from decimal import Decimal

import pytest
from pydantic import ValidationError

from payslip_ingest.schema import ExtractedPayslip, validate_totals


def _sample_payload() -> dict[str, object]:
    return {
        "pay_date": "2026-03-28",
        "pay_period_start": "2026-03-01",
        "pay_period_end": "2026-03-31",
        "employer": "Acme Ltd",
        "currency": "GBP",
        "gross_pay": "5000.00",
        "income_tax": "800.00",
        "national_insurance": "350.00",
        "pension_employee": "250.00",
        "pension_employer": "150.00",
        "student_loan": "100.00",
        "other_deductions": {
            "cycle_to_work": "50.00"
        },
        "net_pay": "3450.00",
    }


def test_schema_accepts_realistic_payload() -> None:
    model = ExtractedPayslip.model_validate(_sample_payload())
    assert model.employer == "Acme Ltd"
    assert model.gross_pay == Decimal("5000.00")
    assert model.other_deductions == {"cycle_to_work": Decimal("50.00")}


def test_schema_rejects_extra_fields() -> None:
    payload = _sample_payload()
    payload["bonus_field"] = "not allowed"
    with pytest.raises(ValidationError):
        ExtractedPayslip.model_validate(payload)


def test_validate_totals_true_for_matched_numbers() -> None:
    model = ExtractedPayslip.model_validate(_sample_payload())
    assert validate_totals(model) is True


def test_validate_totals_false_for_mismatch() -> None:
    payload = _sample_payload()
    payload["net_pay"] = "4000.00"
    model = ExtractedPayslip.model_validate(payload)
    assert validate_totals(model) is False