"""Canonical tests: WESP GfE 2001 ingredient derive (не Excel CSV)."""

from __future__ import annotations

import json
import math
import unittest
from pathlib import Path

from app.lab.calc.gfe_policies import DeriveContext, default_om_digestibility_pct
from app.lab.calc.ingredient_derive import derive_ingredient_nutrients

_FIXTURES = Path(__file__).resolve().parent / "fixtures" / "lab_derive_canonical.json"


def _load_cases() -> list[dict]:
    with _FIXTURES.open(encoding="utf-8") as f:
        return json.load(f)


class LabIngredientDeriveTests(unittest.TestCase):
    def _assert_close(self, expected: float, actual: float, label: str) -> None:
        tol = max(1e-3, abs(expected) * 1e-4)
        self.assertTrue(
            math.isclose(expected, actual, abs_tol=tol),
            f"{label}: expected {expected}, got {actual}",
        )

    def test_derive_canonical_cases(self) -> None:
        for case in _load_cases():
            if "expected" not in case:
                continue
            ctx_raw = case.get("context") or {}
            ctx = DeriveContext(
                feed_group=ctx_raw.get("feed_group", "unknown"),
                is_main_feed=bool(ctx_raw.get("is_main_feed")),
            )
            derived = derive_ingredient_nutrients(case["input"], context=ctx)
            for key, expected in case["expected"].items():
                self.assertIn(key, derived, msg=f"{case['id']}: missing {key}")
                self._assert_close(float(expected), derived[key], f"{case['id']}/{key}")

    def test_rnb_from_derive(self) -> None:
        case = next(c for c in _load_cases() if c.get("id") == "rnb_formula")
        ctx = DeriveContext(feed_group="concentrate")
        derived = derive_ingredient_nutrients(case["input"], context=ctx)
        cp = derived["уСП формул"]
        rnb = (derived["Сыр. Протеин"] - cp) / 6.25
        self._assert_close(case["expected_rnb"], rnb, "rnb_formula")
        self._assert_close(case["expected_rnb"], derived["БРА"], "rnb_header")

    def test_omd_default_by_feed_class(self) -> None:
        self.assertEqual(default_om_digestibility_pct(DeriveContext(feed_group="rough")), 65.0)
        self.assertEqual(
            default_om_digestibility_pct(DeriveContext(feed_group="succulent")),
            72.0,
        )
        self.assertEqual(
            default_om_digestibility_pct(DeriveContext(feed_group="concentrate")),
            91.0,
        )
        self.assertEqual(
            default_om_digestibility_pct(DeriveContext(is_main_feed=True)),
            65.0,
        )

    def test_straw_without_omd_not_91_pct(self) -> None:
        case = next(c for c in _load_cases() if c.get("id") == "straw_default_omd_65")
        ctx = DeriveContext(feed_group="rough", is_main_feed=True)
        derived = derive_ingredient_nutrients(case["input"], context=ctx)
        organic = case["input"]["СВ"] - case["input"]["Сырая зола"]
        wrong = organic * 0.91
        self.assertLess(derived["Перевар Орг Вещ"], wrong - 100)


if __name__ == "__main__":
    unittest.main()