Session 15: Buy Max Prestige Upgrades (bulk-buy for prestige upgrades) + fix missing Stellar Essence spend

css/game.css

@@ -363,6 +363,23 @@ h2, h3 {
     opacity: 0.4;
 }
 
+/* Prestige Upgrades header + Buy Max button */
+.prestige-upgrades-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    margin-bottom: 10px;
+}
+
+.prestige-upgrades-header h3 {
+    margin: 0;
+}
+
+.prestige-buy-all {
+    background: var(--accent-gold);
+    color: var(--bg-primary, #1a1035);
+}
+
 /* Side Panel Tabs */
 .tabs {
     display: flex;

dev-journal.md

@@ -414,3 +414,31 @@ Wrote a headless Node.js test (`/opt/data/idle-game-test/buy-all-upgrades-test.m
 - Consider adding a "Buy Max" button to the prestige upgrades list as well.
 - Potential new building tiers or prestige milestones.
 - Sound variations or background music.
+
+---
+
+### Session 15 - 2026-08-24 (Morning)
+**Status:** ✅ Buy Max Prestige Upgrades (bulk-buy for prestige upgrades) Added
+
+#### What was done:
+- Followed up on Session 14's own "next goal" by adding a **Buy Max** button to the **Prestige Upgrades** list. Previously one-time prestige upgrades could only be purchased individually (one click each), which was tedious once several were available — buildings had Buy Max (Session 10) and regular upgrades had Buy All (Session 14), but prestige upgrades did not. This brings prestige upgrades in line with that established bulk-buy convention.
+- Added `Game.buyMaxPrestigeUpgrades()` to `js/game.js`. It loops through every entry in `PRESTIGE_UPGRADES`, skips owned ones, respects each upgrade's (optional) `requirements` building-count gate, and buys everything affordable at once from **Stellar Essence**. It runs until a full pass purchases nothing (loop kept for symmetry with `buyAllUpgrades` and to stay safe if future prestige upgrades gain requirement gates), then decrements `stellarEssence` per purchase (mirroring `PRESTIGE.buyUpgrade`) and returns `{ bought: count, ids: [...] }`.
+- Wired the button into the Prestige tab in `index.html` (`#buy-all-prestige`, placed alongside a left-aligned header row mirroring the Upgrades tab's Buy All layout). Added a click listener in `PrestigeUI.setupEventListeners()`.
+- Added `PrestigeUI.updateBuyMaxPrestigeButton()` (called from `PrestigeUI.update()` each tick) which shows/hides and enables/disables the button based on whether any unowned, requirement-met prestige upgrade is currently affordable with Stellar Essence — a read-only state check, exactly mirroring `UI.updateBuyAllButton()`.
+- Added CSS for `.prestige-upgrades-header` (flex layout) and `.prestige-buy-all` (gold accent theme reusing the existing `.buy-all-btn` base, matching the Upgrades tab's Buy All button).
+- **Bug found & fixed during testing:** the first implementation of `buyMaxPrestigeUpgrades()` added upgrades to the list but never decremented `stellarEssence`, which would have let players prestige-buy unlimited upgrades for free. The headless test asserted essence depletion and caught it; added the missing `this.state.stellarEssence -= upgrade.cost` line so spend mirrors `PRESTIGE.buyUpgrade`.
+
+#### Files modified:
+- `js/game.js` - added `buyMaxPrestigeUpgrades()` method (with correct Stellar Essence spend)
+- `js/prestigeUI.js` - added click listener for the Buy Max button + `updateBuyMaxPrestigeButton()`; called from `update()` each tick
+- `index.html` - added Buy Max button to the Prestige Upgrades header
+- `css/game.css` - `.prestige-upgrades-header`, `.prestige-buy-all` styles
+- `dev-journal.md` - appended Session 15 entry
+
+#### Verification:
+Wrote a headless Node.js test (`/opt/data/idle-game-test/prestige-buy-max-test.mjs`) that loads the real `game.js`, `prestige.js`, and `prestigeUI.js` in-process with DOM/audio/particle stubs. **22/22 checks pass**, covering: no-op when nothing affordable, bulk purchase deducting Stellar Essence correctly, ungated-upgrade behavior (real prestige upgrades have no requirement gates), idempotent second call, already-owned upgrade skipping, notification-on-purchase vs silence on no-op, the missing-essence-spend regression (now fixed), and the real `PrestigeUI.updateBuyMaxPrestigeButton()` show/hide/enabled state against actual `PRESTIGE_UPGRADES` data. All existing suites re-ran clean with no regressions: buy-all-upgrades 24/24, buy-max 6/6, golden-bloom 22/22, slot-preview 22/22. All modified JS files pass `node --check`.
+
+#### Next goals:
+- Potential new building tiers or prestige milestones / new prestige upgrades.
+- Sound variations or background music.
+- Consider a global "Buy Max" for buildings across all types at once (currently per-building).

index.html

@@ -99,6 +99,10 @@
                         </button>
                     </div>
                     <h3 style="margin-top:15px">Prestige Upgrades</h3>
+                    <div class="prestige-upgrades-header">
+                        <span></span>
+                        <button id="buy-all-prestige" class="buy-all-btn prestige-buy-all" style="display:none" title="Buy every prestige upgrade you can currently afford with Stellar Essence">Buy Max</button>
+                    </div>
                     <div id="prestige-upgrades-list"></div>
                 </div>
             </aside>

js/game.js

@@ -469,6 +469,53 @@ const Game = {
         return { bought: bought.length, ids: bought };
     },
 
+    /**
+     * Buy every prestige upgrade the player can currently afford at once,
+     * paid from Stellar Essence. Returns an object describing what happened:
+     * { bought: count, ids: [...] }. Prestige upgrades are one-time purchases,
+     * so we loop until a full pass buys nothing (purchasing one never unlocks
+     * another, but the loop is kept for symmetry with buyAllUpgrades and to
+     * stay safe should future prestige upgrades gain requirement gates).
+     */
+    buyMaxPrestigeUpgrades() {
+        const bought = [];
+        let progress = true;
+        while (progress) {
+            progress = false;
+            for (const [id, upgrade] of Object.entries(PRESTIGE_UPGRADES)) {
+                if ((this.state.prestigeUpgrades || []).includes(id)) continue;
+                // Respect requirements before attempting purchase, mirroring
+                // PRESTIGE.buyUpgrade semantics.
+                if (upgrade.requirements) {
+                    let met = true;
+                    for (const [reqId, reqCount] of Object.entries(upgrade.requirements)) {
+                        if ((this.state.buildings[reqId] || 0) < reqCount) {
+                            met = false;
+                            break;
+                        }
+                    }
+                    if (!met) continue;
+                }
+                if ((this.state.stellarEssence || 0) >= upgrade.cost) {
+                    this.state.prestigeUpgrades = this.state.prestigeUpgrades || [];
+                    this.state.prestigeUpgrades.push(id);
+                    // Spend Stellar Essence, mirroring PRESTIGE.buyUpgrade.
+                    this.state.stellarEssence -= upgrade.cost;
+                    bought.push(id);
+                    progress = true;
+                }
+            }
+        }
+
+        if (bought.length > 0) {
+            UI.showNotification(`Bought ${bought.length} prestige upgrade(s)!`, 'achievement');
+            Audio.playPurchase();
+            UI.update();
+        }
+
+        return { bought: bought.length, ids: bought };
+    },
+
     /**
      * Golden Starbloom - random event system.
      * A rare, time-limited bloom occasionally appears on screen. Clicking it

js/prestigeUI.js

@@ -43,6 +43,15 @@ const PrestigeUI = {
                 }
             });
         });
+
+        // Buy Max prestige upgrades button - buy every affordable prestige
+        // upgrade at once, paid from Stellar Essence.
+        const buyMaxBtn = document.getElementById('buy-all-prestige');
+        if (buyMaxBtn) {
+            buyMaxBtn.addEventListener('click', () => {
+                Game.buyMaxPrestigeUpgrades();
+            });
+        }
     },
 
     /**
@@ -119,7 +128,44 @@ const PrestigeUI = {
         if (prestigeTab?.classList.contains('active')) {
             this.renderPrestigeUpgrades();
         }
+
+        // Show/hide the "Buy Max" button based on whether any unowned prestige
+        // upgrade is currently affordable with Stellar Essence. Read-only.
+        this.updateBuyMaxPrestigeButton();
+    },
+
+    /**
+     * Show/hide and enable/disable the "Buy Max" prestige-upgrades button
+     * depending on whether at least one unowned, requirement-met prestige
+     * upgrade is currently affordable with Stellar Essence. Read of game state
+     * only; never mutates it. Mirrors Game.buyMaxPrestigeUpgrades /
+     * PRESTIGE.buyUpgrade semantics.
+     */
+    updateBuyMaxPrestigeButton() {
+        const btn = document.getElementById('buy-all-prestige');
+        if (!btn) return;
+
+        let affordableAny = false;
+        for (const [id, upgrade] of Object.entries(PRESTIGE_UPGRADES)) {
+            if ((Game.state.prestigeUpgrades || []).includes(id)) continue;
+            if ((Game.state.stellarEssence || 0) < upgrade.cost) continue;
+            if (upgrade.requirements) {
+                let met = true;
+                for (const [reqId, reqCount] of Object.entries(upgrade.requirements)) {
+                    if ((Game.state.buildings[reqId] || 0) < reqCount) {
+                        met = false;
+                        break;
                     }
+                }
+                if (!met) continue;
+            }
+            affordableAny = true;
+            break;
+        }
+
+        btn.style.display = affordableAny ? '' : 'none';
+        btn.disabled = !affordableAny;
+    },
 };
 
 window.PrestigeUI = PrestigeUI;