Prevent the snake move opposite

src/models/WebSocketModel.js

@@ -144,22 +144,28 @@ class WebSocketModel {
       for (var j = 0; j < gameBoard[0].length; j++) {
         if (gameBoard[i][j].type === 1 && gameBoard[i][j].pid === pid) {
           console.log("Updating direction to: " + movement);
+		  
+		  let currentDirection = gameBoard[i][j].direction;
+          let newDirection = currentDirection;
+		  
         switch (movement) {
           case "up":
-              gameBoard[i][j].direction = 0;
+            if (currentDirection !== 2) newDirection = 0; // Cannot move up if going down
             break;
           case "right":
-              gameBoard[i][j].direction = 1;
-              cell.direction = 1;
+            if (currentDirection !== 3) newDirection = 1; // Cannot move right if going left
             break;
           case "down":
-              gameBoard[i][j].direction = 2;
+            if (currentDirection !== 0) newDirection = 2; // Cannot move down if going up
             break;
           case "left":
-              gameBoard[i][j].direction = 3;
+            if (currentDirection !== 1) newDirection = 3; // Cannot move left if going right
             break;
         }
-          console.log("New direction set to: " + gameBoard[i][j].direction);
+		if (newDirection !== currentDirection) {
+          console.log("Updating direction to: " + movement);
+          gameBoard[i][j].direction = newDirection;
+        }
           return;
         }
       }