#pragma once

#include "CoreMinimal.h"
#include "Subsystems/GameInstanceSubsystem.h"
#include "Telemetry/TelemetryEvent.h"
#include "Telemetry/TelemetrySink.h"
#include "TelemetrySubsystem.generated.h"

// The one seam gameplay emits through. Owns the sink, stamps the envelope, exposes Emit. Gameplay code resolves it
// from its game instance once and keeps the pointer; there is no static helper and there will not be one
// (Docs/Spec/Telemetry.md). Every peer has its own subsystem and its own file; nothing is forwarded.
UCLASS()
class SALTY_API UTelemetrySubsystem : public UGameInstanceSubsystem
{
	GENERATED_BODY()

public:
	virtual void Initialize(FSubsystemCollectionBase& Collection) override;
	virtual void Deinitialize() override;

	// Stamps the envelope and hands the event to the sink. Name comes from TelemetryEvents, never a literal.
	void Emit(FName Name, TSharedPtr<FJsonObject> Payload = nullptr);

	// The server mints the id in ASaltyGameMode; a client adopts the id replicated through ASaltyGameState.
	void BeginSession(FGuid InSessionId);

	// Log in the editor, Jsonl with -telemetry or telemetry.File 1, Null otherwise. Public so a test can substitute.
	void SetSink(TUniquePtr<ITelemetrySink> InSink);

	// Called by every bs.* console command. Sticky for the session: tainted sessions are filterable, not deleted.
	void MarkCheatUsed(FName Command = NAME_None);

	bool HasSession() const { return SessionId.IsValid(); }
	FGuid GetSessionId() const { return SessionId; }
	bool WereCheatsUsed() const { return bCheatsUsed; }

private:
	FTelemetryEnvelope StampEnvelope() const;
	TUniquePtr<ITelemetrySink> MakeDefaultSink() const;

	TUniquePtr<ITelemetrySink> Sink;
	FGuid SessionId;
	bool bCheatsUsed = false;
	FString BuildString;
};