Semantic Kernel AlgoliaMemory

AlgoliaMemory.cs

using System.Runtime.CompilerServices;
using Microsoft.SemanticKernel.Memory;
using Algolia.Search.Clients;
using Algolia.Search.Models.Search;
using System.Text.Json;

public class AlgoliaMemory : ISemanticTextMemory
{
    private readonly ISearchClient _searchClient;

    private readonly IEnumerable<string>? _attributesToRetrieve = null;
    private readonly IDictionary<string, string>? _attributesMapping = null;

    public AlgoliaMemory(ISearchClient searchClient, IEnumerable<string>? attributesToRetrieve = null, IDictionary<string, string>? attributesMapping = null)
    {
        this._searchClient = searchClient ?? throw new ArgumentNullException(nameof(searchClient));
        this._attributesToRetrieve = attributesToRetrieve;
        this._attributesMapping = attributesMapping;
    }

    public async Task<MemoryQueryResult?> GetAsync(string collection, string key, bool withEmbedding = false, CancellationToken cancellationToken = default)
    {
        var searchIndex = this._searchClient.InitIndex(collection);
        var objectResult = await searchIndex.GetObjectAsync<Dictionary<string, object?>>(objectId: key);
        var memoryResult = BuildMemoryQueryResult(objectResult);

        return memoryResult;
    }

    public async Task<IList<string>> GetCollectionsAsync(CancellationToken cancellationToken = default)
    {
        var indices = await this._searchClient.ListIndicesAsync(ct: cancellationToken);
        var collections = indices.Items
            .Select(index => index.Name)
            .ToList();

        return collections;
    }

    public Task RemoveAsync(string collection, string key, CancellationToken cancellationToken = default)
    {
        throw new NotImplementedException();
    }

    public Task<string> SaveInformationAsync(string collection, string text, string id, string? description = null, string? additionalMetadata = null, CancellationToken cancellationToken = default)
    {
        throw new NotImplementedException();
    }

    public Task<string> SaveReferenceAsync(string collection, string text, string externalId, string externalSourceName, string? description = null, string? additionalMetadata = null, CancellationToken cancellationToken = default)
    {
        throw new NotImplementedException();
    }

    public async IAsyncEnumerable<MemoryQueryResult> SearchAsync(string collection, string query, int limit = 1, double minRelevanceScore = 0.7, bool withEmbeddings = false, [EnumeratorCancellation] CancellationToken cancellationToken = default)
    {
        var searchIndex = this._searchClient.InitIndex(collection);
        var algoliaQuery = new Query(query)
        {
            AttributesToRetrieve = this._attributesToRetrieve, //https://www.algolia.com/doc/api-reference/api-parameters/attributesToRetrieve/
            RelevancyStrictness = (int)(minRelevanceScore * 100), //https://www.algolia.com/doc/api-reference/api-parameters/relevancyStrictness/
            Length = limit, //https://www.algolia.com/doc/api-reference/api-parameters/length/
            Offset = 0 //https://www.algolia.com/doc/api-reference/api-parameters/offset/
        };

        var searchResponse = await searchIndex.SearchAsync<Dictionary<string, object?>>(query: algoliaQuery, ct: cancellationToken);
        foreach (var searchResult in searchResponse.Hits)
        {
            var memoryResult = BuildMemoryQueryResult(searchResult);
            yield return memoryResult;
        }
    }

    protected MemoryQueryResult BuildMemoryQueryResult(Dictionary<string, object?> searchResult)
    {
        bool isReference = Convert.ToBoolean(this.GetMappedAttributeValue(searchResult, "isReference") ?? false);
        string id = Convert.ToString(this.GetMappedAttributeValue(searchResult, "objectID")) ?? string.Empty;
        string text = Convert.ToString(this.GetMappedAttributeValue(searchResult, "text")) ?? string.Empty;
        string description = Convert.ToString(this.GetMappedAttributeValue(searchResult, "description")) ?? string.Empty;
        string externalSourceName = Convert.ToString(this.GetMappedAttributeValue(searchResult, "externalSourceName")) ?? string.Empty;

        string additionalMetadata = SerializeMetadata(searchResult);

        var memoryMetadata = new MemoryRecordMetadata(isReference: isReference, id: id, text: text, description: description, externalSourceName: externalSourceName, additionalMetadata: additionalMetadata);
        var memoryResult = new MemoryQueryResult(metadata: memoryMetadata, relevance: 0, embedding: ReadOnlyMemory<float>.Empty);

        return memoryResult;
    }

    protected object? GetMappedAttributeValue(Dictionary<string, object?> searchResult, string attribute)
    {
        string? attributeMapping = attribute;
        this._attributesMapping?.TryGetValue(attribute, out attributeMapping);

        if(string.IsNullOrWhiteSpace(attributeMapping))
            return null;

        return searchResult.GetValueOrDefault(attributeMapping);
    }

    protected static string SerializeMetadata(Dictionary<string, object?> searchResult)
    {
        var additionalMetadataDict = searchResult.ToDictionary(kv => kv.Key, kv => kv.Value is string stringValue
            ? stringValue
            : JsonSerializer.Serialize(kv.Value));

        string additionalMetadata = JsonSerializer.Serialize(additionalMetadataDict);
        return additionalMetadata;
    }
}