Partial rewrite, missing:

- Correctly parsing incoming messages
- Sending the gamestate after relevant actions

Mau/Managers/TurnManager.cs

@@ -0,0 +1,80 @@
+namespace MauMau_Server.Mau.Managers;
+
+public class TurnManager
+{
+    private const int CLOCKWISE = 1;
+    private const int COUNTER_CLOCKWISE = -1;
+     
+    private int _currentDirection { get; set; } = CLOCKWISE;
+    public List<Player> Players;
+    public Player CurrentPlayer;
+
+    /**
+     * <summary>
+     * Initialize the turn manager with a list of players.
+     * </summary>
+     * <param name="players">The list of players to initialize the turn manager with.</param>
+     */
+    public void Initialize(IEnumerable<Player> players)
+    {
+        Players = players.OrderBy(x => Guid.NewGuid()).ToList();
+        ShufflePlayers();
+        CurrentPlayer = Players.First();
+        CurrentPlayer.State = PlayerState.TURN;
+    }
+    
+    /**
+     * <summary>
+     * Change the direction of the turn.
+     * If the direction is clockwise, it will change to counter-clockwise and vice versa.
+     * </summary>
+     */
+    public void ChangeDirection()
+    {
+        _currentDirection *= COUNTER_CLOCKWISE;
+    }
+    
+    /**
+     * <summary>
+     * Change the turn to another player.
+     * If no player is given, the next player in the current direction is chosen.
+     * </summary>
+     * <param name="nextPlayer">The player to change the turn to. Defaults to the next player in the current direction.</param>
+     */
+    public void ChangeTurn(Player? nextPlayer = null)
+    {
+        var player = nextPlayer ?? GetNextPlayer();
+        CurrentPlayer.State = PlayerState.WAIT;
+        player.State = PlayerState.TURN;
+        CurrentPlayer = player;
+    }
+    
+    /**
+     * <summary>
+     * Get a player that is a given amount of players away from the current player in the current direction.
+     * </summary>
+     * <param name="numberOfPlayers">The amount of players to skip. Defaults to 1</param>
+     */
+    public Player GetNextPlayer(int numberOfPlayers = 1)
+    {
+        var playerIndex = Players.IndexOf(CurrentPlayer);
+        for (var i = 0; i < numberOfPlayers; i++)
+        {
+            playerIndex += _currentDirection;
+            if (playerIndex >= Players.Count) playerIndex = 0;
+            if (playerIndex < 0) playerIndex = Players.Count - 1;
+        }
+
+        return Players[playerIndex];
+    }
+
+    /**
+     * <summary>
+     * Shuffle the list of players for a play random order.
+     * </summary>
+     */
+    private void ShufflePlayers()
+    {
+        Players = Players.OrderBy(x => Guid.NewGuid()).ToList();
+    }
+}