Added reranker exploration setup

src/Client/Client.cs

@@ -160,6 +160,21 @@ public class Client
             return await FetchUrlAndProcessJson<EntityQueryResults>(HttpMethod.Post, GetUrl($"{baseUri}/Searchdomain", "Query", parameters), null);
         }
 
+        public async Task<EntityQueryResults> SearchdomainQueryRerankedAsync(string searchdomain, string query, string rerankerModel, int topN, int topNRetrieval, bool returnAttributes = false)
+        {
+            Dictionary<string, string> parameters = new()
+            {
+                { "searchdomain", searchdomain },
+                { "query", query },
+                { "rerankerModel", (rerankerModel).ToString() },
+                { "topN", (topN).ToString() },
+                { "topNRetrieval", (topNRetrieval).ToString() }
+            };
+            if (returnAttributes) parameters.Add("returnAttributes", returnAttributes.ToString());
+
+            return await FetchUrlAndProcessJson<EntityQueryResults>(HttpMethod.Post, GetUrl($"{baseUri}/Searchdomain", "QueryReranked", parameters), null);
+        }
+
         public async Task<SearchdomainDeleteSearchResult> SearchdomainDeleteQueryAsync(string searchdomain, string query)
         {
             Dictionary<string, string> parameters = new()

src/Server/AIProvider.cs

@@ -132,6 +132,107 @@ public class AIProvider
         }
     }
 
+    public IEnumerable<(int index, float score)> Rerank(string modelUri, string input, string[] documents, int topN)
+    {
+        Uri uri = new(modelUri);
+        string provider = uri.Scheme;
+        string model = uri.AbsolutePath;
+        AiProvider? aIProvider = AiProvidersConfiguration
+            .FirstOrDefault(x => string.Equals(x.Key.ToLower(), provider.ToLower()))
+            .Value;
+        if (aIProvider is null)
+        {
+            _logger.LogError("Model provider {provider} not found in configuration. Requested model: {modelUri}", [provider, modelUri]);
+            throw new ServerConfigurationException($"Model provider {provider} not found in configuration. Requested model: {modelUri}");
+        }
+        using var httpClient = new HttpClient();
+        httpClient.Timeout = TimeSpan.FromMinutes(150);
+
+        string indexJsonPath = "";
+        string scoreJsonPath = "";
+        IEnumerable<(string, float)> values = [];
+        Uri baseUri = new(aIProvider.BaseURL);
+        Uri requestUri;
+        IRerankRequestBody rerankRequestBody;
+        string[][] requestHeaders = [];
+        switch (aIProvider.Handler)
+        {
+            case "openai":
+                indexJsonPath = "$.results[*].index";
+                scoreJsonPath = "$.results[*].relevance_score";
+                requestUri = new Uri(baseUri, "/v1/rerank");
+                rerankRequestBody = new OpenAIRerankRequestBody()
+                {
+                    model = model,
+                    query = input,
+                    documents = documents,
+                    top_n = topN
+                };
+                if (aIProvider.ApiKey is not null)
+                {
+                    requestHeaders = [
+                        ["Authorization", $"Bearer {aIProvider.ApiKey}"]
+                    ];
+                }
+                break;
+            default:
+                _logger.LogError("Invalid reranking handler {aIProvider.Handler} in AiProvider {provider}.", [aIProvider.Handler, provider]);
+                throw new ServerConfigurationException($"Unknown handler {aIProvider.Handler} in AiProvider {provider}.");
+        }
+        var requestContent = new StringContent(
+            JsonConvert.SerializeObject(rerankRequestBody),
+            Encoding.UTF8,
+            "application/json"
+        );
+
+        var request = new HttpRequestMessage()
+        {
+            RequestUri = requestUri,
+            Method = HttpMethod.Post,
+            Content = requestContent
+        };
+        
+        foreach (var header in requestHeaders)
+        {
+            request.Headers.Add(header[0], header[1]);
+        }
+        HttpResponseMessage response = httpClient.PostAsync(requestUri, requestContent).Result;
+        string responseContent = response.Content.ReadAsStringAsync().Result;
+        try
+        {
+            JObject responseContentJson = JObject.Parse(responseContent);
+            List<JToken>? responseContentIndexTokens = [.. responseContentJson.SelectTokens(indexJsonPath)];
+            List<JToken>? responseContentScoreTokens = [.. responseContentJson.SelectTokens(scoreJsonPath)];
+            if (responseContentIndexTokens is null || responseContentIndexTokens.Count == 0
+                || responseContentScoreTokens is null || responseContentScoreTokens.Count == 0)
+            {
+                if (responseContentJson.TryGetValue("error", out JToken? errorMessageJson) && errorMessageJson is not null)
+                {
+                    string errorMessage = (string?)errorMessageJson.Value<string>("message") ?? "";
+                    string errorCode = (string?)errorMessageJson.Value<string>("code") ?? "";
+                    string errorType = (string?)errorMessageJson.Value<string>("type") ?? "";
+                    _logger.LogError("Unable to retrieve reranking results due to error: {errorCode} - {errorMessage} - {errorType}", [errorCode, errorMessage, errorType]);
+                    throw new Exception($"Unable to retrieve reranking results due to error: {errorMessage}");
+                    
+                } else
+                {
+                    _logger.LogError("Unable to select tokens using JSONPath {indexJsonPath} for string: {responseContent}.", [indexJsonPath, responseContent]);
+                    throw new JSONPathSelectionException(indexJsonPath, responseContent);
+                }
+            }
+            IEnumerable<int> indices = responseContentIndexTokens.Select(token => token.ToObject<int>());
+            IEnumerable<float> scores = responseContentScoreTokens.Select(token => token.ToObject<float>());
+            IEnumerable<(int index, float score)> zipped = indices.Zip(scores, (index, score) => (index, score));
+            
+            return zipped;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError("Unable to parse the response to valid embeddings. {ex.Message}", [ex.Message]);
+            throw;
+        }
+    }
+
     public string[] GetModels()
     {
         var aIProviders = AiProvidersConfiguration;
@@ -239,4 +340,16 @@ public class OpenAIEmbedRequestBody : IEmbedRequestBody
 {
     public required string model { get; set; }
     public required string[] input { get; set; }
+}
+
+
+public interface IRerankRequestBody { }
+
+
+public class OpenAIRerankRequestBody : IRerankRequestBody
+{
+    public required string model { get; set; }
+    public required string query { get; set; }
+    public required int top_n { get; set; }
+    public required string[] documents { get; set; }
 }

src/Server/Controllers/SearchdomainController.cs

@@ -148,6 +148,78 @@ public class SearchdomainController : ControllerBase
         return Ok(new SearchdomainQueriesResults() { Searches = searchCache, Success = true });
     }
 
+
+
+    /// <summary>
+    /// Executes a query in the searchdomain and reranks the result using a specified reranker
+    /// </summary>
+    /// <param name="searchdomain">Name of the searchdomain</param>
+    /// <param name="query">Query to execute</param>
+    /// <param name="topN">Return only the top N results</param>
+    /// <param name="returnAttributes">Return the attributes of the object</param>
+    [HttpPost("QueryReranked")]
+    public ActionResult<EntityRerankResults> QueryReranked([Required]string searchdomain, [Required]string query, [Required]string rerankerModel, int topN, int topNRetrieval, ProbMethodEnum probMethod = ProbMethodEnum.HVEWAvg, bool returnAttributes = false)
+    {
+        
+        (Searchdomain? searchdomain_, int? httpStatusCode, string? message) = SearchdomainHelper.TryGetSearchdomain(_domainManager, searchdomain, _logger);
+        if (searchdomain_ is null || httpStatusCode is not null) return StatusCode(httpStatusCode ?? 500, new SearchdomainUpdateResults(){Success = false, Message = message});
+        List<(float, string)> results = searchdomain_.Search(query, topNRetrieval);
+        List<(string Name, Dictionary<string, string> Attributes)> queryResults = [.. results.Select(r => (
+            Name: r.Item2,
+            Attributes: searchdomain_.EntityCache[r.Item2]?.Attributes ?? []
+        ))];
+
+
+        // Key: Attribute name
+        Dictionary<string, List<(string EntityName, string AttributeValue)>> resultsByAttribute = [];
+        queryResults.ForEach(r =>
+        {
+            foreach (var kv in r.Attributes)
+            {
+                if (!resultsByAttribute.TryGetValue(kv.Key, out List<(string EntityName, string AttributeValue)>? values) || values is null)
+                {
+                    values = [];
+                    resultsByAttribute[kv.Key] = values;
+                }
+                values.Add((r.Name, kv.Value));
+            }
+        });
+
+        // Key: EntityName
+        Dictionary<string, List<(string attribute, float score)>> scoresByEntity = [];
+        foreach (var kv in resultsByAttribute)
+        {
+            string attributeName = kv.Key;
+            List<(string EntityName, string AttributeValue)> nameValuePairs = kv.Value;
+            
+            List<string> documents = [.. nameValuePairs.Select(r => r.AttributeValue)];
+            List<(int index, float score)> rerankResults = [.. searchdomain_.AiProvider.Rerank(rerankerModel, query, [.. documents], topN)];
+            List<(string entityName, float score)> rerankedScores = [.. rerankResults.Select(r => (nameValuePairs.ElementAt(r.index).EntityName, r.score))];
+            foreach ((string entityName, float score) in rerankedScores)
+            {
+                if (!scoresByEntity.TryGetValue(entityName, out List<(string attribute, float score)>? values) || values is null)
+                {
+                    values = [];
+                    scoresByEntity[entityName] = values;
+                }
+                values.Add((attributeName, score));
+            }
+        }
+        List<EntityRerankResult> entityRerankResults = [.. scoresByEntity.Select(scoreKV =>
+        {
+            string entityName = scoreKV.Key;
+            float score = new ProbMethod(probMethod).Method(scoreKV.Value);
+            return new EntityRerankResult()
+            {
+                Name = entityName,
+                Value = score,
+                Attributes = returnAttributes ? (searchdomain_.EntityCache[entityName]?.Attributes ?? []) : null
+            };
+        })];
+        
+        return Ok(new EntityRerankResults(){Results = entityRerankResults, Success = true });
+    }
+
     /// <summary>
     /// Executes a query in the searchdomain
     /// </summary>

src/Shared/Models/EntityResults.cs

@@ -20,6 +20,23 @@ public class EntityQueryResult
     public Dictionary<string, string>? Attributes { get; set; }
 }
 
+public class EntityRerankResults : SuccesMessageBaseModel
+{
+    [JsonPropertyName("Results")]
+    public required List<EntityRerankResult> Results { get; set; }
+}
+
+public class EntityRerankResult
+{
+    [JsonPropertyName("Name")]
+    public required string Name { get; set; }
+    [JsonPropertyName("Value")]
+    public float Value { get; set; }
+    [JsonPropertyName("Attributes")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public Dictionary<string, string>? Attributes { get; set; }
+}
+
 public class EntityIndexResult : SuccesMessageBaseModel {}
 
 public class EntityListResults