add TempStorage class

SimpleTGBot/TelegramBot.cs

@@ -10,10 +10,12 @@ namespace SimpleTGBot;
 public class TelegramBot
 {
     private string token;
+    private TempStorage temp;
 
     public TelegramBot(string token)
     {
         this.token = token;
+        temp = new TempStorage();
     }
     
     /// <summary>
@@ -50,6 +52,7 @@ public class TelegramBot
 
     botQuit:
         cts.Cancel();
+        temp.Dispose();
     }
     
     /// <summary>

SimpleTGBot/TempStorage.cs

@@ -0,0 +1,56 @@
+namespace SimpleTGBot;
+
+internal class TempStorage : IDisposable
+{
+    private string directory;
+    private Dictionary<FileStream, string> createdTempFiles;
+    private Random rng;
+
+    public TempStorage()
+    {
+        rng = new Random();
+
+        do
+        {
+            directory = Path.GetTempPath() + "/demotivatorBot-" + RandomHexString(4);
+        } while (Directory.Exists(directory));
+        Directory.CreateDirectory(directory);
+
+        createdTempFiles = new Dictionary<FileStream, string>();
+    }
+
+    public void Dispose()
+    {
+        foreach (var kv in createdTempFiles)
+        {
+            kv.Key.Dispose();
+            if (File.Exists(kv.Value))
+            {
+                File.Delete(kv.Value);
+            }
+        }
+        Directory.Delete(directory);
+    }
+
+    public (string, FileStream) newTemporaryFile(string? prefix, string? extension)
+    {
+        string filename = directory + "/" + (prefix != null ? prefix + "-" : "") + RandomHexString(8) + (extension != null ? "." + extension : "");
+        FileStream file = File.Open(filename, FileMode.Create, FileAccess.ReadWrite, FileShare.None);
+        createdTempFiles.Add(file, filename);
+        return (filename, file);
+    }
+
+    public void deleteTemporaryFile(FileStream file)
+    {
+        if (createdTempFiles.ContainsKey(file))
+        {
+            File.Delete(createdTempFiles[file]);
+        }
+        file.Dispose();
+    }
+
+    private string RandomHexString(int n)
+    {
+        return rng.NextInt64(1L << (n << 2)).ToString("X" + n);
+    }
+}