"""Загрузка справочников норм RACION (БД → JSON fallback)."""

from __future__ import annotations

import json
from functools import lru_cache
from pathlib import Path

_SEED_DIR = Path(__file__).resolve().parents[4] / "data" / "seed" / "racion"


def _read_json(name: str) -> dict:
    path = _SEED_DIR / name
    if not path.exists():
        raise FileNotFoundError(f"Справочник не найден: {path}")
    return json.loads(path.read_text(encoding="utf-8"))


def _load_from_db(loader_name: str) -> dict | None:
    try:
        from flask import has_app_context

        if not has_app_context():
            return None
        from app.modules.zootech.lab.services.racion_reference import (
            load_moskwa_lactir_from_db,
            load_normy_info_from_db,
            load_piter_lactir_from_db,
        )

        loaders = {
            "moskwa": load_moskwa_lactir_from_db,
            "piter": load_piter_lactir_from_db,
            "info": load_normy_info_from_db,
        }
        fn = loaders.get(loader_name)
        if fn is None:
            return None
        data = fn()
        return data if data else None
    except Exception:
        return None


@lru_cache(maxsize=1)
def load_moskwa_lactir() -> dict:
    data = _load_from_db("moskwa")
    if data:
        return data
    return _read_json("moskwa_lactir.json")


@lru_cache(maxsize=1)
def load_piter_lactir() -> dict:
    data = _load_from_db("piter")
    if data:
        return data
    return _read_json("piter_lactir.json")


@lru_cache(maxsize=1)
def load_normy_info() -> dict:
    data = _load_from_db("info")
    if data:
        return data
    try:
        return _read_json("normy_info.json")
    except FileNotFoundError:
        return {"rows": [], "mass_kg_values": [400, 450, 500, 550, 600, 650, 700, 750]}


def clear_tables_cache() -> None:
    load_moskwa_lactir.cache_clear()
    load_piter_lactir.cache_clear()
    load_normy_info.cache_clear()