Added playlist repository logic.

Harmonia.Core/Data/FileRepository.cs

@@ -0,0 +1,94 @@
+namespace Harmonia.Core.Data;
+
+public abstract class FileRepository<TObject> : IRepository<TObject> where TObject : notnull
+{
+    private readonly Dictionary<TObject, string> _fileNameMap = [];
+
+    protected abstract string DirectoryName { get; }
+    protected abstract string Extension { get; }
+
+    protected abstract string GetNewFileName();
+    protected abstract string Serialize(TObject playlist);
+    protected abstract TObject Deserialize(Stream stream);
+
+    public FileRepository()
+    {
+        if (string.IsNullOrWhiteSpace(DirectoryName) || Directory.Exists(DirectoryName) == false)
+            return;
+
+        if (string.IsNullOrWhiteSpace(Extension))
+            return;
+
+        List<string> fileNames = GetAllFileNames();
+        LoadFileNamesIntoMap(fileNames);
+    }
+
+    private List<string> GetAllFileNames()
+    {
+        var directoryInfo = new DirectoryInfo(DirectoryName);
+        var directories = directoryInfo.GetDirectories().Where(x => x.Attributes.HasFlag(FileAttributes.Hidden) == false);
+
+        var fileInfoList = directoryInfo.EnumerateFiles("*." + Extension, SearchOption.TopDirectoryOnly).Where(x => x.Attributes.HasFlag(FileAttributes.Hidden) == false);
+
+        return fileInfoList.Select(fileInfo => fileInfo.FullName).ToList();
+    }
+
+    private void LoadFileNamesIntoMap(List<string> fileNames)
+    {
+        foreach (var fileName in fileNames)
+        {
+            using StreamReader textReader = new(fileName);
+
+            try
+            {
+                TObject obj = Deserialize(textReader.BaseStream);
+                _fileNameMap.Add(obj, fileName);
+            }
+            catch (Exception)
+            {
+
+            }
+        }
+    }
+
+    public List<TObject> Get()
+    {
+        return [.. _fileNameMap.Keys];
+    }
+
+    public void Save(TObject obj)
+    {
+        string serializedObject = Serialize(obj);
+
+        string fileName = Path.Combine(DirectoryName, GetFileName(obj));
+        string? path = Path.GetDirectoryName(fileName);
+
+        if (string.IsNullOrWhiteSpace(path))
+            return;
+
+        if (Directory.Exists(path) == false)
+            Directory.CreateDirectory(path);
+
+        using TextWriter textWriter = new StreamWriter(fileName);
+        textWriter.Write(serializedObject);
+    }
+
+    private string GetFileName(TObject obj)
+    {
+        if (_fileNameMap.TryGetValue(obj, out string? value))
+            return value;
+
+        string fileName = GetNewFileName();
+        _fileNameMap.Add(obj, fileName);
+
+        return fileName;
+    }
+
+    public void Delete(TObject obj)
+    {
+        string fileName = Path.Combine(DirectoryName, GetFileName(obj));
+
+        if (File.Exists(fileName))
+            File.Delete(fileName);
+    }
+}