Improve handling of hidden videos (#70)

* Initial working version

* Minor cleanup

* Add `TrimTerminalLineBreak()` extension method

* Trim errors separately

* Create new method for exit code check

* Add comment about errors on success

src/CCVTAC.Console/Downloading/Downloader.cs

@@ -33,25 +33,36 @@ internal static Result<MediaTypeWithUrls> WrapUrlInMediaType(string url)
 
         if (!mediaType.IsVideo && !mediaType.IsPlaylistVideo)
         {
-            printer.Info("Please wait for the multiple videos to be downloaded...");
+            printer.Info("Please wait for multiple videos to be downloaded...");
         }
 
         var rawUrls = FSharp.Downloading.ExtractDownloadUrls(mediaType);
         var urls = new Urls(rawUrls[0], rawUrls.Length == 2 ? rawUrls[1] : null);
 
-        Result downloadResult = new();
+        var downloadResult = new Result<(int, string)> ();
         string? successfulFormat = null;
 
         foreach (string format in settings.AudioFormats)
         {
             string args = GenerateDownloadArgs(format, settings, mediaType, urls.Primary);
             var downloadSettings = new ToolSettings(ExternalTool, args, settings.WorkingDirectory!);
 
-            downloadResult = Runner.Run(downloadSettings, printer);
+            downloadResult = Runner.Run(downloadSettings, otherSuccessExitCodes: [1], printer);
 
             if (downloadResult.IsSuccess)
             {
                 successfulFormat = format;
+
+                var (exitCode, warnings) = downloadResult.Value;
+                if (exitCode != 0)
+                {
+                    printer.Warning($"Downloading completed with minor issues.");
+                    if (warnings.HasText())
+                    {
+                        printer.Warning(warnings);
+                    }
+                }
+
                 break;
             }
 
@@ -60,7 +71,16 @@ internal static Result<MediaTypeWithUrls> WrapUrlInMediaType(string url)
 
         var errors = downloadResult.Errors.Select(e => e.Message).ToList();
 
-        if (downloadResult.IsFailed)
+        int audioFileCount = IoUtilties.Directories.AudioFileCount(settings.WorkingDirectory);
+        if (audioFileCount == 0)
+        {
+            return Result.Fail(string.Join(
+                Environment.NewLine,
+                ["No audio files were downloaded.", ..errors])
+            );
+        }
+
+        if (errors.Count != 0)
         {
             downloadResult.Errors.ForEach(e => printer.Error(e.Message));
             printer.Info("Post-processing will still be attempted."); // For any partial downloads
@@ -75,7 +95,11 @@ internal static Result<MediaTypeWithUrls> WrapUrlInMediaType(string url)
                     supplementaryArgs,
                     settings.WorkingDirectory!);
 
-            var supplementaryDownloadResult = Runner.Run(supplementaryDownloadSettings, printer);
+            var supplementaryDownloadResult =
+                Runner.Run(
+                    supplementaryDownloadSettings,
+                    otherSuccessExitCodes: [1],
+                    printer);
 
             if (supplementaryDownloadResult.IsSuccess)
             {

src/CCVTAC.Console/ExtensionMethods.cs

@@ -66,4 +66,8 @@ public static string ReplaceInvalidPathChars(
         );
     }
 
+    public static string TrimTerminalLineBreak(this string text) =>
+        text.HasText()
+            ? text.TrimEnd(Environment.NewLine.ToCharArray())
+            : text;
 }

src/CCVTAC.Console/ExternalTools/Runner.cs

@@ -4,7 +4,22 @@ namespace CCVTAC.Console.ExternalTools;
 
 internal static class Runner
 {
-    internal static Result Run(ToolSettings settings, Printer printer)
+    private const int AuthenticSuccessExitCode = 0;
+
+    private static bool IsSuccessExitCode(HashSet<int> otherSuccessExitCodes, int exitCode) =>
+        otherSuccessExitCodes.Append(AuthenticSuccessExitCode).Contains(exitCode);
+
+    /// <summary>
+    /// Calls an external application.
+    /// </summary>
+    /// <param name="settings"></param>
+    /// <param name="otherSuccessExitCodes">Additional exit codes, other than 0, that can be treated as non-failures.</param>
+    /// <param name="printer"></param>
+    /// <returns>A `Result` containing the exit code, if successful, or else an error message.</returns>
+    internal static Result<(int SuccessExitCode, string Warnings)> Run(
+        ToolSettings settings,
+        HashSet<int> otherSuccessExitCodes,
+        Printer printer)
     {
         Watch watch = new();
 
@@ -29,18 +44,13 @@ internal static Result Run(ToolSettings settings, Printer printer)
             return Result.Fail($"Could not locate {settings.Program.Name}. If it's not installed, please install from {settings.Program.Url}.");
         }
 
-
-        string error = process.StandardError.ReadToEnd(); // Must precede `WaitForExit()`.
+        string errors = process.StandardError.ReadToEnd(); // Must precede `WaitForExit()`
         process.WaitForExit();
-
         printer.Info($"Completed {settings.Program.Purpose} in {watch.ElapsedFriendly}.");
 
-        int exitCode = process.ExitCode;
-        if (exitCode == 0)
-        {
-            return Result.Ok();
-        }
-
-        return Result.Fail($"[{settings.Program.Name}] {error.Replace(Environment.NewLine, string.Empty)}.");
+        var trimmedErrors = errors.TrimTerminalLineBreak();
+        return IsSuccessExitCode(otherSuccessExitCodes ?? [], process.ExitCode)
+            ? Result.Ok((process.ExitCode, trimmedErrors)) // Errors will be considered warnings.
+            : Result.Fail($"[{settings.Program.Name}] Exit code {process.ExitCode}: {trimmedErrors}.");
     }
 }

src/CCVTAC.Console/IoUtilties/Directories.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using System.Text;
+using CCVTAC.Console.PostProcessing;
 
 namespace CCVTAC.Console.IoUtilties;
 
@@ -8,6 +9,13 @@ internal static class Directories
     private static readonly string AllFilesSearchPattern = "*";
     private static readonly EnumerationOptions EnumerationOptions = new();
 
+    internal static int AudioFileCount(string directory)
+    {
+        return new DirectoryInfo(directory)
+            .EnumerateFiles()
+            .Count(f => PostProcessor.AudioExtensions.CaseInsensitiveContains(f.Extension));
+    }
+
     internal static Result WarnIfAnyFiles(string directory, int showMax)
     {
         var fileNames = GetDirectoryFileNames(directory);

src/CCVTAC.Console/PostProcessing/ImageProcessor.cs

@@ -18,6 +18,6 @@ internal static void Run(string workingDirectory, Printer printer)
             workingDirectory
         );
 
-        Runner.Run(imageEditToolSettings, printer);
+        Runner.Run(imageEditToolSettings, [], printer);
     }
 }