2 files changed, 52 insertions, 2 deletions

diff --git a/src/main/java/org/luxons/sevenwonders/game/Lobby.java b/src/main/java/org/luxons/sevenwonders/game/Lobby.java
index 30b31d4b..b115d32e 100644
--- a/src/main/java/org/luxons/sevenwonders/game/Lobby.java
+++ b/src/main/java/org/luxons/sevenwonders/game/Lobby.java
@@ -2,6 +2,7 @@ package org.luxons.sevenwonders.game;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.luxons.sevenwonders.game.data.GameDefinition;
 
@@ -13,10 +14,10 @@ public class Lobby {
 
     private final Player owner;
 
-    private final List<Player> players;
-
     private final GameDefinition gameDefinition;
 
+    private List<Player> players;
+
     private State state = State.LOBBY;
 
     public Lobby(long id, String name, Player owner, GameDefinition gameDefinition) {
@@ -36,6 +37,10 @@ public class Lobby {
         return name;
     }
 
+    public List<Player> getPlayers() {
+        return players;
+    }
+
     public synchronized int addPlayer(Player player) throws GameAlreadyStartedException, PlayerOverflowException {
         if (hasStarted()) {
             throw new GameAlreadyStartedException();
@@ -76,6 +81,17 @@ public class Lobby {
         return players.size() >= gameDefinition.getMinPlayers();
     }
 
+    public void reorderPlayers(List<String> orderedUserNames) {
+        players = orderedUserNames.stream().map(this::getPlayer).collect(Collectors.toList());
+    }
+
+    private Player getPlayer(String userName) {
+        return players.stream()
+                      .filter(p -> p.getUserName().equals(userName))
+                      .findAny()
+                      .orElseThrow(() -> new UnknownPlayerException(userName));
+    }
+
     public boolean isOwner(String userName) {
         return owner.getUserName().equals(userName);
     }
@@ -98,4 +114,10 @@ public class Lobby {
             super(name);
         }
     }
+
+    static class UnknownPlayerException extends IllegalArgumentException {
+        UnknownPlayerException(String userName) {
+            super(userName);
+        }
+    }
 }
diff --git a/src/test/java/org/luxons/sevenwonders/game/LobbyTest.java b/src/test/java/org/luxons/sevenwonders/game/LobbyTest.java
index 8e59dea1..65069b88 100644
--- a/src/test/java/org/luxons/sevenwonders/game/LobbyTest.java
+++ b/src/test/java/org/luxons/sevenwonders/game/LobbyTest.java
@@ -1,5 +1,7 @@
 package org.luxons.sevenwonders.game;
 
+import java.util.Arrays;
+
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Rule;
@@ -13,6 +15,7 @@ import org.luxons.sevenwonders.game.Lobby.GameAlreadyStartedException;
 import org.luxons.sevenwonders.game.Lobby.PlayerNameAlreadyUsedException;
 import org.luxons.sevenwonders.game.Lobby.PlayerOverflowException;
 import org.luxons.sevenwonders.game.Lobby.PlayerUnderflowException;
+import org.luxons.sevenwonders.game.Lobby.UnknownPlayerException;
 import org.luxons.sevenwonders.game.data.GameDefinition;
 import org.luxons.sevenwonders.game.data.GameDefinitionLoader;
 
@@ -110,6 +113,31 @@ public class LobbyTest {
         }
     }
 
+    @Test
+    public void reorderPlayers_failsOnSameName() {
+        Player player1 = new Player("Test User 1", "testuser1");
+        Player player2 = new Player("Test User 2", "testuser2");
+        Player player3 = new Player("Test User 3", "testuser3");
+        lobby.addPlayer(player1);
+        lobby.addPlayer(player2);
+        lobby.addPlayer(player3);
+        lobby.reorderPlayers(Arrays.asList("testuser3", "testuser1", "testuser2"));
+        assertEquals("testuser3", lobby.getPlayers().get(0).getUserName());
+        assertEquals("testuser1", lobby.getPlayers().get(1).getUserName());
+        assertEquals("testuser2", lobby.getPlayers().get(2).getUserName());
+    }
+
+    @Test(expected = UnknownPlayerException.class)
+    public void reorderPlayers_failsOnUnknownPlayer() {
+        Player player1 = new Player("Test User 1", "testuser1");
+        Player player2 = new Player("Test User 2", "testuser2");
+        Player player3 = new Player("Test User 3", "testuser3");
+        lobby.addPlayer(player1);
+        lobby.addPlayer(player2);
+        lobby.addPlayer(player3);
+        lobby.reorderPlayers(Arrays.asList("testuser4", "testuser1", "testuser2"));
+    }
+
     @Theory
     public void startGame_failsBelowMinPlayers(int nbPlayers) {
         assumeTrue(nbPlayers < gameDefinition.getMinPlayers());