import json
from pathlib import Path

from ingestion.extract.formulas import (
    BARLESS_FORMULA_BOTTOM_PT,
    FORMULA_BAND_HEIGHT_PT,
    FORMULA_SIDE_MARGIN_PT,
    load_formula_regions,
)
from ingestion.tables import QUARANTINE_SHAPES, SHAPE_FORMULA_2D

VERIFIED = (Path(__file__).resolve().parents[1] / "data" / "verified"
            / "formula_regions_2d.json")
TRANSCRIPTIONS = (Path(__file__).resolve().parents[1] / "data" / "verified"
                  / "outlined_text_transcriptions.json")


def test_a_2d_formula_is_always_quarantined():
    # linearised, "a / b" reads as "a x b" — a dosing error, not a cosmetic one
    assert SHAPE_FORMULA_2D in QUARANTINE_SHAPES


def test_verified_formula_regions_load_with_the_confirmed_pages():
    regions = load_formula_regions()
    assert {r.physical_page for r in regions} == {
        43, 92, 147, 202, 325, 349, 1042, 1043, 1132, 1402,
    }
    assert all(r.shape == SHAPE_FORMULA_2D for r in regions)


def test_the_region_covers_numerator_and_denominator_not_just_the_bar():
    payload = json.loads(VERIFIED.read_text(encoding="utf-8"))
    bar = next(r for r in payload["regions"] if r["physical_page"] == 1042)
    region = next(r for r in load_formula_regions() if r.physical_page == 1042)
    x0, y0, x1, y1 = bar["bar_bbox"]
    assert region.bbox[1] == y0 - FORMULA_BAND_HEIGHT_PT
    assert region.bbox[3] == y1 + FORMULA_BAND_HEIGHT_PT
    assert region.bbox[0] == x0 - FORMULA_SIDE_MARGIN_PT


def test_the_barless_adenosin_formula_is_recorded_as_a_recall_limit():
    """The source prints no bar, so no geometric detector can find it.

    Recorded so a later reader does not mistake the fraction-bar scan for
    complete formula coverage — how many bar-less formulas the book contains
    has never been measured.
    """
    payload = json.loads(VERIFIED.read_text(encoding="utf-8"))
    barless = [r for r in payload["regions"] if r.get("source_prints_no_bar")]
    assert [r["physical_page"] for r in barless] == [147]
    assert "UNMEASURED" in payload["recall_limit"]


def test_barless_adenosin_band_reaches_its_printed_denominator():
    payload = json.loads(VERIFIED.read_text(encoding="utf-8"))
    entry = next(r for r in payload["regions"] if r.get("source_prints_no_bar"))
    region = next(r for r in load_formula_regions() if r.physical_page == 147)
    assert region.bbox[3] == entry["bar_bbox"][3] + BARLESS_FORMULA_BOTTOM_PT
    # "Ví dụ:" begins immediately afterwards with its span centre at ~704.3;
    # the formula band must stop before that prose and the following table.
    assert region.bbox[3] < 704


def test_outlined_text_transcriptions_cover_every_detected_run():
    payload = json.loads(TRANSCRIPTIONS.read_text(encoding="utf-8"))
    runs = payload["runs"]
    assert len(runs) == 51
    assert all(r["text"] for r in runs), "a run with no transcription is data loss"
    pages = {}
    for run in runs:
        pages[run["physical_page"]] = pages.get(run["physical_page"], 0) + 1
    assert pages == {714: 31, 736: 16, 1373: 1, 1444: 1, 1445: 2}


def test_single_glyph_transcriptions_name_the_line_they_were_dropped_from():
    """The subtlest form of the defect: one character missing mid-sentence.

    "Độ ổn định" extracts as "Độ n định" and reads as ordinary text, so
    nothing downstream can notice. Keeping the owning line in the record is
    what makes the repair checkable.
    """
    payload = json.loads(TRANSCRIPTIONS.read_text(encoding="utf-8"))
    singles = [r for r in payload["runs"] if r["single_glyph"]]
    assert len(singles) == 29
    with_context = [r for r in singles if r["extracted_line_it_belongs_to"]]
    assert with_context, "no dropped glyph could be tied back to its line"