Council sells useless stockpile items into the treasury

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

game.py

@@ -379,7 +379,7 @@ RAID_TRAITS = ["lightly armoured, heavy on archers", "mounted and fast, few bows
 
 # --- world ---------------------------------------------------------------
 
-WORLD_VERSION = 3
+WORLD_VERSION = 4
 
 
 def new_world(now: float, speed: float = 1.0) -> dict:
@@ -429,9 +429,28 @@ def migrate(world: dict) -> dict:
             player.setdefault("hp", max_hp(player))
             player.setdefault("hp_at", now)
         world["version"] = 3
+    if world["version"] < 4:
+        _sell_useless_stock(world, world["city"]["last_tick"])
+        world["version"] = 4
     return world
 
 
+def _sell_useless_stock(world: dict, now: float) -> None:
+    """The council sells what the city can't use, into the treasury."""
+    city = world["city"]
+    sold = {item: qty for item, qty in city["stockpile"].items() if item in ITEMS and not city_uses(item)}
+    if not sold:
+        return
+    gold = sum(qty * ITEMS[item]["value"] for item, qty in sold.items())
+    for item in sold:
+        del city["stockpile"][item]
+    city["treasury"] += gold
+    names = [amount(i, q) for i, q in sold.items()]
+    names = ", ".join(names[:-1]) + " and " + names[-1] if len(names) > 1 else names[0]
+    log(world, now, "city", f"The council sold {names} "
+        f"from the stockpile for {gold:,} gold")
+
+
 def speed(world: dict) -> float:
     return world["config"]["speed"]
 

tests/test_game.py

@@ -265,6 +265,17 @@ class CityTest(unittest.TestCase):
         self.assertEqual(world["city"]["queue"], [])
         self.assertEqual(world["city"]["buildings"]["walls"]["fund"], {})
 
+    def test_v3_worlds_sell_useless_stock_into_the_treasury(self):
+        world = world_with()
+        world["version"] = 3
+        world["city"]["stockpile"] = {"copper_ore": 8, "raw_meat": 1, "bricks": 500, "bread": 30}
+        world["city"]["treasury"] = 10
+        game.migrate(world)
+        self.assertEqual(world["city"]["stockpile"], {"bricks": 500, "bread": 30})
+        self.assertEqual(world["city"]["treasury"], 10 + 8 * 2 + 1 * 2)
+        self.assertEqual(world["ledger"][-1]["text"],
+                         "The council sold 8 copper ore and 1 raw meat from the stockpile for 18 gold")
+
     def test_population_view_explains_growth(self):
         world = world_with()
         view = game.population_view(world)