#pragma once

#include "Scene/EditorSceneBackend.h"
#include "Scene/SceneToolState.h"
#include "State/EditorSelectionService.h"

#include <memory>

#include <filesystem>
#include <optional>
#include <cstdint>
#include <string>
#include <string_view>
#include <vector>

namespace XCEngine::Math {

struct Quaternion;
struct Vector3;

} // namespace XCEngine::Math

namespace XCEngine::Components {

class Scene;

} // namespace XCEngine::Components

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

class EditorSceneRuntime {
public:
    EditorSceneRuntime() = default;
    EditorSceneRuntime(const EditorSceneRuntime&) = delete;
    EditorSceneRuntime& operator=(const EditorSceneRuntime&) = delete;
    EditorSceneRuntime(EditorSceneRuntime&&) = delete;
    EditorSceneRuntime& operator=(EditorSceneRuntime&&) = delete;

    void Reset();
    void SetBackend(std::unique_ptr<EditorSceneBackend> backend);
    EditorStartupSceneResult Initialize(const std::filesystem::path& projectRoot);
    void BindSelectionService(EditorSelectionService* selectionService);

    void RefreshScene();
    void EnsureSceneSelection();

    EditorSceneHierarchySnapshot BuildHierarchySnapshot() const;
    std::vector<EditorSceneViewportIconSnapshot> BuildSceneViewportIconSnapshots() const;
    std::optional<EditorSceneViewportSelectionSnapshot> BuildSceneViewportSelectionSnapshot() const;
    std::vector<EditorSceneViewportHelperSnapshot> BuildSelectedViewportHelperSnapshots() const;

    bool HasSceneSelection() const;
    std::optional<EditorSceneObjectId> GetSelectedObjectId() const;
    std::string GetSelectedItemId() const;
    std::string GetSelectedDisplayName() const;
    std::optional<EditorSceneObjectSnapshot> GetSelectedObjectSnapshot() const;
    std::vector<EditorSceneComponentDescriptor> GetSelectedComponents() const;
    std::uint64_t GetSelectionStamp() const;
    std::uint64_t GetInspectorRevision() const;
    std::uint64_t GetSceneContentRevision() const;

    bool SetSelection(std::string_view itemId);
    bool SetSelection(EditorSceneObjectId id);
    void ClearSelection();
    bool NewScene(std::string_view sceneName);
    bool OpenSceneAsset(const std::filesystem::path& scenePath);
    bool SaveScene(const std::filesystem::path& scenePath);
    ::XCEngine::Components::Scene* GetActiveScene() const;
    std::string GetActiveSceneName() const;
    std::unique_ptr<EditorScenePlaySession> BeginPlaySession();

    bool RenameGameObject(
        std::string_view itemId,
        std::string_view newName);
    bool DeleteGameObject(std::string_view itemId);
    std::string DuplicateGameObject(std::string_view itemId);
    bool ReparentGameObject(
        std::string_view itemId,
        std::string_view parentItemId);
    bool MoveGameObjectBefore(
        std::string_view itemId,
        std::string_view targetItemId);
    bool MoveGameObjectAfter(
        std::string_view itemId,
        std::string_view targetItemId);
    bool MoveGameObjectToRoot(std::string_view itemId);
    bool AddComponentToSelectedGameObject(std::string_view componentTypeName);
    bool CanRemoveSelectedComponent(std::string_view componentId) const;
    bool RemoveSelectedComponent(std::string_view componentId);
    bool SetSelectedTransformLocalPosition(
        std::string_view componentId,
        const ::XCEngine::Math::Vector3& position);
    bool SetSelectedTransformLocalEulerAngles(
        std::string_view componentId,
        const ::XCEngine::Math::Vector3& eulerAngles);
    bool SetSelectedTransformLocalScale(
        std::string_view componentId,
        const ::XCEngine::Math::Vector3& scale);
    bool ApplySelectedComponentMutation(
        const EditorSceneComponentMutation& mutation);

    bool CaptureSelectedTransformSnapshot(SceneTransformSnapshot& outSnapshot) const;
    bool ApplyTransformToolWorldPreview(
        EditorSceneObjectId targetId,
        const ::XCEngine::Math::Vector3& position,
        const ::XCEngine::Math::Quaternion& rotation);
    bool ApplyTransformToolLocalScalePreview(
        EditorSceneObjectId targetId,
        const ::XCEngine::Math::Vector3& localScale);

    bool BeginSceneEditTransaction(std::string_view label);
    bool HasPendingSceneEditTransaction() const;
    bool CommitSceneEditTransaction();
    bool CancelSceneEditTransaction();

    bool CanUndoSceneEdit() const;
    bool CanRedoSceneEdit() const;
    bool UndoSceneEdit();
    bool RedoSceneEdit();
    void NotifyExternalInspectorStateChanged();

private:
    struct SceneEditStateSnapshot {
        std::string sceneSnapshot = {};
        EditorSelectionState selection = {};
    };

    struct SceneEditTransaction {
        std::string label = {};
        SceneEditStateSnapshot before = {};
        SceneEditStateSnapshot after = {};
    };

    struct PendingSceneEditTransaction {
        std::string label = {};
        SceneEditStateSnapshot before = {};
    };

    EditorSelectionService& SelectionService();
    const EditorSelectionService& SelectionService() const;
    bool HasHierarchySelection() const;
    void RevalidateSelection();
    bool HasValidSelection() const;
    std::optional<EditorSceneObjectSnapshot> GetObjectSnapshot(
        std::string_view itemId) const;
    EditorSceneComponentDescriptor ResolveSelectedComponentDescriptor(
        std::string_view componentId) const;
    bool SelectFirstAvailableGameObject();
    bool CaptureSceneEditState(SceneEditStateSnapshot& outSnapshot) const;
    bool RestoreSceneEditState(const SceneEditStateSnapshot& snapshot);
    void ResetSceneEditHistory();
    void ClearPendingSceneEditTransaction();
    bool FinalizePendingSceneEditTransaction(bool& outChanged);
    void IncrementInspectorRevision();
    void IncrementSceneContentRevision();

    std::filesystem::path m_projectRoot = {};
    std::unique_ptr<EditorSceneBackend> m_backend = {};
    EditorSelectionService m_ownedSelectionService = {};
    EditorSelectionService* m_selectionService = &m_ownedSelectionService;
    std::vector<SceneEditTransaction> m_sceneUndoStack = {};
    std::vector<SceneEditTransaction> m_sceneRedoStack = {};
    std::optional<PendingSceneEditTransaction> m_pendingSceneEditTransaction = {};
    std::uint64_t m_inspectorRevision = 0u;
    std::uint64_t m_sceneContentRevision = 0u;
};

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