feat: Enhance track model and import functionality

- Added new fields to TrackModel: status, is_bidirectional, and coordinates.
- Updated network service to handle new track attributes and geometry extraction.
- Introduced CLI scripts for importing and loading tracks from OpenStreetMap.
- Implemented normalization of track elements to ensure valid geometries.
- Enhanced tests for track model, network service, and import/load scripts.
- Updated frontend to accommodate new track attributes and improve route computation.
- Documented OSM ingestion process in architecture and runtime views.

backend/app/core/osm_config.py

@@ -75,6 +75,18 @@ STATION_TAG_FILTERS: Mapping[str, Tuple[str, ...]] = {
 }
 
 
+# Tags that describe rail infrastructure usable for train routing.
+TRACK_TAG_FILTERS: Mapping[str, Tuple[str, ...]] = {
+    "railway": (
+        "rail",
+        "light_rail",
+        "subway",
+        "tram",
+        "narrow_gauge",
+    ),
+}
+
+
 def compile_overpass_filters(filters: Mapping[str, Iterable[str]]) -> str:
     """Build an Overpass boolean expression that matches the provided filters."""
 
@@ -89,5 +101,6 @@ __all__ = [
     "BoundingBox",
     "DEFAULT_REGIONS",
     "STATION_TAG_FILTERS",
+    "TRACK_TAG_FILTERS",
     "compile_overpass_filters",
 ]

backend/app/models/base.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 from datetime import datetime
 from typing import Generic, Sequence, TypeVar
 
-from pydantic import BaseModel, ConfigDict
+from pydantic import BaseModel, ConfigDict, Field
 
 
 def to_camel(string: str) -> str:
@@ -53,6 +53,9 @@ class TrackModel(IdentifiedModel[str]):
     end_station_id: str
     length_meters: float
     max_speed_kph: float
+    status: str | None = None
+    is_bidirectional: bool = True
+    coordinates: list[tuple[float, float]] = Field(default_factory=list)
 
 
 class TrainModel(IdentifiedModel[str]):

backend/app/services/network.py

@@ -8,9 +8,10 @@ from geoalchemy2.elements import WKBElement, WKTElement
 from geoalchemy2.shape import to_shape
 
 try:  # pragma: no cover - optional dependency guard
-    from shapely.geometry import Point  # type: ignore
+    from shapely.geometry import LineString, Point  # type: ignore
 except ImportError:  # pragma: no cover - allow running without shapely at import time
     Point = None  # type: ignore[assignment]
+    LineString = None  # type: ignore[assignment]
 
 from sqlalchemy.exc import SQLAlchemyError
 from sqlalchemy.orm import Session
@@ -51,6 +52,12 @@ def _fallback_snapshot() -> dict[str, list[dict[str, object]]]:
             end_station_id="station-2",
             length_meters=289000.0,
             max_speed_kph=230.0,
+            status="operational",
+            is_bidirectional=True,
+            coordinates=[
+                (stations[0].latitude, stations[0].longitude),
+                (stations[1].latitude, stations[1].longitude),
+            ],
             created_at=now,
             updated_at=now,
         )
@@ -134,6 +141,20 @@ def get_network_snapshot(session: Session) -> dict[str, list[dict[str, object]]]
 
     track_models: list[TrackModel] = []
     for track in tracks_entities:
+        coordinates: list[tuple[float, float]] = []
+        geometry = track.track_geometry
+        shape = (
+            to_shape(cast(WKBElement | WKTElement, geometry))
+            if geometry is not None and LineString is not None
+            else None
+        )
+        if LineString is not None and shape is not None and isinstance(shape, LineString):
+            coords_list: list[tuple[float, float]] = []
+            for coord in shape.coords:
+                lon = float(coord[0])
+                lat = float(coord[1])
+                coords_list.append((lat, lon))
+            coordinates = coords_list
         track_models.append(
             TrackModel(
                 id=str(track.id),
@@ -141,6 +162,9 @@ def get_network_snapshot(session: Session) -> dict[str, list[dict[str, object]]]
                 end_station_id=str(track.end_station_id),
                 length_meters=_to_float(track.length_meters),
                 max_speed_kph=_to_float(track.max_speed_kph),
+                status=track.status,
+                is_bidirectional=track.is_bidirectional,
+                coordinates=coordinates,
                 created_at=cast(datetime, track.created_at),
                 updated_at=cast(datetime, track.updated_at),
             )

backend/scripts/tracks_import.py

@@ -0,0 +1,234 @@
+from __future__ import annotations
+
+"""CLI utility to export rail track geometries from OpenStreetMap."""
+
+import argparse
+import json
+import math
+import sys
+from dataclasses import asdict
+from pathlib import Path
+from typing import Any, Iterable
+from urllib.parse import quote_plus
+
+from backend.app.core.osm_config import (
+    DEFAULT_REGIONS,
+    TRACK_TAG_FILTERS,
+    compile_overpass_filters,
+)
+
+OVERPASS_ENDPOINT = "https://overpass-api.de/api/interpreter"
+
+
+def build_argument_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(
+        description="Export OSM rail track ways for ingestion",
+    )
+    parser.add_argument(
+        "--output",
+        type=Path,
+        default=Path("data/osm_tracks.json"),
+        help=(
+            "Destination file for the exported track geometries "
+            "(default: data/osm_tracks.json)"
+        ),
+    )
+    parser.add_argument(
+        "--region",
+        choices=[region.name for region in DEFAULT_REGIONS] + ["all"],
+        default="all",
+        help="Region name to export (default: all)",
+    )
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Do not fetch data; print the Overpass payload only",
+    )
+    return parser
+
+
+def build_overpass_query(region_name: str) -> str:
+    if region_name == "all":
+        regions = DEFAULT_REGIONS
+    else:
+        regions = tuple(
+            region for region in DEFAULT_REGIONS if region.name == region_name)
+        if not regions:
+            available = ", ".join(region.name for region in DEFAULT_REGIONS)
+            msg = f"Unknown region {region_name}. Available regions: [{available}]"
+            raise ValueError(msg)
+
+    filters = compile_overpass_filters(TRACK_TAG_FILTERS)
+
+    parts = ["[out:json][timeout:120];", "("]
+    for region in regions:
+        parts.append(f"  way{filters}\n    ({region.to_overpass_arg()});")
+    parts.append(")")
+    parts.append("; out body geom; >; out skel qt;")
+    return "\n".join(parts)
+
+
+def perform_request(query: str) -> dict[str, Any]:
+    import urllib.request
+
+    payload = f"data={quote_plus(query)}".encode("utf-8")
+    request = urllib.request.Request(
+        OVERPASS_ENDPOINT,
+        data=payload,
+        headers={"Content-Type": "application/x-www-form-urlencoded"},
+    )
+    with urllib.request.urlopen(request, timeout=180) as response:
+        payload = response.read()
+    return json.loads(payload)
+
+
+def normalize_track_elements(elements: Iterable[dict[str, Any]]) -> list[dict[str, Any]]:
+    """Convert Overpass way elements into TrackCreate-compatible payloads."""
+
+    tracks: list[dict[str, Any]] = []
+    for element in elements:
+        if element.get("type") != "way":
+            continue
+
+        raw_geometry = element.get("geometry") or []
+        coordinates: list[list[float]] = []
+        for node in raw_geometry:
+            lat = node.get("lat")
+            lon = node.get("lon")
+            if lat is None or lon is None:
+                coordinates = []
+                break
+            coordinates.append([float(lat), float(lon)])
+
+        if len(coordinates) < 2:
+            continue
+
+        tags: dict[str, Any] = element.get("tags", {})
+        name = tags.get("name")
+        maxspeed = _parse_maxspeed(tags.get("maxspeed"))
+        status = _derive_status(tags.get("railway"))
+        is_bidirectional = not _is_oneway(tags.get("oneway"))
+
+        length_meters = _polyline_length(coordinates)
+
+        tracks.append(
+            {
+                "osmId": str(element.get("id")),
+                "name": str(name) if name else None,
+                "lengthMeters": length_meters,
+                "maxSpeedKph": maxspeed,
+                "status": status,
+                "isBidirectional": is_bidirectional,
+                "coordinates": coordinates,
+            }
+        )
+
+    return tracks
+
+
+def _parse_maxspeed(value: Any) -> float | None:
+    if value is None:
+        return None
+
+    # Overpass may return values such as "80" or "80 km/h" or "signals".
+    if isinstance(value, (int, float)):
+        return float(value)
+
+    text = str(value).strip()
+    number = ""
+    for char in text:
+        if char.isdigit() or char == ".":
+            number += char
+        elif number:
+            break
+    try:
+        return float(number) if number else None
+    except ValueError:
+        return None
+
+
+def _derive_status(value: Any) -> str:
+    tag = str(value or "").lower()
+    if tag in {"abandoned", "disused"}:
+        return tag
+    if tag in {"construction", "proposed"}:
+        return "construction"
+    return "operational"
+
+
+def _is_oneway(value: Any) -> bool:
+    if value is None:
+        return False
+    normalized = str(value).strip().lower()
+    return normalized in {"yes", "true", "1"}
+
+
+def _polyline_length(points: list[list[float]]) -> float:
+    if len(points) < 2:
+        return 0.0
+
+    total = 0.0
+    for index in range(len(points) - 1):
+        total += _haversine(points[index], points[index + 1])
+    return total
+
+
+def _haversine(a: list[float], b: list[float]) -> float:
+    """Return distance in meters between two [lat, lon] coordinates."""
+
+    lat1, lon1 = a
+    lat2, lon2 = b
+    radius = 6_371_000
+
+    phi1 = math.radians(lat1)
+    phi2 = math.radians(lat2)
+    delta_phi = math.radians(lat2 - lat1)
+    delta_lambda = math.radians(lon2 - lon1)
+
+    sin_dphi = math.sin(delta_phi / 2)
+    sin_dlambda = math.sin(delta_lambda / 2)
+    root = sin_dphi**2 + math.cos(phi1) * math.cos(phi2) * sin_dlambda**2
+    distance = 2 * radius * math.atan2(math.sqrt(root), math.sqrt(1 - root))
+    return distance
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = build_argument_parser()
+    args = parser.parse_args(argv)
+
+    query = build_overpass_query(args.region)
+
+    if args.dry_run:
+        print(query)
+        return 0
+
+    output_path: Path = args.output
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+
+    data = perform_request(query)
+    raw_elements = data.get("elements", [])
+    tracks = normalize_track_elements(raw_elements)
+
+    payload = {
+        "metadata": {
+            "endpoint": OVERPASS_ENDPOINT,
+            "region": args.region,
+            "filters": TRACK_TAG_FILTERS,
+            "regions": [asdict(region) for region in DEFAULT_REGIONS],
+            "raw_count": len(raw_elements),
+            "track_count": len(tracks),
+        },
+        "tracks": tracks,
+    }
+
+    with output_path.open("w", encoding="utf-8") as handle:
+        json.dump(payload, handle, indent=2)
+
+    print(
+        f"Normalized {len(tracks)} tracks from {len(raw_elements)} elements into {output_path}"
+    )
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

backend/scripts/tracks_load.py

@@ -0,0 +1,243 @@
+from __future__ import annotations
+
+"""CLI for loading normalized track JSON into the database."""
+
+import argparse
+import json
+import math
+import sys
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any, Iterable, Mapping, Sequence
+
+from geoalchemy2.elements import WKBElement, WKTElement
+from geoalchemy2.shape import to_shape
+
+from backend.app.db.session import SessionLocal
+from backend.app.models import TrackCreate
+from backend.app.repositories import StationRepository, TrackRepository
+
+
+@dataclass(slots=True)
+class ParsedTrack:
+    coordinates: list[tuple[float, float]]
+    name: str | None = None
+    length_meters: float | None = None
+    max_speed_kph: float | None = None
+    status: str = "operational"
+    is_bidirectional: bool = True
+
+
+@dataclass(slots=True)
+class StationRef:
+    id: str
+    latitude: float
+    longitude: float
+
+
+def build_argument_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(
+        description="Load normalized track data into PostGIS",
+    )
+    parser.add_argument(
+        "input",
+        type=Path,
+        help="Path to the normalized track JSON file produced by tracks_import.py",
+    )
+    parser.add_argument(
+        "--commit/--no-commit",
+        dest="commit",
+        default=True,
+        help="Commit the transaction (default: commit). Use --no-commit for dry runs.",
+    )
+    return parser
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = build_argument_parser()
+    args = parser.parse_args(argv)
+
+    if not args.input.exists():
+        parser.error(f"Input file {args.input} does not exist")
+
+    with args.input.open("r", encoding="utf-8") as handle:
+        payload = json.load(handle)
+
+    track_entries = payload.get("tracks") or []
+    if not isinstance(track_entries, list):
+        parser.error("Invalid payload: 'tracks' must be a list")
+
+    try:
+        tracks = _parse_track_entries(track_entries)
+    except ValueError as exc:
+        parser.error(str(exc))
+
+    created = load_tracks(tracks, commit=args.commit)
+    print(f"Loaded {created} tracks from {args.input}")
+    return 0
+
+
+def _parse_track_entries(entries: Iterable[Mapping[str, Any]]) -> list[ParsedTrack]:
+    parsed: list[ParsedTrack] = []
+    for entry in entries:
+        coordinates = entry.get("coordinates")
+        if not isinstance(coordinates, Sequence) or len(coordinates) < 2:
+            raise ValueError(
+                "Invalid track entry: 'coordinates' must contain at least two points")
+
+        processed_coordinates: list[tuple[float, float]] = []
+        for pair in coordinates:
+            if not isinstance(pair, Sequence) or len(pair) != 2:
+                raise ValueError(
+                    f"Invalid coordinate pair {pair!r} in track entry")
+            lat, lon = pair
+            processed_coordinates.append((float(lat), float(lon)))
+
+        name = entry.get("name")
+        length = _safe_float(entry.get("lengthMeters"))
+        max_speed = _safe_float(entry.get("maxSpeedKph"))
+        status = entry.get("status", "operational")
+        is_bidirectional = entry.get("isBidirectional", True)
+
+        parsed.append(
+            ParsedTrack(
+                coordinates=processed_coordinates,
+                name=str(name) if name else None,
+                length_meters=length,
+                max_speed_kph=max_speed,
+                status=str(status) if status else "operational",
+                is_bidirectional=bool(is_bidirectional),
+            )
+        )
+    return parsed
+
+
+def load_tracks(tracks: Iterable[ParsedTrack], commit: bool = True) -> int:
+    created = 0
+    with SessionLocal() as session:
+        station_repo = StationRepository(session)
+        track_repo = TrackRepository(session)
+
+        station_index = _build_station_index(station_repo.list_active())
+        existing_pairs = {
+            (str(track.start_station_id), str(track.end_station_id))
+            for track in track_repo.list_all()
+        }
+
+        for track_data in tracks:
+            start_station = _nearest_station(
+                track_data.coordinates[0], station_index)
+            end_station = _nearest_station(
+                track_data.coordinates[-1], station_index)
+
+            if not start_station or not end_station:
+                continue
+
+            pair = (start_station.id, end_station.id)
+            if pair in existing_pairs:
+                continue
+
+            length = track_data.length_meters or _polyline_length(
+                track_data.coordinates)
+            create_schema = TrackCreate(
+                name=track_data.name,
+                start_station_id=start_station.id,
+                end_station_id=end_station.id,
+                coordinates=track_data.coordinates,
+                length_meters=length,
+                max_speed_kph=track_data.max_speed_kph,
+                status=track_data.status,
+                is_bidirectional=track_data.is_bidirectional,
+            )
+
+            track_repo.create(create_schema)
+            existing_pairs.add(pair)
+            created += 1
+
+        if commit:
+            session.commit()
+        else:
+            session.rollback()
+
+    return created
+
+
+def _nearest_station(
+    coordinate: tuple[float, float], stations: Sequence[StationRef]
+) -> StationRef | None:
+    best_station: StationRef | None = None
+    best_distance = math.inf
+    for station in stations:
+        distance = _haversine(
+            coordinate, (station.latitude, station.longitude))
+        if distance < best_distance:
+            best_station = station
+            best_distance = distance
+    return best_station
+
+
+def _build_station_index(stations: Iterable[Any]) -> list[StationRef]:
+    index: list[StationRef] = []
+    for station in stations:
+        location = getattr(station, "location", None)
+        if location is None:
+            continue
+        point = _to_point(location)
+        if point is None:
+            continue
+        index.append(
+            StationRef(
+                id=str(station.id),
+                latitude=float(point.y),
+                longitude=float(point.x),
+            )
+        )
+    return index
+
+
+def _to_point(geometry: WKBElement | WKTElement | Any):
+    try:
+        point = to_shape(geometry)
+        return point if getattr(point, "geom_type", None) == "Point" else None
+    except Exception:  # pragma: no cover - defensive, should not happen with valid geometry
+        return None
+
+
+def _polyline_length(points: Sequence[tuple[float, float]]) -> float:
+    if len(points) < 2:
+        return 0.0
+
+    total = 0.0
+    for index in range(len(points) - 1):
+        total += _haversine(points[index], points[index + 1])
+    return total
+
+
+def _haversine(a: tuple[float, float], b: tuple[float, float]) -> float:
+    lat1, lon1 = a
+    lat2, lon2 = b
+    radius = 6_371_000
+
+    phi1 = math.radians(lat1)
+    phi2 = math.radians(lat2)
+    delta_phi = math.radians(lat2 - lat1)
+    delta_lambda = math.radians(lon2 - lon1)
+
+    sin_dphi = math.sin(delta_phi / 2)
+    sin_dlambda = math.sin(delta_lambda / 2)
+    root = sin_dphi**2 + math.cos(phi1) * math.cos(phi2) * sin_dlambda**2
+    distance = 2 * radius * math.atan2(math.sqrt(root), math.sqrt(1 - root))
+    return distance
+
+
+def _safe_float(value: Any) -> float | None:
+    if value is None or value == "":
+        return None
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return None
+
+
+if __name__ == "__main__":
+    sys.exit(main())

backend/tests/test_models.py

@@ -29,11 +29,15 @@ def test_track_model_properties() -> None:
         end_station_id="station-2",
         length_meters=1500.0,
         max_speed_kph=120.0,
+        status="operational",
+        is_bidirectional=True,
+        coordinates=[(52.52, 13.405), (52.6, 13.5)],
         created_at=timestamp,
         updated_at=timestamp,
     )
     assert track.length_meters > 0
     assert track.start_station_id != track.end_station_id
+    assert len(track.coordinates) == 2
 
 
 def test_train_model_operating_tracks() -> None:

backend/tests/test_network_service.py

@@ -26,6 +26,9 @@ def sample_entities() -> dict[str, SimpleNamespace]:
         end_station_id=station.id,
         length_meters=1234.5,
         max_speed_kph=160,
+        status="operational",
+        is_bidirectional=True,
+        track_geometry=None,
         created_at=timestamp,
         updated_at=timestamp,
     )
@@ -47,7 +50,8 @@ def test_network_snapshot_prefers_repository_data(
     track = sample_entities["track"]
     train = sample_entities["train"]
 
-    monkeypatch.setattr(StationRepository, "list_active", lambda self: [station])
+    monkeypatch.setattr(StationRepository, "list_active",
+                        lambda self: [station])
     monkeypatch.setattr(TrackRepository, "list_all", lambda self: [track])
     monkeypatch.setattr(TrainRepository, "list_all", lambda self: [train])
 
@@ -55,7 +59,8 @@ def test_network_snapshot_prefers_repository_data(
 
     assert snapshot["stations"]
     assert snapshot["stations"][0]["name"] == station.name
-    assert snapshot["tracks"][0]["lengthMeters"] == pytest.approx(track.length_meters)
+    assert snapshot["tracks"][0]["lengthMeters"] == pytest.approx(
+        track.length_meters)
     assert snapshot["trains"][0]["designation"] == train.designation
     assert snapshot["trains"][0]["operatingTrackIds"] == []
 
@@ -71,4 +76,5 @@ def test_network_snapshot_falls_back_when_repositories_empty(
 
     assert snapshot["stations"]
     assert snapshot["trains"]
-    assert any(station["name"] == "Central" for station in snapshot["stations"])
+    assert any(station["name"] ==
+               "Central" for station in snapshot["stations"])

backend/tests/test_tracks_import.py

@@ -0,0 +1,69 @@
+from __future__ import annotations
+
+from backend.scripts import tracks_import
+
+
+def test_normalize_track_elements_excludes_invalid_geometries() -> None:
+    elements = [
+        {
+            "type": "way",
+            "id": 123,
+            "geometry": [
+                {"lat": 52.5, "lon": 13.4},
+                {"lat": 52.6, "lon": 13.5},
+            ],
+            "tags": {
+                "name": "Main Line",
+                "railway": "rail",
+                "maxspeed": "120",
+            },
+        },
+        {
+            "type": "way",
+            "id": 456,
+            "geometry": [
+                {"lat": 51.0},
+            ],
+            "tags": {"railway": "rail"},
+        },
+        {
+            "type": "node",
+            "id": 789,
+        },
+    ]
+
+    tracks = tracks_import.normalize_track_elements(elements)
+
+    assert len(tracks) == 1
+    track = tracks[0]
+    assert track["osmId"] == "123"
+    assert track["name"] == "Main Line"
+    assert track["maxSpeedKph"] == 120.0
+    assert track["status"] == "operational"
+    assert track["isBidirectional"] is True
+    assert track["coordinates"] == [[52.5, 13.4], [52.6, 13.5]]
+    assert track["lengthMeters"] > 0
+
+
+def test_normalize_track_elements_marks_oneway_and_status() -> None:
+    elements = [
+        {
+            "type": "way",
+            "id": 42,
+            "geometry": [
+                {"lat": 48.1, "lon": 11.5},
+                {"lat": 48.2, "lon": 11.6},
+            ],
+            "tags": {
+                "railway": "disused",
+                "oneway": "yes",
+            },
+        }
+    ]
+
+    tracks = tracks_import.normalize_track_elements(elements)
+
+    assert len(tracks) == 1
+    track = tracks[0]
+    assert track["status"] == "disused"
+    assert track["isBidirectional"] is False

backend/tests/test_tracks_load.py

@@ -0,0 +1,168 @@
+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