"""Combat data model — the boundary contract for the whole simulator.

Every combatant (PC from a Foundry sheet or hand-authored monster JSON) is
parsed into a `Combatant` exactly once, at the loading boundary. The engine
never sees raw JSON.
"""

from __future__ import annotations

from typing import Literal

from pydantic import BaseModel, ConfigDict, Field, field_validator

from pf1e_simulator.abilities import AbilitySpec  # noqa: TC001
from pf1e_simulator.dice import DiceExpr, DiceParseError, parse_dice


class _FrozenModel(BaseModel):
    model_config = ConfigDict(frozen=True, extra="forbid")


class AbilityScores(_FrozenModel):
    str_score: int
    dex_score: int
    con_score: int
    int_score: int
    wis_score: int
    cha_score: int

    @property
    def str_mod(self) -> int:
        """Strength ability modifier."""
        return (self.str_score - 10) // 2

    @property
    def dex_mod(self) -> int:
        """Dexterity ability modifier."""
        return (self.dex_score - 10) // 2


class ACProfile(_FrozenModel):
    total: int
    touch: int
    flat_footed: int


class Saves(_FrozenModel):
    fort: int
    ref: int
    will: int


class SkillSpec(_FrozenModel):
    """Definition of a PF1e skill."""

    name: str
    ability: Literal["str", "dex", "con", "int", "wis", "cha"]
    trained_only: bool = False
    armor_check_penalty: bool = False


class SkillRank(_FrozenModel):
    """A combatant's rank in a skill."""

    rank: int = 0
    class_skill: bool = False
    armor_penalty: int = 0


# Predefined PF1e skills (37 skills)
PREDEFINED_SKILLS: dict[str, SkillSpec] = {
    "acrobatics": SkillSpec(
        name="Acrobatics", ability="dex",
        trained_only=False, armor_check_penalty=True
    ),
    "appraise": SkillSpec(
        name="Appraise", ability="int",
        trained_only=False, armor_check_penalty=False
    ),
    "bluff": SkillSpec(
        name="Bluff", ability="cha",
        trained_only=False, armor_check_penalty=False
    ),
    "climb": SkillSpec(
        name="Climb", ability="str",
        trained_only=False, armor_check_penalty=True
    ),
    "craft": SkillSpec(
        name="Craft", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "diplomacy": SkillSpec(
        name="Diplomacy", ability="cha",
        trained_only=False, armor_check_penalty=False
    ),
    "disable_device": SkillSpec(
        name="Disable Device", ability="dex",
        trained_only=True, armor_check_penalty=False
    ),
    "disguise": SkillSpec(
        name="Disguise", ability="cha",
        trained_only=False, armor_check_penalty=False
    ),
    "escape_artist": SkillSpec(
        name="Escape Artist", ability="dex",
        trained_only=False, armor_check_penalty=True
    ),
    "fly": SkillSpec(
        name="Fly", ability="dex",
        trained_only=False, armor_check_penalty=True
    ),
    "handle_animal": SkillSpec(
        name="Handle Animal", ability="cha",
        trained_only=True, armor_check_penalty=False
    ),
    "heal": SkillSpec(
        name="Heal", ability="wis",
        trained_only=False, armor_check_penalty=False
    ),
    "intimidate": SkillSpec(
        name="Intimidate", ability="cha",
        trained_only=False, armor_check_penalty=False
    ),
    "knowledge_arcana": SkillSpec(
        name="Knowledge (Arcana)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_dungeoneering": SkillSpec(
        name="Knowledge (Dungeoneering)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_engineering": SkillSpec(
        name="Knowledge (Engineering)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_geography": SkillSpec(
        name="Knowledge (Geography)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_history": SkillSpec(
        name="Knowledge (History)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_local": SkillSpec(
        name="Knowledge (Local)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_nature": SkillSpec(
        name="Knowledge (Nature)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_nobility": SkillSpec(
        name="Knowledge (Nobility)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_planes": SkillSpec(
        name="Knowledge (Planes)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "knowledge_religion": SkillSpec(
        name="Knowledge (Religion)", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "linguistics": SkillSpec(
        name="Linguistics", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "perception": SkillSpec(
        name="Perception", ability="wis",
        trained_only=False, armor_check_penalty=False
    ),
    "perform": SkillSpec(
        name="Perform", ability="cha",
        trained_only=False, armor_check_penalty=False
    ),
    "profession": SkillSpec(
        name="Profession", ability="wis",
        trained_only=True, armor_check_penalty=False
    ),
    "ride": SkillSpec(
        name="Ride", ability="dex",
        trained_only=False, armor_check_penalty=True
    ),
    "sense_motive": SkillSpec(
        name="Sense Motive", ability="wis",
        trained_only=False, armor_check_penalty=False
    ),
    "sleight_of_hand": SkillSpec(
        name="Sleight of Hand", ability="dex",
        trained_only=True, armor_check_penalty=True
    ),
    "spellcraft": SkillSpec(
        name="Spellcraft", ability="int",
        trained_only=True, armor_check_penalty=False
    ),
    "stealth": SkillSpec(
        name="Stealth", ability="dex",
        trained_only=False, armor_check_penalty=True
    ),
    "survival": SkillSpec(
        name="Survival", ability="wis",
        trained_only=False, armor_check_penalty=False
    ),
    "swim": SkillSpec(
        name="Swim", ability="str",
        trained_only=False, armor_check_penalty=True
    ),
    "use_magic_device": SkillSpec(
        name="Use Magic Device", ability="cha",
        trained_only=True, armor_check_penalty=False
    ),
}
class DamageComponent(_FrozenModel):
    """One damage roll with its types (e.g. 1d8 piercing).

    The formula accepts an already-parsed DiceExpr (Foundry loader path) or a
    plain notation string like "2d6+3" (hand-authored monster JSON path).
    """

    formula: DiceExpr
    types: list[str] = Field(min_length=1)

    @field_validator("formula", mode="before")
    @classmethod
    def _parse_formula(cls, value: object) -> object:
        if isinstance(value, str):
            try:
                return parse_dice(value)
            except DiceParseError as exc:
                msg = str(exc)
                raise ValueError(msg) from exc
        return value


class AttackSpec(_FrozenModel):
    """One attack menu entry (weapon or natural attack).

    `count` captures repeated identical swings ("2x Talons") without listing
    the same entry twice. `reach_ft` applies to melee/touch kinds,
    `range_increment_ft` to ranged/touch kinds. `firearm` marks a ranged-touch
    weapon (gun) whose shots resolve against touch AC within the first range
    increment and against full AC beyond it. `two_handed` marks a weapon swung
    in two hands (two-handed weapon, one-handed weapon used two hands, or a
    primary natural with 1.5x Strength) — PF1e Power Attack rolls +50% damage
    with such a weapon (CRB "Power Attack").     `reach_weapon` marks a weapon
    with the reach weapon quality (CRB "Big and Little Creatures in Combat"):
    it doubles the wielder's NATURAL reach but cannot strike at the wielder's
    natural reach or less — the usable zone is a RING (dead zone = natural
    reach). Without the flag a melee attack follows the creature's natural
    reach, which is a DISK: a Large creature's natural attack (its JSON
    `reach_ft` IS its natural reach, 10 ft) still strikes and threatens
    adjacent squares. `natural` marks a natural weapon (bite, claw, etc.):
    PF1e (CRB "Natural Attacks") grants no BAB iteratives for natural
    weapons. `secondary` marks a secondary natural attack (tail, wing, etc.):
    the engine applies -5 to the attack bonus (reduced to -2 with the
    Multiattack feat).
    """

    id: str
    name: str
    kind: Literal["melee", "ranged", "touch"]
    attack_bonus: int
    damage: list[DamageComponent] = Field(min_length=1)
    damage_bonus: int = 0
    crit_range: int = Field(default=20, ge=2, le=20)
    crit_mult: int = Field(default=2, ge=2, le=4)
    reach_ft: int = 5
    reach_weapon: bool = False
    range_increment_ft: int | None = None
    count: int = Field(default=1, ge=1)
    firearm: bool = False
    two_handed: bool = False
    natural: bool = False
    secondary: bool = False


class DamageReduction(_FrozenModel):
    """DR amount and the damage types that bypass it; empty bypass = DR/—."""

    amount: int = Field(ge=1)
    bypass: frozenset[str] = frozenset()


class Combatant(_FrozenModel):
    """A fully parsed combatant, ready for the engine."""

    id: str
    name: str
    level: int = Field(ge=1)
    size: str = "Medium"
    creature_type: Literal["living", "undead", "construct"] = "living"
    abilities: AbilityScores
    hp_max: int = Field(ge=1)
    ac: ACProfile
    bab: int
    initiative_mod: int
    speed_land_ft: int = Field(ge=0)
    speed_fly_ft: int | None = None
    saves: Saves
    attacks: list[AttackSpec]
    dr: DamageReduction | None = None
    cr: str | None = None
    xp: int | None = None
    source: str = ""
    notes: str = ""
    features: list[AbilitySpec] = []
    skills: dict[str, SkillRank] = Field(default_factory=dict)
    cmb: int | None = None  # Combat Maneuver Bonus
    cmd: int | None = None  # Combat Maneuver Defense
    casting_ability: str = "wis"  # ability used for spell DCs: str/dex/con/int/wis/cha
    spell_slots: dict[int, int] = Field(default_factory=dict)  # max slots per spell level
    resources: dict[str, int] = Field(default_factory=dict)  # resource pools per combat
    metamagic_feats: list[str] = Field(default_factory=list)  # e.g. Empower/Maximize/Extend Spell
    spells: list[str] = Field(default_factory=list)
    spell_resistance: int = 0
    resistances: dict[str, int] = Field(default_factory=dict)
    immunities: tuple[str, ...] = ()
    # PF1e (SRD "Surprise"): "If some but not all of the combatants are aware
    # of their opponents, a surprise round happens before regular rounds
    # begin." Unaware combatants do not act in the surprise round. Default
    # True keeps every existing encounter on a full first round.
    aware: bool = True