review way to map metadata

LangChain/src/Databases/DuckDb/src/DuckDbVectorCollection.cs

Line 19 in 384a807

//TODO: review way to map metadata

using Microsoft.SemanticKernel.Connectors.DuckDB;
using Microsoft.SemanticKernel.Memory;

namespace LangChain.Databases.DuckDb
{
    public class DuckDbVectorCollection(
        DuckDBMemoryStore store,
        string name = VectorCollection.DefaultName,
        string? id = null) : VectorCollection(name, id), IVectorCollection
    {
        public async Task<IReadOnlyCollection<string>> AddAsync(IReadOnlyCollection<Vector> items, CancellationToken cancellationToken = default)
        {
            items = items ?? throw new ArgumentNullException(nameof(items));

            List<string> list = [];
            foreach (var item in items)
            {
                string? metadata = null;
                //TODO: review way to map metadata
                if (item.Metadata != null)
                    metadata = string.Join("#", item.Metadata.Select(kv => kv.Key + "&" + kv.Value));
                var record = MemoryRecord.LocalRecord(item.Id, item.Text, null, item.Embedding, metadata);
                var insert = await store.UpsertAsync(Name, record, cancellationToken).ConfigureAwait(false);
                list.Add(insert);
            }
            return list;

        }

        public async Task<bool> DeleteAsync(IEnumerable<string> ids, CancellationToken cancellationToken = default)
        {
            await store.RemoveBatchAsync(Name, ids, cancellationToken).ConfigureAwait(false);
            return true;
        }

        public async Task<Vector?> GetAsync(string id, CancellationToken cancellationToken = default)
        {
            var record = await store.GetAsync(Name, id, cancellationToken: cancellationToken).ConfigureAwait(false);

            Dictionary<string, object>? metadata = null;
            if(record?.Metadata?.AdditionalMetadata!=null)
                metadata = record.Metadata.AdditionalMetadata
                .Split('#')
                .Select(part => part.Split('&'))
                .ToDictionary(split => split[0], split => (object)split[1]);

            return record != null ? new Vector { Id = id, Text = record.Metadata.Text, Metadata = metadata } : null;
        }

        public async Task<bool> IsEmptyAsync(CancellationToken cancellationToken = default)
        {
            var collections = store.GetCollectionsAsync(cancellationToken);
            return !(await collections.CountAsync(cancellationToken).ConfigureAwait(false) > 0);
        }

        public async Task<VectorSearchResponse> SearchAsync(VectorSearchRequest request, VectorSearchSettings? settings = null, CancellationToken cancellationToken = default)
        {
            request = request ?? throw new ArgumentNullException(nameof(request));
            settings ??= new VectorSearchSettings();
            var results = await store.GetNearestMatchesAsync(Name, request.Embeddings.First(), limit: settings.NumberOfResults, cancellationToken: cancellationToken)
                .ToListAsync(cancellationToken).ConfigureAwait(false);
            return new VectorSearchResponse { Items = results.Select(x => new Vector { Text = x.Item1.Metadata.Text }).ToList() };
        }
    }
}

Closed in 937cbe1