feat: Add combined track functionality with repository and service layers

- Introduced CombinedTrackModel, CombinedTrackCreate, and CombinedTrackRepository for managing combined tracks.
- Implemented logic to create combined tracks based on existing tracks between two stations.
- Added methods to check for existing combined tracks and retrieve constituent track IDs.
- Enhanced TrackModel and TrackRepository to support OSM ID and track updates.
- Created migration scripts for adding combined tracks table and OSM ID to tracks.
- Updated services and API endpoints to handle combined track operations.
- Added tests for combined track creation, repository methods, and API interactions.

backend/app/db/models.py

@@ -41,11 +41,14 @@ class User(Base, TimestampMixin):
     id: Mapped[uuid.UUID] = mapped_column(
         UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
     )
-    username: Mapped[str] = mapped_column(String(64), unique=True, nullable=False)
-    email: Mapped[str | None] = mapped_column(String(255), unique=True, nullable=True)
+    username: Mapped[str] = mapped_column(
+        String(64), unique=True, nullable=False)
+    email: Mapped[str | None] = mapped_column(
+        String(255), unique=True, nullable=True)
     full_name: Mapped[str | None] = mapped_column(String(128), nullable=True)
     password_hash: Mapped[str] = mapped_column(String(256), nullable=False)
-    role: Mapped[str] = mapped_column(String(32), nullable=False, default="player")
+    role: Mapped[str] = mapped_column(
+        String(32), nullable=False, default="player")
     preferences: Mapped[str | None] = mapped_column(Text, nullable=True)
 
 
@@ -62,12 +65,50 @@ class Station(Base, TimestampMixin):
         Geometry(geometry_type="POINT", srid=4326), nullable=False
     )
     elevation_m: Mapped[float | None] = mapped_column(Float, nullable=True)
-    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
+    is_active: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=True)
 
 
 class Track(Base, TimestampMixin):
     __tablename__ = "tracks"
 
+    id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
+    )
+    osm_id: Mapped[str | None] = mapped_column(String(32), nullable=True)
+    name: Mapped[str | None] = mapped_column(String(128), nullable=True)
+    start_station_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("stations.id", ondelete="RESTRICT"),
+        nullable=False,
+    )
+    end_station_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("stations.id", ondelete="RESTRICT"),
+        nullable=False,
+    )
+    length_meters: Mapped[float | None] = mapped_column(
+        Numeric(10, 2), nullable=True)
+    max_speed_kph: Mapped[int | None] = mapped_column(Integer, nullable=True)
+    is_bidirectional: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=True
+    )
+    status: Mapped[str] = mapped_column(
+        String(32), nullable=False, default="planned")
+    track_geometry: Mapped[str] = mapped_column(
+        Geometry(geometry_type="LINESTRING", srid=4326), nullable=False
+    )
+
+    __table_args__ = (
+        UniqueConstraint(
+            "start_station_id", "end_station_id", name="uq_tracks_station_pair"
+        ),
+    )
+
+
+class CombinedTrack(Base, TimestampMixin):
+    __tablename__ = "combined_tracks"
+
     id: Mapped[uuid.UUID] = mapped_column(
         UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
     )
@@ -82,19 +123,25 @@ class Track(Base, TimestampMixin):
         ForeignKey("stations.id", ondelete="RESTRICT"),
         nullable=False,
     )
-    length_meters: Mapped[float | None] = mapped_column(Numeric(10, 2), nullable=True)
+    length_meters: Mapped[float | None] = mapped_column(
+        Numeric(10, 2), nullable=True)
     max_speed_kph: Mapped[int | None] = mapped_column(Integer, nullable=True)
     is_bidirectional: Mapped[bool] = mapped_column(
         Boolean, nullable=False, default=True
     )
-    status: Mapped[str] = mapped_column(String(32), nullable=False, default="planned")
-    track_geometry: Mapped[str] = mapped_column(
+    status: Mapped[str] = mapped_column(
+        String(32), nullable=False, default="planned")
+    combined_geometry: Mapped[str] = mapped_column(
         Geometry(geometry_type="LINESTRING", srid=4326), nullable=False
     )
+    # JSON array of constituent track IDs
+    constituent_track_ids: Mapped[str] = mapped_column(
+        Text, nullable=False
+    )
 
     __table_args__ = (
         UniqueConstraint(
-            "start_station_id", "end_station_id", name="uq_tracks_station_pair"
+            "start_station_id", "end_station_id", name="uq_combined_tracks_station_pair"
         ),
     )
 
@@ -105,7 +152,8 @@ class Train(Base, TimestampMixin):
     id: Mapped[uuid.UUID] = mapped_column(
         UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
     )
-    designation: Mapped[str] = mapped_column(String(64), nullable=False, unique=True)
+    designation: Mapped[str] = mapped_column(
+        String(64), nullable=False, unique=True)
     operator_id: Mapped[uuid.UUID | None] = mapped_column(
         UUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL")
     )