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

namespace Gallium
{
    public static class WhereAllComponentsExtensions
    {
        public static IEnumerable<Entity> WhereAllComponents<T1>(
            this IEnumerable<Entity> entities)
        {
            return entities.Where(x => x.Has<T1>());
        }

        public static IEnumerable<Entity> WhereAllComponents<T1, T2>(
            this IEnumerable<Entity> entities)
        {
            return entities.Where(x => x.Has<T1>() && x.Has<T2>());
        }

        public static IEnumerable<Entity> WhereAllComponents<T1, T2, T3>(
            this IEnumerable<Entity> entities)
        {
            return entities.Where(
                x => x.Has<T1>() && x.Has<T2>() && x.Has<T3>());
        }

        public static IEnumerable<Entity> WhereAllComponents<T1, T2, T3, T4>(
            this IEnumerable<Entity> entities)
        {
            return entities.Where(
                x => x.Has<T1>() && x.Has<T2>() && x.Has<T3>() && x.Has<T4>());
        }
    }
}