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

namespace Encompass
{
    public abstract class Renderer
    {
        internal EntityManager entityManager;
        internal ComponentManager componentManager;

        internal void AssignEntityManager(EntityManager entityManager)
        {
            this.entityManager = entityManager;
        }

        internal void AssignComponentManager(ComponentManager componentManager)
        {
            this.componentManager = componentManager;
        }

        internal Guid GetEntityIDByComponentID(Guid componentID)
        {
            return componentManager.GetEntityIDByComponentID(componentID);
        }

        internal Entity GetEntity(Guid entityID)
        {
            return entityManager.GetEntity(entityID);
        }

        protected IEnumerable<Entity> ReadEntities<TComponent>() where TComponent : struct, IComponent
        {
            return ReadComponentsIncludingEntity<TComponent>().Select(tuple => tuple.Item2);
        }

        protected Entity ReadEntity<TComponent>() where TComponent : struct, IComponent
        {
            return ReadComponentIncludingEntity<TComponent>().Item2;
        }

        protected IEnumerable<TComponent> ReadComponents<TComponent>() where TComponent : struct, IComponent
        {
            return componentManager.GetComponentsByType<TComponent>().Select(tuple => tuple.Item2);
        }

        protected IEnumerable<(TComponent, Entity)> ReadComponentsIncludingEntity<TComponent>() where TComponent : struct, IComponent
        {
            return componentManager.GetComponentsByType<TComponent>().Select(tuple => (tuple.Item2, GetEntity(GetEntityIDByComponentID(tuple.Item1))));
        }

        protected TComponent ReadComponent<TComponent>() where TComponent : struct, IComponent
        {
            return ReadComponents<TComponent>().First();
        }

        protected (TComponent, Entity) ReadComponentIncludingEntity<TComponent>() where TComponent : struct, IComponent
        {
            return ReadComponentsIncludingEntity<TComponent>().First();
        }

        protected TComponent GetComponent<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            return componentManager.GetComponentByEntityAndType<TComponent>(entity).Item2;
        }

        protected bool HasComponent<TComponent>(Entity entity) where TComponent : struct, IComponent
        {
            return componentManager.EntityHasComponentOfType<TComponent>(entity);
        }

        protected bool SomeComponent<TComponent>() where TComponent : struct, IComponent
        {
            return componentManager.ComponentOfTypeExists<TComponent>();
        }
    }
}