#pragma once

#include "Hierarchy/ProductHierarchyModel.h"

#include <XCEditor/Collections/UIEditorTreeViewInteraction.h>
#include <XCEditor/Shell/UIEditorPanelContentHost.h>

#include <XCEngine/UI/DrawData.h>
#include <XCEngine/UI/Widgets/UIExpansionModel.h>
#include <XCEngine/UI/Widgets/UISelectionModel.h>

#include <cstdint>
#include <string>
#include <vector>

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

class ProductBuiltInIcons;

class ProductHierarchyPanel {
public:
    enum class EventKind : std::uint8_t {
        None = 0,
        SelectionChanged,
        Reparented,
        MovedToRoot,
        RenameRequested
    };

    struct Event {
        EventKind kind = EventKind::None;
        std::string itemId = {};
        std::string targetItemId = {};
        std::string label = {};
    };

    void Initialize();
    void SetBuiltInIcons(const ProductBuiltInIcons* icons);
    void Update(
        const UIEditorPanelContentHostFrame& contentHostFrame,
        const std::vector<::XCEngine::UI::UIInputEvent>& inputEvents,
        bool allowInteraction,
        bool panelActive);
    void Append(::XCEngine::UI::UIDrawList& drawList) const;
    bool WantsHostPointerCapture() const;
    bool WantsHostPointerRelease() const;
    bool HasActivePointerCapture() const;
    const std::vector<Event>& GetFrameEvents() const;

private:
    struct DragState {
        std::string armedItemId = {};
        std::string draggedItemId = {};
        std::string dropTargetItemId = {};
        ::XCEngine::UI::UIPoint pressPosition = {};
        bool armed = false;
        bool dragging = false;
        bool dropToRoot = false;
        bool validDropTarget = false;
        bool requestPointerCapture = false;
        bool requestPointerRelease = false;
    };

    const UIEditorPanelContentHostPanelState* FindMountedHierarchyPanel(
        const UIEditorPanelContentHostFrame& contentHostFrame) const;
    void ResetTransientState();
    void RebuildItems();
    void ProcessDragAndFrameEvents(
        const std::vector<::XCEngine::UI::UIInputEvent>& inputEvents,
        const ::XCEngine::UI::UIRect& bounds,
        bool allowInteraction,
        bool panelActive);
    void EmitSelectionEvent();
    void EmitReparentEvent(
        EventKind kind,
        std::string itemId,
        std::string targetItemId);
    std::vector<::XCEngine::UI::UIInputEvent> BuildInteractionInputEvents(
        const std::vector<::XCEngine::UI::UIInputEvent>& inputEvents,
        const ::XCEngine::UI::UIRect& bounds,
        bool allowInteraction,
        bool panelActive) const;

    const ProductBuiltInIcons* m_icons = nullptr;
    ProductHierarchyModel m_model = {};
    std::vector<Widgets::UIEditorTreeViewItem> m_treeItems = {};
    ::XCEngine::UI::Widgets::UISelectionModel m_selection = {};
    ::XCEngine::UI::Widgets::UIExpansionModel m_expansion = {};
    UIEditorTreeViewInteractionState m_treeInteractionState = {};
    UIEditorTreeViewInteractionFrame m_treeFrame = {};
    std::vector<Event> m_frameEvents = {};
    DragState m_dragState = {};
    bool m_visible = false;
};

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