from pathlib import Path

import pytest

from ingestion.extract import OutlinedTextRun
from ingestion.tables import TableRegion
from ingestion.validation import (
    FRACTION_BAR_CANDIDATE,
    HEADER_RULE,
    RULE_FRAGMENT,
    TABLE_FRAME,
    TEXT_AS_VECTOR_OUTLINE,
    UNCLASSIFIED,
    PageContext,
    ResidualRegion,
    classify,
    scan_page,
)
from ingestion.validation.residual_ink import FRACTION_BAR_CANDIDATE as BAR

PDF_PATH = Path(__file__).resolve().parents[1] / "data" / "raw" / (
    "duoc-thu-quoc-gia-viet-nam-2018.pdf"
)
needs_pdf = pytest.mark.skipif(not PDF_PATH.exists(), reason="source PDF not present")


def _region(x0, y0, x1, y1, page=100, ink=500):
    return ResidualRegion(physical_page=page, bbox=(x0, y0, x1, y1), ink_px=ink)


def test_running_header_rule_is_named_not_left_unclassified():
    # measured on real pages: a ~516pt wide, 0pt tall rule at y≈48-52 appears
    # on essentially every page of the book
    assert classify(_region(36.0, 48.5, 552.0, 48.5)) == HEADER_RULE


def test_a_thin_bar_below_the_header_band_is_a_fraction_bar_candidate():
    # NETILMICIN, physical page 1042: the Cockcroft-Gault fraction bar
    assert classify(_region(97.9, 492.0, 286.5, 492.0)) == FRACTION_BAR_CANDIDATE


def test_ink_inside_a_known_table_region_is_a_table_frame_not_a_formula():
    table = TableRegion(
        table_id="p202_t0", physical_page=202, bbox=(299.0, 189.6, 552.4, 300.5),
        n_rows=4, n_cols=3, shape="simple_table",
    )
    region = _region(299.0, 189.6, 552.4, 300.5, page=202)
    assert classify(region, PageContext(tables=[table])) == TABLE_FRAME
    # ...and the same geometry with no table map degrades to "look at it",
    # never to a silent pass
    assert classify(region) == UNCLASSIFIED


def test_a_wide_rule_outside_the_header_band_is_not_treated_as_a_header_rule():
    assert classify(_region(36.0, 700.0, 552.0, 700.0)) == FRACTION_BAR_CANDIDATE


def test_a_tall_block_of_unaccounted_ink_stays_unclassified():
    # a figure or an image of text must never be silently absorbed by a rule
    assert classify(_region(100.0, 300.0, 400.0, 500.0)) == UNCLASSIFIED


def test_hairline_shorter_than_the_minimum_bar_width_is_a_rule_fragment():
    # too short to be a fraction bar, too thin to be anything but a rule
    assert classify(_region(100.0, 300.0, 105.0, 300.0)) == RULE_FRAGMENT


@needs_pdf
@pytest.mark.parametrize(
    "page,expected_bar_width_pt",
    [
        (1042, 188.6),  # NETILMICIN — Cockcroft-Gault
        (202, 118.1),   # AMPICILIN VÀ SULBACTAM — Cockcroft-Gault
    ],
)
def test_confirmed_2d_formula_bars_survive_the_span_mask(page, expected_bar_width_pt):
    """Regression fixture for the two visually confirmed corrupted formulas.

    Both pages are reported as having zero tables by `pdfplumber` and zero by
    `opendataloader-pdf`; the bar is only findable as ink. If the mask padding
    is ever loosened again the bar disappears (at 1.0pt page 1042's bar
    shrinks from 188.6pt to 9.1pt) — this test is what catches that.
    """
    import fitz

    doc = fitz.open(PDF_PATH)
    bars = [
        r for r in scan_page(doc[page])
        if classify(r) == BAR and r.bbox[1] > 60.0
    ]
    assert bars, f"no fraction-bar candidate found on physical page {page}"
    assert max(b.width_pt for b in bars) == pytest.approx(expected_bar_width_pt, abs=1.0)


def test_vector_outlined_text_is_named_rather_than_left_unclassified():
    # physical page 714 prints 17 lines of Gatifloxacin prose as filled paths;
    # no text extractor returns them, so the gate must name the defect
    line = OutlinedTextRun(
        physical_page=714, bbox=(35.3, 75.8, 286.7, 84.4), path_items=1638,
    )
    region = _region(35.5, 76.0, 120.0, 84.0, page=714)
    context = PageContext(outlined_runs=[line])
    assert classify(region, context) == TEXT_AS_VECTOR_OUTLINE
    # an untranscribed line must never be mistaken for recovered content
    assert not line.is_transcribed


@needs_pdf
def test_outlined_text_lines_are_found_on_exactly_the_five_known_pages():
    """Whole-document regression: 51 outlined runs on 5 pages.

    Cross-checked two ways at the time of writing — the drawing-shape scan
    below, and independently by counting glyph-shaped leftovers in the
    residual-ink mask, which found the same five pages.
    """
    import fitz

    from ingestion.extract import detect_outlined_text

    lines = list(detect_outlined_text(fitz.open(PDF_PATH)))
    by_page = {}
    for line in lines:
        by_page[line.physical_page] = by_page.get(line.physical_page, 0) + 1
    assert by_page == {714: 31, 736: 16, 1373: 1, 1444: 1, 1445: 2}