6 files changed, 37 insertions, 14 deletions

diff --git a/src/ch/epfl/xblast/Lists.java b/src/ch/epfl/xblast/Lists.java
index 22d9d06..ef17f05 100644
--- a/src/ch/epfl/xblast/Lists.java
+++ b/src/ch/epfl/xblast/Lists.java
@@ -13,6 +13,29 @@ import java.util.stream.Stream;
 public final class Lists {
 
     /**
+     * Returns an immutable copy of a list.
+     *
+     * @param l   a list
+     * @param <T> the element type
+     * @return the immutable list
+     */
+    public static <T> List<T> immutableList(List<T> l) {
+        return Collections.unmodifiableList(new ArrayList<>(l));
+    }
+
+    /**
+     * Returns an immutable copy of a map.
+     *
+     * @param m   a mab
+     * @param <K> the key type
+     * @param <V> the value type
+     * @return the immutable copy
+     */
+    public static <K, V> Map<K, V> immutableMap(Map<K, V> m) {
+        return Collections.unmodifiableMap(new HashMap<>(m));
+    }
+
+    /**
      * Returns a symmetric version of the list, without repeating the last element of the input list.
      * For instance, mirrored([kay]) will return [kayak].
      *
diff --git a/src/ch/epfl/xblast/SubCell.java b/src/ch/epfl/xblast/SubCell.java
index 51cbbb4..4278fab 100644
--- a/src/ch/epfl/xblast/SubCell.java
+++ b/src/ch/epfl/xblast/SubCell.java
@@ -31,7 +31,7 @@ public final class SubCell {
     /**
      * The coordinates of the SubCell.
      */
-    private int x, y;
+    private final int x, y;
 
     /**
      * Instantiates a new SubCell with the given coordinates.
diff --git a/src/ch/epfl/xblast/server/Board.java b/src/ch/epfl/xblast/server/Board.java
index a18422a..4519781 100644
--- a/src/ch/epfl/xblast/server/Board.java
+++ b/src/ch/epfl/xblast/server/Board.java
@@ -4,7 +4,6 @@ import ch.epfl.cs108.Sq;
 import ch.epfl.xblast.Cell;
 import ch.epfl.xblast.Lists;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -41,7 +40,7 @@ public final class Board {
     /**
      * List containing all the blocks of the board.
      */
-    private List<Sq<Block>> blocks;
+    private final List<Sq<Block>> blocks;
 
     /**
      * Instantiates a new Board with the given sequence of blocks.
@@ -53,7 +52,7 @@ public final class Board {
         if (blocks == null || blocks.size() != BLOCKS_LIST_SIZE)
             throw new IllegalArgumentException();
 
-        this.blocks = new ArrayList<>(blocks);
+        this.blocks = Lists.immutableList(blocks);
     }
 
     /**
diff --git a/src/ch/epfl/xblast/server/Bomb.java b/src/ch/epfl/xblast/server/Bomb.java
index 535573f..57c271f 100644
--- a/src/ch/epfl/xblast/server/Bomb.java
+++ b/src/ch/epfl/xblast/server/Bomb.java
@@ -28,22 +28,22 @@ public final class Bomb {
     /**
      * Owner of the Bomb.
      */
-    private PlayerID ownerId;
+    private final PlayerID ownerId;
 
     /**
      * Position of the Bomb.
      */
-    private Cell position;
+    private final Cell position;
 
     /**
      * Fuse of the Bomb.
      */
-    private Sq<Integer> fuseLengths;
+    private final Sq<Integer> fuseLengths;
 
     /**
      * Range of the Bomb.
      */
-    private int range;
+    private final int range;
 
     /**
      * Instantiates a new Bomb.
diff --git a/src/ch/epfl/xblast/server/GameState.java b/src/ch/epfl/xblast/server/GameState.java
index 44fd5d1..abd07b3 100644
--- a/src/ch/epfl/xblast/server/GameState.java
+++ b/src/ch/epfl/xblast/server/GameState.java
@@ -52,7 +52,7 @@ public final class GameState {
      * @param players list of the players
      */
     public GameState(Board board, List<Player> players) {
-        this(0, board, players, new ArrayList<>(), new ArrayList<>(), new ArrayList<>());
+        this(0, board, players, Collections.emptyList(), Collections.emptyList(), Collections.emptyList());
     }
 
     /**
@@ -72,11 +72,11 @@ public final class GameState {
         this.board = Objects.requireNonNull(board);
 
         if (players.size() != PlayerID.values().length) throw new IllegalArgumentException();
-        this.players = new ArrayList<>(players);
+        this.players = Lists.immutableList(players);
 
-        this.bombs = new ArrayList<>(Objects.requireNonNull(bombs));
-        this.explosions = new ArrayList<>(Objects.requireNonNull(explosions));
-        this.blasts = new ArrayList<>(Objects.requireNonNull(blasts));
+        this.bombs = Lists.immutableList(Objects.requireNonNull(bombs));
+        this.explosions = Lists.immutableList(Objects.requireNonNull(explosions));
+        this.blasts = Lists.immutableList(Objects.requireNonNull(blasts));
     }
 
     /**
diff --git a/src/ch/epfl/xblast/server/painter/BoardPainter.java b/src/ch/epfl/xblast/server/painter/BoardPainter.java
index 8378cce..34d0974 100644
--- a/src/ch/epfl/xblast/server/painter/BoardPainter.java
+++ b/src/ch/epfl/xblast/server/painter/BoardPainter.java
@@ -2,6 +2,7 @@ package ch.epfl.xblast.server.painter;
 
 import ch.epfl.xblast.Cell;
 import ch.epfl.xblast.Direction;
+import ch.epfl.xblast.Lists;
 import ch.epfl.xblast.server.Block;
 import ch.epfl.xblast.server.Board;
 
@@ -26,7 +27,7 @@ public final class BoardPainter {
      * @param shadowedFreeBlock a "shadowed" block image
      */
     public BoardPainter(Map<Block, BlockImage> blocksMap, BlockImage shadowedFreeBlock) {
-        this.blocksMap = Collections.unmodifiableMap(blocksMap);
+        this.blocksMap = Lists.immutableMap(blocksMap);
         this.shadowedFreeBlock = shadowedFreeBlock;
     }