"""Thickness band resolution (METADATA-15 / QUALITY-95).

The owner never picks the Woo thickness band in the UI — the server derives it
from the measured thickness_in against the live synced bands. These tests pin the
derivation on the real live band names (from the UAT taxonomy) and on the
quarter-inch slug fallback.
"""

import pytest

from backend.thickness_band import (
    parse_inch_token,
    resolve_thickness_band_id,
    term_bounds,
)

# The live UAT Thickness attribute (pa_thk) as synced: name, slug.
LIVE_TERMS = [
    {"id": 347, "name": "Under 1/2\"", "slug": "xthin"},
    {"id": 348, "name": "1/2\" - 3/4\"", "slug": "2-3qtr"},
    {"id": 349, "name": "3/4\" - 1\"", "slug": "3-4qtr"},
    {"id": 350, "name": "1\"- 1 1/2\"", "slug": "4-6qtr"},
    {"id": 351, "name": "1 1/2\" - 2\"", "slug": "6-8qtr"},
    {"id": 352, "name": "2\" - 3\"", "slug": "8-12qtr"},
    {"id": 353, "name": "Over 3\"", "slug": "12qtr"},
]


@pytest.mark.parametrize(
    "text,expected",
    [
        ("1 1/2", 1.5),
        ("3/4", 0.75),
        ("2", 2.0),
        ("1.75", 1.75),
        ("2\"", 2.0),
        ("1 1/2\"", 1.5),
    ],
)
def test_parse_inch_token(text, expected):
    assert parse_inch_token(text) == pytest.approx(expected)


def test_parse_inch_token_rejects_junk():
    assert parse_inch_token("") is None
    assert parse_inch_token("   ") is None


def test_term_bounds_from_live_names():
    assert term_bounds(LIVE_TERMS[0]) == (0.0, 0.5)
    assert term_bounds(LIVE_TERMS[1]) == (0.5, 0.75)
    assert term_bounds(LIVE_TERMS[3]) == (1.0, 1.5)
    assert term_bounds(LIVE_TERMS[6]) == (3.0, float("inf"))


def test_term_bounds_falls_back_to_qtr_slug():
    assert term_bounds({"id": 9, "name": "weird", "slug": "4-6qtr"}) == (1.0, 1.5)
    assert term_bounds({"id": 9, "name": "weird", "slug": "12qtr"}) == (3.0, float("inf"))
    assert term_bounds({"id": 9, "name": "weird", "slug": "xthin"}) == (0.0, 0.5)


@pytest.mark.parametrize(
    "thickness,expected_id",
    [
        (0.25, 347),  # Under 1/2"
        (0.5, 348),   # boundary rounds UP into 1/2"-3/4", not down
        (0.625, 348),
        (0.75, 349),  # boundary rounds UP
        (0.875, 349),
        (1.0, 350),   # QUALITY-95: 1 inch rounds up into 1"-1 1/2", not a hardcoded band
        (1.25, 350),
        (1.5, 351),
        (1.75, 351),  # the UAT sample thickness
        (2.0, 352),
        (2.75, 352),
        (3.0, 353),
        (4.0, 353),
    ],
)
def test_resolve_rounds_up_on_boundary(thickness, expected_id):
    assert resolve_thickness_band_id(thickness, LIVE_TERMS) == expected_id


def test_resolve_handles_missing_inputs():
    assert resolve_thickness_band_id(None, LIVE_TERMS) is None
    assert resolve_thickness_band_id(-1, LIVE_TERMS) is None
    assert resolve_thickness_band_id(1.0, []) is None
    # A term with no parseable name/slug is skipped, never guessed at.
    assert resolve_thickness_band_id(1.0, [{"id": 1, "name": "mystery", "slug": "mystery"}]) is None


def test_resolve_is_id_order_independent():
    """The result must not depend on the sync order of the terms."""
    assert resolve_thickness_band_id(1.75, list(reversed(LIVE_TERMS))) == 351