Update app.py

app.py

@@ -388,4 +388,42 @@ async def game_loop():
 
 @app.on_event("startup")
 async def on_startup():
+    global MARKET, EVENTS, CURRENT_DAY, CURRENT_VOL
+
+    # ---- Load default scenario file (Option B) ----
+    scenario_path = os.getenv("DEFAULT_SCENARIO_FILE", "default_scenario.json")
+    if os.path.exists(scenario_path):
+        with open(scenario_path, "r", encoding="utf-8") as f:
+            scn = json.load(f)
+
+        start_day = int(scn.get("startDay", 0))
+        base_price = float(scn.get("basePrice", START_PRICE))
+        default_vol = float(scn.get("defaultVolatility", DEFAULT_VOLATILITY))
+        evs_raw = scn.get("events", [])
+        if not isinstance(evs_raw, list):
+            evs_raw = []
+
+        evs = [parse_event(e) for e in evs_raw]
+        max_day_in_scenario = max((ev.day for ev in evs), default=0)
+
+        # If scenario provides marketLength, use it as a hint; always ensure it's big enough.
+        requested_len = scn.get("marketLength", None)
+        if requested_len is None or str(requested_len).strip() == "":
+            desired_len = max(MIN_MARKET_LENGTH, MARKET_LENGTH, max_day_in_scenario + 1)
+        else:
+            desired_len = max(MIN_MARKET_LENGTH, int(requested_len), max_day_in_scenario + 1)
+
+        async with STATE_LOCK:
+            CURRENT_VOL = default_vol
+            MARKET = regen_market(length=desired_len, start_price=base_price, vol=default_vol)
+
+            EVENTS.clear()
+            for ev in evs:
+                EVENTS.setdefault(ev.day, []).append(ev)
+
+        async with DAY_LOCK:
+            CURRENT_DAY = max(0, min(start_day, len(MARKET) - 1))
+
+    # ---- Start the tick loop ----
     asyncio.create_task(game_loop())
+