using System;
using System.Collections.Generic;
using System.Reflection;

namespace Encompass
{
    class UberRenderer : Renderer
    {
        private readonly IEnumerable<Type> _componentTypes;
        private Entity _entity;

        public UberRenderer(IEnumerable<Type> componentTypes)
        {
            _componentTypes = componentTypes;
        }

        public void SetEntity(Entity entity)
        {
            _entity = entity;
        }

        // can't reflect invoke on Span returns...
        public void Render()
        {
            foreach (var type in _componentTypes)
            {
                CallGenericWrappedMethod(type, "ReadEntitiesWrapper", null);
                CallGenericMethod(type, "ReadEntity", null);
                CallGenericWrappedMethod(type, "ReadComponentsWrapper", null);
                CallGenericMethod(type, "ReadComponent", null);
                CallGenericMethod(type, "GetComponent", new object[] { _entity });
                CallGenericMethod(type, "HasComponent", new object[] { _entity });
                CallGenericMethod(type, "SomeComponent", null);
            }
        }

        protected void ReadEntitiesWrapper<TComponent>() where TComponent : struct, IComponent
        {
            ReadEntities<TComponent>();
        }

        protected void ReadComponentsWrapper<TComponent>() where TComponent : struct, IComponent
        {
            ReadComponents<TComponent>();
        }

        private void CallGenericMethod(Type type, string methodName, object[] parameters)
        {
            var readComponentMethod = typeof(Renderer).GetMethod(methodName, BindingFlags.NonPublic | BindingFlags.Instance);
            var genericReadComponentMethod = readComponentMethod.MakeGenericMethod(type);
            genericReadComponentMethod.Invoke(this, parameters);
        }

        private void CallGenericWrappedMethod(Type type, string methodName, object[] parameters)
        {
            var readComponentMethod = typeof(UberRenderer).GetMethod(methodName, BindingFlags.NonPublic | BindingFlags.Instance);
            var genericReadComponentMethod = readComponentMethod.MakeGenericMethod(type);
            genericReadComponentMethod.Invoke(this, parameters);
        }
    }
}