using ln.collections;
using System;
using System.Collections.Generic;
using System.Text;

namespace ln.objects.index
{
    class SimpleIndex<T> : Index
    {
        BTreeValueSet<T, Guid> index = new BTreeValueSet<T, Guid>();
        BTree<Guid, T> reverseIndex = new BTree<Guid, T>();

        public SimpleIndex()
        {
        }

        public override void Clear()
        {
            index.Clear();
            reverseIndex.Clear();
        }

        public override void Match(Func<object, bool> criterion, ISet<Guid> matches)
        {
            foreach (T ivalue in index.Keys)
            {
                if (criterion(ivalue))
                    matches.UnionWith(index[ivalue]);
            }
        }

        public override void Reindex(Guid uid, object value)
        {
            Remove(uid);
            index.Add((T)value, uid);
        }

        public override void Remove(Guid uid)
        {
            if (reverseIndex.ContainsKey(uid))
            {
                index.TryRemove(reverseIndex[uid], uid);
                reverseIndex.TryRemove(uid);
            }
        }

        public override bool TryDeserializeIndex(byte[] serializedIndex)
        {
            throw new NotImplementedException();
        }

        public override bool TrySerializeIndex(out byte[] serializedIndex)
        {
            throw new NotImplementedException();
        }
    }
}