feat: text to speech support (srcnalt#103)

* feat: add text to speech support

* feat: add text to speech sample

Runtime/DataTypes.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using Newtonsoft.Json;
+using UnityEngine;
 
 namespace OpenAI
 {
@@ -162,6 +163,26 @@ public struct CreateAudioResponse: IResponse
     }
     #endregion
 
+    #region Text To Speech Data Types
+
+    public class CreateTextToSpeechRequestBase
+    {
+        public string Input { get; set; }
+        public string Voice { get; set; }
+        public string Model { get; set; }
+    }
+
+    public class CreateTextToSpeechRequest: CreateTextToSpeechRequestBase { }
+
+    public struct CreateTextToSpeechResponse: IAudioResponse
+    {
+        public ApiError Error { get; set; }
+        public string Warning { get; set; }
+        public AudioClip AudioClip { get; set; }
+    }
+
+    #endregion
+
     #region Images API Data Types
     public class CreateImageRequestBase
     {

Runtime/Interfaces/IAudioResponse.cs

@@ -0,0 +1,9 @@
+using UnityEngine;
+
+namespace OpenAI
+{
+    public interface IAudioResponse: IResponse
+    {
+        public AudioClip AudioClip { get; set; }
+    }
+}

Runtime/OpenAIApi.cs

@@ -95,6 +95,55 @@ private async Task<T> DispatchRequest<T>(string path, string method, byte[] payl
             return data;
         }
 
+        /// <summary>
+        ///     Dispatches an HTTP request for an audio file to the specified path with the specified method and optional payload.
+        /// </summary>
+        /// <param name="path">The path to send the request to.</param>
+        /// <param name="method">The HTTP method to use for the request.</param>
+        /// <param name="payload">An optional byte array of json payload to include in the request.</param>
+        /// <typeparam name="T">Response type of the request.</typeparam>
+        /// <returns>A Task containing the response from the request as the specified type.</returns>
+        private async Task<T> DispatchAudioRequest<T>(string path, string method, byte[] payload = null) where T: IAudioResponse
+        {
+            T data = default;
+
+            using (var request = UnityWebRequest.Put(path, payload))
+            {
+                request.method = method;
+                request.SetHeaders(Configuration, ContentType.ApplicationJson);
+
+                var downloadHandlerAudioClip = new DownloadHandlerAudioClip(string.Empty, AudioType.MPEG);
+                request.downloadHandler = downloadHandlerAudioClip;
+
+                var asyncOperation = request.SendWebRequest();
+
+                while (!asyncOperation.isDone) await Task.Yield();
+
+                if (request.result == UnityWebRequest.Result.Success)
+                {
+                    if(data != null) data.AudioClip = DownloadHandlerAudioClip.GetContent(request);
+                }
+                else
+                {
+                    if(data != null) data.Error = new ApiError 
+                        { Code = request.responseCode, Message = request.error, Type = request.error };
+                }
+            }
+
+            if (data?.Error != null)
+            {
+                ApiError error = data.Error;
+                Debug.LogError($"Error Message: {error.Message}\nError Type: {error.Type}\n");
+            }
+
+            if (data?.Warning != null)
+            {
+                Debug.LogWarning(data.Warning);
+            }
+
+            return data;
+        }
+
         /// <summary>
         ///     Dispatches an HTTP request to the specified path with the specified method and optional payload.
         /// </summary>
@@ -308,6 +357,19 @@ public async Task<CreateEmbeddingsResponse> CreateEmbeddings(CreateEmbeddingsReq
             var payload = CreatePayload(request);
             return await DispatchRequest<CreateEmbeddingsResponse>(path, UnityWebRequest.kHttpVerbPOST, payload);
         }
+
+        /// <summary>
+        ///     Returns speech audio for the provided text.
+        /// </summary>
+        /// <param name="request">See <see cref="CreateTextToSpeechRequest"/></param>
+        /// <returns>See <see cref="CreateTextToSpeechResponse"/></returns>
+        public async Task<CreateTextToSpeechResponse> CreateTextToSpeech(CreateTextToSpeechRequest request)
+        {
+            var path = $"{BASE_PATH}/audio/speech";
+            var payload = CreatePayload(request);
+
+            return await DispatchAudioRequest<CreateTextToSpeechResponse>(path, UnityWebRequest.kHttpVerbPOST, payload);
+        }
 
         /// <summary>
         ///     Transcribes audio into the input language.