using System;
using ln.types.btree;
using System.Reflection;
using ln.types.attributes;
using System.Collections.Generic;
using System.Linq;
namespace ln.types.reflection
{
    public class ObjectPoolContainer
    {
        BTree<string, ObjectPool> objectPools = new BTree<string, ObjectPool>();
        public IEnumerable<ObjectPool> Pools => objectPools.Values;
        public IEnumerable<Type> Types => objectPools.Values.Select((pool) => pool.ObjectType);

        public ObjectPoolContainer()
        {
        }

        public ObjectPool this[string typeName] => objectPools[typeName];
        public ObjectPool this[Type type] => objectPools[type.Name];

        public bool KnowsType(Type type) => objectPools.ContainsKey(type.Name);

        public ObjectPoolContainer AddType(Type type) => AddType(type, null);
        public ObjectPoolContainer AddType(Type type,String identityAttribute)
        {
            foreach (FieldInfo fieldInfo in type.GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
            {
                if (((identityAttribute == null) && (fieldInfo.GetCustomAttribute<IdentityAttribute>()!=null)) || fieldInfo.Name.Equals(identityAttribute))
                {
                    objectPools.Add(type.Name, new ObjectPool(type, fieldInfo.FieldType, fieldInfo.GetValue));
                }
            }
            foreach (PropertyInfo propertyInfo in type.GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
            {
                if (((identityAttribute == null) && (propertyInfo.GetCustomAttribute<IdentityAttribute>() != null)) || propertyInfo.Name.Equals(identityAttribute))
                {
                    objectPools.Add(type.Name, new ObjectPool(type, propertyInfo.PropertyType, propertyInfo.GetValue));
                }
            }

            SetupDerivedTypes(type);

            return this;
        }

        public void SetupDerivedTypes(Type type)
        {
            Type current = type.BaseType;
            while (!object.Equals(current, typeof(object)))
            {
                if (objectPools.ContainsKey(current.Name))
                {
                    objectPools[current.Name].AddDerivedTypePool(objectPools[type.Name]);
                    break;
                }

                current = current.BaseType;
            }
        }




    }
}