// Bounded, opt-in startup trace for the complete streaming path.
// The trace is deliberately independent of the shared Unreal log: callers provide an
// absolute output path and every record is one JSON object per line.
#pragma once

#include "CoreMinimal.h"

namespace VoxelForgeStartupTrace
{
    struct VOXELFORGE_API FTileSample
    {
        int32 TileX = 0;
        int32 TileY = 0;
        int32 TileZ = 0;
        int32 Level = -1;
        int32 WorkPriority = 0;
        int32 Verdict = -1; // Mixed=0, AllSolid=1, AllAir=2, -1=not classified (early path)
        uint64 RequestOrdinal = 0;
        uint64 GenerationOrdinal = 0;
        uint64 RequestStartCycles = 0;
        uint64 WorkerTaskStartCycles = 0;
        uint64 WorkerTaskEndCycles = 0;
        uint32 WorkerThreadId = 0;
        bool bResidentAtRequest = false;
        bool bSealedSolidProof = false;
        bool bEmpty = true;
        int32 Vertices = 0;
        int32 Triangles = 0;
        uint64 GeometryBytes = 0;
        // This is worker-result -> game-thread mesh submission. Collision readiness is a later
        // per-tile RMC completion event recorded separately as collision_ready.
        double RequestToApplySeconds = 0.0;
        double QueueWaitSeconds = 0.0;
        double WorkerQueueSeconds = 0.0;
        double ResultQueueSeconds = 0.0;
        double WorkerTaskSeconds = 0.0;
        double GenerationSeconds = 0.0;
        double CoreGenerateSeconds = 0.0;
        double MeshCopySeconds = 0.0;
        double StreamBuildSeconds = 0.0;
        double ClassifySeconds = 0.0;
        double MeshSeconds = 0.0;
        double StreamSeconds = 0.0;
        double ApplySeconds = 0.0;
    };

    struct VOXELFORGE_API FApplyFrameSample
    {
        uint64 Frame = 0;
        double FrameSeconds = 0.0;
        double SpeedCmPerSecond = 0.0;
        double ApplySeconds = 0.0;
        double DrainSeconds = 0.0;
        int32 ActiveTasks = 0;
        int32 RunningWorkerTasks = 0;
        int32 TaskCap = 0;
        int32 PendingTiles = 0;
        int32 PendingResultsEstimate = 0;
        int32 ResultsDrained = 0;
        int32 ApplyResultsByLevelTotal = 0;
        int32 MeshesApplied = 0;
        int32 MaxApplies = 0;
        double ApplyBudgetMilliseconds = 0.0;
        bool bCountLimitReached = false;
        bool bTimeLimitReached = false;
        TStaticArray<int32, 9> PendingByLevel{};
        TStaticArray<int32, 9> ApplyResultsByLevel{};
        TStaticArray<int32, 9> MeshesAppliedByLevel{};
        TStaticArray<double, 9> ApplySecondsByLevel{};
    };

    struct VOXELFORGE_API FWriteMetrics
    {
        double JsonWriteMilliseconds = 0.0;
        double ArchiveSerializeMilliseconds = 0.0;
    };

    /** Starts when -voxel.StartupTraceFile=<absolute path> is present. */
    VOXELFORGE_API void BeginFromCommandLine();

    VOXELFORGE_API bool IsActive();

    /** Returns and resets startup-trace writes performed by the current game-thread frame. */
    VOXELFORGE_API FWriteMetrics ConsumeCurrentThreadWriteMetrics();

    /** FieldsJson is the contents after the type/timestamp object prefix, without braces. */
    VOXELFORGE_API void RecordEvent(const TCHAR* Type, const FString& FieldsJson = FString());

    VOXELFORGE_API void RecordRequest(const FTileSample& Sample, uint32 Epoch);

    VOXELFORGE_API void StageBegin(const TCHAR* Name);
    VOXELFORGE_API void StageEnd(const TCHAR* Name);

    VOXELFORGE_API void RecordTile(const FTileSample& Sample);

    /** One game-thread result-drain sample, including worker occupancy and per-LOD applies. */
    /** Echantillon de vidage des resultats, avec occupation des travailleurs et applications par LOD. */
    VOXELFORGE_API void RecordApplyFrame(const FApplyFrameSample& Sample);

    /** Writes the final bounded summary and closes the file. Safe to call more than once. */
    VOXELFORGE_API void Finish(const TCHAR* Reason);

    /** RAII helper for stages which have early-return failure paths. */
    class VOXELFORGE_API FStageScope
    {
    public:
        explicit FStageScope(const TCHAR* InName);
        ~FStageScope();

        FStageScope(const FStageScope&) = delete;
        FStageScope& operator=(const FStageScope&) = delete;

    private:
        FString Name;
        bool bActive = false;
    };
}