Added AIProvider and support for OpenAI compatible APIs

2025-07-06 22:28:45 +02:00
parent 84a4a9d51e
commit b596695fd9
11 changed files with 196 additions and 38 deletions
--- a/src/Server/AIProvider.cs
+++ b/src/Server/AIProvider.cs
@@ -0,0 +1,147 @@
+
+using System.Collections.Frozen;
+using System.Collections.Immutable;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using Server.Exceptions;
+
+namespace server;
+
+public class AIProvider
+{
+    private readonly ILogger<AIProvider> _logger;
+    private readonly IConfiguration _configuration;
+    public AIProvidersConfiguration aIProvidersConfiguration;
+
+    public AIProvider(ILogger<AIProvider> logger, IConfiguration configuration)
+    {
+        _logger = logger;
+        _configuration = configuration;
+        AIProvidersConfiguration? retrievedAiProvidersConfiguration = _configuration
+            .GetSection("Embeddingsearch")
+            .Get<AIProvidersConfiguration>();
+        if (retrievedAiProvidersConfiguration is null)
+        {
+            _logger.LogCritical("Unable to build AIProvidersConfiguration. Please check your configuration.");
+            throw new ServerConfigurationException("Unable to build AIProvidersConfiguration. Please check your configuration.");
+        }
+        else
+        {
+            aIProvidersConfiguration = retrievedAiProvidersConfiguration;
+        }
+    }
+
+    public float[] GenerateEmbeddings(string modelUri, string[] input)
+    {
+        Uri uri = new(modelUri);
+        string provider = uri.Scheme;
+        string model = uri.AbsolutePath;
+        AIProviderConfiguration? aIProvider = aIProvidersConfiguration.AiProviders
+            .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($"Model provider {provider} not found in configuration. Requested model: {modelUri}");
+        }
+        using var httpClient = new HttpClient();
+
+        string embeddingsJsonPath = "";
+        Uri baseUri = new(aIProvider.BaseURL);
+        Uri requestUri;
+        IEmbedRequestBody embedRequest;
+        string[][] requestHeaders = [];
+        switch (aIProvider.Handler)
+        {
+            case "ollama":
+                embeddingsJsonPath = "$.embeddings[*]";
+                requestUri = new Uri(baseUri, "/api/embed");
+                embedRequest = new OllamaEmbedRequestBody()
+                {
+                    input = input,
+                    model = model
+                };
+                break;
+            case "openai":
+                embeddingsJsonPath = "$.data[*].embedding";
+                requestUri = new Uri(baseUri, "/v1/embeddings");
+                embedRequest = new OpenAIEmbedRequestBody()
+                {
+                    input = input,
+                    model = model
+                };
+                if (aIProvider.ApiKey is not null)
+                {
+                    requestHeaders = [
+                        ["Authorization", $"Bearer {aIProvider.ApiKey}"]
+                    ];
+                }
+                break;
+            default:
+                _logger.LogError("Unknown handler {aIProvider.Handler} in AiProvider {provider}.", [aIProvider.Handler, provider]);
+                throw new ServerConfigurationException($"Unknown handler {aIProvider.Handler} in AiProvider {provider}.");
+        }
+        var requestContent = new StringContent(
+            JsonConvert.SerializeObject(embedRequest),
+            UnicodeEncoding.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);
+            JToken? responseContentTokens = responseContentJson.SelectToken(embeddingsJsonPath);
+            if (responseContentTokens is null)
+            {
+                throw new Exception($"Unable to select tokens using JSONPath {embeddingsJsonPath}."); // TODO add proper exception
+            }
+            return [.. responseContentTokens.Values<float>()];
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError("Unable to parse the response to valid embeddings. {ex.Message}", [ex.Message]);
+            throw new Exception($"Unable to parse the response to valid embeddings. {ex.Message}"); // TODO add proper exception
+        }
+    }
+}
+
+public class AIProvidersConfiguration
+{
+    public required Dictionary<string, AIProviderConfiguration> AiProviders { get; set; }
+}
+
+public class AIProviderConfiguration
+{
+    public required string Handler { get; set; }
+    public required string BaseURL { get; set; }
+    public string? ApiKey { get; set; }
+}
+public interface IEmbedRequestBody { }
+
+public class OllamaEmbedRequestBody : IEmbedRequestBody
+{
+    public required string model { get; set; }
+    public required string[] input { get; set; }
+}
+
+public class OpenAIEmbedRequestBody : IEmbedRequestBody
+{
+    public required string model { get; set; }
+    public required string[] input { get; set; }
+}