from __future__ import annotations

from dataclasses import dataclass, field

import pytest

from backend.scripts import stations_load


def test_parse_station_entries_returns_models() -> None:
    entries = [
        {
            "name": "Central",
            "latitude": 52.52,
            "longitude": 13.405,
            "osm_id": "123",
            "code": "BER",
            "elevation_m": 34.5,
            "is_active": True,
        }
    ]

    parsed = stations_load._parse_station_entries(entries)

    assert parsed[0].name == "Central"
    assert parsed[0].latitude == 52.52
    assert parsed[0].osm_id == "123"


def test_parse_station_entries_invalid_raises_value_error() -> None:
    entries = [
        {
            "latitude": 52.52,
            "longitude": 13.405,
            "is_active": True,
        }
    ]

    with pytest.raises(ValueError):
        stations_load._parse_station_entries(entries)


@dataclass
class DummySession:
    committed: bool = False
    rolled_back: bool = False
    closed: bool = False

    def __enter__(self) -> "DummySession":
        return self

    def __exit__(self, exc_type, exc, traceback) -> None:
        self.closed = True

    def commit(self) -> None:
        self.committed = True

    def rollback(self) -> None:
        self.rolled_back = True


@dataclass
class DummyRepository:
    session: DummySession
    created: list = field(default_factory=list)

    def create(self, data) -> None:  # pragma: no cover - simple delegation
        self.created.append(data)


class DummySessionFactory:
    def __call__(self) -> DummySession:
        return DummySession()


def test_load_stations_commits_when_requested(monkeypatch: pytest.MonkeyPatch) -> None:
    repo_instances: list[DummyRepository] = []

    def fake_session_local() -> DummySession:
        return DummySession()

    def fake_repo(session: DummySession) -> DummyRepository:
        repo = DummyRepository(session)
        repo_instances.append(repo)
        return repo

    monkeypatch.setattr(stations_load, "SessionLocal", fake_session_local)
    monkeypatch.setattr(stations_load, "StationRepository", fake_repo)

    stations = stations_load._parse_station_entries(
        [
            {
                "name": "Central",
                "latitude": 52.52,
                "longitude": 13.405,
                "osm_id": "123",
                "is_active": True,
            }
        ]
    )

    created = stations_load.load_stations(stations, commit=True)

    assert created == 1
    assert repo_instances[0].session.committed is True
    assert repo_instances[0].session.rolled_back is False
    assert len(repo_instances[0].created) == 1


def test_load_stations_rolls_back_when_no_commit(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    repo_instances: list[DummyRepository] = []

    def fake_session_local() -> DummySession:
        return DummySession()

    def fake_repo(session: DummySession) -> DummyRepository:
        repo = DummyRepository(session)
        repo_instances.append(repo)
        return repo

    monkeypatch.setattr(stations_load, "SessionLocal", fake_session_local)
    monkeypatch.setattr(stations_load, "StationRepository", fake_repo)

    stations = stations_load._parse_station_entries(
        [
            {
                "name": "Central",
                "latitude": 52.52,
                "longitude": 13.405,
                "osm_id": "123",
                "is_active": True,
            }
        ]
    )

    created = stations_load.load_stations(stations, commit=False)

    assert created == 1
    assert repo_instances[0].session.committed is False
    assert repo_instances[0].session.rolled_back is True