using System;

using Microsoft.Xna.Framework.Input;

using Syntriax.Engine.Core;
using Syntriax.Engine.Network;
using Syntriax.Engine.Systems.Input;

namespace Pong.Behaviours;

public class PongManagerBehaviour : Behaviour, INetworkEntity,
    IPacketListenerServer<PongManagerBehaviour.RequestStartPacket>
{
    public Action<PongManagerBehaviour>? OnReset { get; set; } = null;
    public Action<PongManagerBehaviour>? OnFinished { get; set; } = null;
    public Action<PongManagerBehaviour>? OnScored { get; set; } = null;

    private Random random = new();
    private BallBehaviour ball = null!;

    private INetworkCommunicatorClient? networkClient = null!;
    private INetworkCommunicatorServer? networkServer = null;

    public int ScoreLeft { get; private set; } = 0;
    public int ScoreRight { get; private set; } = 0;
    public int ScoreSum => ScoreLeft + ScoreRight;

    public int WinScore { get; } = 5;

    public PongManagerBehaviour() => WinScore = 5;
    public PongManagerBehaviour(int winScore) => WinScore = winScore;

    protected override void OnFirstActiveFrame()
    {
        IButtonInputs<Keys> buttonInputs = Universe.FindRequired<IButtonInputs<Keys>>();
        buttonInputs.RegisterOnRelease(Keys.Space, (_, _1) => networkClient?.SendToServer(new RequestStartPacket()));

        ball = Universe.FindRequiredBehaviour<BallBehaviour>();
        networkClient = Universe.Find<INetworkCommunicatorClient>();
        networkServer = Universe.Find<INetworkCommunicatorServer>();
    }

    public void ScoreToLeft()
    {
        ScoreLeft++;
        OnScored?.Invoke(this);

        CheckFinish();
    }

    public void ScoreToRight()
    {
        ScoreRight++;
        OnScored?.Invoke(this);

        CheckFinish();
    }

    public void Reset()
    {
        ScoreLeft = ScoreRight = 0;

        ball.ResetBall();
        ball.LaunchBall(GetBallLaunchDirection());

        OnReset?.Invoke(this);
    }

    private void CheckFinish()
    {
        int halfwayScore = (int)(WinScore * .5f);
        ball.ResetBall();

        if (ScoreLeft > halfwayScore || ScoreRight > halfwayScore)
        {
            OnFinished?.Invoke(this);
            return;
        }

        ball.ResetBall();
        ball.LaunchBall(GetBallLaunchDirection());
    }

    private Vector2D GetBallLaunchDirection()
    {
        const float AllowedRadians = 45f * Syntriax.Engine.Core.Math.DegreeToRadian;
        float rotation = (float)random.NextDouble() * 2f * AllowedRadians - AllowedRadians;
        bool isBackwards = (random.Next() % 2) == 1;
        return Vector2D.Right.Rotate(isBackwards ? rotation + Syntriax.Engine.Core.Math.PI : rotation);
    }

    void IPacketListenerServer<RequestStartPacket>.OnServerPacketArrived(string sender, RequestStartPacket packet)
    {
        if (ball.RigidBody.Velocity.MagnitudeSquared > 0.01f)
            return;

        ball.LaunchBall(GetBallLaunchDirection());
    }

    private class RequestStartPacket : INetworkPacket;
}