using System;
using System.Collections.Generic;
using System.Linq;
using Encompass.Exceptions;

namespace Encompass
{
    [AttributeUsage(AttributeTargets.Class)]
    public class Reads : Attribute
    {
        public readonly HashSet<Type> readTypes = new HashSet<Type>();

        public Reads(params Type[] readTypes)
        {
            foreach (var readType in readTypes)
            {
                var isComponent = readType.GetInterfaces().Contains(typeof(IComponent));

                if (!isComponent)
                {
                    throw new IllegalReadTypeException("{0} must be a Component", readType.Name);
                }

                this.readTypes.Add(typeof(ComponentMessage<>).MakeGenericType(readType));
            }
        }
    }
}