feat: add steal mechanic to Code Farm with 60s protection window and half-coin reward

devplacepy/services/game/economy.py

@@ -15,6 +15,9 @@ MAX_WATERS_PER_PLOT = 3
 WATER_REWARD_COINS = 6
 WATER_REWARD_XP = 3
 
+STEAL_GRACE_SECONDS = 60
+STEAL_FRACTION = 0.5
+
 
 @dataclass(frozen=True)
 class Crop:
@@ -220,6 +223,10 @@ def effective_reward_xp(crop: Crop, xp_level: int = 0) -> int:
     return round(crop.reward_xp * (1 + PERK_BY_KEY["xp"].step * xp_level))
 
 
+def steal_reward_coins(crop: Crop, yield_level: int = 0, prestige: int = 0) -> int:
+    return max(1, round(effective_reward_coins(crop, yield_level, prestige) * STEAL_FRACTION))
+
+
 def daily_reward(streak: int) -> int:
     effective = min(max(streak, 1), DAILY_STREAK_CAP)
     return DAILY_BASE + DAILY_STREAK_STEP * (effective - 1)

devplacepy/services/game/store.py

@@ -133,7 +133,15 @@ def _plot_state(plot: dict, now: datetime) -> str:
     return "growing"
 
 
-def serialize_plot(plot: dict, *, viewer_uid: str, owner_uid: str, now: datetime) -> dict:
+def serialize_plot(
+    plot: dict,
+    *,
+    viewer_uid: str,
+    owner_uid: str,
+    now: datetime,
+    yield_level: int = 0,
+    prestige: int = 0,
+) -> dict:
     state = _plot_state(plot, now)
     crop = economy.crop_for(plot.get("crop_key", ""))
     ready_at = _parse(plot.get("ready_at", ""))
@@ -149,6 +157,17 @@ def serialize_plot(plot: dict, *, viewer_uid: str, owner_uid: str, now: datetime
         and viewer_uid not in watered
         and len(watered) < economy.MAX_WATERS_PER_PLOT
     )
+    can_steal = (
+        state == "ready"
+        and not is_owner
+        and bool(viewer_uid)
+        and bool(crop)
+        and ready_at is not None
+        and now >= ready_at + timedelta(seconds=economy.STEAL_GRACE_SECONDS)
+    )
+    steal_coins = (
+        economy.steal_reward_coins(crop, yield_level, prestige) if can_steal else 0
+    )
     return {
         "slot": plot.get("slot_index", 0),
         "state": state,
@@ -162,6 +181,8 @@ def serialize_plot(plot: dict, *, viewer_uid: str, owner_uid: str, now: datetime
         "watered_count": len(watered),
         "max_waters": economy.MAX_WATERS_PER_PLOT,
         "can_water": can_water,
+        "can_steal": can_steal,
+        "steal_coins": steal_coins,
         "fertilize_cost": (
             economy.fertilize_cost(remaining) if state == "growing" and is_owner else 0
         ),
@@ -174,9 +195,20 @@ def serialize_farm(
     now = now or _now()
     viewer_uid = viewer["uid"] if viewer else ""
     owner_uid = owner["uid"]
+    prestige = _lvl(farm, "prestige")
+    growth_level = _lvl(farm, "perk_growth")
+    discount_level = _lvl(farm, "perk_discount")
+    yield_level = _lvl(farm, "perk_yield")
     plots = get_plots(farm["uid"])
     serialized_plots = [
-        serialize_plot(plot, viewer_uid=viewer_uid, owner_uid=owner_uid, now=now)
+        serialize_plot(
+            plot,
+            viewer_uid=viewer_uid,
+            owner_uid=owner_uid,
+            now=now,
+            yield_level=yield_level,
+            prestige=prestige,
+        )
         for plot in plots
     ]
     progress = economy.level_progress(int(farm.get("xp", 0)))
@@ -185,10 +217,6 @@ def serialize_farm(
     next_tier = economy.next_ci_tier(ci_tier)
     ci_entry = economy.CI_BY_TIER.get(ci_tier)
     is_owner = viewer_uid == owner_uid
-    prestige = _lvl(farm, "prestige")
-    growth_level = _lvl(farm, "perk_growth")
-    discount_level = _lvl(farm, "perk_discount")
-    yield_level = _lvl(farm, "perk_yield")
     streak = _lvl(farm, "streak")
     daily_available = is_owner and _daily_available(farm, now)
     return {
@@ -401,6 +429,49 @@ def water(visitor: dict, owner: dict, slot: int) -> dict:
     }
 
 
+def steal(thief: dict, owner: dict, slot: int) -> dict:
+    if thief["uid"] == owner["uid"]:
+        raise GameError("You cannot steal from your own farm.")
+    farm = ensure_farm(owner["uid"])
+    plot = _plot_at(farm["uid"], slot)
+    if not plot or not plot.get("crop_key"):
+        raise GameError("That plot is empty.")
+    now = _now()
+    if _plot_state(plot, now) != "ready":
+        raise GameError("That build is not ready.")
+    crop = economy.crop_for(plot.get("crop_key", ""))
+    if not crop:
+        raise GameError("Unknown crop type.")
+    ready_at = _parse(plot.get("ready_at", "")) or now
+    if now < ready_at + timedelta(seconds=economy.STEAL_GRACE_SECONDS):
+        raise GameError("That harvest is still protected.")
+    _plots().update(
+        {
+            "uid": plot["uid"],
+            "crop_key": "",
+            "planted_at": "",
+            "ready_at": "",
+            "watered_by": "[]",
+            "updated_at": _iso(now),
+        },
+        ["uid"],
+    )
+    coins_gain = economy.steal_reward_coins(
+        crop, _lvl(farm, "perk_yield"), _lvl(farm, "prestige")
+    )
+    thief_farm = ensure_farm(thief["uid"])
+    _update_farm(
+        thief_farm["uid"],
+        {"coins": int(thief_farm.get("coins", 0)) + coins_gain},
+    )
+    return {
+        "slot": slot,
+        "crop": crop.key,
+        "coins": coins_gain,
+        "owner_uid": owner["uid"],
+    }
+
+
 def leaderboard(limit: int = 25) -> list[dict]:
     farms = sorted(
         _farms().find(),