// Copyright Epic Games, Inc. All Rights Reserved.

#include "EditorConfig.h"
#include "UObject/UnrealType.h"

FEditorConfig::FEditorConfig()
{
	JsonConfig = MakeShared<UE::FJsonConfig>();
}

void FEditorConfig::SetParent(TSharedPtr<FEditorConfig> InConfig)
{
	ParentConfig = InConfig;

	if (ParentConfig.IsValid())
	{
		JsonConfig->SetParent(ParentConfig->JsonConfig);
	}
	else
	{
		JsonConfig->SetParent(TSharedPtr<UE::FJsonConfig>());
	}
}

bool FEditorConfig::LoadFromFile(FStringView FilePath)
{
	JsonConfig = MakeShared<UE::FJsonConfig>();
	if (!JsonConfig->LoadFromFile(FilePath))
	{
		return false;
	}

	if (ParentConfig.IsValid())
	{
		JsonConfig->SetParent(ParentConfig->JsonConfig);
	}

	return true;
}
	
bool FEditorConfig::LoadFromString(FStringView Content)
{
	JsonConfig = MakeShared<UE::FJsonConfig>();
	if (!JsonConfig->LoadFromString(Content))
	{
		return false;
	}

	if (ParentConfig.IsValid())
	{
		JsonConfig->SetParent(ParentConfig->JsonConfig);
	}

	return true;
}

bool FEditorConfig::SaveToString(FString& OutResult) const
{
	if (!IsValid())
	{
		return false;
	}

	return JsonConfig->SaveToString(OutResult);
}

bool FEditorConfig::SaveToFile(FStringView FilePath) const
{
	if (!IsValid())
	{
		return false;
	}

	return JsonConfig->SaveToFile(FilePath);
}

bool FEditorConfig::HasOverride(FStringView Key) const
{
	return JsonConfig->HasOverride(UE::FJsonPath(Key));
}

void FEditorConfig::ReadStruct(TSharedPtr<FJsonObject> JsonObject, const UStruct* Struct, void* Instance, UObject* Owner)
{
	FString TypeName;
	JsonObject->TryGetStringField(TEXT("$type"), TypeName);

	if (!ensureAlways(Struct->GetName() != TypeName))
	{
		return;
	}

	for (TFieldIterator<FProperty> It(Struct); It; ++It)
	{
		FProperty* Property = *It;
		if (Property != nullptr)
		{
			void* DataPtr = Property->ContainerPtrToValuePtr<void>(Instance);
			
			TSharedPtr<FJsonValue> Value = JsonObject->TryGetField(Property->GetName());
			if (Value.IsValid())
			{
				ReadValue(Value, Property, DataPtr, Owner);
			}
		}
	}
}

void FEditorConfig::ReadUObject(TSharedPtr<FJsonObject> JsonObject, const UClass* Class, UObject* Instance)
{
	FString TypeName;
	JsonObject->TryGetStringField(TEXT("$type"), TypeName);

	if (!ensureAlways(Class->GetName() != TypeName))
	{
		return;
	}

	for (TFieldIterator<FProperty> It(Class); It; ++It)
	{
		FProperty* Property = *It;
		if (Property != nullptr)
		{
			void* DataPtr = Property->ContainerPtrToValuePtr<void>(Instance);

			TSharedPtr<FJsonValue> Value = JsonObject->TryGetField(Property->GetName());
			if (Value.IsValid())
			{
				ReadValue(Value, Property, DataPtr, Instance);
			}
		}
	}
}

void FEditorConfig::ReadValue(TSharedPtr<FJsonValue> JsonValue, const FProperty* Property, void* DataPtr, UObject* Owner)
{
	if (const FStrProperty* StrProperty = CastField<FStrProperty>(Property))
	{
		FString* Value = (FString*) DataPtr;
		JsonValue->TryGetString(*Value);
	}
	else if (const FNameProperty* NameProperty = CastField<FNameProperty>(Property))
	{
		FString TempValue;
		JsonValue->TryGetString(TempValue);

		*(FName*) DataPtr = *TempValue;
	}
	else if (const FTextProperty* TextProperty = CastField<FTextProperty>(Property))
	{
		FString TempValue;
		JsonValue->TryGetString(TempValue);

		*(FText*) DataPtr = FText::FromString(TempValue);
	}
	else if (const FBoolProperty* BoolProperty = CastField<FBoolProperty>(Property))
	{
		bool Value = BoolProperty->GetDefaultPropertyValue();
		if (JsonValue->TryGetBool(Value))
		{
			BoolProperty->SetPropertyValue(DataPtr, Value);
		}
	}
	else if (const FFloatProperty* FloatProperty = CastField<FFloatProperty>(Property))
	{
		float* Value = (float*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FDoubleProperty* DoubleProperty = CastField<FDoubleProperty>(Property))
	{
		double* Value = (double*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	} 
	else if (const FInt8Property* Int8Property = CastField<FInt8Property>(Property))
	{
		int8* Value = (int8*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FInt16Property* Int16Property = CastField<FInt16Property>(Property))
	{
		int16* Value = (int16*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FIntProperty* Int32Property = CastField<FIntProperty>(Property))
	{
		int32* Value = (int32*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FInt64Property* Int64Property = CastField<FInt64Property>(Property))
	{
		int64* Value = (int64*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FByteProperty* ByteProperty = CastField<FByteProperty>(Property))
	{
		uint8* Value = (uint8*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FUInt16Property* Uint16Property = CastField<FUInt16Property>(Property))
	{
		uint16* Value = (uint16*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FUInt32Property* Uint32Property = CastField<FUInt32Property>(Property))
	{
		uint32* Value = (uint32*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FUInt64Property* Uint64Property = CastField<FUInt64Property>(Property))
	{
		uint64* Value = (uint64*) DataPtr;
		JsonValue->TryGetNumber(*Value);
	}
	else if (const FEnumProperty* EnumProperty = CastField<FEnumProperty>(Property))
	{
		int64* Value = (int64*) DataPtr;

		UEnum* Enum = EnumProperty->GetEnum();
		if (Enum != nullptr)
		{
			FString ValueString;
			if (JsonValue->TryGetString(ValueString))
			{
				int64 Index = Enum->GetIndexByNameString(ValueString);
				if (Index != INDEX_NONE)
				{
					*Value = Enum->GetValueByIndex(Index);
				}
			}
		}
	}
	else if (const FObjectPropertyBase* ObjectProperty = CastField<FObjectPropertyBase>(Property))
	{
		FString PathString;
		if (JsonValue->TryGetString(PathString))
		{
			Property->ImportText(*PathString, DataPtr, 0, Owner);
		}
	}
	else if (const FStructProperty* StructProperty = CastField<FStructProperty>(Property))
	{
		const TSharedPtr<FJsonObject>* ObjectJsonValue;
		if (JsonValue->TryGetObject(ObjectJsonValue))
		{
			ReadStruct(*ObjectJsonValue, StructProperty->Struct, DataPtr, Owner);
		}
	}
	else if (const FArrayProperty* ArrayProperty = CastField<FArrayProperty>(Property))
	{
		const TArray<TSharedPtr<FJsonValue>>* ArrayJsonValue;
		if (JsonValue->TryGetArray(ArrayJsonValue))
		{
			FProperty* InnerProperty = ArrayProperty->Inner;
			FScriptArrayHelper ArrayHelper(ArrayProperty, DataPtr);

			ArrayHelper.EmptyAndAddValues(ArrayJsonValue->Num());

			for (int32 Idx = 0; Idx < ArrayHelper.Num(); ++Idx)
			{
				TSharedPtr<FJsonValue> Value = (*ArrayJsonValue)[Idx];
				ReadValue(Value, InnerProperty, ArrayHelper.GetRawPtr(Idx), Owner);
			}
		}
	}
	else if (const FSetProperty* SetProperty = CastField<FSetProperty>(Property))
	{
		const TArray<TSharedPtr<FJsonValue>>* SetJsonValue;
		if (JsonValue->TryGetArray(SetJsonValue))
		{
			const FProperty* InnerProperty = SetProperty->ElementProp;
			FScriptSetHelper SetHelper(SetProperty, DataPtr);
			SetHelper.EmptyElements(SetJsonValue->Num());

			// temporary buffer to read elements into
			TArray<uint8> TempBuffer;
			TempBuffer.AddUninitialized(InnerProperty->ElementSize);

			for (int32 Idx = 0; Idx < SetJsonValue->Num(); ++Idx)
			{
				InnerProperty->InitializeValue(TempBuffer.GetData());

				TSharedPtr<FJsonValue> Value = (*SetJsonValue)[Idx];
				ReadValue(Value, InnerProperty, TempBuffer.GetData(), Owner); 

				SetHelper.AddElement(TempBuffer.GetData());

				InnerProperty->DestroyValue(TempBuffer.GetData());
			}
		}
	}
	else if (const FMapProperty* MapProperty = CastField<FMapProperty>(Property))
	{
		const FProperty* KeyProperty = MapProperty->KeyProp;
		const FProperty* ValueProperty = MapProperty->ValueProp;

		FScriptMapHelper MapHelper(MapProperty, DataPtr);

		// maps can either be stored as a simple JSON object, or as an array of { $key, $value } pairs
		// first check for object storage - this will cover eg. numbers and strings as keys
		const TSharedPtr<FJsonObject>* JsonObjectValue;
		if (JsonValue->TryGetObject(JsonObjectValue))
		{
			MapHelper.EmptyValues((*JsonObjectValue)->Values.Num());

			// temporary buffers to read elements into
			TArray<uint8> TempKey;
			TempKey.AddZeroed(KeyProperty->ElementSize);

			TArray<uint8> TempValue;
			TempValue.AddZeroed(ValueProperty->ElementSize);

			for (const TPair<FString, TSharedPtr<FJsonValue>>& JsonPair : (*JsonObjectValue)->Values)
			{
				KeyProperty->InitializeValue(TempKey.GetData());
				KeyProperty->ImportText(*JsonPair.Key, TempKey.GetData(), 0, Owner);

				ValueProperty->InitializeValue(TempValue.GetData());
				ReadValue(JsonPair.Value, ValueProperty, TempValue.GetData(), Owner); 

				MapHelper.AddPair(TempKey.GetData(), TempValue.GetData());

				KeyProperty->DestroyValue(TempKey.GetData());
				ValueProperty->DestroyValue(TempValue.GetData());
			}
		
			return;
		}

		// then check for array storage, this will cover complex keys eg. custom structs
		const TArray<TSharedPtr<FJsonValue>>* JsonArrayPtr = nullptr;
		if (JsonValue->TryGetArray(JsonArrayPtr))
		{
			MapHelper.EmptyValues(JsonArrayPtr->Num());
			
			// temporary buffers to read elements into
			TArray<uint8> TempKey;
			TempKey.AddUninitialized(KeyProperty->ElementSize);

			TArray<uint8> TempValue;
			TempValue.AddUninitialized(ValueProperty->ElementSize);

			for (const TSharedPtr<FJsonValue>& JsonElement : *JsonArrayPtr)
			{
				TSharedPtr<FJsonObject>* JsonObject = nullptr;
				if (JsonElement->TryGetObject(JsonObject))
				{
					TSharedPtr<FJsonValue> JsonKeyField = (*JsonObject)->TryGetField(TEXT("$key"));
					TSharedPtr<FJsonValue> JsonValueField = (*JsonObject)->TryGetField(TEXT("$value"));

					if (JsonKeyField.IsValid() && JsonValueField.IsValid())
					{
						KeyProperty->InitializeValue(TempKey.GetData());
						ReadValue(JsonKeyField, KeyProperty, TempKey.GetData(), Owner); 

						ValueProperty->InitializeValue(TempValue.GetData());
						ReadValue(JsonValueField, ValueProperty, TempValue.GetData(), Owner); 

						MapHelper.AddPair(TempKey.GetData(), TempValue.GetData());

						KeyProperty->DestroyValue(TempKey.GetData());
						ValueProperty->DestroyValue(TempValue.GetData());
					}
				}
			}

			return;
		}
	}
}

TSharedPtr<FJsonValue> FEditorConfig::WriteValue(const FProperty* Property, const void* DataPtr)
{
	TSharedPtr<FJsonValue> ResultValue;

	if (const FStrProperty* StrProperty = CastField<FStrProperty>(Property))
	{
		FString* Value = (FString*) DataPtr;
		ResultValue = MakeShared<FJsonValueString>(*Value);
	}
	else if (const FNameProperty* NameProperty = CastField<FNameProperty>(Property))
	{
		FName* Value = (FName*) DataPtr;
		ResultValue = MakeShared<FJsonValueString>(Value->ToString());
	}
	else if (const FTextProperty* TextProperty = CastField<FTextProperty>(Property))
	{
		FText* Value = (FText*) DataPtr;
		ResultValue = MakeShared<FJsonValueString>(Value->ToString());
	}
	else if (const FBoolProperty* BoolProperty = CastField<FBoolProperty>(Property))
	{
		bool Value = BoolProperty->GetPropertyValue(DataPtr);
		ResultValue = MakeShared<FJsonValueBoolean>(Value);
	}
	else if (const FFloatProperty* FloatProperty = CastField<FFloatProperty>(Property))
	{
		float* Value = (float*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FDoubleProperty* DoubleProperty = CastField<FDoubleProperty>(Property))
	{
		double* Value = (double*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	} 
	else if (const FInt8Property* Int8Property = CastField<FInt8Property>(Property))
	{
		int8* Value = (int8*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FInt16Property* Int16Property = CastField<FInt16Property>(Property))
	{
		int16* Value = (int16*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FIntProperty* Int32Property = CastField<FIntProperty>(Property))
	{
		int32* Value = (int32*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FInt64Property* Int64Property = CastField<FInt64Property>(Property))
	{
		int64* Value = (int64*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FByteProperty* ByteProperty = CastField<FByteProperty>(Property))
	{
		uint8* Value = (uint8*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FUInt16Property* Uint16Property = CastField<FUInt16Property>(Property))
	{
		uint16* Value = (uint16*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FUInt32Property* Uint32Property = CastField<FUInt32Property>(Property))
	{
		uint32* Value = (uint32*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FUInt64Property* Uint64Property = CastField<FUInt64Property>(Property))
	{
		uint64* Value = (uint64*) DataPtr;
		ResultValue = MakeShared<FJsonValueNumber>(*Value);
	}
	else if (const FEnumProperty* EnumProperty = CastField<FEnumProperty>(Property))
	{
		int64* Value = (int64*) DataPtr;

		UEnum* Enum = EnumProperty->GetEnum();
		FName ValueName = Enum->GetNameByValue(*Value);
		ResultValue = MakeShared<FJsonValueString>(ValueName.ToString());
	}
	else if (const FObjectPropertyBase* ObjectProperty = CastField<FObjectPropertyBase>(Property))
	{
		FString ObjectPath;
		// TODO: No idea how we're meant to get object paths, might be this:
		//ObjectProperty->ExportTextItem(ObjectPath, DataPtr, ??? /*DefaultValue*/, ??? /*Parent*/, 0, ??? /*ExportRootScope*/);
		ResultValue = MakeShared<FJsonValueString>(ObjectPath);
	}
	else if (const FStructProperty* StructProperty = CastField<FStructProperty>(Property))
	{
		ResultValue = MakeShared<FJsonValueObject>(WriteStruct(StructProperty->Struct, DataPtr));
	}
	else if (const FArrayProperty* ArrayProperty = CastField<FArrayProperty>(Property))
	{
		FProperty* InnerProperty = ArrayProperty->Inner;
		FScriptArrayHelper ArrayHelper(ArrayProperty, DataPtr);

		TArray<TSharedPtr<FJsonValue>> JsonValuesArray;
		JsonValuesArray.Reserve(ArrayHelper.Num());

		for (int32 Idx = 0; Idx < ArrayHelper.Num(); ++Idx)
		{
			TSharedPtr<FJsonValue> ElementValue = WriteValue(InnerProperty, ArrayHelper.GetRawPtr(Idx));
			JsonValuesArray.Add(ElementValue);
		}

		ResultValue = MakeShared<FJsonValueArray>(JsonValuesArray);
	}
	else if (const FSetProperty* SetProperty = CastField<FSetProperty>(Property))
	{
		FProperty* InnerProperty = SetProperty->ElementProp;
		FScriptSetHelper SetHelper(SetProperty, DataPtr);

		TArray<TSharedPtr<FJsonValue>> JsonValuesArray;
		JsonValuesArray.Reserve(SetHelper.Num());

		for (int32 Idx = 0; Idx < SetHelper.Num(); ++Idx)
		{
			if (SetHelper.IsValidIndex(Idx))
			{
				TSharedPtr<FJsonValue> ElementValue = WriteValue(InnerProperty, SetHelper.GetElementPtr(Idx));
				JsonValuesArray.Add(ElementValue);
			}
		}

		ResultValue = MakeShared<FJsonValueArray>(JsonValuesArray);
	}
	else if (const FMapProperty* MapProperty = CastField<FMapProperty>(Property))
	{
		FProperty* KeyProperty = MapProperty->KeyProp;
		FProperty* ValueProperty = MapProperty->ValueProp;

		FScriptMapHelper MapHelper(MapProperty, DataPtr);

		if (MapHelper.Num() == 0)
		{
			ResultValue = MakeShared<FJsonValueObject>(MakeShared<FJsonObject>());
		}
		else
		{
			TArray<TSharedPtr<FJsonValue>> JsonKeysArray;
			JsonKeysArray.Reserve(MapHelper.Num());

			TArray<TSharedPtr<FJsonValue>> JsonValuesArray;
			JsonValuesArray.Reserve(MapHelper.Num());

			for (int32 Idx = 0; Idx < MapHelper.Num(); ++Idx)
			{
				TSharedPtr<FJsonValue> JsonKey = WriteValue(KeyProperty, MapHelper.GetKeyPtr(Idx));
				JsonKeysArray.Add(JsonKey);

				TSharedPtr<FJsonValue> JsonValue = WriteValue(ValueProperty, MapHelper.GetValuePtr(Idx));
				JsonValuesArray.Add(JsonValue);
			}

			// maps can either be stored as $key, $value pairs or, if the keys can be stringified, as a JSON object
			// check which we should use based on the first element
			EJson KeyType = JsonKeysArray[0]->Type;
			if (KeyType == EJson::Object)
			{
				TArray<TSharedPtr<FJsonValue>> ResultArray;
				ResultArray.Reserve(MapHelper.Num());

				for (int32 Idx = 0; Idx < MapHelper.Num(); ++Idx)
				{
					TSharedPtr<FJsonObject> ElementObject = MakeShared<FJsonObject>();
					ElementObject->SetField(TEXT("$key"), JsonKeysArray[Idx]);
					ElementObject->SetField(TEXT("$value"), JsonValuesArray[Idx]);

					ResultArray.Add(MakeShared<FJsonValueObject>(ElementObject));
				}

				ResultValue = MakeShared<FJsonValueArray>(ResultArray);
			}
			else if (KeyType == EJson::Boolean || 
				KeyType == EJson::Number || 
				KeyType == EJson::String)
			{
				TSharedPtr<FJsonObject> ResultObject = MakeShared<FJsonObject>();

				for (int32 Idx = 0; Idx < MapHelper.Num(); ++Idx)
				{
					FString KeyString;
					check(JsonKeysArray[Idx]->TryGetString(KeyString));

					ResultObject->SetField(KeyString, JsonValuesArray[Idx]);
				}
				
				ResultValue = MakeShared<FJsonValueObject>(ResultObject);
			}

			ensureMsgf(ResultValue.IsValid(), TEXT("Map key type is invalid."));
		}
	}

	ensureMsgf(ResultValue.IsValid(), TEXT("Property type is unsupported."));
	return ResultValue;
}

bool FEditorConfig::IsDefault(const FProperty* Property, TSharedPtr<FJsonValue> JsonValue, const void* NativeValue)
{
	if (JsonValue->Type == EJson::Array)
	{
		return JsonValue->AsArray().Num() == 0;
	}
	else if (JsonValue->Type == EJson::Object)
	{
		return JsonValue->AsObject()->Values.Num() == 0;
	}
	else
	{
		// have the property initialize some temp storage, then check against that
		uint8 Temp[256];
		Property->InitializeValue(Temp);

		return Property->Identical(NativeValue, Temp);
	}

	return false;
}

TSharedPtr<FJsonObject> FEditorConfig::WriteStruct(const UStruct* Struct, const void* Instance) 
{
	TSharedPtr<FJsonObject> JsonObject = MakeShared<FJsonObject>();

	for (TFieldIterator<FProperty> It(Struct); It; ++It)
	{
		const FProperty* Property = *It;
		const void* ValuePtr = Property->ContainerPtrToValuePtr<void>(Instance); 

		TSharedPtr<FJsonValue> PropertyValue = WriteValue(Property, ValuePtr);
		if (!IsDefault(Property, PropertyValue, ValuePtr))
		{
			JsonObject->SetField(Property->GetName(), PropertyValue);
		}
	}

	return JsonObject;
}

/** 
	* This exists because of sparse class data that can exist for UObjects only, and which is handled in ContainerPtrToValuePtr.
	*/
TSharedPtr<FJsonObject> FEditorConfig::WriteUObject(const UStruct* Struct, const UObject* Instance) 
{
	TSharedPtr<FJsonObject> JsonObject = MakeShared<FJsonObject>();

	for (TFieldIterator<FProperty> It(Struct); It; ++It)
	{
		const FProperty* Property = *It;
		const void* ValuePtr = Property->ContainerPtrToValuePtr<void>(Instance); 

		TSharedPtr<FJsonValue> PropertyValue = WriteValue(Property, ValuePtr);
		if (!IsDefault(Property, PropertyValue, ValuePtr))
		{
			JsonObject->SetField(Property->GetName(), PropertyValue);
		}
	}

	return JsonObject;
}