"""Regression sweep over all invoice fixtures.

Every fixture PDF is extracted and validated end-to-end on every test run.
Known limitations of extractor and validator are catalogued explicitly in
KNOWN_GAPS and VALIDATION_EXCLUDED below. The sweep fails when:

- any fixture stops extracting (exception),
- a fixture that used to be clean produces new critical errors,
- a fixture with known gaps produces more/different errors than catalogued,
- a gap was fixed but its catalogue entry was not removed.

So: fix a gap, then remove its entry — the sweep enforces honest bookkeeping.
"""

from pathlib import Path

import pytest

from src.extractor import extract_zugferd
from src.models import ValidateRequest
from src.validator import validate_invoice

FIXTURES = Path(__file__).parent / "fixtures"
ALL_CHECKS = ["pflichtfelder", "betraege", "ustid", "pdf_abgleich"]

EXPECTED_NON_ZUGFERD = {"EmptyPDFA1.pdf"}

VALIDATION_EXCLUDED = {
    "ORDER-X_EX01_ORDER_FULL_DATA-COMFORT.pdf": (
        "ORDER-X order document, not an invoice"
    ),
    "zugferd_invoice.pdf": (
        "ZUGFeRD 1.0 uses a different XML namespace (not supported)"
    ),
}

KNOWN_GAPS: dict[str, set[str]] = {
    "EN16931_1_Teilrechnung.pdf": {
        "line_items[3].line_total",
        "totals.net",
    },
    "MustangBeispiel20221026.pdf": {
        "totals.net",
    },
    "validAvoir_FR_type380_BASICWL.pdf": {
        "line_items",
        "totals.net",
        "vat_id",
    },
    "zugferd_2p1_EXTENDED_PDFA-3A.pdf": {
        "totals.net",
    },
}


def _pdf_files() -> list[str]:
    return sorted(path.name for path in FIXTURES.glob("*.pdf"))


@pytest.mark.parametrize("filename", _pdf_files())
def test_fixture_sweep(filename: str) -> None:
    """Extract and validate one fixture; deviations from the catalogue fail."""
    pdf_bytes = (FIXTURES / filename).read_bytes()
    result = extract_zugferd(pdf_bytes)

    if filename in EXPECTED_NON_ZUGFERD:
        assert result.is_zugferd is False
        return

    assert result.is_zugferd is True, f"{filename}: expected ZUGFeRD XML"
    assert result.xml_data is not None

    if filename in VALIDATION_EXCLUDED:
        return

    request = ValidateRequest(
        xml_data=result.xml_data.model_dump(),
        pdf_text=result.pdf_text,
        checks=ALL_CHECKS,
    )
    validation = validate_invoice(request)
    critical_fields = {error.field for error in validation.errors}
    expected_fields = KNOWN_GAPS.get(filename, set())

    assert critical_fields == expected_fields, (
        f"{filename}: critical fields changed — update KNOWN_GAPS "
        f"(new state: {sorted(critical_fields)})"
    )