LiveConfigPropertyTreeSubsystem.h

// Copyright (c) 2026 Nicholas Arthur
// Licensed under the MIT License
 
#pragma once
 
#include "CoreMinimal.h"
#include "LiveConfigTypes.h"
#include "EditorSubsystem.h"
#include "LiveConfigPropertyTreeSubsystem.generated.h"
 
// Canonical, shared tree node built from live config property definitions.
// This model is owned by the subsystem and should be treated as read-only by views.
struct FLiveConfigPropertyModelNode : public TSharedFromThis<FLiveConfigPropertyModelNode>
{
    FString DisplayName;
    FString FullPath;
    TSharedPtr<FLiveConfigPropertyDefinition> PropertyDefinition;
    TArray<TSharedRef<FLiveConfigPropertyModelNode>> Children;
    TWeakPtr<FLiveConfigPropertyModelNode> Parent;
 
    bool IsProperty() const { return PropertyDefinition.IsValid() && PropertyDefinition->PropertyType != ELiveConfigPropertyType::Struct; }
    bool IsStruct() const { return PropertyDefinition.IsValid() && PropertyDefinition->PropertyType == ELiveConfigPropertyType::Struct; }
};
 
// Editor-only subsystem that owns the property tree and shared definition list,
// rebuilt on LiveConfigSystem updates for all manager views to consume.
UCLASS()
class LIVECONFIGEDITOR_API ULiveConfigPropertyTreeSubsystem : public UEditorSubsystem
{
    GENERATED_BODY()
 
public:
    static ULiveConfigPropertyTreeSubsystem& Get();
    
    // USubsystem
    virtual void Initialize(FSubsystemCollectionBase& Collection) override;
    virtual void Deinitialize() override;
    // ~USubsystem
 
    // Root nodes for the tree (folders/structs/properties).
    const TArray<TSharedRef<FLiveConfigPropertyModelNode>>& GetRootNodes() const { return RootNodes; }
    
    // Fast lookup of nodes by full property path.
    const TMap<FString, TSharedPtr<FLiveConfigPropertyModelNode>>& GetNodeByPath() const { return NodeByPath; }
    
    // Flat, alphabetically (natural) sorted list of shared property definitions backing the tree.
    const TArray<TSharedPtr<FLiveConfigPropertyDefinition>>& GetDefinitions() const { return Definitions; }
 
    void RebuildFromSystem();
 
    // Shared definitions backing the canonical tree.
    TArray<TSharedPtr<FLiveConfigPropertyDefinition>> Definitions;
 
private:
    void Rebuild(const TMap<FLiveConfigProperty, FLiveConfigPropertyDefinition>& InDefs);
 
    TArray<TSharedRef<FLiveConfigPropertyModelNode>> RootNodes;
    TMap<FString, TSharedPtr<FLiveConfigPropertyModelNode>> NodeByPath;
    TMap<FString, TSharedPtr<FLiveConfigPropertyDefinition>> StructByName;
    FDelegateHandle PropertiesUpdatedHandle;
};