using System.Numerics;
using LiteNetLib.Utils;
using OnekoOnline.Net;
using Raylib_cs;

namespace OnekoOnline;

class OnekoLocal : Oneko
{
    public static Oneko? Instance;

    static int Id => OnekoOnline.Client?.Id ?? -1;

    OnekoAIState CurrentAIState;
    readonly OnekoAIState[] AIStates;

    OnekoAnimation Animation;
    float updateTimer = 0f;
    const float updateRate = 1f/5f;
    int Frame = 0;
    int FrameCounter = 0;

    public OnekoLocal() : base()
    {
        Instance ??= this;

        Name = OnekoOnline.Config.GetValue("NekoName", "Oneko");

        AIStates = [new BoredState(this), new ChaseMouseState(this), new ItchyState(this)];
        CurrentAIState = AIStates[0];
    }

    public override void Update(float delta)
    {
        updateTimer += delta;
        if (updateTimer < updateRate) return;

        OnekoUpdate(updateTimer);
        updateTimer = 0f;
    }

    public void OnekoUpdate(float delta)
    {
        //AI STUFF
        OnekoAIState HighestPriority = AIStates.MaxBy(state => state.GetPriority())!;
        if (HighestPriority != CurrentAIState) {
            CurrentAIState.ExitState();
            CurrentAIState = HighestPriority;
            CurrentAIState.StartState();
        }
        CurrentAIState.Update(delta);

        FrameCounter = (FrameCounter+1)%(Animation.AnimSpeed+1);
        Frame = (int)MathF.Round(FrameCounter/(float)Animation.AnimSpeed);

        Sprite = Animation.GetFrame(Frame);

        if (OnekoOnline.Client!.Connected) {
            NetDataWriter writer = new();
            writer.Put(new PacketInfo(PacketType.OnekoState, Id));
            writer.Put(Position);
            writer.Put(FrameId);
            OnekoOnline.Client?.ConnectedServer.Send(writer, LiteNetLib.DeliveryMethod.Unreliable);
        }
    }

    void MoveTowardsPosition(Vector2 TargetPosition)
    {
        Vector2 TargetDirection = (TargetPosition-Position).LimitLength(10f);
        if (TargetDirection.Length() > 1) {
            Animation = GetDirectionalRun(TargetDirection);
        }

        Position += TargetDirection;
    }

    protected abstract class OnekoAIState(OnekoLocal neko)
    {
        protected OnekoLocal Neko = neko;

        public abstract int GetPriority();
        public abstract void Update(float delta);
        public virtual void StartState() {}
        public virtual void ExitState() {}
        protected bool IsCurrentState => Neko.CurrentAIState == this;
    }

    class BoredState(OnekoLocal neko) : OnekoAIState(neko)
    {
        float InactivityTimer = 0f;

        public override int GetPriority() => 0;

        public override void Update(float delta)
        {
            InactivityTimer += delta;

            Neko.Animation = Idle;
            if (InactivityTimer > 1.5f && InactivityTimer < 3f) Neko.Animation = Clean;
            if (InactivityTimer > 5f) Neko.Animation = ScratchSelf;
            if (InactivityTimer > 7f) Neko.Animation = Yawn;
            if (InactivityTimer > 8f) Neko.Animation = Sleep;
        }

        public override void ExitState() => InactivityTimer = 0f;
    }

    class ChaseMouseState : OnekoAIState
    {
        Mouse? MouseToChase;
        float AlertTimer = 0f;

        public ChaseMouseState(OnekoLocal neko) : base(neko)
        {
            Mouse.Clicked += mouse => {
                if (MouseToChase != mouse && Random.Shared.NextSingle() > 0.3f) {
                    AlertTimer = 0.5f;
                    MouseToChase = mouse;
                }
            };
        }

        public override int GetPriority()
        {
            MouseToChase ??= Mouse.AllMice.Where(m => m.Visible).MinBy(m => Vector2.Distance(m.Position, Neko.Position));
            if (MouseToChase != null && MouseToChase.Visible && Vector2.Distance(MouseToChase.Position, Neko.Position) > 15) return 100;
            return -1;
        }

        public override void Update(float delta)
        {
            if (AlertTimer < 1f) {
                AlertTimer += delta;
                Neko.Animation = Alert;
                return;
            }

            if (MouseToChase is null || !MouseToChase.Visible) return;
            Neko.MoveTowardsPosition(MouseToChase.Position);
        }

        public override void ExitState() {
            MouseToChase = null;
            AlertTimer = 0f;
        }
    }

    class ItchyState(OnekoLocal neko) : OnekoAIState(neko)
    {
        float ItchTimer = -1f;
        bool Cleaning = false;

        public override int GetPriority()
        {
            if (ItchTimer > 0f || Random.Shared.NextSingle() > 0.997f) return 1000;
            else return -1;
        }

        public override void StartState() {
            ItchTimer = 1f + Random.Shared.NextSingle()*4f;
            Cleaning = Random.Shared.NextSingle() > 0.5f;
        }

        public override void Update(float delta) {
            ItchTimer -= delta;
            Neko.Animation = Cleaning ? Clean : ScratchSelf;
        }
    }
}