pf1e-simulator/tests/test_models.py

"""Unit tests for the combat data models (contracts for later stages)."""

import pytest
from pydantic import ValidationError

from pf1e_simulator.dice import DiceExpr
from pf1e_simulator.models import (
    AbilityScores,
    AttackSpec,
    Combatant,
    DamageComponent,
    DamageReduction,
)


def _abilities() -> AbilityScores:
    return AbilityScores(
        str_score=10,
        dex_score=11,
        con_score=12,
        int_score=13,
        wis_score=14,
        cha_score=15,
    )


def _attack_dict(**overrides: object) -> dict[str, object]:
    base: dict[str, object] = {
        "id": "dummy:0",
        "name": "bite",
        "kind": "melee",
        "attack_bonus": 3,
        "damage": [{"formula": "1d6", "types": ["piercing"]}],
    }
    base.update(overrides)
    return base


def _combatant_dict(**overrides: object) -> dict[str, object]:
    base: dict[str, object] = {
        "id": "dummy",
        "name": "Dummy",
        "level": 1,
        "abilities": _abilities(),
        "hp_max": 10,
        "ac": {"total": 15, "touch": 12, "flat_footed": 13},
        "bab": 1,
        "initiative_mod": 2,
        "speed_land_ft": 30,
        "saves": {"fort": 2, "ref": 3, "will": 4},
        "attacks": [_attack_dict()],
    }
    base.update(overrides)
    return base


class TestDamageComponent:
    def test_parses_string_formula(self) -> None:
        # Given a raw string formula
        # When the component is validated
        component = DamageComponent.model_validate({"formula": "2d6+3", "types": ["fire"]})
        # Then the formula is parsed into a DiceExpr
        assert component.formula == DiceExpr(count=2, sides=6, bonus=3)
        assert component.types == ["fire"]

    def test_accepts_dice_expr_formula(self) -> None:
        # Given an already-parsed DiceExpr
        expr = DiceExpr(count=1, sides=4)
        # When the component is built with it
        component = DamageComponent(formula=expr, types=["slashing"])
        # Then it is kept as-is
        assert component.formula is expr

    def test_rejects_empty_types(self) -> None:
        # Given a component with no damage type
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            DamageComponent.model_validate({"formula": "1d6", "types": []})

    def test_rejects_unparseable_formula(self) -> None:
        # Given a formula that is not dice notation
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            DamageComponent.model_validate({"formula": "not dice", "types": ["fire"]})


class TestAttackSpec:
    def test_defaults(self) -> None:
        # Given a minimal attack spec
        # When validated
        attack = AttackSpec.model_validate(_attack_dict())
        # Then the optional fields take their contract defaults
        assert attack.damage_bonus == 0
        assert attack.crit_range == 20
        assert attack.crit_mult == 2
        assert attack.reach_ft == 5
        assert attack.range_increment_ft is None
        assert attack.count == 1

    @pytest.mark.parametrize("kind", ["melee", "ranged", "touch"])
    def test_accepts_all_kinds(self, kind: str) -> None:
        # Given each allowed kind
        # When/Then validation succeeds
        attack = AttackSpec.model_validate(_attack_dict(kind=kind))
        assert attack.kind == kind

    def test_rejects_unknown_kind(self) -> None:
        # Given a kind outside the Literal
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            AttackSpec.model_validate(_attack_dict(kind="spell"))

    def test_rejects_empty_damage_list(self) -> None:
        # Given an attack with no damage component
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            AttackSpec.model_validate(_attack_dict(damage=[]))

    def test_rejects_crit_mult_below_2(self) -> None:
        # Given crit_mult=1 (a weapon that never multiplies is not PF1e)
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            AttackSpec.model_validate(_attack_dict(crit_mult=1))

    def test_rejects_crit_mult_above_4(self) -> None:
        # Given crit_mult=5
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            AttackSpec.model_validate(_attack_dict(crit_mult=5))

    @pytest.mark.parametrize("crit_range", [0, 1, 21])
    def test_rejects_crit_range_out_of_bounds(self, crit_range: int) -> None:
        # Given a crit range outside 2..20
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            AttackSpec.model_validate(_attack_dict(crit_range=crit_range))

    def test_rejects_zero_count(self) -> None:
        # Given count=0
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            AttackSpec.model_validate(_attack_dict(count=0))


class TestCombatant:
    def test_defaults(self) -> None:
        # Given a minimal combatant
        # When validated
        combatant = Combatant.model_validate(_combatant_dict())
        # Then the optional fields take their contract defaults
        assert combatant.size == "Medium"
        assert combatant.speed_fly_ft is None
        assert combatant.dr is None
        assert combatant.cr is None
        assert combatant.xp is None
        assert combatant.source == ""
        assert combatant.notes == ""

    def test_rejects_hp_max_zero(self) -> None:
        # Given hp_max=0
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            Combatant.model_validate(_combatant_dict(hp_max=0))

    def test_rejects_negative_land_speed(self) -> None:
        # Given a negative land speed
        # When/Then validation rejects it
        with pytest.raises(ValidationError):
            Combatant.model_validate(_combatant_dict(speed_land_ft=-5))

    def test_rejects_unknown_extra_key(self) -> None:
        # Given an unknown top-level key
        # When/Then validation rejects it (strict schema)
        with pytest.raises(ValidationError):
            Combatant.model_validate(_combatant_dict(hit_dice="1d8"))

    def test_frozen(self) -> None:
        # Given a validated combatant
        combatant = Combatant.model_validate(_combatant_dict())
        # When/Then mutation is rejected
        with pytest.raises(ValidationError):
            combatant.name = "Mutilated"

    def test_full_combatant_roundtrip(self) -> None:
        # Given a fully populated combatant
        combatant = Combatant.model_validate(
            _combatant_dict(
                size="Small",
                speed_fly_ft=80,
                dr={"amount": 5, "bypass": ["magic"]},
                cr="1/3",
                xp=135,
                source="Bestiary > Goblin",
                notes="note",
            )
        )
        # Then every field round-trips
        assert combatant.size == "Small"
        assert combatant.speed_fly_ft == 80
        assert combatant.dr is not None
        assert combatant.dr.amount == 5
        assert combatant.dr.bypass == frozenset({"magic"})
        assert combatant.cr == "1/3"
        assert combatant.xp == 135
        assert combatant.source == "Bestiary > Goblin"
        assert combatant.notes == "note"


class TestDamageReduction:
    def test_empty_bypass_means_dr_dash(self) -> None:
        # Given DR with an empty bypass set
        dr = DamageReduction(amount=10, bypass=frozenset())
        # Then it represents DR 10/—
        assert dr.amount == 10
        assert dr.bypass == frozenset()