adding new mindforge applications

Mindforge.API/Providers/OpenAIApiProvider.cs

@@ -0,0 +1,110 @@
+using System;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Text;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Configuration;
+
+namespace Mindforge.API.Providers
+{
+    public class OpenAIApiProvider : ILlmApiProvider
+    {
+        private readonly HttpClient _httpClient;
+        private readonly IConfiguration _configuration;
+        private readonly ILogger<OpenAIApiProvider> _logger;
+
+        public OpenAIApiProvider(HttpClient httpClient, IConfiguration configuration, ILogger<OpenAIApiProvider> logger)
+        {
+            _httpClient = httpClient;
+            _httpClient.Timeout = TimeSpan.FromMinutes(5);
+            _configuration = configuration;
+            _logger = logger;
+        }
+
+        public async Task<string> SendRequestAsync(string systemPrompt, string userPrompt, string model)
+        {
+            var apiKey = _configuration["OPENAI_API_KEY"];
+            if (string.IsNullOrEmpty(apiKey))
+            {
+                throw new Exception("OPENAI_API_KEY not found in configuration.");
+            }
+
+            var apiBase = "https://api.openai.com/v1";
+            var url = $"{apiBase.TrimEnd('/')}/responses";
+
+            var reqBody = new
+            {
+                model = model,
+                input = new[]
+                {
+                    new { role = "developer", content = systemPrompt },
+                    new { role = "user", content = userPrompt }
+                },
+                reasoning = new
+                {
+                    effort = "low"
+                }
+            };
+
+            var jsonBody = JsonSerializer.Serialize(reqBody);
+
+            Exception? lastErr = null;
+
+            for (int i = 0; i < 5; i++)
+            {
+                using var request = new HttpRequestMessage(HttpMethod.Post, url);
+                request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
+                request.Content = new StringContent(jsonBody, Encoding.UTF8, "application/json");
+
+                try
+                {
+                    var response = await _httpClient.SendAsync(request);
+                    var responseBody = await response.Content.ReadAsStringAsync();
+
+                    if (!response.IsSuccessStatusCode)
+                    {
+                        lastErr = new Exception($"OpenAI API error status {(int)response.StatusCode}: {responseBody}");
+                        await Task.Delay(TimeSpan.FromSeconds(1 << i));
+                        continue;
+                    }
+
+                    var result = JsonSerializer.Deserialize<JsonElement>(responseBody);
+                    if (result.TryGetProperty("output", out var outputArray))
+                    {
+                        foreach (var outputItem in outputArray.EnumerateArray())
+                        {
+                            if (outputItem.TryGetProperty("content", out var contentArray))
+                            {
+                                foreach (var contentItem in contentArray.EnumerateArray())
+                                {
+                                    if (contentItem.TryGetProperty("text", out var textContent))
+                                    {
+                                        return textContent.GetString() ?? string.Empty;
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    _logger.LogWarning("OpenAI API raw response: {responseBody}", responseBody);
+
+                    throw new Exception("empty response from OpenAI API");
+                }
+                catch (Exception ex)
+                {
+                    _logger.LogError(ex, "Error in OpenAI API request");
+                    lastErr = ex;
+                    await Task.Delay(TimeSpan.FromSeconds(1 << i));
+                }
+            }
+
+            throw new Exception($"failed to get OpenAI response after 5 attempts. Last error: {lastErr?.Message}", lastErr);
+        }
+
+        public async Task<string> SendRequestBatchAsync(string systemPrompt, string userPrompt, string model)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}