from datetime import datetime, timezone

import pytest
from sqlalchemy import create_engine
from sqlalchemy.orm import Session


CEST_HTML = b"""
<html><body>
  <table><tr><td>Ignored</td></tr></table>
  <h2>ANEXO II</h2>
  <table>
    <tr><th>ITEM</th><th>CEST</th><th>NCM/SH</th><th>DESCRICAO</th></tr>
    <tr><td>1.0</td><td>01.001.00</td><td>0804.30.00</td><td>Abacaxis</td></tr>
    <tr><td>2.0</td><td>01.002.00</td><td>0804.30.00<br>0207.14.00</td><td>Frutas e aves</td></tr>
  </table>
  <h2>ANEXO XXVII</h2>
  <table><tr><th>CEST</th><th>NCM</th></tr><tr><td>99.999.99</td><td>9999.99.99</td></tr></table>
</body></html>
"""


def test_cest_parser_accepts_only_covered_annex_tables_and_hashes_raw_html():
    from central.app.datasets.cest import parse_cest_html

    parsed = parse_cest_html(CEST_HTML)

    assert parsed.version == "CV142_18"
    assert parsed.sha256
    assert parsed.entries[0].annex == "II"
    assert parsed.entries[1].ncm_codes == ("08043000", "02071400")
    assert len(parsed.entries) == 2


def test_cest_parser_fails_closed_when_an_annex_table_has_no_required_columns():
    from central.app.datasets.cest import parse_cest_html

    with pytest.raises(ValueError, match="required columns"):
        parse_cest_html(b"<h2>ANEXO II</h2><table><tr><th>CEST</th></tr><tr><td>01.001.00</td></tr></table>")


def test_cest_parser_accepts_official_four_digit_ncm_headings():
    from central.app.datasets.cest import parse_cest_html

    parsed = parse_cest_html(b"<h2>ANEXO III</h2><table><tr><th>CEST</th><th>NCM/SH</th></tr><tr><td>02.001.00</td><td>2205</td></tr></table>")

    assert parsed.entries[0].ncm_codes == ("2205",)


def test_cest_parser_ignores_official_editorial_rows_without_cest_data():
    from central.app.datasets.cest import parse_cest_html

    parsed = parse_cest_html(b"<h2>ANEXO II</h2><table><tr><th>CEST</th><th>NCM/SH</th></tr><tr><td>Nova redacao dada ao item.</td></tr><tr><td>01.001.00</td><td>3815.12.10</td></tr></table>")

    assert [entry.code for entry in parsed.entries] == ["01.001.00"]


def test_cest_parser_preserves_chapter_ncm_prefixes_and_empty_official_ncm_cells():
    from central.app.datasets.cest import parse_cest_html

    parsed = parse_cest_html(b"<h2>ANEXO XXVI</h2><table><tr><th>CEST</th><th>NCM/SH</th></tr><tr><td>28.055.00</td><td>Capitulo 33</td></tr><tr><td>28.056.00</td><td></td></tr></table>")

    assert parsed.entries[0].ncm_codes == ("33",)
    assert parsed.entries[1].ncm_codes == ()


def test_classifier_distinguishes_exact_legacy_and_invalid_ncm_and_uses_cest_matches():
    from central.app.classification import Classifier

    class Repository:
        def active_entries(self):
            return [type("Entry", (), {"code": "08043000", "description": "Abacaxis"})()]

        def cest_for_ncm(self, code):
            return [type("Cest", (), {"code": "01.001.00", "description": "Abacaxis"})()] if code == "08043000" else []

        def legacy_ncm(self, code):
            return {"code": code, "source": "Siscomex", "source_date": "2026-09-17", "reason": "NCM not present in current official nomenclature; no official successor."} if code == "02071400" else None

        def dataset_versions(self):
            return {"ncm": "ncm-version", "cest": "cest-version"}

    classifier = Classifier(Repository())

    exact = classifier.classify({"current_ncm": "0804.30.00", "description": "abacaxi"})
    legacy = classifier.classify({"current_ncm": "0207.14.00"})
    invalid = classifier.classify({"current_ncm": "0000.00.00"})

    assert exact["status"] == "EXACT_NCM"
    assert exact["classification"]["cest"] == ["01.001.00"]
    assert legacy["status"] == "LEGACY_NCM"
    assert legacy["classification"]["ncm"] == "02071400"
    assert legacy["legacy_ncm"]["reason"].endswith("no official successor.")
    assert invalid["status"] == "INVALID_NCM"


def test_classifier_reports_confirmed_cest_only_for_one_distinct_official_candidate():
    from central.app.classification import Classifier

    class Repository:
        def active_entries(self):
            return [type("Entry", (), {"code": "08043000", "description": "Abacaxi"})()]
        def cest_for_ncm(self, code):
            return [type("Cest", (), {"code": "01.001.00", "description": "Abacaxi"})()]
        def legacy_ncm(self, code): return None
        def dataset_versions(self): return {"ncm": "n", "cest": "c"}

    result = Classifier(Repository()).classify({"current_ncm": "08043000", "description": "Abacaxi"})
    assert result["cest_status"] == "CEST_CONFIRMED"


def test_classifier_reports_candidates_for_multiple_distinct_cest_codes():
    from central.app.classification import Classifier

    class Repository:
        def active_entries(self):
            return [type("Entry", (), {"code": "08043000", "description": "Abacaxi"})()]
        def cest_for_ncm(self, code):
            return [type("Cest", (), {"code": "01.001.00", "description": "Abacaxi"})(), type("Cest", (), {"code": "01.002.00", "description": "Frutas"})()]
        def legacy_ncm(self, code): return None
        def dataset_versions(self): return {"ncm": "n", "cest": "c"}

    result = Classifier(Repository()).classify({"current_ncm": "08043000", "description": "Abacaxi"})
    assert result["cest_status"] == "CEST_CANDIDATES"
    assert result["classification"]["cest"] == ["01.001.00", "01.002.00"]


def test_cest_import_creates_many_to_many_ncm_links_and_stores_html_metadata():
    from central.app.datasets.cest import parse_cest_html
    from central.app.datasets.service import DatasetService
    from central.app.models import Base, CestEntry, CestNcmEntry, Dataset

    engine = create_engine("sqlite://")
    Base.metadata.create_all(engine)
    with Session(engine) as session:
        dataset = DatasetService(session).import_cest_payload(
            parse_cest_html(CEST_HTML), "https://www.confaz.fazenda.gov.br/legislacao/convenios/2018/CV142_18", datetime.now(timezone.utc)
        )

        assert dataset.kind == "CEST"
        assert dataset.raw_sha256 == dataset.sha256
        assert session.query(CestEntry).filter_by(dataset_id=dataset.id).count() == 2
        assert session.query(CestNcmEntry).count() == 3


def test_cest_lookup_matches_official_ncm_prefix_links():
    from central.app.datasets.cest import parse_cest_html
    from central.app.datasets.service import DatasetService
    from central.app.models import Base

    engine = create_engine("sqlite://")
    Base.metadata.create_all(engine)
    with Session(engine) as session:
        service = DatasetService(session)
        service.import_cest_payload(parse_cest_html(b"<h2>ANEXO III</h2><table><tr><th>CEST</th><th>NCM</th></tr><tr><td>02.001.00</td><td>2205</td></tr></table>"), "https://source", datetime.now(timezone.utc))

        assert [entry.code for entry in service.cest_for_ncm("22051000")] == ["02.001.00"]


def test_cest_import_unions_repeated_official_cest_codes_into_one_link_set():
    from central.app.datasets.cest import parse_cest_html
    from central.app.datasets.service import DatasetService
    from central.app.models import Base, CestEntry, CestNcmEntry

    payload = parse_cest_html(b"<h2>ANEXO II</h2><table><tr><th>CEST</th><th>NCM</th></tr><tr><td>01.042.00</td><td>8421.32.00</td></tr><tr><td>01.042.00</td><td>8421.39.20</td></tr></table>")
    engine = create_engine("sqlite://")
    Base.metadata.create_all(engine)
    with Session(engine) as session:
        dataset = DatasetService(session).import_cest_payload(payload, "https://source", datetime.now(timezone.utc))

        assert session.query(CestEntry).filter_by(dataset_id=dataset.id).count() == 1
        assert {link.ncm_code for link in session.query(CestNcmEntry).all()} == {"84213200", "84213920"}