"""API-boundary translation: marts now carry GIAS codes; the DataFrame the
rest of the backend sees must carry today's name strings."""

import numpy as np
import pandas as pd

from backend.data_loader import translate_gias_code_columns
from backend.gias_codes import ESTABLISHMENT_STATUS, PHASE_OF_EDUCATION


def _code_for(mapping, name):
    return next(c for c, n in mapping.items() if n == name)


def test_codes_become_todays_names():
    df = pd.DataFrame([{
        "urn": 1,
        "phase_code": float(_code_for(PHASE_OF_EDUCATION, "Primary")),
        "school_type_code": np.nan,
        "status_code": float(_code_for(ESTABLISHMENT_STATUS, "Open, but proposed to close")),
        "religious_character_code": np.nan,
        "admissions_policy_code": np.nan,
    }])
    out = translate_gias_code_columns(df)
    row = out.iloc[0]
    assert row["phase"] == "Primary"
    assert row["status"] == "Open, but proposed to close"
    assert row["school_type"] is None
    assert row["religious_denomination"] is None
    assert row["admissions_policy"] is None


def test_unknown_code_degrades_not_blanks():
    df = pd.DataFrame([{"urn": 1, "phase_code": 9999.0}])
    out = translate_gias_code_columns(df)
    assert out.iloc[0]["phase"] == "Unknown (9999)"


def test_missing_code_columns_are_a_noop():
    """Old-schema DataFrames (tests, pre-pipeline DBs) pass through untouched."""
    df = pd.DataFrame([{"urn": 1, "phase": "Primary", "status": "Open"}])
    out = translate_gias_code_columns(df)
    assert out.iloc[0]["phase"] == "Primary"
    assert out.iloc[0]["status"] == "Open"