Session 10: Buy Max bulk-buy feature for buildings

js/game.js

@@ -233,7 +233,7 @@ const Game = {
     },
 
     /**
-     * Buy a building
+     * Buy a single building
      */
     buyBuilding(buildingId) {
         const cost = this.getBuildingCost(buildingId);
@@ -261,6 +261,63 @@ const Game = {
         return false;
     },
 
+    /**
+     * Calculate how many of a building the player can currently afford.
+     * Does not modify game state.
+     */
+    getMaxAffordable(buildingId) {
+        const building = BUILDINGS[buildingId];
+        if (!building) return 0;
+
+        let stardust = this.state.stardust;
+        let count = 0;
+        let owned = this.state.buildings[buildingId] || 0;
+
+        while (true) {
+            const cost = Math.floor(building.baseCost * Math.pow(this.config.costScaling, owned + count));
+            if (stardust < cost) break;
+            stardust -= cost;
+            count++;
+        }
+
+        return count;
+    },
+
+    /**
+     * Buy as many of a building as the player can afford at once.
+     * Returns the number purchased.
+     */
+    buyMaxBuilding(buildingId) {
+        const building = BUILDINGS[buildingId];
+        if (!building) return 0;
+
+        let count = 0;
+        while (this.state.stardust >= this.getBuildingCost(buildingId)) {
+            const cost = this.getBuildingCost(buildingId);
+            this.state.stardust -= cost;
+            this.state.buildings[buildingId] = (this.state.buildings[buildingId] || 0) + 1;
+            count++;
+        }
+
+        if (count > 0) {
+            UI.showNotification(`Bought ${count}x ${building.name}!`, 'success');
+
+            // Audio feedback
+            Audio.playPurchase();
+
+            // Particle effect on building purchase
+            const card = document.getElementById(`building-${buildingId}`);
+            if (card) {
+                const rect = card.getBoundingClientRect();
+                Particles.createBuildingEffect(rect.left + rect.width / 2, rect.top + rect.height / 2);
+            }
+
+            UI.update();
+        }
+
+        return count;
+    },
+
     /**
      * Buy an upgrade
      */

js/ui.js

@@ -69,6 +69,7 @@ const UI = {
                     <div class="building-cost">${Game.formatNumber(cost)} ✨</div>
                     <div class="building-count">${count}</div>
                     <button class="buy-btn" ${!canAfford || locked ? 'disabled' : ''}>Buy</button>
+                    <button class="buy-max-btn" data-building="${id}" ${locked || count === 0 ? 'title="Buy as many as you can afford"' : 'disabled'}>${Game.formatNumber(Game.getMaxAffordable(id))}x Max</button>
                 </div>
             `;
             
@@ -76,6 +77,12 @@ const UI = {
                 card.querySelector('.buy-btn').addEventListener('click', () => {
                     Game.buyBuilding(id);
                 });
+                const maxBtn = card.querySelector('.buy-max-btn');
+                if (maxBtn) {
+                    maxBtn.addEventListener('click', () => {
+                        Game.buyMaxBuilding(id);
+                    });
+                }
             }
             
             container.appendChild(card);
@@ -103,6 +110,15 @@ const UI = {
                 btn.disabled = !canAfford || locked;
             }
             
+            // Buy Max button - reflect how many can be bought at current stardust
+            const maxBtn = card.querySelector('.buy-max-btn');
+            if (maxBtn) {
+                const affordable = Game.getMaxAffordable(id);
+                maxBtn.textContent = `${Game.formatNumber(affordable)}x Max`;
+                maxBtn.disabled = locked || affordable === 0;
+                maxBtn.title = affordable > 0 ? `Buy up to ${affordable} ${building.name}(s)` : 'Not enough stardust';
+            }
+            
             card.classList.toggle('locked', locked);
         }
     },