pf1e-simulator/tests/test_conformance_pa.py

"""B16 PF1e conformance: Power Attack two-handed scaling + CMB penalty.

CRB "Power Attack": a -X penalty on all melee attack rolls AND combat maneuver
checks buys +2X melee damage; that damage bonus is increased by half (+3X) with
a two-handed weapon, a one-handed weapon used in two hands, or a primary
natural weapon that adds 1.5x Strength, and halved (+1X) with an off-hand /
secondary natural weapon (NOT modeled — no two-weapon fighting in the engine).

Sections:
  (a) two-handed Power Attack deals +3X damage
  (b) one-handed Power Attack still deals +2X damage (unchanged)
  (c) the Power Attack -X penalty reduces the combat maneuver check (CMB)
  (d) AttackSpec.two_handed validates True and defaults False
  (e) the orc falchion loads with two_handed=True
"""

from __future__ import annotations

from pathlib import Path

from pf1e_simulator.abilities import AbilitySpec
from pf1e_simulator.combat import CombatantState, CombatEngine
from pf1e_simulator.dice import parse_dice
from pf1e_simulator.grid import Grid
from pf1e_simulator.loaders.combatant import load_combatant
from pf1e_simulator.map import MapSpec, TerrainType
from pf1e_simulator.models import (
    AbilityScores,
    ACProfile,
    AttackSpec,
    Combatant,
    DamageComponent,
    Saves,
)
from pf1e_simulator.rng import ScriptedRng

MONSTERS_DIR = Path(__file__).resolve().parents[1] / "data" / "monsters"


def _sword(cid: str, *, two_handed: bool = False) -> AttackSpec:
    return AttackSpec(
        id=f"{cid}-sword",
        name="longsword",
        kind="melee",
        attack_bonus=5,
        damage=[DamageComponent(formula=parse_dice("1d6"), types=["slashing"])],
        two_handed=two_handed,
    )


def _combatant(
    cid: str,
    *,
    bab: int = 5,
    ac: int = 10,
    attacks: tuple[AttackSpec, ...] = (),
    features: tuple[str, ...] = (),
    cmd: int | None = None,
) -> Combatant:
    return Combatant(
        id=cid,
        name=cid,
        level=1,
        size="Medium",
        creature_type="living",
        abilities=AbilityScores(
            str_score=10, dex_score=10, con_score=10,
            int_score=10, wis_score=10, cha_score=10,
        ),
        hp_max=100,
        ac=ACProfile(total=ac, touch=ac, flat_footed=ac),
        bab=bab,
        initiative_mod=0,
        speed_land_ft=30,
        saves=Saves(fort=0, ref=0, will=0),
        attacks=list(attacks) or [_sword(cid)],
        features=[AbilitySpec(name=f, category="feat") for f in features],
        cmd=cmd,
    )


def _engine(
    combatants: list[Combatant],
    positions: list[tuple[int, int]],
    sides: list[str],
    rng: list[int],
) -> CombatEngine:
    states = [
        CombatantState(combatant=c, side=side, pos=pos, hp=c.hp_max)
        for c, pos, side in zip(combatants, positions, sides, strict=True)
    ]
    legend = {".": TerrainType(type="floor", move_cost=1)}
    spec = MapSpec(name="test", terrain=tuple(["." * 8] * 8), legend=legend)
    grid = Grid.from_spec(spec)
    return CombatEngine(ScriptedRng(rng), grid, states)


# ── (a)+(b): two-handed Power Attack deals +3X, one-handed +2X ───────────────


def test_two_handed_power_attack_deals_3x_damage() -> None:
    atk = _combatant(
        "atk", bab=5, attacks=(_sword("atk", two_handed=True),),
        features=("Power Attack",),
    )
    tgt = _combatant("tgt")
    eng = _engine([atk, tgt], [(0, 0), (0, 1)], ["players", "monsters"], [15, 4])
    a = eng._states[0]
    a.power_attack = True
    # bab 5 -> X = 5//4 + 1 = 2. Attack roll 15, weapon 1d6 = 4.
    result = eng.resolve_attack(a, eng._states[1], _sword("atk", two_handed=True))
    assert result.hit is True
    # 4 (weapon) + 3*2 (two-handed Power Attack) = 10.
    assert result.damage == 10


def test_one_handed_power_attack_deals_2x_damage() -> None:
    atk = _combatant("atk", bab=5, features=("Power Attack",))
    tgt = _combatant("tgt")
    eng = _engine([atk, tgt], [(0, 0), (0, 1)], ["players", "monsters"], [15, 4])
    a = eng._states[0]
    a.power_attack = True
    result = eng.resolve_attack(a, eng._states[1], _sword("atk"))
    assert result.hit is True
    # 4 (weapon) + 2*2 (one-handed Power Attack) = 8 — unchanged.
    assert result.damage == 8


# ── (c): the Power Attack penalty reduces the CMB check ──────────────────────


def test_power_attack_penalty_reduces_cmb_check() -> None:
    # bab 5 -> CMB 5, X = 2. d20 = 10, CMD 14: without the penalty 15 >= 14
    # (trip lands); with the -2 Power Attack penalty 13 < 14 (trip fails).
    a = _combatant("a", bab=5, features=("Power Attack", "Improved Trip"))
    tgt = _combatant("tgt", cmd=14)
    eng = _engine([a, tgt], [(1, 1), (1, 2)], ["players", "monsters"], [10])
    s = eng._states[0]
    s.power_attack = True
    eng._execute_maneuver(s, eng._states[1], "trip")
    assert not any(
        ac.condition.name == "prone" for ac in eng._states[1].active_conditions
    )
    assert any("d20=10+3=13" in line for line in eng._transcript)


def test_trip_lands_without_power_attack_penalty() -> None:
    # Control: same geometry, Power Attack inactive -> 15 >= 14 succeeds.
    a = _combatant("a", bab=5, features=("Power Attack", "Improved Trip"))
    tgt = _combatant("tgt", cmd=14)
    eng = _engine([a, tgt], [(1, 1), (1, 2)], ["players", "monsters"], [10])
    eng._execute_maneuver(eng._states[0], eng._states[1], "trip")
    assert any(
        ac.condition.name == "prone" for ac in eng._states[1].active_conditions
    )


# ── (d): AttackSpec.two_handed validates and defaults False ──────────────────


def test_attack_spec_two_handed_validates_and_defaults() -> None:
    assert _sword("x", two_handed=True).two_handed is True
    assert _sword("x").two_handed is False


# ── (e): the orc falchion loads with two_handed=True ─────────────────────────


def test_orc_falchion_loads_two_handed() -> None:
    orc = load_combatant(MONSTERS_DIR / "orc.json")
    falchion = next(a for a in orc.attacks if a.name == "falchion")
    assert falchion.two_handed is True
    javelin = next(a for a in orc.attacks if a.name == "javelin")
    assert javelin.two_handed is False