"""Тесты read-only API для location (#948 Part B, ТЗ §8.2).

Покрывает:
1. GET /api/v1/locations → LocationList (total + rows с индексами)
2. GET /api/v1/locations/{district_name} → 200 (одна локация)
3. GET /api/v1/locations/{district_name} → 404 если нет
4. Индексы-None (нет данных) корректно сериализуются как null
5. Нет write-методов: POST/PUT/DELETE → 405 (read-only сущность)

Стратегия mock: сервисные функции (list_locations / get_location) патчим через
unittest.mock.patch; get_db переопределяем заглушкой (сервис запатчен — БД не
трогается). settings.testing=True (conftest) отключает rbac_guard.
"""

from __future__ import annotations

from datetime import UTC, datetime
from unittest.mock import MagicMock, patch

from fastapi.testclient import TestClient

from app.main import app
from app.schemas.location import LocationList, LocationOut

_TS = datetime(2026, 6, 7, 10, 0, 0, tzinfo=UTC)
_DISTRICT = "Кировский"


def _make_out(
    district_name: str = _DISTRICT,
    infra: float | None = 0.82,
    competition: float | None = 0.6,
    demand: float | None = 0.5,
    future_supply: float | None = 0.3,
    lon: float | None = 60.6,
    lat: float | None = 56.84,
) -> LocationOut:
    return LocationOut(
        id=1,
        district_name=district_name,
        region=None,
        lon=lon,
        lat=lat,
        infra_index=infra,
        competition_index=competition,
        demand_index=demand,
        future_supply_index=future_supply,
        indices_computed_at=_TS,
        created_at=_TS,
        updated_at=_TS,
    )


def _override_db():
    """Заглушка get_db — сервис запатчен, реальная сессия не нужна."""

    def _get_db_override():
        yield MagicMock()

    return _get_db_override


# ── 1. LIST ─────────────────────────────────────────────────────────────────────


def test_list_locations_returns_list_with_indices() -> None:
    from app.core.db import get_db

    expected = LocationList(
        total=2,
        rows=[_make_out("Кировский"), _make_out("Ленинский", infra=None)],
    )
    app.dependency_overrides[get_db] = _override_db()
    with patch("app.api.v1.locations.list_locations", return_value=expected) as mock_list:
        client = TestClient(app)
        resp = client.get("/api/v1/locations")
    assert resp.status_code == 200, resp.text
    body = resp.json()
    assert body["total"] == 2
    assert len(body["rows"]) == 2
    assert body["rows"][0]["district_name"] == "Кировский"
    assert body["rows"][0]["competition_index"] == 0.6
    # None-индекс сериализуется как null (нет данных, не 0).
    assert body["rows"][1]["infra_index"] is None
    mock_list.assert_called_once()


def test_list_locations_empty() -> None:
    from app.core.db import get_db

    app.dependency_overrides[get_db] = _override_db()
    with patch("app.api.v1.locations.list_locations", return_value=LocationList(total=0, rows=[])):
        client = TestClient(app)
        resp = client.get("/api/v1/locations")
    assert resp.status_code == 200, resp.text
    assert resp.json() == {"total": 0, "rows": []}


# ── 2 + 3. GET BY NAME ──────────────────────────────────────────────────────────


def test_get_location_by_name_returns_200() -> None:
    from app.core.db import get_db

    app.dependency_overrides[get_db] = _override_db()
    with patch("app.api.v1.locations.get_location", return_value=_make_out()) as mock_get:
        client = TestClient(app)
        resp = client.get(f"/api/v1/locations/{_DISTRICT}")
    assert resp.status_code == 200, resp.text
    body = resp.json()
    assert body["district_name"] == _DISTRICT
    assert body["demand_index"] == 0.5
    assert body["future_supply_index"] == 0.3
    assert body["lon"] == 60.6
    # district_name пробрасывается из path в сервис.
    assert mock_get.call_args[0][1] == _DISTRICT


def test_get_location_unknown_returns_404() -> None:
    from app.core.db import get_db

    app.dependency_overrides[get_db] = _override_db()
    with patch("app.api.v1.locations.get_location", return_value=None):
        client = TestClient(app)
        resp = client.get("/api/v1/locations/НесуществующийРайон")
    assert resp.status_code == 404, resp.text
    assert resp.json()["detail"] == "Location not found"


def test_get_location_null_indices_serialize_as_null() -> None:
    from app.core.db import get_db

    app.dependency_overrides[get_db] = _override_db()
    out = _make_out(
        infra=None, competition=None, demand=None, future_supply=None, lon=None, lat=None
    )
    with patch("app.api.v1.locations.get_location", return_value=out):
        client = TestClient(app)
        resp = client.get(f"/api/v1/locations/{_DISTRICT}")
    assert resp.status_code == 200, resp.text
    body = resp.json()
    assert body["infra_index"] is None
    assert body["competition_index"] is None
    assert body["demand_index"] is None
    assert body["future_supply_index"] is None
    assert body["lon"] is None


# ── 5. READ-ONLY: no write methods ──────────────────────────────────────────────


def test_post_location_not_allowed() -> None:
    """Локации вычисляются, не вводятся → POST не зарегистрирован (405)."""
    client = TestClient(app)
    resp = client.post("/api/v1/locations", json={"district_name": "Кировский"})
    assert resp.status_code == 405


def test_delete_location_not_allowed() -> None:
    client = TestClient(app)
    resp = client.delete(f"/api/v1/locations/{_DISTRICT}")
    assert resp.status_code == 405