The SpaceShoot server

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Json;
using SpaceShooterServer.Interfaces;
using SpaceShooterServer.Structures;

namespace SpaceShooterServer.Game
{
    public class Particle : GameObject, IShipCollision, IAsteroidCollision, IBombCollision, IOwner, IVelocity
    {
        #region Constants

        const int MAX_PARTICLE_TIME = 120;
        const int DAMAGE_FACTOR = 14;
        const int PARTICLE_SIZE = 6;
        const double PARTICLE_SPEED_OFFSET = 4.0;

        #endregion

        #region ctor

        public Particle()
        {
            Lifetime = MAX_PARTICLE_TIME;
            Size = PARTICLE_SIZE;
            DamageFactor = DAMAGE_FACTOR;
            IsIntelligent = false;
        }

        #endregion

        #region Creator

        public static Particle Create(Ship ship, ParticleUpgrades ups = null)
        {
            var x = ship.X;
            var y = ship.Y;
            var particle = new Particle { Game = ship.Game, Owner = ship };
            var speed = PARTICLE_SPEED_OFFSET + ship.Speed;
            var ta = particle.DegreeToGrad(ship.DegreeAngle);
            particle.Vx = speed * Math.Sin(ta);
            particle.Vy = -speed * Math.Cos(ta);

            if (ups != null)
                ups.Upgrade(particle);

            var radius = particle.Size / 2.0 + ship.Size / 2.0 + 1.0;
            x += radius * Math.Sin(ta);
            y -= radius * Math.Cos(ta);
            particle.X = x;
            particle.Y = y;
            ship.Game.Objects.Add(particle);
            return particle;
        }

        #endregion

        #region Properties

        public double Vx { get; set; }
	    public double Vy { get; set; }
	    public Ship Owner { get; set; }
        public int Lifetime { get; set; }
        public int DamageFactor { get; set; }
        public bool IsIntelligent { get; set; }
        public override int Damage { get { return (DamageFactor * Lifetime) / MAX_PARTICLE_TIME; } set { } }

        #endregion

        #region Methods

        public override void Logic()
        {
            if (IsIntelligent)
                ArtificialIntelligence();

            X += Vx;
            Y += Vy;
            PeriodicBoundaryConditions();
            Lifetime--;

            if (Lifetime == 0)
                Dead();
        }

        private void ArtificialIntelligence()
        {
            if (Game.ActiveShips == (Owner.Respawn ? 0 : 1))
                return;

            var from = Point.CreateFromObject(this);
            var enemy = Owner.ClosestEnemy();

            if (enemy == null)
                return;

            var to = Point.CreateFromObject(enemy);
            var angle = Game.AngleBetween(from, to);
            var speed = Math.Sqrt(Vx * Vx + Vy * Vy);
            var dsp = Math.Sqrt(Math.Pow(Owner.X - X, 2.0) + Math.Pow(Owner.Y - Y, 2.0));
            var radiuses = (Owner.Size + Size) / 2.0;
            
            if (dsp < radiuses + speed)
            {
                var gamma = Game.AngleBetween(from, Point.CreateFromObject(Owner));
                var alpha = Game.AngleBetween(Point.Origin, new Point { X = dsp, Y = radiuses + 1.0 });

                if (angle > gamma - alpha && angle < gamma + alpha)
                {
                    if (angle < gamma)
                        angle = gamma - alpha;
                    else
                        angle = gamma + alpha;
                }
            }

            Vx = speed * Math.Sin(angle);
            Vy = speed * Math.Cos(angle);
        }

        public override JsonObject ToJson()
        {
            var json = new JsonObject();
            json["owner"] = Owner.Id;
            json["x"] = X;
            json["y"] = Y;
            json["size"] = Size;
            json["lifetime"] = Lifetime;
            json["remove"] = Remove;
            return json;
        }

        public void OnCollision(Ship ship)
        {
            if (Game.FriendlyFire || Owner != ship)
            {
                if (ship.Hit(this) && Owner != null)
                {
                    Owner.Points++;
                    InfoText.Add(ship, "+1", 50, this);
                }

                Dead();
            }
        }

        public void OnCollision(Asteroid asteroid)
        {
            if (asteroid.Hit(this) && Owner != null)
                InfoText.Add(asteroid, "Awesome", 50, this);

            Dead();
        }

        public void OnCollision(Bomb bomb)
        {
            if (bomb.Physical)
            {
                Dead();

                if(bomb.Hit(this))
                    InfoText.Add(bomb, "Nice!", 50, this);
            }
        }

        #endregion
    }
}