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

namespace DanieleMarotta.RiversongCodeShowcase
{
    public class GameDatabase : IGameDatabase
    {
        private Dictionary<int, object> _idLookup = new();

        private Dictionary<Type, object> _typeLookup = new();

        public void Add<T>(int id, T asset) where T : class
        {
            _idLookup.Add(id, asset);

            InvokeAddToTypeLookupWithType(asset, asset.GetType());

            if (asset is IGameDataRuntimeId runtimeId) runtimeId.RuntimeId = id;
        }

        private void InvokeAddToTypeLookupWithType(object asset, Type type)
        {
            var bindingAttr = BindingFlags.Instance | BindingFlags.NonPublic;
            var method = GetType().GetMethod(nameof(AddToTypeLookup), bindingAttr)!.MakeGenericMethod(type);
            method.Invoke(this, new[] { asset });
        }

        private void AddToTypeLookup<T>(T asset)
        {
            var type = typeof(T);

            if (!_typeLookup.TryGetValue(type, out var list))
            {
                list = new List<T>();
                _typeLookup.Add(type, list);
            }
            ((List<T>)list).Add(asset);

            var nextType = type.BaseType;
            if (nextType == typeof(object)) return;

            InvokeAddToTypeLookupWithType(asset, nextType);
        }

        public T WithId<T>(int id) where T : class
        {
            return _idLookup.TryGetValue(id, out var asset) ? (T)asset : null;
        }

        public List<T> OfType<T>() where T : class
        {
            if (!_typeLookup.TryGetValue(typeof(T), out var assets))
            {
                assets = new List<T>();
                _typeLookup.Add(typeof(T), assets);
            }
            return (List<T>)assets;
        }
    }
}