"""Confidence bands: thresholds, the worst-word rule and the blank-mandatory flag (spec: Banding)."""
import importlib.util
from pathlib import Path

BANDS = Path(__file__).resolve().parents[1] / "rpa-dashboard-ai" / "templates" / "web" / "bands.py"
spec = importlib.util.spec_from_file_location("bands", BANDS)
bands = importlib.util.module_from_spec(spec)
spec.loader.exec_module(bands)


def test_thresholds():
    assert bands.band_of(1.0) == "green"
    assert bands.band_of(0.95) == "green"
    assert bands.band_of(0.9499) == "amber"
    assert bands.band_of(0.90) == "amber"
    assert bands.band_of(0.8999) == "red"
    assert bands.band_of(0.0) == "red"


def test_field_takes_its_worst_word():
    assert bands.field_band([0.99, 0.97, 0.98], "ACME Office Supply") == "green"
    assert bands.field_band([0.99, 0.93, 0.98], "ACME Office Supply") == "amber"
    assert bands.field_band([0.99, 0.97, 0.62], "ACME Office Supply") == "red"


def test_blank_mandatory_field_is_always_flagged():
    assert bands.field_band([1.0], "", mandatory=True) == "blank"
    assert bands.field_band([], "   ", mandatory=True) == "blank"
    assert bands.field_band(None, None, mandatory=True) == "blank"
    assert bands.needs_review("blank")
    # An optional blank is graded like any other field.
    assert bands.field_band([1.0], "", mandatory=False) == "green"


def test_no_scores_means_unscored():
    assert bands.field_band([], "INV-1001") == "unscored"


def test_only_green_skips_review():
    assert not bands.needs_review("green")
    assert all(bands.needs_review(b) for b in ["amber", "red", "blank", "unscored"])