namespace VoxelEngine.Core;

using OpenTK.Mathematics;

public sealed class Configuration
{
    #region -- World --

    // World generation seed. null → a fresh random seed each run; set a value for
    // a reproducible world.
    public int? Seed { get; set; } = null;

    // Blocks above the terrain surface at (0,0) where the player spawns.
    public float SpawnHeightOffset { get; set; } = 2f;

    #endregion -- World --

    #region -- Rendering & View --

    // Horizontal view radius in chunks (Chebyshev). Drives how far terrain loads
    // and the fog / far-plane distance. Higher = see further, much heavier load.
    public int RenderDistanceHorizontal { get; set; } = 8;

    // Camera vertical field of view, in degrees.
    public float Fov { get; set; } = 60f;

    // Near clip plane distance (world units); anything nearer is not drawn.
    // (The far plane is derived from RenderDistanceHorizontal over in Player.)
    public float CameraNearPlane { get; set; } = 0.1f;

    // Distance fog begins at this fraction of the fog-end distance (fog end is
    // derived from RenderDistanceHorizontal). 0.7 → fog starts at 70% of the edge.
    public float FogStartFraction { get; set; } = 0.7f;

    // Sky / clear colour, also the distance-fog target colour (RGB, 0–1).
    public Vector3 SkyColor { get; set; } = new(0.45f, 0.65f, 0.95f);

    #endregion -- Rendering & View --

    #region -- Window --

    // Initial window size in pixels.
    public int WindowWidth  { get; set; } = 1280;
    public int WindowHeight { get; set; } = 720;

    #endregion -- Window --

    #region -- Chunk Streaming --

    // Horizontal radius (chunks) around spawn that must finish loading before the
    // loading screen clears.
    public int SpawnReadyRadiusHorizontal { get; set; } = 1;

    // Max chunk generate/mesh jobs running on worker threads at once.
    public int MaxGenerateJobsInFlight { get; set; } = 8;

    // Max finished chunk meshes uploaded to the GPU per frame (caps per-frame hitches).
    public int MaxMeshUploadsPerFrame { get; set; } = 4;

    // Background worker threads used for chunk generation/meshing.
    public int WorkerThreadCount { get; set; } = Math.Max(1, Environment.ProcessorCount / 2);

    // Multiplier applied to (dy)² in chunk-load priority. >1 prioritizes chunks at
    // the player's Y over equally-distant chunks above/below, so the visible
    // surface fills in before far-underground / overhead chunks.
    public int VerticalPriorityWeight { get; set; } = 4;

    #endregion -- Chunk Streaming --

    #region -- Player & Controls --

    // Movement speed, in blocks per second.
    public float MoveSpeed { get; set; } = 8f;

    // Mouse-look sensitivity (degrees of rotation per pixel of mouse movement).
    public float MouseSensitivity { get; set; } = 0.15f;

    #endregion -- Player & Controls --

    #region -- World Gen: Terrain Shape --

    // Average width in blocks of one biome region (Voronoi cell). Larger = bigger,
    // fewer biomes.
    public float BiomeCellSize { get; set; } = 960f;

    // Blocks over which terrain height eases from one biome to its neighbour across
    // their shared border. Larger = gentler, wider transitions.
    public float BiomeBlendWidth { get; set; } = 128f;

    // Filler layers (dirt/sand) placed directly below the surface block before the
    // biome's solid under-material (usually stone) begins.
    public int SurfaceFillerDepth { get; set; } = 3;

    #endregion -- World Gen: Terrain Shape --

    #region -- World Gen: Climate Noise --
    // Low-frequency fields that decide biome placement. Lower frequency = larger,
    // smoother climate regions; more octaves = more fine variation.

    // Elevation field — high values become Mountains, low values lowland.
    public float ContinentFrequency { get; set; } = 0.0035f;
    public int   ContinentOctaves   { get; set; } = 4;

    // Temperature field — high values become Desert.
    public float TemperatureFrequency { get; set; } = 0.0015f;
    public int   TemperatureOctaves   { get; set; } = 3;

    // Forest-density field — high values become Forest (else Plains).
    public float ForestFrequency { get; set; } = 0.02f;

    #endregion -- World Gen: Climate Noise --

    #region -- World Gen: Biome Selection --
    // Thresholds on the climate fields (values ≈ -1..1), tested in order:
    // mountains → desert → forest → plains.

    // Elevation at/above which a cell is Mountains.
    public float MountainsElevationThreshold { get; set; } = 0.25f;

    // Temperature above which a non-mountain cell is Desert.
    public float DesertTemperatureThreshold { get; set; } = 0.33f;

    // Minimum temperature for Forest (colder than this → Plains).
    public float ForestTemperatureThreshold { get; set; } = -0.33f;

    // Minimum forest-density for Forest (below this → Plains).
    public float ForestDensityThreshold { get; set; } = 0f;

    #endregion -- World Gen: Biome Selection --

    #region -- World Gen: Biome Surface Heights --
    // Per biome: surfaceHeight = SeaLevel + ContinentAmplitude·continentNoise
    // + DetailAmplitude·detailNoise. Amplitudes are in blocks; detail frequency
    // sets the bumpiness scale (higher = smaller, choppier features).

    // Plains — gentle rolling grassland.
    public float PlainsContinentAmplitude { get; set; } = 24f;
    public float PlainsDetailAmplitude    { get; set; } = 8f;
    public float PlainsDetailFrequency    { get; set; } = 0.01f;

    // Forest — like plains, a touch hillier.
    public float ForestContinentAmplitude { get; set; } = 24f;
    public float ForestDetailAmplitude    { get; set; } = 16f;
    public float ForestDetailFrequency    { get; set; } = 0.01f;

    // Desert — flat with low dunes.
    public float DesertContinentAmplitude { get; set; } = 16f;
    public float DesertDetailAmplitude    { get; set; } = 6f;
    public float DesertDetailFrequency    { get; set; } = 0.008f;

    // Mountains — tall ridged peaks (uses ridged noise instead of a smooth detail
    // field). Peaks roughly cap at SeaLevel + ContinentAmplitude + RidgedAmplitude.
    public float MountainsContinentAmplitude { get; set; } = 40f;
    public float MountainsRidgedAmplitude    { get; set; } = 45f;
    public float MountainsRidgedFrequency    { get; set; } = 0.005f;
    public int   MountainsRidgedOctaves      { get; set; } = 4;
    // World-Y at/above which mountain tops render as snow.
    public int   MountainsSnowLine           { get; set; } = 270;

    #endregion -- World Gen: Biome Surface Heights --

    #region -- Cave Generation --

    // Spatial frequency of the 3D simplex cave-density field; higher = smaller,
    // more frequent pockets.
    public float CaveNoiseFrequency { get; set; } = 0.03f;

    // Density cutoff below which a solid voxel becomes air; higher = more cave.
    public float CaveNoiseThreshold { get; set; } = -0.3f;

    // Edge length (blocks) of a worm-spawn grid cell; one worm candidate per cell.
    public int WormCellSize { get; set; } = 64;

    // Per-cell chance out of 1000 that a worm spawns; 300 = 30%.
    public int WormSpawnProbabilityPermille { get; set; } = 300;

    // Number of trace steps (≈ blocks) a worm travels.
    public int WormMaxLength { get; set; } = 80;

    // Worm tunnel radius bounds; interpolated + sine-modulated along the path to
    // form bulges/chambers.
    public float WormMinRadius { get; set; } = 1.5f;
    public float WormMaxRadius { get; set; } = 3.5f;

    // Ceiling: caves carve only at or below this world-Y ("no caves above").
    // Default 256 = SeaLevel → caves stay below sea level, keeping the taller
    // surface terrain solid. Raise toward WorldHeight-1 to allow surface caves.
    public int MinCaveY { get; set; } = 256;

    #endregion -- Cave Generation --

    #region -- Cave Lighting --
    // Underground darkening: brightness fades from CaveDarkStartY down to
    // CaveDarkEndY, never dropping below CaveMinBrightness.

    public float CaveDarkStartY    { get; set; } = 264f;  // WorldConstants.SeaLevel + 8
    public float CaveDarkEndY      { get; set; } = 224f;  // WorldConstants.SeaLevel - 32
    public float CaveMinBrightness { get; set; } = 0.15f; // floor brightness deep underground (0–1)

    #endregion -- Cave Lighting --

    #region -- Debug Overlay --

    // Pixel size of each font "pixel" in the on-screen debug text (biome + coords).
    public int DebugOverlayTextScale { get; set; } = 3;

    #endregion -- Debug Overlay --
}