"""Pydantic contracts for LLM outputs (SPEC §7). Anything the model returns is validated against these."""

from typing import Literal

from pydantic import BaseModel, Field, ValidationInfo, field_validator

SideEffect = Literal["nausea", "insomnia", "headache", "dizziness", "sexual", "agitation", "other"]
AlcoholBucket = Literal["none", "1-2", "more"]
SleepBucket = Literal["<4", "4-6", "6-8", ">8"]


class ItemScore(BaseModel):
    """Score of a single scale item extracted from a free-text answer.

    `score` is bounded by 4 (PCL-5); the per-scale maximum (3 for PHQ-9/GAD-7) is enforced via the
    validation context key `max_score`, because the same model serves scales with different ranges.
    """

    item: str
    score: int = Field(ge=0, le=4)
    confidence: float = Field(ge=0, le=1)
    evidence: str = ""

    @field_validator("score")
    @classmethod
    def _score_within_item_max(cls, v: int, info: ValidationInfo) -> int:
        max_score = (info.context or {}).get("max_score")
        if max_score is not None and v > max_score:
            raise ValueError(f"score {v} exceeds item max {max_score}")
        return v


class CheckinFacts(BaseModel):
    """Facts from a free-text daily check-in (ADR-002). `None` means "not mentioned", not "no"."""

    mood: int | None = Field(default=None, ge=0, le=10)
    med_taken: bool | None = None
    side_effects: list[SideEffect] = Field(default_factory=list)
    quit_intent: bool = False
    alcohol: AlcoholBucket | None = None
    sleep_hours_bucket: SleepBucket | None = None
    nightmares: bool | None = None
    med_question: bool = False
    confidence: float = Field(default=0.0, ge=0, le=1)

    @field_validator("side_effects")
    @classmethod
    def _dedupe(cls, v: list[SideEffect]) -> list[SideEffect]:
        return list(dict.fromkeys(v))


class RiskVerdict(BaseModel):
    """Raw risk classification as returned by the model; the gateway maps it to `RiskLevel`."""

    level: Literal["none", "possible", "acute"]
    confidence: float = Field(default=0.5, ge=0, le=1)