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

#include "inprocsessionlogsink.h"

#include <zencore/logbase.h>

namespace zen {

/// Bias in seconds from DateTime epoch (year 1) to Unix epoch (1970).
static constexpr uint64_t UnixEpochBiasSeconds = uint64_t(double(1970 - 1) * 365.2425) * 86400;

static DateTime
TimePointToDateTime(logging::LogClock::time_point Time)
{
	// DateTime ticks are 100 ns each. Splitting the time_point into whole-second
	// and sub-second parts and converting both lets us preserve sub-second
	// precision; the previous implementation truncated to seconds, which made
	// every entry land at .000 ms in tail / dashboard renderings.
	auto	 Duration		= Time.time_since_epoch();
	auto	 Seconds		= std::chrono::duration_cast<std::chrono::seconds>(Duration);
	auto	 SubSecondNanos = std::chrono::duration_cast<std::chrono::nanoseconds>(Duration - Seconds);
	uint64_t SecondsTicks	= (UnixEpochBiasSeconds + static_cast<uint64_t>(Seconds.count())) * TimeSpan::TicksPerSecond;
	uint64_t SubSecondTicks = static_cast<uint64_t>(SubSecondNanos.count()) / static_cast<uint64_t>(TimeSpan::NanosecondsPerTick);
	return DateTime{SecondsTicks + SubSecondTicks};
}

void
InProcSessionLogSink::Log(const logging::LogMessage& Msg)
{
	// Route through the service-level AppendLog so the log-appended
	// callback fires — otherwise WS subscribers tailing the self-session
	// don't see in-proc lines until they reload and re-fetch via HTTP.
	m_Service.AppendLog(m_SessionId,
						SessionsService::LogEntryInput{
							.Timestamp	= TimePointToDateTime(Msg.GetTime()),
							.Level		= Msg.GetLevel(),
							.LoggerName = Msg.GetLoggerName(),
							.Message	= Msg.GetPayload(),
						});
}

}  // namespace zen