feat: add library scanning mechanic

Tools/LibraryWatcher.cs

@@ -0,0 +1,91 @@
+using Shadow.Data;
+using Shadow.Entities;
+using System;
+using System.IO;
+
+namespace Shadow.Tools;
+public class LibraryWatcher(string watchPath, string[] excludedPaths, ApplicationDbContext dbContext)
+{
+	private readonly string libraryPath = watchPath;
+	private readonly string[] excludedPaths = excludedPaths;
+	private readonly ApplicationDbContext db = dbContext;
+	private readonly GeneralUseHelpers guhf = new();
+
+	/// <summary>
+	/// Returns a sorted list of paths to all files in a directory, recursively.
+	/// </summary>
+	/// <param name="directory">Path to directory</param>
+	/// <returns>Sorted list of filepaths</returns>
+	public async Task<List<string>> GetFilesRecursivelyAsync(string directory)
+	{
+		string[] allowedExtensions = [".flac", ".m4a", ".mp3", ".ogg", ".wav"];
+		try
+		{
+			List<string> files =
+				Directory.GetFiles(directory, "*", SearchOption.AllDirectories)
+				.Where(file => allowedExtensions.Any(file.ToLower().EndsWith))
+				.ToList();
+
+			files.Sort();
+			return files;
+		}
+		catch (DirectoryNotFoundException)
+		{
+			Console.WriteLine($"[Error] Directory \"{directory}\" does not exist!\n" +
+				"        Please create it manually, or use `Shadow setupWizard`.");
+			throw new DirectoryNotFoundException();
+		}
+
+	}
+
+	/// <summary>
+	/// Return all multimedia content inside of library
+	/// </summary>
+	/// <returns>List of multimedia filepaths</returns>
+	public async Task<List<string>> GetAllMultimediaAsync()
+	{
+
+		// List files in cache
+		// Note: currently, the only excluded path from scanning is the thumbnail cache.
+		// This might change in the future.
+		List<string> cacheFiles = await GetFilesRecursivelyAsync(excludedPaths[0]);
+
+		// List files in library excluding cache
+		List<string> libraryContent = await GetFilesRecursivelyAsync(libraryPath);
+		List<string> libraryMultimedia = libraryContent.Except(cacheFiles).ToList();
+
+		return libraryMultimedia;
+	}
+
+	/// <summary>
+	/// Scan the library in its entirety
+	/// </summary>
+	/// <returns></returns>
+	public async Task<List<string>> PerformFullScanAsync()
+	{
+		Console.WriteLine("Performing full library scan...");
+
+		List<string> multimedia = await GetAllMultimediaAsync();
+		foreach (string filepath in multimedia)
+		{
+			Console.WriteLine(filepath);
+			Dictionary<string, string> fileInfo = await MetadataExtractor.ExtractAsync(filepath);
+
+			// Pretend we are doing parsing here...
+			Console.WriteLine(GeneralUseHelpers.DictAsJson(fileInfo));
+			MediaParser.CreateSong(db, fileInfo);
+		}
+
+		Console.WriteLine($"Full scan complete! Processed {multimedia.Count} files.");
+
+		// Update state inside of DB
+		string currentLibraryState = MetadataExtractor.GetStringMD5(string.Join("\n", multimedia));
+		Global lastLibraryState = db.Globals.FirstOrDefault(g => g.Key == "libraryState")
+			?? new() { Key = "libraryState"};
+		lastLibraryState.Value = currentLibraryState;
+		db.Update(lastLibraryState);
+		await db.SaveChangesAsync();
+
+		return multimedia;
+	}
+}