Component system.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace com.skibitsky.components
{
    // Component label interface
    public interface IComponent
    {
        
    }

    public class ComponentsCollection
    {
        public ComponentsCollection()
        {
                
        }

        private readonly Dictionary<Type, List<IComponent>> _components = new Dictionary<Type, List<IComponent>>(0);

        public void Add<T>(T value) where T: IComponent
        {
            var type = typeof(T);
            if (_components.ContainsKey(type))
                _components[type].Add(value);
            else
                _components[type] = new List<IComponent> {value};

            var interfaces = type.GetInterfaces();
            foreach (var i in interfaces)
            {
                if (_components.ContainsKey(i))
                    _components[i].Add(value);
                else
                    _components[i] = new List<IComponent> {value};
            }
        }

        public void Add(object value)
        {
            var type = value.GetType();
            if (!(value is IComponent)) return;
            if (_components.ContainsKey(type))
                _components[type].Add((IComponent) value);
            else
                _components[type] = new List<IComponent> { (IComponent) value};

            var interfaces = type.GetInterfaces();
            foreach (var i in interfaces)
            {
                if (_components.ContainsKey(i))
                    _components[i].Add((IComponent) value);
                else
                    _components[i] = new List<IComponent> { (IComponent) value };
            }
        }

        /// <summary>
        /// Returns component by type
        /// </summary>
        public T GetComponent<T>() where T : IComponent
        {
            if (!_components.ContainsKey(typeof(T))) return default(T);
            return (T)_components[typeof(T)][0];
        }

        /// <summary>
        /// Returns component by reference
        /// </summary>
        public T GetComponent<T>(T value) where T : IComponent
        {
            if (!_components.ContainsKey(typeof(T))) return default(T);
            if (!_components[typeof(T)].Contains(value)) return default(T);

            return (T)_components[typeof(T)].Where(t => t.Equals(value)).ToArray()[0];
        }

        public T[] GetComponents<T>() where T : IComponent
        {
            return !_components.ContainsKey(typeof(T)) ? default(T[]) : _components[typeof(T)].Cast<T>().ToArray();
        }

        public void RemoveComponent<T>(T value) where T : IComponent
        {
            var type = typeof(T);
            if (!_components.ContainsKey(type)) return;
            if (_components[type].Contains(value))
                _components[type].Remove(value);

            if (_components[type].Count == 0)
                _components.Remove(type);

            var interfaces = type.GetInterfaces();
            foreach (var i in interfaces)
            {
                if (_components.ContainsKey(i))
                    _components[i].Remove(value);

                if (_components[i].Count == 0)
                    _components.Remove(type);
            }
        }
    }
}