UnrealEngineUWP/Engine/Source/Runtime/LiveLinkInterface/Public/LiveLinkLog.h

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

#pragma once

#include "CoreMinimal.h"
#include "LiveLinkTypes.h"
#include "Logging/TokenizedMessage.h"

#define ENABLE_LIVELINK_LOGGING (1 && !NO_LOGGING && !(UE_BUILD_SHIPPING || UE_BUILD_TEST))

/** This class represents a log of LiveLink output each of which can be a rich tokenized message */
class LIVELINKINTERFACE_API FLiveLinkLog
{
public:
	/** Write an error in to the LiveLink log. */
	template<typename FormatType, typename... ArgsType>
	static void Error(const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		Log_Internal(EMessageSeverity::Error, NAME_None, FLiveLinkSubjectKey(), Format, Args...);
	}

	/**
	 * Write a error in to the LiveLink log.
	 * If the error occurred more than once for that SubjectKey, a counter will indicate the number of time it did occurred.
	 */
	template<typename FormatType, typename... ArgsType>
	static void ErrorOnce(FName MessageID, const FLiveLinkSubjectKey& SubjectKey, const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		Log_Internal(EMessageSeverity::Error, MessageID, SubjectKey, Format, Args...);
	}
	
	/** Write an warning in to the LiveLink log. */
	template<typename FormatType, typename... ArgsType>
	static void Warning(const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		Log_Internal(EMessageSeverity::Warning, NAME_None, FLiveLinkSubjectKey(), Format, Args...);
	}

	/**
	 * Write a warning in to the LiveLink log.
	 * If the warning occurred more than once for that SubjectKey, a counter will indicate the number of time it did occurred.
	 */
	template<typename FormatType, typename... ArgsType>
	static void WarningOnce(FName MessageID, const FLiveLinkSubjectKey& SubjectKey, const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		Log_Internal(EMessageSeverity::Warning, MessageID, SubjectKey, Format, Args...);
	}
	
	/** Write an info in to the LiveLink log. */
	template<typename FormatType, typename... ArgsType>
	static void Info(const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		Log_Internal(EMessageSeverity::Info, NAME_None, FLiveLinkSubjectKey(), Format, Args...);
	}

	/**
	 * Write a info in to the LiveLink log.
	 * If the info occurred more than once for that SubjectKey, a counter will indicate the number of time it did occurred.
	 */
	template<typename FormatType, typename... ArgsType>
	static void InfoOnce(FName MessageID, const FLiveLinkSubjectKey& SubjectKey, const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		Log_Internal(EMessageSeverity::Info, MessageID, SubjectKey, Format, Args...);
	}

	/**
	 * Write an message in to the LiveLink log.
	 * Will returns a valid TokenizedMessage if a new TokenizedMessage was created.
	 */
	template<typename FormatType, typename... ArgsType>
	static TSharedPtr<FTokenizedMessage> TokenizedMessage(EMessageSeverity::Type Severity, const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		return CreateTokenizedMessage_Internal(Severity, NAME_None, FLiveLinkSubjectKey(), Format, Args...);
	}

	/**
	 * Write a repeatable message in to the LiveLink log.
	 * Will returns a valid TokenizedMessage if a new TokenizedMessage was created.
	 * If the info occurred more than once for that SubjectKey, a counter will indicate the number of time it did occurred.
	 */
	template<typename FormatType, typename... ArgsType>
	static TSharedPtr<FTokenizedMessage> TokenizedMessageOnce(EMessageSeverity::Type Severity, FName MessageID, const FLiveLinkSubjectKey& SubjectKey, const FormatType& Format, ArgsType... Args)
	{
		static_assert(TIsArrayOrRefOfType<FormatType, TCHAR>::Value, "Formatting string must be a TCHAR array.");
		return CreateTokenizedMessage_Internal(Severity, MessageID, SubjectKey, Format, Args...);
	}

	static FLiveLinkLog* GetInstance() { return Instance.Get(); }

public:
	/** Dtor */
	virtual ~FLiveLinkLog() = default;

	/** Get the number of time the message with the MessageID and SubjectKey occurred. */
	virtual TPair<int32, FTimespan> GetOccurrence(FName MessageID, FLiveLinkSubjectKey SubjectKey) const = 0;

	/** Get the number of time the selected message occurred. */
	virtual TPair<int32, FTimespan> GetSelectedOccurrence() const = 0;

	/** Get the total number of error, warning and info messages that occurred. */
	virtual void GetLogCount(int32& OutErrorCount, int32& OutWarningCount, int32& OutInfoCount) const = 0;

private:
	template<typename FormatType, typename... ArgsType>
	static void Log_Internal(EMessageSeverity::Type Severity, FName MessageID, const FLiveLinkSubjectKey& SubjectKey, const FormatType& Format, ArgsType... Args)
	{
#if ENABLE_LIVELINK_LOGGING
		if (Instance)
		{
			Instance->LogMessage(Severity, MessageID, SubjectKey, FString::Printf(Format, Args...));
		}
#endif
	}

	template<typename FormatType, typename... ArgsType>
	static TSharedPtr<FTokenizedMessage> CreateTokenizedMessage_Internal(EMessageSeverity::Type Severity, FName MessageID, const FLiveLinkSubjectKey& SubjectKey, const FormatType& Format, ArgsType... Args)
	{
#if ENABLE_LIVELINK_LOGGING
		if (Instance)
		{
			return Instance->CreateTokenizedMessage(Severity, MessageID, SubjectKey, FString::Printf(Format, Args...));
		}
#endif
		return TSharedPtr<FTokenizedMessage>();
	}

protected:
	virtual void LogMessage(EMessageSeverity::Type Severity, FName MessageID, const FLiveLinkSubjectKey& SubjectKey, FString&& Message) = 0;
	virtual TSharedPtr<FTokenizedMessage> CreateTokenizedMessage(EMessageSeverity::Type Severity, FName MessageID, const FLiveLinkSubjectKey& SubjectKey, FString&& Message) = 0;

protected:
	/** The instance that will manage the logging */
	static TUniquePtr<FLiveLinkLog> Instance;
};