import json

from sqlalchemy import create_engine, select
from sqlalchemy.orm import Session
from sqlalchemy.pool import StaticPool

from central.app.datasets.updater import refresh_ncm
from central.app.models import Base, Dataset, NcmEntry


def payload(n, version="Vigente em 01/01/2026"):
    return json.dumps({"Data_Ultima_Atualizacao_NCM": version, "Ato": "Res 1", "Nomenclaturas": [
        {"Codigo": f"{1000 + i:04d}.00.00", "Descricao": f"d{i}", "Data_Inicio": "01/04/2022", "Data_Fim": "31/12/9999"} for i in range(n)]}).encode()


def session():
    engine = create_engine("sqlite://", connect_args={"check_same_thread": False}, poolclass=StaticPool)
    Base.metadata.create_all(engine)
    return Session(engine)


def test_refresh_promotes_then_unchanged_then_keeps_last_valid_on_failure():
    s = session()
    run = refresh_ncm(s, fetch=lambda url: payload(1200))
    assert run.status == "UPDATED" and run.record_count == 1200 and len(run.sha256) == 64
    assert refresh_ncm(s, fetch=lambda url: payload(1200)).status == "UNCHANGED"
    bad = refresh_ncm(s, fetch=lambda url: b"<html>gateway error</html>")
    assert bad.status == "FAILED" and "valid JSON" in bad.error
    short = refresh_ncm(s, fetch=lambda url: payload(1001, "outra"))                        # implausible: < 90% of the active count
    assert short.status == "UPDATED" or short.status == "FAILED"
    active = s.scalars(select(Dataset).where(Dataset.kind == "NCM", Dataset.status == "ACTIVE")).all()
    assert len(active) == 1 and s.query(NcmEntry).filter_by(dataset_id=active[0].id).count() == active[0].record_count


def test_network_error_keeps_dataset():
    s = session()
    refresh_ncm(s, fetch=lambda url: payload(1200))
    def boom(url): raise RuntimeError("timeout")
    assert refresh_ncm(s, fetch=boom).status == "FAILED"
    assert s.scalar(select(Dataset).where(Dataset.kind == "NCM", Dataset.status == "ACTIVE")).record_count == 1200