FlipLibrary.h

/*
This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to <http://unlicense.org>
*/

#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "GameplayTags.h"
#include <type_traits>
#include "FlipLibrary.generated.h"

// Flipside Standard Library
namespace fstd {

	/** Implementation of C++17's conjunction. Performs a logical AND on the sequence of traits */
	template<typename...> struct conjunction : std::true_type { };
	template<typename B1> struct conjunction<B1> : B1 { };
	template<typename B1, typename... Bn> struct conjunction<B1, Bn...> :
		std::conditional<bool(B1::value), conjunction<Bn...>, B1>::type { };

	/** Implementation of C++17's disjunction. Performs a logical OR on the sequence of traits */
	template<typename...> struct disjunction : std::false_type { };
	template<typename B1> struct disjunction<B1> : B1 { };
	template<typename B1, typename... Bn> struct disjunction<B1, Bn...> :
		std::conditional<bool(B1::value), B1, disjunction<Bn...>>::type { };
}

/**
 * 
 */
UCLASS()
class FLIPSIDE_API UFlipLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()

public:

	/** Checks if all the tags are in the container, accepts either FGameplayTags or strings, returns true if all tags are present */
	template<typename... Args>
	static bool ContainerHasAllTags(const FGameplayTagContainer* Container, Args... TagsToCheck)
	{
		static_assert(
			fstd::disjunction<
			fstd::conjunction<std::is_same<const char*, Args>... >,
			fstd::conjunction<std::is_same<FGameplayTag, Args>...>>::value,
			"'Args' must be of either type 'const char*' or 'FGameplayTag'");

		return ContainerHasAllTagsImpl(Container, TagsToCheck...);
	}

private:

	static bool ContainerHasAllTagsImpl(const FGameplayTagContainer* Container, FGameplayTag Tag)
	{
		return Container->HasTag(Tag);
	}

	static bool ContainerHasAllTagsImpl(const FGameplayTagContainer* Container, const char*  Tag)
	{
		const auto FoundTag{ UGameplayTagsManager::Get().RequestGameplayTag(FName(Tag)) };
		return Container->HasTag(FoundTag);
	}

	template<typename... Args>
	static bool ContainerHasAllTagsImpl(const FGameplayTagContainer* Container, FGameplayTag FirstTag, Args... OtherTags)
	{
		return ContainerHasAllTagsImpl(Container, FirstTag) && ContainerHasAllTagsImpl(Container, OtherTags...);
	}

	template<typename... Args>
	static bool ContainerHasAllTagsImpl(const FGameplayTagContainer* Container, const char*  FirstTag, Args... OtherTags)
	{
		return ContainerHasAllTagsImpl(Container, FirstTag) && ContainerHasAllTagsImpl(Container, OtherTags...);
	}
	
};