Added transcription of audio and video files to local data sources (#1081)

Co-authored-by: Paul Koudelka <106623909+PaulKoudelka@users.noreply.github.com>

app/Tests/Provider/MediaFileRejectionTests.cs

@@ -0,0 +1,78 @@
+using System.Net;
+
+using AIStudio.Provider;
+
+namespace AIStudio.Tests.Provider;
+
+/// <summary>
+/// Checks which answers of a transcription provider refuse the media file itself.
+/// </summary>
+/// <remarks>
+/// A data source records such a file for good, until it changes. An answer counted here by
+/// mistake keeps a file out of the index; one missed here uploads the file again with every run.
+/// </remarks>
+[TestFixture]
+public sealed class MediaFileRejectionTests
+{
+    private const string OPENAI_DAMAGED_FILE = """
+        {
+          "error": {
+            "message": "Audio file might be corrupted or unsupported",
+            "type": "invalid_request_error",
+            "param": "file",
+            "code": "invalid_value"
+          }
+        }
+        """;
+
+    private const string OPENAI_UNKNOWN_MODEL = """
+        {
+          "error": {
+            "message": "Invalid model.",
+            "type": "invalid_request_error",
+            "param": "model",
+            "code": "invalid_value"
+          }
+        }
+        """;
+
+    private const string UNDECODABLE_FORMAT = """
+        {
+          "error": {
+            "message": "Could not decode the audio file.",
+            "param": "file"
+          }
+        }
+        """;
+
+    [Test]
+    public void AFileTheProviderCannotReadIsRefused()
+    {
+        Assert.That(BaseProvider.IsMediaFileRejection(HttpStatusCode.BadRequest, OPENAI_DAMAGED_FILE), Is.True);
+    }
+
+    [TestCase(HttpStatusCode.RequestEntityTooLarge)]
+    [TestCase(HttpStatusCode.UnsupportedMediaType)]
+    public void AFileTooLargeOrOfAnUnacceptedTypeIsRefused(HttpStatusCode statusCode)
+    {
+        Assert.That(BaseProvider.IsMediaFileRejection(statusCode, string.Empty), Is.True);
+    }
+
+    [Test]
+    public void AProviderWhichDecodesNoWebMRefusesNoSingleFile()
+    {
+        Assert.That(BaseProvider.IsMediaFileRejection(HttpStatusCode.BadRequest, UNDECODABLE_FORMAT), Is.False, "Every file fails the same way, and only another provider helps.");
+    }
+
+    [TestCase(HttpStatusCode.BadRequest, OPENAI_UNKNOWN_MODEL)]
+    [TestCase(HttpStatusCode.BadRequest, "Bad request")]
+    [TestCase(HttpStatusCode.BadRequest, "")]
+    [TestCase(HttpStatusCode.TooManyRequests, OPENAI_DAMAGED_FILE)]
+    [TestCase(HttpStatusCode.Unauthorized, "")]
+    [TestCase(HttpStatusCode.InternalServerError, "")]
+    [TestCase(HttpStatusCode.ServiceUnavailable, "")]
+    public void AFailureWhichMayPassRefusesNoFile(HttpStatusCode statusCode, string responseBody)
+    {
+        Assert.That(BaseProvider.IsMediaFileRejection(statusCode, responseBody), Is.False);
+    }
+}