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

#include "zencore/session.h"

#include <zencore/uid.h>

#include <mutex>

namespace zen {

static Oid			  GlobalSessionId;
static Oid::String_t  GlobalSessionString;
static std::once_flag SessionInitFlag;

static Oid			 GlobalParentSessionId;
static Oid::String_t GlobalParentSessionString;
static std::mutex	 GlobalParentSessionMutex;

Oid
GetSessionId()
{
	std::call_once(SessionInitFlag, [&] {
		GlobalSessionId.Generate();
		GlobalSessionId.ToString(GlobalSessionString);
	});

	return GlobalSessionId;
}

std::string_view
GetSessionIdString()
{
	// Ensure we actually have a generated session identifier
	std::ignore = GetSessionId();

	return std::string_view(GlobalSessionString, Oid::StringLength);
}

void
SetParentSessionId(const Oid& ParentSessionId)
{
	std::lock_guard<std::mutex> Lock(GlobalParentSessionMutex);
	GlobalParentSessionId = ParentSessionId;
	GlobalParentSessionId.ToString(GlobalParentSessionString);
}

Oid
GetParentSessionId()
{
	std::lock_guard<std::mutex> Lock(GlobalParentSessionMutex);
	return GlobalParentSessionId;
}

std::string_view
GetParentSessionIdString()
{
	std::lock_guard<std::mutex> Lock(GlobalParentSessionMutex);
	if (GlobalParentSessionId == Oid::Zero)
	{
		return {};
	}
	return std::string_view(GlobalParentSessionString, Oid::StringLength);
}

}  // namespace zen