using System;
using System.Collections.Generic;

namespace Encompass
{
    internal class EntityManager
    {
        private List<Entity> entities = new List<Entity>();
        private Dictionary<Guid, Entity> IDToEntity = new Dictionary<Guid, Entity>();

        private List<Entity> entitiesMarkedForDestroy = new List<Entity>();

        private ComponentManager componentManager;

        public EntityManager(
            ComponentManager componentManager
        )
        {
            this.componentManager = componentManager;
        }

        public Entity CreateEntity()
        {
            return new Entity(NextID(), componentManager);
        }

        public Entity GetEntity(Guid id)
        {
            return this.IDToEntity[id];
        }

        public void MarkForDestroy(Entity entity)
        {
            entitiesMarkedForDestroy.Add(entity);
        }

        internal void DestroyMarkedEntities()
        {
            foreach (var entity in entitiesMarkedForDestroy)
            {
                entity.RemoveAllComponents();
            }
        }

        private Guid NextID()
        {
            return Guid.NewGuid();
        }
    }
}