"""The 2026-08-26 formula change, verified over the wire.

``test_annual_leave_calculator.py`` pins the pure function. This file
pins the part the pure function cannot reach: that ``basis_cap_applied``
survives the schema, the INSERT, the new migration-550 columns and the
history replay — i.e. the exact JSON the calculator page reads to decide
whether to render the 「已按本人年假基数封顶」 tag.

That round trip is the failure mode worth a test. A flag that is correct
in ``calculate()`` and lost in ``_record_to_response`` looks like a
working calculator that silently stops explaining itself.
"""
from __future__ import annotations

from uuid import uuid4

import pytest
import pytest_asyncio

from app.auth.models import AuthUserRole
from app.core.security import create_access_token
from app.identity.person_models import IdentityPerson

# Leap fiscal year 2027 (2027-04-01 → 2028-03-31, 366 days).
# N=17 → legal basis 10, S=12 → welfare basis 5. No N or S anniversary
# lands inside the window, so this is a single clean segment.
_LEAP_INPUTS = {
    "work_start_date": "2010-01-01",
    "hire_date": "2015-01-01",
    "termination_date": "2028-03-31",
    "carry_legal_days": "0",
    "carry_welfare_days": "0",
    "used_legal_days": "0",
    "used_welfare_days": "0",
}


def _bearer(token: str) -> dict[str, str]:
    return {"Authorization": f"Bearer {token}"}


@pytest_asyncio.fixture
async def hr_caller(db_session):
    """HR-role user — ``POST /calculate`` is ``require_hr_admin()``."""
    user_id = uuid4()
    db_session.add(
        IdentityPerson(
            id=user_id,
            work_email="hr-calc-contract@test.com",
            display_name="HR Calc Contract",
            employment_status="active",
            source_system="successfactors",
            hris_person_id="sf-hr-calc-contract",
        )
    )
    await db_session.flush()

    from sqlalchemy import text as _text

    role_id = (
        await db_session.execute(
            _text("SELECT id FROM auth_roles WHERE name = 'hr'")
        )
    ).scalar_one()
    db_session.add(AuthUserRole(user_id=user_id, role_id=role_id))
    await db_session.flush()
    await db_session.commit()
    return user_id, create_access_token(str(user_id), ["hr"])


@pytest.mark.asyncio
async def test_basis_cap_flag_reaches_the_client_and_survives_replay(
    client, hr_caller,
):
    _, token = hr_caller

    r = await client.post(
        "/api/v1/hr-tools/annual-leave/calculate",
        json=_LEAP_INPUTS,
        headers=_bearer(token),
    )
    assert r.status_code == 200, r.text
    body = r.json()
    assert body["success"] is True
    data = body["data"]

    entitlement = data["entitlement"]
    # The 365.25 denominator is visible to HR in the formula string they
    # read back to the employee, so it is part of the contract.
    assert entitlement["segments"][0]["legal_formula"] == "366/365.25×10"
    # Pre-cap and post-cap are BOTH exposed — the page shows 取整后 and
    # 封顶后最终值 side by side, and collapsing them hides the step HR
    # has to explain.
    assert entitlement["legal_rounded"] == "10.5"
    assert entitlement["legal_capped"] == "10.0"
    assert entitlement["basis_cap_applied"] is True
    # Distinct flags: 10 + 5 = 15 exactly, so the 15-day cap is NOT what
    # happened here and must not claim it was.
    assert entitlement["cap_applied"] is False
    assert data["settlement"]["basis_cap_applied"] is True

    # Replay the persisted row: the flag must come back from the
    # migration-550 columns, not be recomputed.
    record_id = data["id"]
    r2 = await client.get(
        f"/api/v1/hr-tools/annual-leave/history/{record_id}",
        headers=_bearer(token),
    )
    assert r2.status_code == 200, r2.text
    replayed = r2.json()["data"]
    assert replayed["entitlement"]["basis_cap_applied"] is True
    assert replayed["settlement"]["basis_cap_applied"] is True
    assert replayed["entitlement"]["legal_capped"] == "10.0"
    assert replayed["entitlement"]["cap_applied"] is False


@pytest.mark.asyncio
async def test_ordinary_year_reports_no_cap_at_all(client, hr_caller):
    """The cap is inert outside the leap case — the tag must not appear
    on the overwhelming majority of settlements."""
    _, token = hr_caller

    r = await client.post(
        "/api/v1/hr-tools/annual-leave/calculate",
        json={**_LEAP_INPUTS, "termination_date": "2027-03-31"},
        headers=_bearer(token),
    )
    assert r.status_code == 200, r.text
    entitlement = r.json()["data"]["entitlement"]
    assert entitlement["segments"][0]["legal_formula"] == "365/365.25×10"
    # A full non-leap year still yields the whole basis, not 9.5.
    assert entitlement["legal_capped"] == "10.0"
    assert entitlement["basis_cap_applied"] is False
    assert entitlement["cap_applied"] is False