feat(combat): add retrieve_weapon action to recover stolen weapons

tests/test_retrieve_weapon.py

@@ -0,0 +1,153 @@
+"""Tests for the ``retrieve_weapon`` action (recovering a stolen weapon).
+
+L7 of the ``llm-policy-contract`` plan: ``Action`` gains a
+``retrieve_weapon`` kind and a ``weapon_id`` field so a policy can restore a
+weapon that a steal maneuver took from its owner. The weapon is removed from
+``state.weapon_stolen`` and becomes usable again via ``usable_attacks()``.
+
+No default policy emits ``retrieve_weapon``; it is only accepted by
+``_execute`` (usage via custom policy / LLM).
+"""
+
+from __future__ import annotations
+
+from pf1e_simulator.combat import Action, CombatantState, CombatEngine
+from pf1e_simulator.grid import Grid
+from pf1e_simulator.map import MapSpec, TerrainType
+from pf1e_simulator.models import (
+    AbilityScores,
+    ACProfile,
+    AttackSpec,
+    Combatant,
+    DamageComponent,
+    Saves,
+)
+from pf1e_simulator.rng import ScriptedRng, SeededRng
+
+
+def make_combatant(cid: str, *, attack_bonus: int = 2) -> Combatant:
+    attack = AttackSpec(
+        id=f"{cid}-w",
+        name="sword",
+        kind="melee",
+        attack_bonus=attack_bonus,
+        damage=[DamageComponent(formula="1d4", types=["slashing"])],
+    )
+    return Combatant(
+        id=cid,
+        name=cid,
+        level=1,
+        size="Medium",
+        abilities=AbilityScores(
+            str_score=10, dex_score=10, con_score=10,
+            int_score=10, wis_score=10, cha_score=10,
+        ),
+        hp_max=6,
+        ac=ACProfile(total=13, touch=13, flat_footed=13),
+        bab=attack_bonus,
+        initiative_mod=0,
+        speed_land_ft=30,
+        saves=Saves(fort=0, ref=0, will=0),
+        attacks=[attack],
+    )
+
+
+def make_state(combatant: Combatant, side: str, pos: tuple[int, int]) -> CombatantState:
+    return CombatantState(combatant=combatant, side=side, pos=pos, hp=combatant.hp_max)
+
+
+def make_grid() -> Grid:
+    legend = {".": TerrainType(type="floor", move_cost=1)}
+    spec = MapSpec(name="test", terrain=tuple(["." * 8] * 8), legend=legend)
+    return Grid.from_spec(spec)
+
+
+def make_engine(queue: list[int], states: list[CombatantState]) -> CombatEngine:
+    return CombatEngine(ScriptedRng(queue), make_grid(), states)
+
+
+def _weapon_ids(state: CombatantState) -> list[str]:
+    return [w.id for w in state.usable_attacks()]
+
+
+# --- Test 1: retrieve restores a stolen weapon -------------------------------
+
+def test_retrieve_restores_stolen_weapon() -> None:
+    a_spec = make_combatant("a", attack_bonus=2)
+    b_spec = make_combatant("b")
+    a = make_state(a_spec, "players", (1, 1))
+    b = make_state(b_spec, "monsters", (1, 2))
+    engine = make_engine([12], [a, b])
+    engine._execute(a, Action(kind="maneuver", target_id="b", maneuver="steal"))
+    assert "b-w" in b.weapon_stolen
+    assert "b-w" not in _weapon_ids(b)
+    engine._execute(b, Action(kind="retrieve_weapon", weapon_id="b-w"))
+    assert not b.weapon_stolen
+    assert "b-w" in _weapon_ids(b)
+
+
+# --- Test 2: weapon_id=None -> nothing to retrieve, state unchanged ----------
+
+def test_retrieve_none_logs_nothing_to_retrieve() -> None:
+    a_spec = make_combatant("a", attack_bonus=2)
+    b_spec = make_combatant("b")
+    a = make_state(a_spec, "players", (1, 1))
+    b = make_state(b_spec, "monsters", (1, 2))
+    b.weapon_stolen.add("b-w")
+    engine = make_engine([], [a, b])
+    engine._execute(b, Action(kind="retrieve_weapon"))
+    assert "nothing to retrieve" in engine._transcript[-1]
+    assert b.weapon_stolen == {"b-w"}
+
+
+# --- Test 3: unknown id (never stolen) -> log, state unchanged ---------------
+
+def test_retrieve_unknown_id_logs_nothing_to_retrieve() -> None:
+    a_spec = make_combatant("a", attack_bonus=2)
+    b_spec = make_combatant("b")
+    a = make_state(a_spec, "players", (1, 1))
+    b = make_state(b_spec, "monsters", (1, 2))
+    b.weapon_stolen.add("b-w")
+    engine = make_engine([], [a, b])
+    engine._execute(b, Action(kind="retrieve_weapon", weapon_id="ghost"))
+    assert "nothing to retrieve" in engine._transcript[-1]
+    assert b.weapon_stolen == {"b-w"}
+
+
+# --- Test 4: real steal then retrieve restores the weapon --------------------
+
+def test_steal_then_retrieve_restores_weapon() -> None:
+    a_spec = make_combatant("a", attack_bonus=2)
+    b_spec = make_combatant("b")
+    a = make_state(a_spec, "players", (1, 1))
+    b = make_state(b_spec, "monsters", (1, 2))
+    engine = make_engine([12], [a, b])
+    engine._execute(a, Action(kind="maneuver", target_id="b", maneuver="steal"))
+    assert "b-w" in b.weapon_stolen
+    assert engine.weapon_for(b, a) is None
+    engine._execute(b, Action(kind="retrieve_weapon", weapon_id="b-w"))
+    assert not b.weapon_stolen
+    assert engine.weapon_for(b, a) is not None
+    assert "retrieve b-w (restored)" in engine._transcript[-1]
+
+
+# --- Test 5: determinism -----------------------------------------------------
+
+def _run_with_retrieve() -> tuple[str, ...]:
+    a_spec = make_combatant("a", attack_bonus=5)
+    b_spec = make_combatant("b")
+    a = make_state(a_spec, "players", (1, 1))
+    b = make_state(b_spec, "monsters", (1, 2))
+    b.weapon_stolen.add("b-w")
+
+    def policy(engine: CombatEngine, state: CombatantState) -> tuple[Action, ...]:
+        if state.combatant.id == "b":
+            return (Action(kind="retrieve_weapon", weapon_id="b-w"),)
+        return (Action(kind="wait"),)
+
+    engine = CombatEngine(SeededRng(42), make_grid(), [a, b], policy=policy)
+    return engine.run().transcript
+
+
+def test_determinism_same_seed_same_transcript() -> None:
+    assert _run_with_retrieve() == _run_with_retrieve()