Add carrier limit to prevent spam

server/services/carrier.ts

@@ -14,6 +14,8 @@ import StarService from './star';
 import TechnologyService from './technology';
 const EventEmitter = require('events');
 
+const CARRIER_LIMIT_MIN = 50;
+
 export default class CarrierService extends EventEmitter {
     gameRepo: Repository<Game>;
     distanceService: DistanceService;
@@ -70,6 +72,12 @@ export default class CarrierService extends EventEmitter {
       return game.galaxy.carriers.filter(carrier => carrier.orbiting && carrier.orbiting.toString() === starId.toString())
     }
 
+    getCarrierLimit(game: Game, player: Player) {
+        const starCount = game.galaxy.stars.filter((star) => star.ownedByPlayerId && star.ownedByPlayerId.toString() === player._id.toString()).length;
+
+        return Math.max(CARRIER_LIMIT_MIN, starCount * 10);
+    }
+
     createAtStar(star: Star, carriers: Carrier[], ships: number = 1): Carrier {
         if (!Math.floor(star.shipsActual!)) {
             throw new ValidationError('Star must have at least 1 ship to build a carrier.');

server/services/starUpgrade.ts

@@ -186,6 +186,15 @@ export default class StarUpgradeService extends EventEmitter {
             throw new ValidationError(`The star does not have enough ships garrisoned (${ships}) to build the carrier.`);
         }
 
+        // check if player has allowed carrier count
+
+        const carrierCount = this.carrierService.listCarriersOwnedByPlayer(game.galaxy.carriers, player._id).length;
+        const carrierLimit = this.carrierService.getCarrierLimit(game, player);
+
+        if (!player.defeated && carrierCount + 1 > carrierLimit) {
+            throw new ValidationError(`The player has reached the carrier limit: ${carrierLimit}.`);
+        }
+
         // Create a carrier at the star.
         let carrier = this.carrierService.createAtStar(star, game.galaxy.carriers, ships);