feat(media): extract archive downloads on import and handle missing root folder

src/Chaptarr.Core.Test/MediaFiles/DownloadedBooksImportServiceFixture.cs

@@ -8,6 +8,7 @@
 using System.Threading.Tasks;
 using NLog;
 using NUnit.Framework;
+using NzbDrone.Common;
 using NzbDrone.Common.Disk;
 using NzbDrone.Core.Books;
 using NzbDrone.Core.Books.Services;
@@ -189,7 +190,7 @@ private sealed class StubDiskProvider : IDiskProvider
             public bool FolderWritable(string path) => throw new NotImplementedException();
             public bool FolderEmpty(string path) => throw new NotImplementedException();
             public IEnumerable<string> GetDirectories(string path) => throw new NotImplementedException();
-            public IEnumerable<string> GetFiles(string path, bool recursive) => throw new NotImplementedException();
+            public IEnumerable<string> GetFiles(string path, bool recursive) => Directory.Exists(path) ? Directory.GetFiles(path, "*", recursive ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly) : Array.Empty<string>();
             public long GetFolderSize(string path) => throw new NotImplementedException();
             public void CreateFolder(string path) => throw new NotImplementedException();
             public void DeleteFile(string path) => throw new NotImplementedException();
@@ -2638,5 +2639,61 @@ private static Dictionary<string, List<string>> CreateAudioTags(string album, st
                 ["TITLE"] = new List<string> { title }
             };
         }
+
+        private sealed class RecordingArchiveService : IArchiveService
+        {
+            public List<(string CompressedFile, string Destination)> Extractions { get; } = new();
+
+            public void Extract(string compressedFile, string destination)
+            {
+                Extractions.Add((compressedFile, destination));
+            }
+
+            public void CreateZip(string path, IEnumerable<string> files) => throw new NotImplementedException();
+        }
+
+        [Test]
+        public void should_extract_archives_when_folder_has_no_direct_importable_files()
+        {
+            var tempDir = Path.Combine(Path.GetTempPath(), "chaptarr-tests", Guid.NewGuid().ToString("N"));
+            Directory.CreateDirectory(tempDir);
+            var zipPath = Path.Combine(tempDir, "Book.zip");
+            File.WriteAllBytes(zipPath, new byte[] { 1, 2, 3, 4 });
+
+            var archiveService = new RecordingArchiveService();
+
+            try
+            {
+                var service = new DownloadedBooksImportService(
+                    new StubDiskProvider(),
+                    new StubDiskScanService(),
+                    new StubFileMatchingService(),
+                    new StubMetadataTagService(),
+                    new RecordingImportApprovedBooks(),
+                    DispatchProxy.Create<IBookService, ThrowingProxy<IBookService>>(),
+                    DispatchProxy.Create<IAuthorService, ThrowingProxy<IAuthorService>>(),
+                    DispatchProxy.Create<IEditionService, ThrowingProxy<IEditionService>>(),
+                    DispatchProxy.Create<IImportOrchestrator, ThrowingProxy<IImportOrchestrator>>(),
+                    new StubAuthorLibraryService(),
+                    new StubRootFolderService(),
+                    ConfigServiceTestProxy.Create(),
+                    DispatchProxy.Create<IHistoryService, ThrowingProxy<IHistoryService>>(),
+                    DispatchProxy.Create<IEventAggregator, ThrowingProxy<IEventAggregator>>(),
+                    DispatchProxy.Create<NzbDrone.Common.EnvironmentInfo.IRuntimeInfo, ThrowingProxy<NzbDrone.Common.EnvironmentInfo.IRuntimeInfo>>(),
+                    DispatchProxy.Create<IMediaInfoExtractor, ThrowingProxy<IMediaInfoExtractor>>(),
+                    LogManager.GetCurrentClassLogger(),
+                    archiveService);
+
+                service.ProcessPath(tempDir, ImportMode.Auto, author: null, downloadClientItem: null);
+
+                Assert.That(archiveService.Extractions, Has.Count.EqualTo(1));
+                Assert.That(archiveService.Extractions[0].CompressedFile, Is.EqualTo(zipPath));
+                Assert.That(archiveService.Extractions[0].Destination, Is.EqualTo(tempDir));
+            }
+            finally
+            {
+                Directory.Delete(tempDir, true);
+            }
+        }
     }
 }

src/Chaptarr.Core.Test/MediaFiles/UpgradeMediaFileServiceFixture.cs

@@ -1,3 +1,4 @@
+using NzbDrone.Core.MediaFiles.BookImport;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -108,6 +109,40 @@ protected override object Invoke(MethodInfo targetMethod, object[] args)
             }
         }
 
+        private class NullRootFolderServiceProxy : DispatchProxy
+        {
+            protected override object Invoke(MethodInfo targetMethod, object[] args)
+            {
+                if (targetMethod?.Name == nameof(IRootFolderService.GetBestRootFolder))
+                {
+                    return null;
+                }
+
+                throw new NotImplementedException($"Test proxy does not implement IRootFolderService.{targetMethod?.Name}");
+            }
+        }
+
+        [Test]
+        public void should_throw_root_folder_not_found_when_best_root_folder_cannot_be_resolved()
+        {
+            var replacement = new BookFile { Id = 2, Path = "/downloads/Book.m4b" };
+            var author = new Author { Id = 1, Path = "/books/Author" };
+            var book = new Book { Id = 2, Author = author, BookFiles = new List<BookFile>() };
+            var localBook = new LocalBook { Author = author, Book = book, Path = replacement.Path };
+
+            var subject = new UpgradeMediaFileService(
+                new RecordingRecycleBinProvider(),
+                DispatchProxy.Create<IMediaFileService, MediaFileServiceProxy>(),
+                DispatchProxy.Create<IMetadataTagService, NoOpProxy<IMetadataTagService>>(),
+                new StubBookFileMover(),
+                DispatchProxy.Create<IDiskProvider, DiskProviderProxy>(),
+                DispatchProxy.Create<IRootFolderService, NullRootFolderServiceProxy>(),
+                DispatchProxy.Create<ICalibreProxy, ThrowingProxy<ICalibreProxy>>(),
+                LogManager.GetCurrentClassLogger());
+
+            Assert.Throws<RootFolderNotFoundException>(() => subject.UpgradeBookFile(replacement, localBook));
+        }
+
         [Test]
         public void should_not_delete_a_loose_path_match_while_replacing_its_stale_row()
         {

src/NzbDrone.Core/MediaFiles/DownloadedBooksImportService.cs

@@ -5,6 +5,7 @@
 using System.Linq;
 using System.Threading.Tasks;
 using NLog;
+using NzbDrone.Common;
 using NzbDrone.Common.Disk;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Common.EnvironmentInfo;
@@ -52,6 +53,7 @@ public class DownloadedBooksImportService : IDownloadedBooksImportService
         private readonly IEventAggregator _eventAggregator;
         private readonly IRuntimeInfo _runtimeInfo;
         private readonly IMediaInfoExtractor _mediaInfoExtractor;
+        private readonly IArchiveService _archiveService;
         private readonly Logger _logger;
 
         public DownloadedBooksImportService(
@@ -71,7 +73,8 @@ public DownloadedBooksImportService(
             IEventAggregator eventAggregator,
             IRuntimeInfo runtimeInfo,
             IMediaInfoExtractor mediaInfoExtractor,
-            Logger logger)
+            Logger logger,
+            IArchiveService archiveService = null)
         {
             _diskProvider = diskProvider;
             _diskScanService = diskScanService;
@@ -90,6 +93,7 @@ public DownloadedBooksImportService(
             _runtimeInfo = runtimeInfo;
             _mediaInfoExtractor = mediaInfoExtractor;
             _logger = logger;
+            _archiveService = archiveService ?? new ArchiveService(logger);
         }
 
         public List<ImportResult> ProcessRootFolder(IDirectoryInfo directoryInfo)
@@ -150,6 +154,15 @@ private List<ImportResult> ProcessFolder(IDirectoryInfo directoryInfo, ImportMod
                 .Where(f => MediaFileExtensions.AllExtensions.Contains(f.Extension))
                 .ToList();
 
+            if (!mediaFiles.Any())
+            {
+                ExtractArchivesInFolder(directoryInfo);
+                visibleFiles = _diskProvider.GetFileInfos(directoryInfo.FullName, true);
+                mediaFiles = visibleFiles
+                    .Where(f => MediaFileExtensions.AllExtensions.Contains(f.Extension))
+                    .ToList();
+            }
+
             if (!mediaFiles.Any())
             {
                 _logger.Debug("[DOWNLOAD-IMPORT] No media files found in: {0}", directoryInfo.FullName);
@@ -1411,5 +1424,31 @@ public List<ImportResult> ProcessFile(string path, ImportMode importMode = Impor
             var fileInfo = _diskProvider.GetFileInfo(path);
             return ProcessFile(fileInfo, importMode, author, downloadClientItem, remoteBook, requireDefaultRootFolderForMissingAuthors: requireDefaultRootFolderForMissingAuthors);
         }
+
+        private void ExtractArchivesInFolder(IDirectoryInfo directoryInfo)
+        {
+            var archives = _diskProvider.GetFiles(directoryInfo.FullName, true)
+                .Where(IsSupportedArchive)
+                .ToList();
+
+            foreach (var archive in archives)
+            {
+                try
+                {
+                    _archiveService.Extract(archive, directoryInfo.FullName);
+                }
+                catch (Exception e)
+                {
+                    _logger.Warn(e, "Failed to extract archive during import: {0}", archive);
+                }
+            }
+        }
+
+        private static bool IsSupportedArchive(string path)
+        {
+            return path.EndsWith(".zip", StringComparison.OrdinalIgnoreCase) ||
+                   path.EndsWith(".tgz", StringComparison.OrdinalIgnoreCase) ||
+                   path.EndsWith(".tar.gz", StringComparison.OrdinalIgnoreCase);
+        }
     }
 }

src/NzbDrone.Core/MediaFiles/UpgradeMediaFileService.cs

@@ -66,9 +66,13 @@ public BookFileMoveResult UpgradeBookFile(BookFile bookFile, LocalBook localBook
             }
 
             var rootFolder = _rootFolderService.GetBestRootFolder(rootFolderPath);
-            var isCalibre = rootFolder?.IsCalibreLibrary == true && rootFolder.CalibreSettings != null;
+            if (rootFolder == null)
+            {
+                throw new RootFolderNotFoundException($"Root folder '{rootFolderPath}' was not found.");
+            }
 
-            var settings = rootFolder?.CalibreSettings;
+            var isCalibre = rootFolder.IsCalibreLibrary && rootFolder.CalibreSettings != null;
+            var settings = rootFolder.CalibreSettings;
 
             // If there are existing book files and the root folder is missing, throw, so the old file isn't left behind during the import process.
             if (existingFiles != null && existingFiles.Any() && !_diskProvider.FolderExists(rootFolderPath))