feat: cancel attack

Canceling attack takes time and incurs a malus (loose some troops).
Also prettier fixed a file HostLobbyModal.

src/core/execution/RetreatExecution.ts

@@ -0,0 +1,50 @@
+import { Execution, Game, Player, PlayerID } from "../game/Game";
+
+const cancelDelay = 2;
+
+export class RetreatExecution implements Execution {
+  private active = true;
+  private retreatOrdered = false;
+  private player: Player;
+  private executionDateInSecs = new Date().getTime() / 1000 + cancelDelay;
+
+  constructor(
+    private playerID: PlayerID,
+    private attackID: string,
+  ) {}
+
+  init(mg: Game, ticks: number): void {
+    if (!mg.hasPlayer(this.playerID)) {
+      console.warn(`RetreatExecution: player ${this.player.id()} not found`);
+      return;
+    }
+
+    this.player = mg.player(this.playerID);
+  }
+
+  tick(ticks: number): void {
+    const nowInSecs = new Date().getTime() / 1000;
+
+    if (!this.retreatOrdered) {
+      this.player.orderRetreat(this.attackID);
+      this.retreatOrdered = true;
+    }
+
+    if (nowInSecs >= this.executionDateInSecs) {
+      this.player.executeRetreat(this.attackID);
+      this.active = false;
+    }
+  }
+
+  owner(): Player {
+    return this.player;
+  }
+
+  isActive(): boolean {
+    return this.active;
+  }
+
+  activeDuringSpawnPhase(): boolean {
+    return false;
+  }
+}