using System.Numerics;
using System.Runtime.InteropServices;
using CounterStrikeSharp.API;
using CounterStrikeSharp.API.Core;
using CounterStrikeSharp.API.Modules.Entities.Constants;
using CounterStrikeSharp.API.Modules.Memory;
using CounterStrikeSharp.API.Modules.Utils;
using Vector = CounterStrikeSharp.API.Modules.Utils.Vector;

namespace RayTraceAPI
{
#region Native Structs (matching C++ layout exactly)
    [Flags]
    public enum InteractionLayers : ulong
    {
        None = 0,
        Solid = 0x1,
        Hitboxes = 0x2,
        Trigger = 0x4,
        Sky = 0x8,
        PlayerClip = 0x10,
        NPCClip = 0x20,
        BlockLOS = 0x40,
        BlockLight = 0x80,
        Ladder = 0x100,
        Pickup = 0x200,
        BlockSound = 0x400,
        NoDraw = 0x800,
        Window = 0x1000,
        PassBullets = 0x2000,
        WorldGeometry = 0x4000,
        Water = 0x8000,
        Slime = 0x10000,
        TouchAll = 0x20000,
        Player = 0x40000,
        NPC = 0x80000,
        Debris = 0x100000,
        Physics_Prop = 0x200000,
        NavIgnore = 0x400000,
        NavLocalIgnore = 0x800000,
        PostProcessingVolume = 0x1000000,
        UnusedLayer3 = 0x2000000,
        CarriedObject = 0x4000000,
        PushAway = 0x8000000,
        ServerEntityOnClient = 0x10000000,
        CarriedWeapon = 0x20000000,
        StaticLevel = 0x40000000,
        csgo_team1 = 0x80000000,
        csgo_team2 = 0x100000000,
        csgo_grenadeclip = 0x200000000,
        csgo_droneclip = 0x400000000,
        csgo_moveable = 0x800000000,
        csgo_opaque = 0x1000000000,
        csgo_monster = 0x2000000000,
        csgo_thrown_grenade = 0x8000000000,

        MASK_SHOT_PHYSICS = Solid | PlayerClip | Window | PassBullets | Player | NPC | Physics_Prop,
        MASK_SHOT_HITBOX = Hitboxes | Player | NPC,
        MASK_SHOT_FULL = MASK_SHOT_PHYSICS | Hitboxes,
        MASK_WORLD_ONLY = Solid | Window | PassBullets,
        MASK_GRENADE = Solid | Window | Physics_Prop | PassBullets,
        MASK_BRUSH_ONLY = Solid | Window,
        MASK_PLAYER_MOVE = Solid | Window | PlayerClip | PassBullets,
        MASK_NPC_MOVE = Solid | Window | NPCClip | PassBullets
    }

    [StructLayout(LayoutKind.Explicit, Size = 24)]
    public struct TraceOptions
    {
        [FieldOffset(0)] public ulong InteractsWith;
        [FieldOffset(8)] public ulong InteractsExclude;
        [FieldOffset(16)] public int DrawBeam;

        public TraceOptions()
        {
            InteractsWith = (ulong)InteractionLayers.MASK_SHOT_PHYSICS;
            InteractsExclude = 0;
            DrawBeam = 0;
        }

        public TraceOptions(InteractionLayers interactsWith, InteractionLayers interactsExclude = 0, bool drawBeam = false)
        {
            InteractsWith = (ulong)interactsWith;
            InteractsExclude = (ulong)interactsExclude;
            DrawBeam = drawBeam ? 1 : 0;
        }
    }

    [StructLayout(LayoutKind.Explicit, Size = 44)]
    public struct TraceResult
    {
        [FieldOffset(0)] public float EndPosX;
        [FieldOffset(4)] public float EndPosY;
        [FieldOffset(8)] public float EndPosZ;
        [FieldOffset(16)] public nint HitEntity;
        [FieldOffset(24)] public float Fraction;
        [FieldOffset(28)] public int AllSolid;
        [FieldOffset(32)] public float NormalX;
        [FieldOffset(36)] public float NormalY;
        [FieldOffset(40)] public float NormalZ;

        public Vector3 EndPos => new(EndPosX, EndPosY, EndPosZ);
        public Vector3 Normal => new(NormalX, NormalY, NormalZ);
        public bool DidHit => Fraction < 1.0f;
        public bool IsAllSolid => AllSolid != 0;
    }
#endregion

    public interface CRayTraceInterface
    {
        public bool TraceShape(Vector start, QAngle angles, CEntityInstance? ignore, TraceOptions options, out TraceResult result);
        public bool TraceEndShape(Vector start, Vector end, CEntityInstance? ignore, TraceOptions options, out TraceResult result);
        public bool TraceHullShape(Vector start, Vector end, Vector mins, Vector maxs, CEntityInstance? ignore, TraceOptions options, out TraceResult result);
        public bool TraceShapeEx(Vector start, Vector end, nint filter, nint ray, out TraceResult result);
    }
}