Add directory watcher functionality

HyperbolicDownloaderApi/FileProcessing/FilesManager.cs

@@ -1,5 +1,6 @@
 using HyperbolicDownloaderApi.Managment;
 
+using System.Diagnostics;
 using System.Text.Json;
 
 namespace HyperbolicDownloaderApi.FileProcessing;
@@ -31,10 +32,16 @@ public class FilesManager
         if (Contains(hash))
         {
             fileInfo = null;
+            Debug.WriteLine(filePath + "-.-" + hash);
             errorMessage = "File already tracked!";
             return false;
         }
 
+        if (files.Exists(f => f.FilePath == fullPath))
+        {
+            _ = files.RemoveAll(f => f.FilePath == fullPath);
+        }
+
         fileInfo = new PrivateHyperFileInfo(hash, fullPath);
 
         files.Add(fileInfo);
@@ -91,6 +98,20 @@ public class FilesManager
         return files.ToList();
     }
 
+    internal void RemoveFilesThatDontExist()
+    {
+        List<PrivateHyperFileInfo> filesToRemove = files
+            .Where(f => !File.Exists(f.FilePath))
+            .ToList();
+
+        foreach (PrivateHyperFileInfo fileToRemove in filesToRemove)
+        {
+            _ = files.Remove(fileToRemove);
+        }
+
+        SaveFiles();
+    }
+
     private void SaveFiles()
     {
         File.WriteAllText(ApiConfiguration.FilesInfoPath, JsonSerializer.Serialize(files));