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

#include <zencore/profiling/counterstrace.h>

#if ZEN_WITH_TRACE

#	include <zencore/timer.h>
#	include <zencore/trace.h>

#	include <atomic>
#	include <cstring>

namespace {

// Wire-compatible with UE's CountersTrace events (Counters.Spec /
// SetValueInt / SetValueFloat). Channel name matches UE so users can mix &
// match analyzers.
UE_TRACE_CHANNEL_DEFINE(CountersChannel)

UE_TRACE_EVENT_BEGIN(Counters, Spec, NoSync | Important)
	UE_TRACE_EVENT_FIELD(uint16_t, Id)
	UE_TRACE_EVENT_FIELD(uint8_t, Type)
	UE_TRACE_EVENT_FIELD(uint8_t, DisplayHint)
	UE_TRACE_EVENT_FIELD(UE::Trace::AnsiString, Name)
UE_TRACE_EVENT_END()

UE_TRACE_EVENT_BEGIN(Counters, SetValueInt)
	UE_TRACE_EVENT_FIELD(uint64_t, Cycle)
	UE_TRACE_EVENT_FIELD(int64_t, Value)
	UE_TRACE_EVENT_FIELD(uint16_t, CounterId)
UE_TRACE_EVENT_END()

UE_TRACE_EVENT_BEGIN(Counters, SetValueFloat)
	UE_TRACE_EVENT_FIELD(uint64_t, Cycle)
	UE_TRACE_EVENT_FIELD(double, Value)
	UE_TRACE_EVENT_FIELD(uint16_t, CounterId)
UE_TRACE_EVENT_END()

}  // namespace

namespace zen::counters_detail {

uint16_t
OutputInitCounter(const char* Name, TraceCounterType Type, TraceCounterDisplayHint Hint)
{
	if (!UE_TRACE_CHANNELEXPR_IS_ENABLED(CountersChannel) || Name == nullptr)
	{
		return 0;
	}

	// Counter ids are uint16; tourist's analyzer truncates anyway. Wrapping
	// past 0xFFFF would re-use ids, so we cap allocation -- in practice no
	// real-world trace uses anywhere near 65k distinct counters.
	static std::atomic<uint32_t> g_NextId{0};
	uint32_t					 Allocated = g_NextId.fetch_add(1, std::memory_order_relaxed) + 1;
	if (Allocated > 0xFFFFu)
	{
		return 0;
	}
	uint16_t Id = uint16_t(Allocated);

	uint16_t NameLen = uint16_t(std::strlen(Name));
	UE_TRACE_LOG(Counters, Spec, CountersChannel, NameLen * sizeof(char))
		<< Spec.Id(Id) << Spec.Type(uint8_t(Type)) << Spec.DisplayHint(uint8_t(Hint)) << Spec.Name(Name, NameLen);

	return Id;
}

void
OutputSetValueInt(uint16_t Id, int64_t Value)
{
	if (Id == 0 || !UE_TRACE_CHANNELEXPR_IS_ENABLED(CountersChannel))
	{
		return;
	}
	UE_TRACE_LOG(Counters, SetValueInt, CountersChannel)
		<< SetValueInt.Cycle(zen::GetHifreqTimerValue()) << SetValueInt.Value(Value) << SetValueInt.CounterId(Id);
}

void
OutputSetValueFloat(uint16_t Id, double Value)
{
	if (Id == 0 || !UE_TRACE_CHANNELEXPR_IS_ENABLED(CountersChannel))
	{
		return;
	}
	UE_TRACE_LOG(Counters, SetValueFloat, CountersChannel)
		<< SetValueFloat.Cycle(zen::GetHifreqTimerValue()) << SetValueFloat.Value(Value) << SetValueFloat.CounterId(Id);
}

bool
IsCountersChannelEnabled()
{
	return UE_TRACE_CHANNELEXPR_IS_ENABLED(CountersChannel);
}

}  // namespace zen::counters_detail

#endif	// ZEN_WITH_TRACE