import importlib.util
import json
import sys
from pathlib import Path

import pytest

ROOT = Path(__file__).parents[1]


def load(name, rel):
    sys.path.insert(0, str(ROOT / "agent" / "src")); sys.path.insert(0, str(ROOT / "src"))
    spec = importlib.util.spec_from_file_location(name, ROOT / rel)
    mod = importlib.util.module_from_spec(spec); sys.modules[name] = mod; spec.loader.exec_module(mod)
    return mod


snap = load("sgv_product_snapshot", "scripts/sgv_product_snapshot.py")
audit = load("audit_firebird_database", "scripts/audit_firebird_database.py")
executor = load("firebird_write_executor", "scripts/firebird_write_executor.py")


def test_diff_lists_changed_columns_and_flags_technical_ones():
    before = {"CFOP": "5102", "CSOSN": "102", "ULTIMA_ALTERACAO": "2026-01-01"}
    after = {"CFOP": "5405", "CSOSN": "102", "ULTIMA_ALTERACAO": "2026-02-02"}
    d = {c["FIELD"]: c for c in snap.compute_diff(before, after)}
    assert d["CFOP"]["BEFORE"] == "5102" and d["CFOP"]["AFTER"] == "5405" and not d["CFOP"]["technical"]
    assert d["ULTIMA_ALTERACAO"]["technical"] and "CSOSN" not in d


def test_ledger_confirms_only_single_column_changes(tmp_path, monkeypatch):
    monkeypatch.setattr(snap, "LEDGER", tmp_path / "ledger.json")
    ok = snap.record("CFOP saída", "1", [{"FIELD": "CFOP", "BEFORE": "a", "AFTER": "b", "technical": False}, {"FIELD": "ULTIMA_ALTERACAO", "BEFORE": 1, "AFTER": 2, "technical": True}])
    two = snap.record("X", "1", [{"FIELD": "A", "BEFORE": 1, "AFTER": 2, "technical": False}, {"FIELD": "B", "BEFORE": 1, "AFTER": 2, "technical": False}])
    none = snap.record("Y", "1", [])
    assert ok["confirmed"] and not two["confirmed"] and not none["confirmed"]
    assert len(json.loads((tmp_path / "ledger.json").read_text(encoding="utf-8"))) == 3


def test_company_context_is_read_generically_and_fails_closed():
    from gti_fiscal_agent.firebird_reader import parse_company_context
    assert parse_company_context([("sp", "3")]) == {"uf": "SP", "crt": "3"}
    for bad in ([], [("BA", "1"), ("SP", "1")], [("", "1")], [("BA", "9")]):
        with pytest.raises(ValueError):
            parse_company_context(bad)


def test_audit_helpers():
    assert audit.ncm_bucket("22030000") == "eight_digits" and audit.ncm_bucket(" ") == "blank" and audit.ncm_bucket("2203.00") == "other_format"
    c = audit.compat({"CFOP": 37, "IPI": 27, "CST": 8})
    assert c["CFOP"] == "OK" and c["IPI"] == "OK" and c["CST"].startswith("TYPE_DIFFERS") and c["CSOSN"] == "MISSING"


@pytest.mark.parametrize("table", ["NFCE", "NFCE_ITENS", "C000032", "C000061", "C000062", "C000088", "INVENTARIO"])
def test_transactional_tables_are_never_writable(table):
    with pytest.raises(executor.WriteRefused):
        executor.assert_allowed_field(table, "CFOP")


def test_ui_map_write_targets_have_evidence_and_transactional_writes_forbidden():
    p = ROOT / "docs" / "SGV_PRODUCT_FISCAL_UI_MAP_V1.json"
    if not p.exists():
        pytest.skip("map not generated")
    d = json.loads(p.read_text(encoding="utf-8"))
    assert d["transactional_table_writes_allowed"] is False
    for f in d["fields"]:
        assert f["table"] == "C000025"
        if f["write_target"]:
            assert f["confirmed_by_ui_diff"] or f["evidence_basis"]
            assert f["field"]
        if f.get("classification") in ("PROBABLE", "AMBIGUOUS", "NO_MATCH"):
            assert not f["write_target"]