"""Russian Recent source transcription, separate from the legacy sequential scale.

This content does not authorize administering or continuing the questionnaire.
Use questionnaire.score_cssrs_recent for required/missing items and risk, and
evaluate_intake for the clinical policy gate before presenting another question.
Never render interviewer guidance as if it were another patient question.
"""

from pathlib import Path
from typing import Literal

import yaml
from pydantic import BaseModel, ConfigDict, Field, model_validator

from app.config import get_settings

ItemId = Literal["q1", "q2", "q3", "q4", "q5", "q6_lifetime", "q6_recent"]


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


class CssrsOption(SourceModel):
    value: int = Field(strict=True, ge=0, le=1)
    label: str


class CssrsItem(SourceModel):
    id: ItemId
    text: str = Field(min_length=1)
    interviewer_guidance: str | None
    recall_period: Literal["past_month", "lifetime", "past_3_months"]
    yes_risk: Literal["low", "moderate", "high"]


class CssrsRussianForm(SourceModel):
    id: Literal["cssrs_recent_ru"]
    version: str = Field(min_length=1)
    title: str
    subtitle: Literal["Screen Version - Recent"]
    period_label_original: str
    initial_instruction: str
    branch_instruction: str
    options: tuple[CssrsOption, CssrsOption]
    items: tuple[CssrsItem, ...]

    @model_validator(mode="after")
    def _structure(self) -> "CssrsRussianForm":
        if tuple(item.id for item in self.items) != ("q1", "q2", "q3", "q4", "q5", "q6_lifetime", "q6_recent"):
            raise ValueError("Recent form requires seven ordered answer fields")
        if tuple(option.value for option in self.options) != (1, 0):
            raise ValueError("source answer columns are Yes, No")
        return self


def load_cssrs_russian(path: Path | None = None) -> CssrsRussianForm:
    path = path or get_settings().config_dir / "instruments" / "cssrs_recent_ru.yaml"
    return CssrsRussianForm.model_validate(yaml.safe_load(path.read_text(encoding="utf-8")))