pf1e-simulator/tests/test_maneuvers.py

"""Tests for combat maneuvers, focused on the sunder result.

A successful sunder damages the defender's WEAPON, never its HP. Repeated
sunders can destroy the weapon, after which the defender can no longer use
it (effectively disarmed). See the plan task-12.
"""

from __future__ import annotations

from pf1e_simulator.combat import _SIZE_MODIFIERS, CombatantState, CombatEngine
from pf1e_simulator.conditions import CONDITIONS_BY_NAME
from pf1e_simulator.effects import ActiveBuff, ActiveCondition, StatModifier
from pf1e_simulator.grid import Grid
from pf1e_simulator.map import MapSpec, TerrainType
from pf1e_simulator.models import (
    AbilityScores,
    ACProfile,
    AttackSpec,
    Combatant,
    DamageComponent,
    Saves,
    SkillRank,
)
from pf1e_simulator.rng import ScriptedRng


def make_combatant(
    cid: str, *, attack_bonus: int = 2, weapon_name: str = "sword"
) -> Combatant:
    attack = AttackSpec(
        id=f"{cid}-w",
        name=weapon_name,
        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:
    # A maneuver provokes an AoO from the (threatening) target BEFORE the CMB
    # check (B13 conformance): scripted queues carry a leading natural 1 so
    # the provoking attack always misses.
    return CombatEngine(ScriptedRng(queue), make_grid(), states)


def test_sunder_damages_weapon_not_hp() -> 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))
    hp_before = b.hp
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "sunder")
    assert b.hp == hp_before
    assert b.weapon_damage["b-w"] == 2
    assert "b-w" not in b.weapon_broken


def test_sunder_destroys_weapon_and_disarms() -> 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))
    # Only the first sunder provokes: b's per-round AoO allowance is spent.
    engine = make_engine([1, 12, 12, 12, 12, 12], [a, b])
    for _ in range(5):
        engine._execute_maneuver(a, b, "sunder")
    assert b.hp == 6
    assert "b-w" in b.weapon_broken
    assert engine.weapon_for(b, a) is None
    assert any(c.condition.name == "disarmed" for c in b.active_conditions)


def test_escape_from_grapple_consumes_single_d20() -> None:
    a_spec = make_combatant("a", attack_bonus=2).model_copy(
        update={"skills": {"escape_artist": SkillRank(rank=10)}}
    )
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    a.active_conditions.append(
        ActiveCondition(
            condition=CONDITIONS_BY_NAME["grappled"],
            rounds_left=1,
            source="test",
        )
    )
    a.grappled_with = b_spec.id
    engine = make_engine([20], [a, b])
    engine._maneuver_escape(a, b)
    assert not engine._rng._queue
    assert a.grappled_with is None
    assert not any(c.condition.name == "grappled" for c in a.active_conditions)


def _grappled_by(a: CombatantState, b: CombatantState) -> None:
    a.active_conditions.append(
        ActiveCondition(
            condition=CONDITIONS_BY_NAME["grappled"],
            rounds_left=1,
            source="test",
        )
    )
    a.grappled_with = b.combatant.id


def test_escape_natural_20_auto_succeeds_below_cmd() -> None:
    # SRD Combat Maneuvers: "Rolling a natural 20 while attempting a combat
    # maneuver is always a success (except when attempting to escape from
    # bonds)" — a grapple is not bonds. Escape bonus 2, b CMD 30 (bab 20):
    # 20+2=22 < 30, so only the natural-20 rule can succeed this.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    b = make_state(make_combatant("b", attack_bonus=20), "monsters", (1, 2))
    _grappled_by(a, b)
    engine = make_engine([20], [a, b])
    engine._maneuver_escape(a, b)
    assert a.grappled_with is None
    assert not any(c.condition.name == "grappled" for c in a.active_conditions)


def test_escape_natural_1_still_fails_above_cmd() -> None:
    # Natural 1 stays an automatic failure even when the total clears CMD:
    # escape_artist rank 20 (+3 class) gives bonus 23 vs CMD 12.
    a_spec = make_combatant("a", attack_bonus=2).model_copy(
        update={"skills": {"escape_artist": SkillRank(rank=20, class_skill=True)}}
    )
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(make_combatant("b"), "monsters", (1, 2))
    _grappled_by(a, b)
    engine = make_engine([1], [a, b])
    engine._maneuver_escape(a, b)
    assert a.grappled_with == b.combatant.id
    assert any(c.condition.name == "grappled" for c in a.active_conditions)


def test_bull_rush_push_scales_with_margin() -> None:
    # SRD Bull Rush: "For every 5 by which your attack exceeds your
    # opponent's CMD you can push the target back an additional 5 feet."
    # d20=20+2=22 vs CMD 12: margin 10 -> push 1 + 10//5 = 3 cells.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    b = make_state(make_combatant("b"), "monsters", (1, 2))
    engine = make_engine([1, 20], [a, b])
    engine._execute_maneuver(a, b, "bull_rush")
    assert b.pos == (1, 5)


def test_bull_rush_push_stops_at_obstacle() -> None:
    # Same margin 10 (3 cells) but a creature blocks (1, 4): the push moves
    # b two cells and stops.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    b = make_state(make_combatant("b"), "monsters", (1, 2))
    c = make_state(make_combatant("c"), "monsters", (1, 4))
    engine = make_engine([1, 20], [a, b, c])
    engine._execute_maneuver(a, b, "bull_rush")
    assert b.pos == (1, 3)


def test_bull_rush_natural_20_below_cmd_pushes_one_cell() -> None:
    # Natural 20 auto-succeeds even below CMD (bab 20 foe: CMD 30, total 22):
    # the margin floors at 0, so only the base 5 ft push applies.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    b = make_state(make_combatant("b", attack_bonus=20), "monsters", (1, 2))
    engine = make_engine([1, 20], [a, b])
    engine._execute_maneuver(a, b, "bull_rush")
    assert b.pos == (1, 3)


def test_trip_fails_by_10_knocks_attacker_prone() -> None:
    # SRD Trip: "If your attack fails by 10 or more, you are knocked prone
    # instead." b CMD 30 (bab 20); a total 10+2=12 fails by 18.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    b = make_state(make_combatant("b", attack_bonus=20), "monsters", (1, 2))
    engine = make_engine([1, 10], [a, b])
    engine._execute_maneuver(a, b, "trip")
    assert not any(c.condition.name == "prone" for c in b.active_conditions)
    prone = next(c for c in a.active_conditions if c.condition.name == "prone")
    assert prone.source == "maneuver: trip retaliation"


def test_trip_fails_by_less_than_10_attacker_stands() -> None:
    # a total 19+2=21 vs CMD 30 fails by 9 — no retaliation.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    b = make_state(make_combatant("b", attack_bonus=20), "monsters", (1, 2))
    engine = make_engine([1, 19], [a, b])
    engine._execute_maneuver(a, b, "trip")
    assert not any(c.condition.name == "prone" for c in a.active_conditions)


def test_overrun_fail_stops_in_front_of_target() -> None:
    # SRD Overrun: "If your overrun attempt fails, you stop in the space
    # directly in front of the opponent." a at (1,0), b at (1,3): the failed
    # attempt parks a on (1,2), the cell in front of b. a is not threatened
    # from (1,0), so no AoO roll is consumed: the single d20 is the maneuver.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 0))
    b = make_state(make_combatant("b"), "monsters", (1, 3))
    engine = make_engine([5], [a, b])
    engine._execute_maneuver(a, b, "overrun")
    assert a.pos == (1, 2)


def test_overrun_fail_nearest_open_when_front_occupied() -> None:
    # "...or the nearest open space in front of the creature if there are
    # other creatures occupying that space." Blocker on (1,2): a stops (1,1).
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 0))
    b = make_state(make_combatant("b"), "monsters", (1, 3))
    c = make_state(make_combatant("c"), "monsters", (1, 2))
    engine = make_engine([1, 5], [a, b, c])
    engine._execute_maneuver(a, b, "overrun")
    assert a.pos == (1, 1)


def test_overrun_fail_adjacent_attacker_does_not_move() -> None:
    # An already-adjacent attacker is in front of the target: it stays put.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    b = make_state(make_combatant("b"), "monsters", (1, 2))
    engine = make_engine([1, 5], [a, b])
    engine._execute_maneuver(a, b, "overrun")
    assert a.pos == (1, 1)
    assert not any("overrun blocked" in line for line in engine._transcript)


def test_maneuver_rejects_target_two_sizes_larger() -> None:
    # SRD Trip/Bull Rush/Overrun: "You can only [affect] an opponent who is
    # no more than one size category larger than you." Medium vs Huge: the
    # attempt is illegal — no d20 consumed, no effect, logged rejection.
    for maneuver in ("trip", "bull_rush", "overrun"):
        a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
        huge = make_state(_resized(make_combatant("h"), "Huge", 10, 10), "monsters", (1, 2))
        engine = make_engine([1, 12], [a, huge])
        engine._execute_maneuver(a, huge, maneuver)
        assert len(engine._rng._queue) == 2
        assert not any(c.condition.name == "prone" for c in huge.active_conditions)
        assert f"{maneuver} vs h rejected (target too large)" in engine._transcript[-1]


def test_maneuver_allows_target_one_size_larger() -> None:
    # Medium vs Large (one category) stays legal; the roll happens.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    large = make_state(_resized(make_combatant("l"), "Large", 10, 10), "monsters", (1, 2))
    engine = make_engine([1, 12], [a, large])
    engine._execute_maneuver(a, large, "trip")
    assert not engine._rng._queue
    assert any(c.condition.name == "prone" for c in large.active_conditions)


def test_unrestricted_maneuver_ignores_size_limit() -> None:
    # The size cap is trip/bull_rush/overrun only: disarm works on Huge.
    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
    huge = make_state(_resized(make_combatant("h"), "Huge", 10, 10), "monsters", (1, 2))
    engine = make_engine([1, 12], [a, huge])
    engine._execute_maneuver(a, huge, "disarm")
    assert not engine._rng._queue


def test_overrun_knocks_prone_and_moves_through() -> None:
    # d20=15+2=17 vs CMD 12: margin 5 -> prone AND moved through (CRB
    # "Overrun": prone only when the attack exceeds CMD by 5 or more).
    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([1, 15], [a, b])
    engine._execute_maneuver(a, b, "overrun")
    prone = next(c for c in b.active_conditions if c.condition.name == "prone")
    assert prone.rounds_left == 1
    assert prone.source == "maneuver: overrun"
    assert a.pos == (1, 3)


def test_overrun_small_margin_moves_through_without_prone() -> None:
    # d20=14+2=16 vs CMD 12: margin 4 -> plain success: moved through,
    # NOT prone (CRB "Overrun").
    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([1, 14], [a, b])
    engine._execute_maneuver(a, b, "overrun")
    assert not any(c.condition.name == "prone" for c in b.active_conditions)
    assert a.pos == (1, 3)
    assert "SUCCESS (moved through)" in engine._transcript[-1]
    assert "prone" not in engine._transcript[-1]


def test_overrun_prone_but_no_space() -> None:
    # d20=15+2=17 vs CMD 12: margin 5 -> prone; the beyond cell is occupied,
    # so no move-through.
    a_spec = make_combatant("a", attack_bonus=2)
    b_spec = make_combatant("b")
    c_spec = make_combatant("c")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    c = make_state(c_spec, "monsters", (1, 3))
    engine = make_engine([1, 15], [a, b, c])
    engine._execute_maneuver(a, b, "overrun")
    assert any(cond.condition.name == "prone" for cond in b.active_conditions)
    assert a.pos == (1, 1)
    assert "SUCCESS (prone)" in engine._transcript[-1]
    assert "moved through" not in engine._transcript[-1]


def test_dirty_trick_dazzles() -> 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([1, 12], [a, b])
    engine._execute_maneuver(a, b, "dirty_trick")
    dazzled = next(c for c in b.active_conditions if c.condition.name == "dazzled")
    assert dazzled.rounds_left == 1
    assert dazzled.source == "maneuver: dirty trick"


def test_dirty_trick_fails_on_natural_1() -> 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([1, 1], [a, b])
    engine._execute_maneuver(a, b, "dirty_trick")
    assert not any(c.condition.name == "dazzled" for c in b.active_conditions)
    assert not any(c.condition.name == "prone" for c in b.active_conditions)
    assert engine._transcript[-1].endswith("-> FAILED")


def test_steal_takes_melee_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))
    hp_before = b.hp
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "steal")
    assert "b-w" in b.weapon_stolen
    assert engine.weapon_for(b, a) is None
    assert b.hp == hp_before


def test_steal_nothing_to_steal() -> None:
    a_spec = make_combatant("a", attack_bonus=2)
    b_spec = make_combatant("b").model_copy(update={"attacks": []})
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([12], [a, b])
    engine._execute_maneuver(a, b, "steal")
    assert not b.weapon_stolen
    assert "nothing to steal" in engine._transcript[-1]


def test_reposition_moves_to_first_free_neighbor() -> None:
    a_spec = make_combatant("a", attack_bonus=2)
    b_spec = make_combatant("b")
    c_spec = make_combatant("c")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    c = make_state(c_spec, "monsters", (1, 3))
    engine = make_engine([1, 12], [a, b, c])
    engine._execute_maneuver(a, b, "reposition")
    assert b.pos == (0, 1)
    assert c.pos == (1, 3)


def test_reposition_no_space() -> None:
    a_spec = make_combatant("a", attack_bonus=2)
    b_spec = make_combatant("b")
    blocker_positions = [(0, 0), (0, 1), (0, 2), (1, 0), (1, 2), (2, 0), (2, 2)]
    blockers = [
        make_state(make_combatant(f"c{idx}"), "monsters", pos)
        for idx, pos in enumerate(blocker_positions)
    ]
    a = make_state(a_spec, "players", (2, 1))
    b = make_state(b_spec, "monsters", (1, 1))
    engine = make_engine([1, 12], [a, b, *blockers])
    engine._execute_maneuver(a, b, "reposition")
    assert b.pos == (1, 1)
    assert "no space" in engine._transcript[-1]


def test_drag_moves_pair_together() -> 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([1, 12], [a, b])
    engine._execute_maneuver(a, b, "drag")
    assert b.pos == (1, 3)
    assert a.pos == (1, 2)


def test_drag_no_space() -> None:
    a_spec = make_combatant("a", attack_bonus=2)
    b_spec = make_combatant("b")
    c_spec = make_combatant("c")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    c = make_state(c_spec, "monsters", (1, 3))
    engine = make_engine([1, 12], [a, b, c])
    engine._execute_maneuver(a, b, "drag")
    assert b.pos == (1, 2)
    assert a.pos == (1, 1)
    assert "no space" in engine._transcript[-1]


def _resized(spec: Combatant, size: str, str_score: int, dex_score: int) -> Combatant:
    return spec.model_copy(
        update={
            "size": size,
            "abilities": spec.abilities.model_copy(
                update={"str_score": str_score, "dex_score": dex_score}
            ),
        }
    )


def test_tiny_or_smaller_cmb_uses_dexterity() -> None:
    # SRD Combat Maneuvers: "Creatures that are size Tiny or smaller use
    # their Dexterity modifier in place of their Strength modifier to
    # determine their CMB." Tiny: str -1, dex +4, bab 2, size -2 -> 2+4-2.
    engine = make_engine([], [])
    for size in ("Tiny", "Diminutive", "Fine"):
        tiny = make_state(_resized(make_combatant("t"), size, 8, 18), "p", (0, 0))
        expected = 2 + 4 + _SIZE_MODIFIERS[size.lower()]
        assert engine._maneuver_cmb(tiny) == expected


def test_small_or_larger_cmb_uses_strength() -> None:
    # The Dex substitution stops at Tiny: Small and larger use Strength.
    engine = make_engine([], [])
    small = make_state(_resized(make_combatant("s"), "Small", 8, 18), "p", (0, 0))
    medium = make_state(_resized(make_combatant("m"), "Medium", 8, 18), "p", (0, 1))
    assert engine._maneuver_cmb(small) == 2 - 1 - 1  # bab + str + size
    assert engine._maneuver_cmb(medium) == 2 - 1 + 0  # bab + str + size


def test_tiny_or_smaller_cmd_uses_strength_and_dexterity() -> None:
    # SRD Combat Maneuvers: "CMD = 10 + Base attack bonus + Strength modifier
    # + Dexterity modifier + special size modifier" — the Tiny-or-smaller
    # Dex-for-Str substitution is CMB-only. Tiny: str -1, dex +4, bab 2,
    # size -2 -> 10 + 2 - 1 + 4 - 2 = 13 (not 10 + 2 + 4 - 2 + 4 = 18).
    engine = make_engine([], [])
    for size in ("Tiny", "Diminutive", "Fine"):
        tiny = make_state(_resized(make_combatant("t"), size, 8, 18), "p", (0, 0))
        expected = 10 + 2 - 1 + 4 + _SIZE_MODIFIERS[size.lower()]
        assert engine._maneuver_cmd(tiny) == expected


def _buffed(spec: Combatant, mods: tuple[StatModifier, ...]) -> CombatantState:
    state = make_state(spec, "p", (0, 0))
    state.active_buffs.append(
        ActiveBuff(modifiers=mods, rounds_left=1, source="test")
    )
    return state


def test_cmd_adds_eligible_ac_bonus_types() -> None:
    # SRD CMD: "A creature can also add any circumstance, deflection, dodge,
    # insight, luck, morale, profane, and sacred bonuses to AC to its CMD."
    # Medium str 10 dex 10 bab 2: base CMD 10 + (2+0+0) + 0 = 12.
    engine = make_engine([], [])
    base = make_state(make_combatant("b"), "p", (0, 0))
    assert engine._maneuver_cmd(base) == 12
    buffed = _buffed(
        make_combatant("b"),
        (
            StatModifier(target="ac", value=4, bonus_type="dodge"),
            StatModifier(target="ac", value=2, bonus_type="morale"),
        ),
    )
    assert engine._maneuver_cmd(buffed) == 12 + 4 + 2


def test_cmd_ignores_non_ac_bonus_types() -> None:
    # Enhancement/natural armor bonuses and untyped penalties are NOT added
    # to CMD (only the eight SRD-listed AC bonus types are).
    engine = make_engine([], [])
    state = _buffed(
        make_combatant("b"),
        (
            StatModifier(target="ac", value=2, bonus_type="enhancement"),
            StatModifier(target="ac", value=-4),
        ),
    )
    assert engine._maneuver_cmd(state) == 12


def test_cmd_flat_footed_drops_dex_bonus_keeps_penalty() -> None:
    # SRD CMD: "A flat-footed creature does not add its Dexterity bonus to
    # its CMD." A Dex penalty is not a bonus, so it still applies.
    engine = make_engine([], [])
    dexy = _resized(make_combatant("d"), "Medium", 10, 18)  # dex +4
    flat = make_state(dexy, "p", (0, 0))
    flat.active_conditions.append(
        ActiveCondition(
            condition=CONDITIONS_BY_NAME["flat_footed"],
            rounds_left=1,
            source="test",
        )
    )
    assert engine._maneuver_cmd(make_state(dexy, "p", (0, 1))) == 10 + 2 + 4
    assert engine._maneuver_cmd(flat) == 10 + 2  # Dex bonus gone
    clumsy = _resized(make_combatant("c"), "Medium", 10, 6)  # dex -2
    clumsy_flat = make_state(clumsy, "p", (0, 2))
    clumsy_flat.active_conditions.append(
        ActiveCondition(
            condition=CONDITIONS_BY_NAME["flat_footed"],
            rounds_left=1,
            source="test",
        )
    )
    assert engine._maneuver_cmd(clumsy_flat) == 10 + 2 - 2  # penalty kept