {
        state.propertyGridState.popupHighlightedIndex = popupHit.index;
        return;
    }
    if (popupHit.kind != UIEditorMenuPopupHitTargetKind::None) {
        return;
    }

    const UIEditorPropertyGridHitTarget hitTarget =
        HitTestUIEditorPropertyGrid(layout, state.pointerPosition);
    state.propertyGridState.hoveredHitTarget = hitTarget.kind;
    if (hitTarget.kind == UIEditorPropertyGridHitTargetKind::SectionHeader &&
        hitTarget.sectionIndex < sections.size()) {
        state.propertyGridState.hoveredSectionId = sections[hitTarget.sectionIndex].sectionId;
        return;
    }

    if ((hitTarget.kind == UIEditorPropertyGridHitTargetKind::FieldRow ||
         hitTarget.kind == UIEditorPropertyGridHitTargetKind::ValueBox) &&
        hitTarget.sectionIndex < sections.size() &&
        hitTarget.fieldIndex < sections[hitTarget.sectionIndex].fields.size()) {
        state.propertyGridState.hoveredFieldId =
            sections[hitTarget.sectionIndex].fields[hitTarget.fieldIndex].fieldId;
    }
}

void SyncKeyboardNavigation(
    UIEditorPropertyGridInteractionState& state,
    const ::XCEngine::UI::Widgets::UISelectionModel& selectionModel,
    const UIEditorPropertyGridLayout& layout,
    const std::vector<UIEditorPropertyGridSection>& sections) {
    state.keyboardNavigation.SetItemCount(layout.visibleFieldIndices.size());
    state.keyboardNavigation.ClampToItemCount();

    if (!selectionModel.HasSelection()) {
        return;
    }

    const std::size_t selectedVisibleIndex =
        FindUIEditorPropertyGridVisibleFieldIndex(
            layout,
            selectionModel.GetSelectedId(),
            sections);
    if (selectedVisibleIndex == UIEditorPropertyGridInvalidIndex) {
        return;
    }

    if (!state.keyboardNavigation.HasCurrentIndex() ||
        state.keyboardNavigation.GetCurrentIndex() != selectedVisibleIndex) {
        state.keyboardNavigation.SetCurrentIndex(selectedVisibleIndex);
    }
}

bool SelectVisibleField(
    UIEditorPropertyGridInteractionState& state,
    ::XCEngine::UI::Widgets::UISelectionModel& selectionModel,
    const UIEditorPropertyGridLayout& layout,
    const std::vector<UIEditorPropertyGridSection>& sections,
    std::size_t visibleFieldIndex,
    UIEditorPropertyGridInteractionResult& result) {
    if (visibleFieldIndex >= layout.visibleFieldIndices.size() ||
        visibleFieldIndex >= layout.visibleFieldSectionIndices.size()) {
        return false;
    }

    const std::size_t sectionIndex = layout.visibleFieldSectionIndices[visibleFieldIndex];
    const std::size_t fieldIndex = layout.visibleFieldIndices[visibleFieldIndex];
    if (sectionIndex >= sections.size() ||
        fieldIndex >= sections[sectionIndex].fields.size()) {
        return false;
    }

    const UIEditorPropertyGridField& field = sections[sectionIndex].fields[fieldIndex];
    result.selectionChanged = selectionModel.SetSelection(field.fieldId);
    result.selectedFieldId = field.fieldId;
    result.consumed = true;
    state.keyboardNavigation.SetCurrentIndex(visibleFieldIndex);
    return true;
}

bool BeginFieldEdit(
    UIEditorPropertyGridInteractionState& state,
    ::XCEngine::UI::Widgets::UIPropertyEditModel& propertyEditModel,
    const UIEditorPropertyGridField& field,
    UIEditorPropertyGridInteractionResult& result) {
    if (field.readOnly || !IsInlineEditable(field)) {
        return false;
    }

    const std::string initialValue =
        field.kind == UIEditorPropertyGridFieldKind::Text
            ? field.valueText
            : ResolveUIEditorPropertyGridFieldValueText(field);
    const bool changed = propertyEditModel.BeginEdit(field.fieldId, initialValue);
    if (!changed &&
        (!propertyEditModel.HasActiveEdit() ||
         propertyEditModel.GetActiveFieldId() != field.fieldId)) {
        return false;
    }

    state.textInputState.value = propertyEditModel.GetStagedValue();
    state.textInputState.caret = state.textInputState.value.size();
    result.editStarted = changed;
    result.activeFieldId = field.fieldId;
    result.consumed = true;
    return true;
}

bool CommitActiveEdit(
    UIEditorPropertyGridInteractionState& state,
    ::XCEngine::UI::Widgets::UIPropertyEditModel& propertyEditModel,
    std::vector<UIEditorPropertyGridSection>& sections,
    UIEditorPropertyGridInteractionResult& result) {
    if (!propertyEditModel.HasActiveEdit()) {
        return false;
    }

    UIEditorPropertyGridField* field =
        FindMutableField(sections, propertyEditModel.GetActiveFieldId());
    if (field == nullptr) {
        propertyEditModel.CancelEdit();
        state.textInputState = {};
        return false;
    }

    result.activeFieldId = field->fieldId;
    if (field->kind == UIEditorPropertyGridFieldKind::Number) {
        Widgets::UIEditorNumberFieldSpec spec = {};
        spec.fieldId = field->fieldId;
        spec.label = field->label;
        spec.value = field->numberValue.value;
        spec.step = field->numberValue.step;
        spec.minValue = field->numberValue.minValue;
        spec.maxValue = field->numberValue.maxValue;
        spec.integerMode = field->numberValue.integerMode;
        spec.readOnly = field->readOnly;

        double parsedValue = field->numberValue.value;
        if (!Widgets::TryParseUIEditorNumberFieldValue(
                spec,
                propertyEditModel.GetStagedValue(),
                parsedValue)) {
            result.editCommitRejected = true;
            result.consumed = true;
            return false;
        }

        field->numberValue.value = parsedValue;
        result.committedFieldId = field->fieldId;
        result.committedValue = ResolveUIEditorPropertyGridFieldValueText(*field);
        SetChangedValueResult(*field, result);
    } else {
        field->valueText = propertyEditModel.GetStagedValue();
        result.committedFieldId = field->fieldId;
        result.committedValue = field->valueText;
        SetChangedValueResult(*field, result);
    }

    propertyEditModel.CommitEdit();
    state.textInputState = {};
    result.editCommitted = true;
    result.consumed = true;
    return true;
}

bool CancelActiveEdit(
    UIEditorPropertyGridInteractionState& state,
    ::XCEngine::UI::Widgets::UIPropertyEditModel& propertyEditModel,
    UIEditorPropertyGridInteractionResult& result) {
    if (!propertyEditModel.HasActiveEdit()) {
        return false;
    }

    result.activeFieldId = propertyEditModel.GetActiveFieldId();
    if (!propertyEditModel.CancelEdit()) {
        return false;
    }

    state.textInputState = {};
    result.editCanceled = true;
    result.consumed = true;
    return true;
}

void ClosePopup(
    UIEditorPropertyGridInteractionState& state,
    UIEditorPropertyGridInteractionResult& result) {
    if (state.propertyGridState.popupFieldId.empty()) {
        return;
    }

    ClearPopupState(state);
    result.popupClosed = true;
    result.consumed = true;
}

void OpenPopup(
    UIEditorPropertyGridInteractionState& state,
    const UIEditorPropertyGridField& field,
    UIEditorPropertyGridInteractionResult& result) {
    if (field.kind != UIEditorPropertyGridFieldKind::Enum ||
        field.readOnly ||
        field.enumValue.options.empty()) {
        return;
    }

    if (state.propertyGridState.popupFieldId == field.fieldId) {
        return;
    }

    state.propertyGridState.popupFieldId = field.fieldId;
    state.propertyGridState.popupHighlightedIndex =
        (std::min)(field.enumValue.selectedIndex, field.enumValue.options.size() - 1u);
    result.popupOpened = true;
    result.consumed = true;
}

void MovePopupHighlight(
    UIEditorPropertyGridInteractionState& state,
    const UIEditorPropertyGridField& field,
    int delta) {
    if (field.kind != UIEditorPropertyGridFieldKind::Enum ||
        field.enumValue.options.empty()) {
        state.propertyGridState.popupHighlightedIndex = UIEditorPropertyGridInvalidIndex;
        return;
    }

    if (state.propertyGridState.popupHighlightedIndex == UIEditorPropertyGridInvalidIndex ||
        state.propertyGridState.popupHighlightedIndex >= field.enumValue.options.size()) {
        state.propertyGridState.popupHighlightedIndex =
            (std::min)(field.enumValue.selectedIndex, field.enumValue.options.size() - 1u);
    }

    const std::size_t currentIndex = state.propertyGridState.popupHighlightedIndex;
    if (delta < 0) {
        state.propertyGridState.popupHighlightedIndex = currentIndex == 0u ? 0u : currentIndex - 1u;
    } else {
        state.propertyGridState.popupHighlightedIndex =
            currentIndex + 1u >= field.enumValue.options.size()
                ? field.enumValue.options.size() - 1u
                : currentIndex + 1u;
    }
}

void JumpPopupHighlightToEdge(
    UIEditorPropertyGridInteractionState& state,
    const UIEditorPropertyGridField& field,
    bool toEnd) {
    if (field.kind != UIEditorPropertyGridFieldKind::Enum ||
        field.enumValue.options.empty()) {
        state.propertyGridState.popupHighlightedIndex = UIEditorPropertyGridInvalidIndex;
        return;
    }

    state.propertyGridState.popupHighlightedIndex = toEnd
        ? field.enumValue.options.size() - 1u
        : 0u;
}

bool CommitPopupSelection(
    UIEditorPropertyGridInteractionState& state,
    std::vector<UIEditorPropertyGridSection>& sections,
    UIEditorPropertyGridInteractionResult& result) {
    UIEditorPropertyGridField* field =
        FindMutableField(sections, state.propertyGridState.popupFieldId);
    if (field == nullptr ||
        field->kind != UIEditorPropertyGridFieldKind::Enum ||
        field->readOnly ||
        field->enumValue.options.empty() ||
        state.propertyGridState.popupHighlightedIndex == UIEditorPropertyGridInvalidIndex ||
        state.propertyGridState.popupHighlightedIndex >= field->enumValue.options.size()) {
        return false;
    }

    field->enumValue.selectedIndex = state.propertyGridState.popupHighlightedIndex;
    SetChangedValueResult(*field, result);
    ClosePopup(state, result);
    return true;
}

bool ToggleBoolField(
    UIEditorPropertyGridField& field,
    UIEditorPropertyGridInteractionResult& result) {
    if (field.kind != UIEditorPropertyGridFieldKind::Bool || field.readOnly) {
        return false;
    }

    field.boolValue = !field.boolValue;
    SetChangedValueResult(field, result);
    result.consumed = true;
    return true;
}

bool ProcessColorFieldEvent(
    UIEditorPropertyGridInteractionState& state,
    ::XCEngine::UI::Widgets::UISelectionModel& selectionModel,
    ::XCEngine::UI::Widgets::UIPropertyEditModel& propertyEditModel,
    const UIEditorPropertyGridLayout& layout,
    std::vector<UIEditorPropertyGridSection>& sections,
    const Widgets::UIEditorPropertyGridMetrics& metrics,
    const UIInputEvent& event,
    UIEditorPropertyGridInteractionResult& result) {
    const Widgets::UIEditorColorFieldMetrics colorMetrics =
        BuildUIEditorPropertyGridColorFieldMetrics(metrics);
    const ::XCEngine::UI::UIRect popupViewportRect = ResolvePopupViewportRect(layout.bounds);
    bool handled = false;

    for (std::size_t visibleFieldIndex = 0u;
         visibleFieldIndex < layout.visibleFieldIndices.size();
         ++visibleFieldIndex) {
        const std::size_t sectionIndex = layout.visibleFieldSectionIndices[visibleFieldIndex];
        const std::size_t fieldIndex = layout.visibleFieldIndices[visibleFieldIndex];
        if (sectionIndex >= sections.size() ||
            fieldIndex >= sections[sectionIndex].fields.size()) {
            continue;
        }

        UIEditorPropertyGridField& field = sections[sectionIndex].fields[fieldIndex];
        if (field.kind != UIEditorPropertyGridFieldKind::Color) {
            continue;
        }

        UIEditorColorFieldInteractionState colorState =
            BuildColorFieldInteractionState(state, field.fieldId);
        const bool popupWasOpen = colorState.colorFieldState.popupOpen;
        UIEditorColorFieldSpec spec = BuildColorFieldSpec(field);
        const UIEditorColorFieldInteractionFrame frame =
            UpdateUIEditorColorFieldInteraction(
                colorState,
                spec,
                layout.fieldRowRects[visibleFieldIndex],
                { event },
                colorMetrics,
                popupViewportRect);

        if (!frame.result.consumed &&
            frame.result.hitTarget.kind == UIEditorColorFieldHitTargetKind::None &&
            !popupWasOpen &&
            !colorState.colorFieldState.popupOpen) {
            continue;
        }

        handled = true;
        field.colorValue.value = spec.value;
        field.colorValue.showAlpha = spec.showAlpha;
        StoreColorFieldVisualState(state, field.fieldId, colorState);

        if (frame.result.popupOpened) {
            ClosePopup(state, result);
            CloseOtherColorFieldPopups(state, field.fieldId);
        }

        state.propertyGridState.focused = colorState.colorFieldState.focused;
        state.propertyGridState.pressedFieldId.clear();

        if (frame.result.hitTarget.kind != UIEditorColorFieldHitTargetKind::None ||
            frame.result.popupOpened ||
            frame.result.colorChanged ||
            popupWasOpen ||
            colorState.colorFieldState.popupOpen) {
            result.selectionChanged =
                selectionModel.SetSelection(field.fieldId) || result.selectionChanged;
            result.selectedFieldId = field.fieldId;
            result.activeFieldId = field.fieldId;
            state.keyboardNavigation.SetCurrentIndex(visibleFieldIndex);
        }

        if (propertyEditModel.HasActiveEdit() &&
            propertyEditModel.GetActiveFieldId() != field.fieldId &&
            (frame.result.hitTarget.kind != UIEditorColorFieldHitTargetKind::None ||
             frame.result.popupOpened)) {
            CommitActiveEdit(state, propertyEditModel, sections, result);
        }

        result.popupOpened = result.popupOpened || frame.result.popupOpened;
        result.popupClosed = result.popupClosed || frame.result.popupClosed;
        result.consumed = result.consumed || frame.result.consumed;
        if (frame.result.colorChanged) {
            SetChangedValueResult(field, result);
        }

        if (frame.result.hitTarget.kind == UIEditorColorFieldHitTargetKind::Row) {
            result.hitTarget.kind = UIEditorPropertyGridHitTargetKind::FieldRow;
            result.hitTarget.sectionIndex = sectionIndex;
            result.hitTarget.fieldIndex = fieldIndex;
            result.hitTarget.visibleFieldIndex = visibleFieldIndex;
        } else if (frame.result.hitTarget.kind != UIEditorColorFieldHitTargetKind::None) {
            result.hitTarget.kind = UIEditorPropertyGridHitTargetKind::ValueBox;
            result.hitTarget.sectionIndex = sectionIndex;
            result.hitTarget.fieldIndex = fieldIndex;
            result.hitTarget.visibleFieldIndex = visibleFieldIndex;
        }
    }

    return handled;
}

} // namespace

UIEditorPropertyGridInteractionFrame UpdateUIEditorPropertyGridInteraction(
    UIEditorPropertyGridInteractionState& state,
    ::XCEngine::UI::Widgets::UISelectionModel& selectionModel,
    ::XCEngine::UI::Widgets::UIExpansionModel& expansionModel,
    ::XCEngine::UI::Widgets::UIPropertyEditModel& propertyEditModel,
    const ::XCEngine::UI::UIRect& bounds,
    std::vector<UIEditorPropertyGridSection>& sections,
    const std::vector<UIInputEvent>& inputEvents,
    const Widgets::UIEditorPropertyGridMetrics& metrics,
    const Widgets::UIEditorMenuPopupMetrics& popupMetrics) {
    UIEditorPropertyGridLayout layout =
        BuildUIEditorPropertyGridLayout(bounds, sections, expansionModel, metrics);
    PruneColorFieldVisualStates(state, layout, sections);
    SyncKeyboardNavigation(state, selectionModel, layout, sections);
    SyncHoverTarget(state, layout, sections, popupMetrics);

    UIEditorPropertyGridInteractionResult interactionResult = {};
    for (const UIInputEvent& event : inputEvents) {
        if (ShouldUsePointerPosition(event)) {
            state.pointerPosition = event.position;
            state.hasPointerPosition = true;
        } else if (event.type == UIInputEventType::PointerLeave) {
            state.hasPointerPosition = false;
        }

        UIEditorPropertyGridInteractionResult eventResult = {};
        const UIEditorMenuPopupHitTarget popupHit = ResolvePopupHit(state, layout, sections, popupMetrics);
        const UIEditorPropertyGridHitTarget hitTarget =
            state.hasPointerPosition
                ? HitTestUIEditorPropertyGrid(layout, state.pointerPosition)
                : UIEditorPropertyGridHitTarget {};
        eventResult.hitTarget = hitTarget;

        if (ProcessColorFieldEvent(
                state,
                selectionModel,
                propertyEditModel,
                layout,
                sections,
                metrics,
                event,
                eventResult)) {
            MergeInteractionResult(interactionResult, eventResult);
            layout = BuildUIEditorPropertyGridLayout(bounds, sections, expansionModel, metrics);
            PruneColorFieldVisualStates(state, layout, sections);
            SyncKeyboardNavigation(state, selectionModel, layout, sections);
            SyncHoverTarget(state, layout, sections, popupMetrics);
            continue;
        }

        switch (event.type) {
        case UIInputEventType::FocusGained:
            state.propertyGridState.focused = true;
            break;

        case UIInputEventType::FocusLost:
            CommitActiveEdit(state, propertyEditModel, sections, eventResult);
            ClosePopup(state, eventResult);
            state.propertyGridState.focused = false;
            state.propertyGridState.pressedFieldId.clear();
            state.hasPointerPosition = false;
            ClearHoverState(state);
            break;

        case UIInputEventType::PointerMove:
        case UIInputEventType::PointerEnter:
        case UIInputEventType::PointerLeave:
            break;

        case UIInputEventType::PointerButtonDown: {
            if (event.pointerButton == UIPointerButton::Left) {
                const bool insideGrid =
                    state.hasPointerPosition &&
                    IsUIEditorPropertyGridPointInside(layout.bounds, state.pointerPosition);
                if (popupHit.kind == UIEditorMenuPopupHitTargetKind::Item) {
                    state.propertyGridState.focused = true;
                    state.pressedPopupIndex = popupHit.index;
                    eventResult.consumed = true;
                } else if (popupHit.kind == UIEditorMenuPopupHitTargetKind::PopupSurface) {
                    state.propertyGridState.focused = true;
                    eventResult.consumed = true;
                } else if (hitTarget.kind == UIEditorPropertyGridHitTargetKind::FieldRow ||
                    hitTarget.kind == UIEditorPropertyGridHitTargetKind::ValueBox) {
                    state.propertyGridState.focused = true;
                    state.propertyGridState.pressedFieldId =
                        sections[hitTarget.sectionIndex].fields[hitTarget.fieldIndex].fieldId;
                    eventResult.consumed = true;
                } else if (hitTarget.kind == UIEditorPropertyGridHitTargetKind::SectionHeader || insideGrid) {
                    state.propertyGridState.focused = true;
                    state.propertyGridState.pressedFieldId.clear();
                    eventResult.consumed = true;
                } else {
                    state.propertyGridState.focused = false;
                    state.propertyGridState.pressedFieldId.clear();
                }
            }
            break;
        }

        case UIInputEventType::PointerButtonUp: {
            if (event.pointerButton == UIPointerButton::Left) {
                const bool insideGrid =
                    state.hasPointerPosition &&
                    IsUIEditorPropertyGridPointInside(layout.bounds, state.pointerPosition);

                if (state.pressedPopupIndex != UIEditorPropertyGridInvalidIndex) {
                    if (popupHit.kind == UIEditorMenuPopupHitTargetKind::Item &&
                        popupHit.index == state.pressedPopupIndex) {
                        eventResult.fieldValueChanged =
                            CommitPopupSelection(state, sections, eventResult);
                    } else if (popupHit.kind == UIEditorMenuPopupHitTargetKind::None) {
                        ClosePopup(state, eventResult);
                    }
                    state.pressedPopupIndex = UIEditorPropertyGridInvalidIndex;
                    state.propertyGridState.pressedFieldId.clear();
                    eventResult.consumed = true;
                    break;
                }

                if (popupHit.kind == UIEditorMenuPopupHitTargetKind::PopupSurface) {
                    state.propertyGridState.pressedFieldId.clear();
                    eventResult.consumed = true;
                    break;
                }

                if (hitTarget.kind == UIEditorPropertyGridHitTargetKind::None) {
                    CommitActiveEdit(state, propertyEditModel, sections, eventResult);
                    ClosePopup(state, eventResult);
                    state.propertyGridState.focused = insideGrid;
                    state.propertyGridState.pressedFieldId.clear();
                    if (insideGrid) {
                        eventResult.consumed = true;
                    }
                    break;
                }

                if (hitTarget.kind == UIEditorPropertyGridHitTargetKind::SectionHeader &&
                    hitTarget.sectionIndex < sections.size()) {
                    CommitActiveEdit(state, propertyEditModel, sections, eventResult);
                    ClosePopup(state, eventResult);
                    const std::string& sectionId = sections[hitTarget.sectionIndex].sectionId;
                    eventResult.sectionToggled = expansionModel.ToggleExpanded(sectionId);
                    eventResult.toggledSectionId = sectionId;
                    eventResult.consumed = true;
                    state.propertyGridState.focused = true;
                    state.propertyGridState.pressedFieldId.clear();
                    break;
                }

                if ((hitTarget.kind == UIEditorPropertyGridHitTargetKind::FieldRow ||
                     hitTarget.kind == UIEditorPropertyGridHitTargetKind::ValueBox) &&
                    hitTarget.sectionIndex < sections.size() &&
                    hitTarget.fieldIndex < sections[hitTarget.sectionIndex].fields.size()) {
                    UIEditorPropertyGridField& field =
                        sections[hitTarget.sectionIndex].fields[hitTarget.fieldIndex];
                    state.propertyGridState.focused = true;
                    SelectVisibleField(
                        state,
                        selectionModel,
                        layout,
                        sections,
                        hitTarget.visibleFieldIndex,
                        eventResult);

                    if (hitTarget.kind == UIEditorPropertyGridHitTargetKind::ValueBox) {
                        if (field.kind == UIEditorPropertyGridFieldKind::Bool) {
                            CommitActiveEdit(state, propertyEditModel, sections, eventResult);
                            ClosePopup(state, eventResult);
                            ToggleBoolField(field, eventResult);
                        } else if (field.kind == UIEditorPropertyGridFieldKind::Enum) {
                            CommitActiveEdit(state, propertyEditModel, sections, eventResult);
                            if (state.propertyGridState.popupFieldId == field.fieldId) {
                                ClosePopup(state, eventResult);
                            } else {
                                ClearPopupState(state);
                                OpenPopup(state, field, eventResult);
                            }
                        } else {
                            ClosePopup(state, eventResult);
                            if (!(propertyEditModel.HasActiveEdit() &&
                                    propertyEditModel.GetActiveFieldId() == field.fieldId)) {
                                CommitActiveEdit(state, propertyEditModel, sections, eventResult);
                                BeginFieldEdit(state, propertyEditModel, field, eventResult);
                            }
                        }
                    } else if (state.propertyGridState.popupFieldId != field.fieldId) {
                        ClosePopup(state, eventResult);
                    }
                }

                state.propertyGridState.pressedFieldId.clear();
            } else if (event.pointerButton == UIPointerButton::Right &&
                (hitTarget.kind == UIEditorPropertyGridHitTargetKind::FieldRow ||
                 hitTarget.kind == UIEditorPropertyGridHitTargetKind::ValueBox) &&
                hitTarget.sectionIndex < sections.size() &&
                hitTarget.fieldIndex < sections[hitTarget.sectionIndex].fields.size()) {
                const UIEditorPropertyGridField& field =
                    sections[hitTarget.sectionIndex].fields[hitTarget.fieldIndex];
                eventResult.selectionChanged = selectionModel.SetSelection(field.fieldId);
                eventResult.selectedFieldId = field.fieldId;
                eventResult.secondaryClicked = true;
                eventResult.consumed = true;
                state.propertyGridState.focused = true;
                if (hitTarget.visibleFieldIndex != UIEditorPropertyGridInvalidIndex) {
                    state.keyboardNavigation.SetCurrentIndex(hitTarget.visibleFieldIndex);
                }
            }
            break;
        }

        case UIInputEventType::KeyDown:
            if (!state.propertyGridState.focused) {
                break;
            }

            if (!state.propertyGridState.popupFieldId.empty()) {
                const UIEditorPropertyGridField* popupField =
                    FindField(sections, state.propertyGridState.popupFieldId);
                if (popupField != nullptr) {
                    switch (static_cast<KeyCode>(event.keyCode)) {
                    case KeyCode::Up:
                        MovePopupHighlight(state, *popupField, -1);
                        eventResult.consumed = true;
                        break;
                    case KeyCode::Down:
                        MovePopupHighlight(state, *popupField, 1);
                        eventResult.consumed = true;
                        break;
                    case KeyCode::Home:
                        JumpPopupHighlightToEdge(state, *popupField, false);
                        eventResult.consumed = true;
                        break;
                    case KeyCode::End:
                        JumpPopupHighlightToEdge(state, *popupField, true);
                        eventResult.consumed = true;
                        break;
                    case KeyCode::Enter:
                    case KeyCode::Space:
                        CommitPopupSelection(state, sections, eventResult);
                        eventResult.consumed = true;
                        break;
                    case KeyCode::Escape:
                        ClosePopup(state, eventResult);
                        break;
                    default:
                        break;
                    }
                }
                break;
            }

            if (propertyEditModel.HasActiveEdit()) {
                if (static_cast<KeyCode>(event.keyCode) == KeyCode::Escape) {
                    CancelActiveEdit(state, propertyEditModel, eventResult);
                    break;
                }

                const auto editResult = HandleKeyDown(
                    state.textInputState,
                    event.keyCode,
                    event.modifiers,
                    {});
                if (editResult.handled) {
                    eventResult.consumed = true;
                    eventResult.activeFieldId = propertyEditModel.GetActiveFieldId();
                    if (editResult.valueChanged) {
                        propertyEditModel.UpdateStagedValue(state.textInputState.value);
                        eventResult.editValueChanged = true;
                    }
                    if (editResult.submitRequested) {
                        CommitActiveEdit(state, propertyEditModel, sections, eventResult);
                    }
                }
                break;
            }

            if ((static_cast<KeyCode>(event.keyCode) == KeyCode::Enter ||
                 static_cast<KeyCode>(event.keyCode) == KeyCode::Space) &&
                selectionModel.HasSelection()) {
                UIEditorPropertyGridField* field =
                    FindMutableField(sections, selectionModel.GetSelectedId());
                if (field != nullptr) {
                    if (field->kind == UIEditorPropertyGridFieldKind::Bool) {
                        ToggleBoolField(*field, eventResult);
                    } else if (field->kind == UIEditorPropertyGridFieldKind::Enum) {
                        OpenPopup(state, *field, eventResult);
                    } else if (static_cast<KeyCode>(event.keyCode) == KeyCode::Enter) {
                        BeginFieldEdit(state, propertyEditModel, *field, eventResult);
                    }
                }
                break;
            }

            if (!event.modifiers.shift &&
                !HasSystemModifiers(event.modifiers) &&
                ApplyKeyboardNavigation(state, event.keyCode) &&
                state.keyboardNavigation.HasCurrentIndex()) {
                const std::size_t currentIndex = state.keyboardNavigation.GetCurrentIndex();
                if (SelectVisibleField(
                        state,
                        selectionModel,
                        layout,
                        sections,
                        currentIndex,
                        eventResult)) {
                    eventResult.keyboardNavigated = true;
                }
            }
            break;

        case UIInputEventType::Character:
            if (!state.propertyGridState.focused ||
                !propertyEditModel.HasActiveEdit() ||
                HasSystemModifiers(event.modifiers)) {
                break;
            }

            if (const UIEditorPropertyGridField* field =
                    FindField(sections, propertyEditModel.GetActiveFieldId());
                field == nullptr || !IsNumberEditCharacter(*field, event.character)) {
                break;
            }

            if (InsertCharacter(state.textInputState, event.character)) {
                propertyEditModel.UpdateStagedValue(state.textInputState.value);
                eventResult.consumed = true;
                eventResult.editValueChanged = true;
                eventResult.activeFieldId = propertyEditModel.GetActiveFieldId();
            }
            break;

        default:
            break;
        }

        layout = BuildUIEditorPropertyGridLayout(bounds, sections, expansionModel, metrics);
        PruneColorFieldVisualStates(state, layout, sections);
        SyncKeyboardNavigation(state, selectionModel, layout, sections);
        SyncHoverTarget(state, layout, sections, popupMetrics);
        if (eventResult.hitTarget.kind == UIEditorPropertyGridHitTargetKind::None &&
            state.hasPointerPosition) {
            eventResult.hitTarget = HitTestUIEditorPropertyGrid(layout, state.pointerPosition);
        }

        if (eventResult.consumed ||
            eventResult.sectionToggled ||
            eventResult.selectionChanged ||
            eventResult.keyboardNavigated ||
            eventResult.editStarted ||
            eventResult.editValueChanged ||
            eventResult.editCommitted ||
            eventResult.editCommitRejected ||
            eventResult.editCanceled ||
            eventResult.popupOpened ||
            eventResult.popupClosed ||
            eventResult.fieldValueChanged ||
            eventResult.secondaryClicked ||
            eventResult.hitTarget.kind != UIEditorPropertyGridHitTargetKind::None ||
            !eventResult.toggledSectionId.empty() ||
            !eventResult.selectedFieldId.empty() ||
            !eventResult.activeFieldId.empty() ||
            !eventResult.committedFieldId.empty() ||
            !eventResult.changedFieldId.empty()) {
            interactionResult = std::move(eventResult);
        }
    }

    layout = BuildUIEditorPropertyGridLayout(bounds, sections, expansionModel, metrics);
    PruneColorFieldVisualStates(state, layout, sections);
    SyncKeyboardNavigation(state, selectionModel, layout, sections);
    SyncHoverTarget(state, layout, sections, popupMetrics);
    if (interactionResult.hitTarget.kind == UIEditorPropertyGridHitTargetKind::None &&
        state.hasPointerPosition) {
        interactionResult.hitTarget = HitTestUIEditorPropertyGrid(layout, state.pointerPosition);
    }

    return {
        std::move(layout),
        std::move(interactionResult)
    };
}

} // namespace XCEngine::UI::Editor