from __future__ import annotations

from dataclasses import dataclass, field
from typing import List

import pytest
from geoalchemy2.shape import from_shape
from shapely.geometry import Point

from backend.scripts import tracks_load


def test_parse_track_entries_returns_models() -> None:
    entries = [
        {
            "name": "Connector",
            "coordinates": [[52.5, 13.4], [52.6, 13.5]],
            "lengthMeters": 1500,
            "maxSpeedKph": 120,
            "status": "operational",
            "isBidirectional": True,
        }
    ]

    parsed = tracks_load._parse_track_entries(entries)

    assert parsed[0].name == "Connector"
    assert parsed[0].coordinates[0] == (52.5, 13.4)
    assert parsed[0].length_meters == 1500
    assert parsed[0].max_speed_kph == 120


def test_parse_track_entries_invalid_raises_value_error() -> None:
    entries = [
        {
            "coordinates": [[52.5, 13.4]],
        }
    ]

    with pytest.raises(ValueError):
        tracks_load._parse_track_entries(entries)


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

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

    def __exit__(self, exc_type, exc, traceback) -> None:
        pass

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

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


@dataclass
class DummyStation:
    id: str
    location: object


@dataclass
class DummyStationRepository:
    session: DummySession
    stations: List[DummyStation]

    def list_active(self) -> List[DummyStation]:
        return self.stations


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

    def list_all(self):
        return self.existing

    def create(self, data):  # pragma: no cover - simple delegation
        self.created.append(data)


def _point(lat: float, lon: float) -> object:
    return from_shape(Point(lon, lat), srid=4326)


def test_load_tracks_creates_entries(monkeypatch: pytest.MonkeyPatch) -> None:
    session_instance = DummySession()
    station_repo_instance = DummyStationRepository(
        session_instance,
        stations=[
            DummyStation(id="station-a", location=_point(52.5, 13.4)),
            DummyStation(id="station-b", location=_point(52.6, 13.5)),
        ],
    )
    track_repo_instance = DummyTrackRepository(session_instance)

    monkeypatch.setattr(tracks_load, "SessionLocal", lambda: session_instance)
    monkeypatch.setattr(
        tracks_load, "StationRepository", lambda session: station_repo_instance
    )
    monkeypatch.setattr(
        tracks_load, "TrackRepository", lambda session: track_repo_instance
    )

    parsed = tracks_load._parse_track_entries(
        [
            {
                "name": "Connector",
                "coordinates": [[52.5, 13.4], [52.6, 13.5]],
            }
        ]
    )

    created = tracks_load.load_tracks(parsed, commit=True)

    assert created == 1
    assert session_instance.committed is True
    assert track_repo_instance.created
    track = track_repo_instance.created[0]
    assert track.start_station_id == "station-a"
    assert track.end_station_id == "station-b"
    assert track.coordinates == [(52.5, 13.4), (52.6, 13.5)]


def test_load_tracks_skips_existing_pairs(monkeypatch: pytest.MonkeyPatch) -> None:
    session_instance = DummySession()
    station_repo_instance = DummyStationRepository(
        session_instance,
        stations=[
            DummyStation(id="station-a", location=_point(52.5, 13.4)),
            DummyStation(id="station-b", location=_point(52.6, 13.5)),
        ],
    )
    existing_track = type(
        "ExistingTrack",
        (),
        {
            "start_station_id": "station-a",
            "end_station_id": "station-b",
        },
    )
    track_repo_instance = DummyTrackRepository(
        session_instance,
        existing=[existing_track],
    )

    monkeypatch.setattr(tracks_load, "SessionLocal", lambda: session_instance)
    monkeypatch.setattr(
        tracks_load, "StationRepository", lambda session: station_repo_instance
    )
    monkeypatch.setattr(
        tracks_load, "TrackRepository", lambda session: track_repo_instance
    )

    parsed = tracks_load._parse_track_entries(
        [
            {
                "name": "Connector",
                "coordinates": [[52.5, 13.4], [52.6, 13.5]],
            }
        ]
    )

    created = tracks_load.load_tracks(parsed, commit=False)

    assert created == 0
    assert session_instance.rolled_back is True
    assert not track_repo_instance.created


def test_load_tracks_skips_when_station_too_far(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    session_instance = DummySession()
    station_repo_instance = DummyStationRepository(
        session_instance,
        stations=[
            DummyStation(id="remote-station", location=_point(53.5, 14.5)),
        ],
    )
    track_repo_instance = DummyTrackRepository(session_instance)

    monkeypatch.setattr(tracks_load, "SessionLocal", lambda: session_instance)
    monkeypatch.setattr(
        tracks_load, "StationRepository", lambda session: station_repo_instance
    )
    monkeypatch.setattr(
        tracks_load, "TrackRepository", lambda session: track_repo_instance
    )

    parsed = tracks_load._parse_track_entries(
        [
            {
                "name": "Isolated Segment",
                "coordinates": [[52.5, 13.4], [52.51, 13.41]],
            }
        ]
    )

    created = tracks_load.load_tracks(parsed, commit=True)

    assert created == 0
    assert session_instance.committed is True
    assert not track_repo_instance.created