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

namespace Encompass
{
    internal class UberEngine : Engine
    {
        private IEnumerable<Type> _componentTypes;
        private IEnumerable<Type> _messageTypes;
        private Entity _entity;

        public UberEngine(Entity entity, IEnumerable<Type> componentTypes, IEnumerable<Type> messageTypes)
        {
            _componentTypes = componentTypes;
            _messageTypes = messageTypes;
            readTypes.UnionWith(componentTypes);
            writeTypes.UnionWith(componentTypes);
            sendTypes.UnionWith(messageTypes);
            receiveTypes.UnionWith(messageTypes);
            _entity = entity;
        }

        public void Write()
        {
            foreach (var type in _componentTypes)
            {
                var instanceParam = new object[] { _entity, Activator.CreateInstance(type) };
                var setComponentMethod = typeof(Engine).GetMethod("SetComponent", BindingFlags.NonPublic | BindingFlags.Instance);
                var genericSetComponentMethod = setComponentMethod.MakeGenericMethod(type);
                genericSetComponentMethod.Invoke(this, instanceParam);
            }
        }

        public override void Update(double dt)
        {
            foreach (var type in _componentTypes)
            {
                CallGenericMethod(type, "ReadComponent", null);
                CallGenericMethod(type, "ReadComponentIncludingEntity", null);
                CallGenericMethod(type, "ReadComponents", null);
                CallGenericMethod(type, "ReadComponentsIncludingEntity", null);
                CallGenericMethod(type, "GetComponent", new Type[] { typeof(Entity) }, new object[] { _entity });
                CallGenericMethod(type, "HasComponent", new Type[] { typeof(Entity) }, new object[] { _entity });
                CallGenericMethod(type, "SomeComponent", null);
                CallGenericMethod(type, "RemoveComponent", new Type[] { typeof(Entity) }, new object[] { _entity });
                CallGenericMethod(type, "DestroyWith", null);
                CallGenericMethod(type, "DestroyAllWith", null);
            }

            foreach (var type in _messageTypes)
            {
                CallGenericMethod(type, "SendMessageIgnoringTimeDilation", new object[] { Activator.CreateInstance(type), 1 });
                CallGenericMethod(type, "SendMessage", 1, new object[] { Activator.CreateInstance(type) });
                CallGenericMethod(type, "SendMessage", 2, new object[] { Activator.CreateInstance(type), 1 });
                CallGenericMethod(type, "ReadMessage", null);
                CallGenericMethod(type, "ReadMessages", null);
                CallGenericMethod(type, "SomeMessage", null);
            }
        }

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

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

        private void CallGenericMethod(Type type, string methodName, int argumentNum, object[] parameters)
        {
            var method = typeof(Engine).GetRuntimeMethods().Where(m => m.Name == methodName && m.GetParameters().Length == argumentNum).First();
            var genericMethod = method.MakeGenericMethod(type);
            genericMethod.Invoke(this, parameters);
        }
    }
}