feat: LLM API endpoint

Controllers/QuoteController.cs

@@ -2,6 +2,7 @@ using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Cors;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
+using Newtonsoft.Json.Linq;
 using QuotifyBE.Data;
 using QuotifyBE.DTOs;
 using QuotifyBE.Entities;
@@ -481,4 +482,75 @@ public class QuotesController : ControllerBase
         return Ok(quote.ToQuoteShortDTO());
     }
 
+    // POST /api/v1/quotes/ai
+    /// <summary>
+    /// [AUTHED] Request a LLM-generated quote
+    /// </summary>
+    /// <returns>Generated quote's text</returns>
+    /// <remarks>
+    /// <b>Notes</b>:<br/>
+    ///
+    /// <ul>
+    /// If <i>customPrompt</i> is passed:
+    /// <li>The default prompt is overriden by whatever has been passed by the user.</li>
+    /// </ul><br/>
+    /// 
+    /// <ul>
+    /// If <i>model</i> is passed:
+    /// <li>The default large language model is overriden by whatever has been passed by the user.</li>
+    /// </ul><br/>
+    /// 
+    /// <ul>
+    /// If <i>temperature</i> is passed:
+    /// <li>The default temperature (= 0.8) is overriden by whatever has been passed by the user.</li>
+    /// </ul><br/>
+    /// 
+    /// <ul>
+    /// If <i>categoryId</i> is passed:
+    /// <li>The prompt is appended with an instruction in Polish to generate quotes based on the provided category
+    /// (both name and description get passed to the model).</li>
+    /// <li><b>Heads up!</b> The text is appended even if <i>customPrompt</i> has been provided.</li>
+    /// </ul><br/>
+    /// 
+    /// <ul>
+    /// If <i>useSampleQuote</i> is passed:
+    /// <li>The prompt will be appended with a randomly chosen quote from the categoryId (if any exist),
+    /// thus passing categoryId becomes a prerequisite.</li>
+    /// <li><b>Heads up!</b> The request will fail returning status code 400 if categoryId isn't provided!</li>
+    /// </ul>
+    /// </remarks>
+    /// <param name="request">Form data containing required quote information</param>
+    /// <response code="200">Returned on valid request</response>
+    /// <response code="400">Returned when generation failed due to remote server error (likely because of a bad request)</response>
+    /// <response code="500">Returned when response has been generated, but couldn't be parsed (likely because of incompatible server or bad URL)</response>
+    [HttpPost("ai")]
+    [Authorize]
+    [EnableCors]
+    [ProducesResponseType(200)]
+    [ProducesResponseType(typeof(ErrorDTO), 400)]
+    [ProducesResponseType(typeof(ErrorDTO), 500)]
+    public async Task<IActionResult> CreateLLMQuote([FromBody] AskLLMInDTO request)
+    {
+
+        JObject? generatedResponse = await guhf.GenerateLLMResponse(
+            request.CustomPrompt, request.Model, request.Temperature, request.CategoryId, request.UseSampleQuote
+        );
+
+        // Check if any errors occurred
+        if (generatedResponse == null)
+        {
+            return StatusCode(400, new ErrorDTO { Status = "error", Error_msg = "Generation failed most likely due to bad request" });
+        }
+
+        // Parse JSON to get the bot reply
+        string? llmResponse = generatedResponse["choices"]?[0]?["message"]?["content"]?.ToString().Trim('"');
+
+        // If response string is not where we expect it, return 500
+        if (llmResponse == null)
+            return StatusCode(500, new ErrorDTO { Status = "error", Error_msg = "Unexpected API response" });
+
+        // Otherwise, return the response
+        return Ok(new { Status = "ok", BotResponse = llmResponse });
+    }
+
 }