#include "OwnerWorldLoader.h"
#include "StandaloneCoreScheduler.h"
#include "StreamBenchmarkPipeline.h"
#include "WorldAssemblyPrototype.h"
#include "StandaloneTlsProbe.h"
#include "../Core/src/StandaloneSnapshotAdapter.h"

#include <algorithm>
#include <chrono>
#include <cmath>
#include <cstdint>
#include <ctime>
#include <cstdio>
#include <cstdlib>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <iterator>
#include <limits>
#include <memory>
#include <string>
#include <string_view>

namespace
{
    struct FOptions
    {
        std::filesystem::path DataPath;
        int WorkerCount=8;
        int ClipRadius=3;
        int MaxClipLevel=8;
        int MaxLevel=-1;
        int FarHorizonLOD8InteriorStepVoxels=0;
        bool WorldAssemblerPrototype=false;
        bool StreamBenchmark=false;
        bool StreamPipeline=false;
        bool StreamHash=false;
        bool ProfileColumnOverlap=false;
        bool UseSharedColumnCache=true;
        bool ForceGenerate=false;
        bool MeshCoverage=false;
        bool ScreenSpaceGate=false;
        bool AuditUniformBlockProofs=false;
        bool ProfileLodWork=false;
        bool AuditBasePageEquivalence=false;
        bool AuditRouteParity=false;
        bool RegionCrossing=false;
        bool AuditTileShapeReadiness=false;
        int DiagnosticSlowShapeCompileMs=0;
        bool HasSeedOverride=false;
        int SeedOverride=0;
        bool HasRenderDistanceOverride=false;
        int RenderDistanceOverride=0;
        bool FloatingIslandsRecipe=false;
        bool TlsProbeRequested=false;
        int TlsProbeWorkers=0;
        std::string TlsProbeTouch="none";
        bool HasCamera=false;
        bool HasCameraStep=false;
        bool AutoSurfaceCamera=false;
        FVector CameraMeters=FVector::ZeroVector;
        FVector CameraStepMeters=FVector::ZeroVector;
        float CameraYawDegrees=0.0f;
        float CameraPitchDegrees=0.0f;
        std::filesystem::path MeshExportPath;
        std::filesystem::path WorldAssemblyManifestOutputPath;
    };

    bool ParseInteger(std::string_view text,int& output)
    {
        if(text.empty())return false;
        char* end=nullptr;
        const std::string value(text);
        const long parsed=std::strtol(value.c_str(),&end,10);
        if(end==value.c_str()||*end!='\0'||parsed<INT32_MIN||parsed>INT32_MAX)return false;
        output=static_cast<int>(parsed);
        return true;
    }

    bool ParseCamera(std::string_view text,FVector& meters,float& yawDegrees,float& pitchDegrees)
    {
        const std::string values(text);
        float x=0.0f,y=0.0f,z=0.0f,yaw=0.0f,pitch=0.0f;
        if(std::sscanf(values.c_str(),"%f,%f,%f,%f,%f",&x,&y,&z,&yaw,&pitch)!=5)
            return false;
        meters={x,y,z};
        yawDegrees=yaw;
        pitchDegrees=pitch;
        return true;
    }

    bool ParseCameraStep(std::string_view text,FVector& meters)
    {
        const std::string values(text);
        float x=0.0f,y=0.0f,z=0.0f;
        if(std::sscanf(values.c_str(),"%f,%f,%f",&x,&y,&z)!=3)return false;
        meters={x,y,z};
        return true;
    }

    bool ParseOptions(int argc,char** argv,FOptions& options)
    {
        const std::filesystem::path executable=std::filesystem::absolute(argv[0]);
        options.DataPath=executable.parent_path().parent_path()/"data/owner_world.json";
        for(int index=1;index<argc;++index)
        {
            const std::string_view arg(argv[index]);
            const auto readInt=[&](std::string_view prefix,int& value)
            {return arg.starts_with(prefix)&&ParseInteger(arg.substr(prefix.size()),value);};
            if(arg=="--help"||arg=="-h")
            {
                std::printf("Usage: %s [owner_world.json] --world-assembler-prototype --stream-benchmark --stream-pipeline [options]\n"
                    "  --workers=N --clip-radius=N --max-clip-level=N --max-level=N\n"
                    "  --camera=X,Y,Z,YAW,PITCH (position in metres) --stream-hash\n"
                    "  --camera-step=X,Y,Z (optional second view step in metres)\n"
                    "  --region-crossing (compile entering Core regions at the camera step)\n"
                    "  --column-cache=shared|thread-local (default: shared)\n"
                    "  --mesh-export=FILE (write the exact generated tile meshes for offline rendering)\n"
                    "  --world-assembler-manifest-output=FILE (write the resolved plan for diagnostics)\n"
                    "  --profile-column-overlap --far-horizon-lod8-step=N --force-generate\n"
                    "  --seed=N --recipe=surface-world|floating-islands\n"
                    "  --auto-surface-camera (place the 27-tile cube on this seed's surface)\n"
                    "  --mesh-coverage (report non-empty tiles and indexed triangles)\n"
                    "  --screen-space-gate (measure display error and historical negative controls)\n"
                    "  --audit-uniform-block-proofs (fill and check every interval-certified block)\n"
                    "  --profile-lod-work (report per-LOD density sample counts)\n"
                    "  --audit-base-page-equivalence (hash one tile through both shape routes)\n"
                    "  --audit-route-parity (compare page, native-only, exact-query and mesh routes)\n"
                    "  --audit-tile-shape-readiness (run a deliberately mis-marked tile against the native-only guard)\n"
                    "  --diagnostic-slow-shape-compile-ms=N (diagnostic overlap control; default 0)\n"
                    "  --render-distance-chunks=N (0 disables the extra far ring)\n"
                    "  --tls-probe=N (Linux worker TLS/stack measurement; N=0..12)\n"
                    "  --tls-probe-touch=none|surface-world|floating-islands (first-use probe)\n"
                    "  --process-affinity=MASK --process-priority=Normal --frame-limit=FPS (viewer compatibility only)\n",
                    argv[0]);
                return false;
            }
            if(arg=="--world-assembler-prototype")options.WorldAssemblerPrototype=true;
            else if(arg=="--stream-benchmark")options.StreamBenchmark=true;
            else if(arg=="--stream-pipeline")options.StreamPipeline=true;
            else if(arg=="--stream-hash")options.StreamHash=true;
            else if(arg=="--profile-column-overlap")options.ProfileColumnOverlap=true;
            else if(arg=="--force-generate")options.ForceGenerate=true;
            else if(arg=="--mesh-coverage")options.MeshCoverage=true;
            else if(arg=="--screen-space-gate")options.ScreenSpaceGate=true;
            else if(arg=="--audit-uniform-block-proofs")options.AuditUniformBlockProofs=true;
            else if(arg=="--profile-lod-work")options.ProfileLodWork=true;
            else if(arg=="--audit-base-page-equivalence")options.AuditBasePageEquivalence=true;
            else if(arg=="--audit-route-parity")options.AuditRouteParity=true;
            else if(arg=="--region-crossing")options.RegionCrossing=true;
            else if(arg=="--audit-tile-shape-readiness")options.AuditTileShapeReadiness=true;
            else if(arg=="--auto-surface-camera")options.AutoSurfaceCamera=true;
            else if(arg.starts_with("--recipe="))
            {
                const std::string_view recipe=arg.substr(std::string_view("--recipe=").size());
                if(recipe=="surface-world")options.FloatingIslandsRecipe=false;
                else if(recipe=="floating-islands")options.FloatingIslandsRecipe=true;
                else {std::fprintf(stderr,"Invalid --recipe value: %.*s\n",static_cast<int>(recipe.size()),recipe.data());return false;}
            }
            else if(arg.starts_with("--seed="))
            {if(!readInt("--seed=",options.SeedOverride))return false;options.HasSeedOverride=true;}
            else if(arg.starts_with("--render-distance-chunks="))
            {
                if(!readInt("--render-distance-chunks=",options.RenderDistanceOverride))return false;
                options.RenderDistanceOverride=std::max(0,options.RenderDistanceOverride);
                options.HasRenderDistanceOverride=true;
            }
            else if(arg.starts_with("--tls-probe="))
            {
                if(!readInt("--tls-probe=",options.TlsProbeWorkers))return false;
                if(options.TlsProbeWorkers<0||options.TlsProbeWorkers>12)
                {std::fprintf(stderr,"--tls-probe must be in 0..12\n");return false;}
                options.TlsProbeRequested=true;
            }
            else if(arg.starts_with("--tls-probe-touch="))
            {
                const std::string_view touch=arg.substr(std::string_view("--tls-probe-touch=").size());
                if(touch!="none"&&touch!="surface-world"&&touch!="floating-islands")
                {std::fprintf(stderr,"Invalid --tls-probe-touch value: %.*s\n",static_cast<int>(touch.size()),touch.data());return false;}
                options.TlsProbeTouch=touch;
            }
            else if(arg.starts_with("--camera="))
            {
                if(!ParseCamera(arg.substr(9),options.CameraMeters,
                    options.CameraYawDegrees,options.CameraPitchDegrees))
                {std::fprintf(stderr,"Invalid --camera value: %.*s\n",static_cast<int>(arg.size()),arg.data());return false;}
                options.HasCamera=true;
            }
            else if(arg.starts_with("--camera-step="))
            {
                if(!ParseCameraStep(arg.substr(std::string_view("--camera-step=").size()),
                    options.CameraStepMeters))
                {std::fprintf(stderr,"Invalid --camera-step value: %.*s\n",static_cast<int>(arg.size()),arg.data());return false;}
                options.HasCameraStep=true;
            }
            else if(arg.starts_with("--column-cache="))
            {
                const std::string_view mode=arg.substr(std::string_view("--column-cache=").size());
                if(mode=="shared")options.UseSharedColumnCache=true;
                else if(mode=="thread-local")options.UseSharedColumnCache=false;
                else {std::fprintf(stderr,"Invalid --column-cache value: %.*s\n",static_cast<int>(arg.size()),arg.data());return false;}
            }
            else if(arg.starts_with("--mesh-export="))
            {
                options.MeshExportPath=std::filesystem::path(arg.substr(14));
                if(options.MeshExportPath.empty())
                {std::fprintf(stderr,"--mesh-export needs a file path\n");return false;}
            }
            else if(arg.starts_with("--world-assembler-manifest-output="))
            {
                options.WorldAssemblyManifestOutputPath=std::filesystem::path(
                    arg.substr(std::string_view("--world-assembler-manifest-output=").size()));
                if(options.WorldAssemblyManifestOutputPath.empty())
                {std::fprintf(stderr,"--world-assembler-manifest-output needs a file path\n");return false;}
            }
            else if(arg.starts_with("--workers="))
            {if(!readInt("--workers=",options.WorkerCount))return false;}
            else if(arg.starts_with("--clip-radius="))
            {if(!readInt("--clip-radius=",options.ClipRadius))return false;}
            else if(arg.starts_with("--max-clip-level="))
            {if(!readInt("--max-clip-level=",options.MaxClipLevel))return false;}
            else if(arg.starts_with("--max-level="))
            {if(!readInt("--max-level=",options.MaxLevel))return false;}
            else if(arg.starts_with("--far-horizon-lod8-step="))
            {if(!readInt("--far-horizon-lod8-step=",options.FarHorizonLOD8InteriorStepVoxels))return false;}
            else if(arg.starts_with("--diagnostic-slow-shape-compile-ms="))
            {if(!readInt("--diagnostic-slow-shape-compile-ms=",options.DiagnosticSlowShapeCompileMs))return false;}
            else if(arg.starts_with("--process-affinity=")||arg.starts_with("--process-priority=")
                ||arg.starts_with("--frame-limit="))
            {
                // These viewer switches are accepted for command-line parity. The caller pins
                // this headless process with taskset, and a headless run has no frame limiter.
            }
            else if(!arg.empty()&&arg.front()!='-')options.DataPath=std::filesystem::path(arg);
            else
            {std::fprintf(stderr,"Unknown option: %.*s\n",static_cast<int>(arg.size()),arg.data());return false;}
        }
        options.WorkerCount=std::clamp(options.WorkerCount,1,16);
        options.ClipRadius=std::clamp(options.ClipRadius,1,64);
        options.MaxClipLevel=std::clamp(options.MaxClipLevel,0,8);
        options.FarHorizonLOD8InteriorStepVoxels=std::max(0,options.FarHorizonLOD8InteriorStepVoxels);
        options.DiagnosticSlowShapeCompileMs=std::clamp(options.DiagnosticSlowShapeCompileMs,0,30000);
        if(!options.TlsProbeRequested&&options.TlsProbeTouch!="none")
        {std::fprintf(stderr,"--tls-probe-touch requires --tls-probe=N\n");return false;}
        if(options.RegionCrossing&&!options.HasCameraStep)
        {std::fprintf(stderr,"--region-crossing requires --camera-step=X,Y,Z\n");return false;}
        if(options.TlsProbeRequested)return true;
        if(!options.WorldAssemblerPrototype||!options.StreamBenchmark||!options.StreamPipeline)
        {
            std::fprintf(stderr,"This headless target runs the world-assembler streaming pipeline; pass --world-assembler-prototype --stream-benchmark --stream-pipeline.\n");
            return false;
        }
        return true;
    }
}

int main(int argc,char** argv)
{
    using Clock=std::chrono::steady_clock;
    const auto coldStart=Clock::now();
    FOptions options;
    if(!ParseOptions(argc,argv,options))return 2;
    if(options.TlsProbeRequested)
        return StandaloneTlsProbe::Run(options.TlsProbeWorkers,options.TlsProbeTouch);
    std::printf("[HeadlessConfig] data=%s workers=%d clip_radius=%d max_clip_level=%d max_level=%d hash=%s column_overlap=%s force_generate=%s recipe=%s shared_column_cache=%s camera_step_m=(%.3f,%.3f,%.3f) seed_override=%s render_distance_override=%s\n",
        options.DataPath.string().c_str(),options.WorkerCount,options.ClipRadius,options.MaxClipLevel,
        options.MaxLevel,options.StreamHash?"on":"off",options.ProfileColumnOverlap?"on":"off",
        options.ForceGenerate?"on":"off",options.FloatingIslandsRecipe?"floating-islands":"surface-world",
        options.UseSharedColumnCache?"on":"off",options.CameraStepMeters.X,options.CameraStepMeters.Y,
        options.CameraStepMeters.Z,
        options.HasSeedOverride?"yes":"no",options.HasRenderDistanceOverride?"yes":"no");
    std::printf("[ColdTimeline] stage=owner_data_load begin_ms=%.3f\n",
        std::chrono::duration<double,std::milli>(Clock::now()-coldStart).count());

    std::string error;
    auto ownerWorld=std::make_shared<FStandaloneOwnerWorld>();
    VFJson::Value ownerJsonRoot;
    {
        std::ifstream jsonFile(options.DataPath,std::ios::binary);
        if(!jsonFile)
        {std::fprintf(stderr,"Owner data load failed: cannot open %s\n",options.DataPath.string().c_str());return 2;}
        std::string ownerJsonText{std::istreambuf_iterator<char>(jsonFile),std::istreambuf_iterator<char>{}};
        if(!jsonFile&&!jsonFile.eof())
        {std::fprintf(stderr,"Owner data load failed: read error for %s\n",options.DataPath.string().c_str());return 2;}
        if(!VFJson::Parser(std::move(ownerJsonText)).Parse(ownerJsonRoot,error))
        {std::fprintf(stderr,"Owner data load failed: %s\n",error.c_str());return 2;}
    }
    if(options.HasSeedOverride
        &&!StandaloneWorldAssemblyPrototype::OverrideStandaloneSeed(ownerJsonRoot,options.SeedOverride,error))
    {std::fprintf(stderr,"Seed override failed: %s\n",error.c_str());return 2;}
    if(options.HasRenderDistanceOverride
        &&!StandaloneWorldAssemblyPrototype::OverrideStandaloneRenderDistance(
            ownerJsonRoot,options.RenderDistanceOverride,error))
    {std::fprintf(stderr,"Render-distance override failed: %s\n",error.c_str());return 2;}
    if(options.FloatingIslandsRecipe
        &&!StandaloneWorldAssemblyPrototype::SelectTopStrateAsFloatingIslands(ownerJsonRoot,error))
    {std::fprintf(stderr,"Floating-island recipe selection failed: %s\n",error.c_str());return 2;}
    if(!StandaloneOwnerLoader::Resolve(ownerJsonRoot,*ownerWorld,error))
    {std::fprintf(stderr,"Owner data load failed: %s\n",error.c_str());return 2;}
    std::printf("[ColdTimeline] stage=owner_data_load end_ms=%.3f\n",
        std::chrono::duration<double,std::milli>(Clock::now()-coldStart).count());

    const int seed=ownerWorld->Seed;
    const int exportedMaxClipLevel=ownerWorld->MaxClipLevel;
    ownerWorld->ClipRadius=options.ClipRadius;
    ownerWorld->Settings->ClipRadius=options.ClipRadius;
    ownerWorld->MaxClipLevel=options.MaxClipLevel;
    ownerWorld->Settings->MaxClipLevel=options.MaxClipLevel;
    if(exportedMaxClipLevel!=options.MaxClipLevel)
        std::printf("Standalone max clip level override: exported=%d -> max_level=%d.\n",
            exportedMaxClipLevel,options.MaxClipLevel);

    FVector cameraVoxels=ownerWorld->ViewerStartVoxels;
    if(options.HasCamera)
        cameraVoxels=FVector(options.CameraMeters.X*4.0f,options.CameraMeters.Y*4.0f,options.CameraMeters.Z*4.0f);

    const auto planStart=Clock::now();
    VoxelForgeCore::WorldAssemblyManifest worldAssembly;
    if(!StandaloneWorldAssemblyPrototype::AttachRound1WorldAssemblyPrototype(
        *ownerWorld,ownerJsonRoot,error,{},&worldAssembly))
    {std::fprintf(stderr,"World assembler prototype setup failed: %s\n",error.c_str());return 2;}
    if(options.FloatingIslandsRecipe
        &&!StandaloneWorldAssemblyPrototype::AttachFloatingIslandWorldAssembly(
            *ownerWorld,ownerJsonRoot,worldAssembly,error))
    {std::fprintf(stderr,"Floating-island assembly setup failed: %s\n",error.c_str());return 2;}
    if(!options.WorldAssemblyManifestOutputPath.empty())
    {
        std::error_code directoryError;
        const auto parent=options.WorldAssemblyManifestOutputPath.parent_path();
        if(!parent.empty())std::filesystem::create_directories(parent,directoryError);
        if(directoryError)
        {std::fprintf(stderr,"Manifest output directory failed: %s\n",directoryError.message().c_str());return 2;}
        std::ofstream manifestFile(options.WorldAssemblyManifestOutputPath,std::ios::binary|std::ios::trunc);
        if(!manifestFile)
        {std::fprintf(stderr,"Cannot write manifest output: %s\n",options.WorldAssemblyManifestOutputPath.string().c_str());return 2;}
        manifestFile<<worldAssembly.ToJson()<<'\n';
        if(!manifestFile)
        {std::fprintf(stderr,"Manifest output write failed: %s\n",options.WorldAssemblyManifestOutputPath.string().c_str());return 2;}
        std::printf("[WorldAssemblyManifest] path=%s status=PASS\n",
            options.WorldAssemblyManifestOutputPath.string().c_str());
    }
    if(options.AutoSurfaceCamera)
    {
        constexpr std::int64_t UnitsPerVoxel=VoxelForgeCore::WorldAssemblySubvoxelsPerVoxel;
        if(options.FloatingIslandsRecipe)
        {
            const VoxelForgeCore::FloatingIslandAnchorV1* chosen=nullptr;
            for(const auto& islandSet:worldAssembly.floatingIslands)
                for(const auto& island:islandSet.manifest.plan.islands)
                    if(!chosen||island.radiusSubvoxels>chosen->radiusSubvoxels)chosen=&island;
            if(!chosen)
            {std::fprintf(stderr,"[SeedSurfacePlacement] FAIL: island plan has no anchors\n");return 2;}
            cameraVoxels={
                static_cast<float>(chosen->centerSubvoxels[0])/UnitsPerVoxel,
                static_cast<float>(chosen->centerSubvoxels[1])/UnitsPerVoxel,
                static_cast<float>(chosen->centerSubvoxels[2])/UnitsPerVoxel};
            std::printf("[SeedSurfacePlacement] recipe=floating-islands seed=%d island_radius_vox=%.3f camera_voxel=(%.6f,%.6f,%.6f) status=PASS\n",
                seed,static_cast<double>(chosen->radiusSubvoxels)/UnitsPerVoxel,
                cameraVoxels.X,cameraVoxels.Y,cameraVoxels.Z);
        }
        else
        {
            const auto xSubvoxels=static_cast<std::int64_t>(std::llround(cameraVoxels.X*UnitsPerVoxel));
            const auto ySubvoxels=static_cast<std::int64_t>(std::llround(cameraVoxels.Y*UnitsPerVoxel));
            const auto currentZSubvoxels=static_cast<std::int64_t>(std::llround(cameraVoxels.Z*UnitsPerVoxel));
            std::int64_t selectedGround=0,bestDistance=std::numeric_limits<std::int64_t>::max();
            for(const auto& stratum:worldAssembly.plan.strates)
            {
                VoxelForgeCore::Heightfield2D field(worldAssembly.recipe,stratum);
                if(!field.isValid())continue;
                const auto column=field.point(xSubvoxels,ySubvoxels,0);
                const std::int64_t distance=std::abs(column.groundHeightSubvoxels-currentZSubvoxels);
                if(distance<bestDistance)
                {bestDistance=distance;selectedGround=column.groundHeightSubvoxels;}
            }
            if(bestDistance==std::numeric_limits<std::int64_t>::max())
            {std::fprintf(stderr,"[SeedSurfacePlacement] FAIL: no valid SurfaceWorld heightfield\n");return 2;}
            cameraVoxels.Z=static_cast<float>(static_cast<double>(selectedGround)/UnitsPerVoxel);
            std::printf("[SeedSurfacePlacement] recipe=surface-world seed=%d ground_voxel=%.6f camera_voxel=(%.6f,%.6f,%.6f) status=PASS\n",
                seed,static_cast<double>(selectedGround)/UnitsPerVoxel,
                cameraVoxels.X,cameraVoxels.Y,cameraVoxels.Z);
        }
    }
    std::printf("[WorldAssemblerPlanTiming] total_ms=%.3f status=PASS\n",
        std::chrono::duration<double,std::milli>(Clock::now()-planStart).count());

    auto snapshot=VoxelForgeCore::MakeStandaloneSnapshotFromParsedJson(ownerJsonRoot,seed,
        options.ClipRadius,options.MaxClipLevel,false,false,error);
    if(!snapshot)
    {std::fprintf(stderr,"Shape interval build failed: %s\n",error.c_str());return 2;}

    FStandaloneCoreScheduler scheduler;
    const FVector cameraStepVoxels=options.HasCameraStep
        ?FVector(options.CameraStepMeters.X*4.0f,options.CameraStepMeters.Y*4.0f,
            options.CameraStepMeters.Z*4.0f):FVector::ZeroVector;
    return StandaloneStreamBenchmark::RunPipelinedStreamingBenchmark(ownerWorld,snapshot,
        cameraVoxels,options.WorkerCount,options.MaxLevel,VoxelForgeCore::DetailVariant::coherent,
        scheduler,options.StreamHash,false,false,false,false,coldStart,
        options.ProfileColumnOverlap,options.FarHorizonLOD8InteriorStepVoxels,
        options.MeshCoverage,options.MeshExportPath,options.CameraYawDegrees,
        options.CameraPitchDegrees,options.ScreenSpaceGate,options.UseSharedColumnCache,
        cameraStepVoxels,options.AuditUniformBlockProofs,options.ProfileLodWork,
        options.RegionCrossing,options.AuditTileShapeReadiness,
        options.DiagnosticSlowShapeCompileMs,options.AuditBasePageEquivalence,
        options.AuditRouteParity);
}