Refactor bus/coach loading and rendering to share code.

Extract `load_road_transport()` as a shared helper for bus and coach,
combining the near-identical route rendering blocks in `get_trip_routes`
and `Trip.elements()` into single `in ("coach", "bus")` branches.
Document transport type patterns in AGENTS.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AGENTS.md

@@ -37,3 +37,20 @@ This is a personal agenda web application built with Flask that tracks various e
   - `travel_legs()` extracts airlines, airports, and stations from individual trip travel legs
   - `calculate_yearly_stats()` aggregates stats per year including flight/train counts, airlines, airports, stations
   - `calculate_overall_stats()` aggregates yearly stats into overall totals for the summary section
+
+## Travel type patterns
+Transport types: `flight`, `train`, `ferry`, `coach`, `bus`.
+
+**Road transport (bus and coach)** share a common loader `load_road_transport()` in `trip.py`. `load_coaches` and `load_buses` are thin wrappers that pass type name, YAML filenames, and CO2 factor (coach: 0.027 kg/km, bus: 0.1 kg/km). Both use `from_station`/`to_station` fields and support scalar or dict-keyed GeoJSON route filenames in the stop/station data.
+
+**Ferry** is loaded separately: uses `from_terminal`/`to_terminal` fields and GeoJSON routes come from the terminal's `routes` dict (always a dict, not scalar).
+
+**Route rendering** (`get_trip_routes`): bus and coach are handled in a single combined block (they use the same pattern — `from_station`/`to_station`, `{type}_routes/` folder). Ferry always has a geojson file and renders as type `"train"` for the map renderer.
+
+**Trip elements** (`Trip.elements()` in `types.py`): bus and coach are handled in a single combined block using `item["type"] in ("coach", "bus")`. Ferry is separate because it uses `from_terminal`/`to_terminal` and always requires `arrive` (not optional).
+
+**Location collection** (`get_locations`): bus → `bus_stop`, coach → `coach_station`, ferry → `ferry_terminal` (all separate map pin types).
+
+**CO2 factors** (kg CO2e per passenger per km): train 0.037, coach 0.027, ferry 0.02254, bus 0.1.
+
+**Schengen tracking**: ferry journeys are tracked for Schengen compliance; bus and coach are not.

agenda/trip.py

@@ -92,62 +92,32 @@ def load_ferries(
     return ferries
 
 
-def load_coaches(
+def load_road_transport(
-    data_dir: str, route_distances: travel.RouteDistances | None = None
+    travel_type: str,
+    plural: str,
+    stops_yaml: str,
+    data_dir: str,
+    co2_factor: float,
+    route_distances: travel.RouteDistances | None = None,
 ) -> list[StrDict]:
-    """Load coaches."""
+    """Load road transport (bus or coach)."""
-    coaches = load_travel("coach", "coaches", data_dir)
+    items = load_travel(travel_type, plural, data_dir)
-    stations = travel.parse_yaml("coach_stations", data_dir)
+    stops = travel.parse_yaml(stops_yaml, data_dir)
-    by_name = {station["name"]: station for station in stations}
-
-    for item in coaches:
-        add_station_objects(item, by_name)
-        # Add route distance and CO2 calculation if available
-        if route_distances:
-            travel.add_leg_route_distance(item, route_distances)
-            if "distance" in item:
-                # Calculate CO2 emissions for coach (0.027 kg CO2e per passenger per km)
-                item["co2_kg"] = item["distance"] * 0.027
-        # Include GeoJSON route if defined in stations data
-        from_station = item.get("from_station")
-        to_station = item.get("to_station")
-        if from_station and to_station:
-            # Support scalar or mapping routes: string or dict of station name -> geojson base name
-            routes_val = from_station.get("routes", {})
-            if isinstance(routes_val, str):
-                geo = routes_val
-            else:
-                geo = routes_val.get(to_station.get("name"))
-            if geo:
-                item["geojson_filename"] = geo
-
-    return coaches
-
-
-def load_buses(
-    data_dir: str, route_distances: travel.RouteDistances | None = None
-) -> list[StrDict]:
-    """Load buses."""
-    items = load_travel("bus", "buses", data_dir)
-    stops = travel.parse_yaml("bus_stops", data_dir)
     by_name = {stop["name"]: stop for stop in stops}
 
     for item in items:
         add_station_objects(item, by_name)
-        # Add route distance and CO2 calculation if available
         if route_distances:
             travel.add_leg_route_distance(item, route_distances)
             if "distance" in item:
-                # Calculate CO2 emissions for bus (0.027 kg CO2e per passenger per km)
+                item["co2_kg"] = item["distance"] * co2_factor
-                item["co2_kg"] = item["distance"] * 0.1
-        # Include GeoJSON route if defined in stations data
         from_station = item.get("from_station")
         to_station = item.get("to_station")
         if from_station and to_station:
-            # Support scalar or mapping routes: string or dict of station name -> geojson base name
+            # Support scalar or mapping routes: string or dict of stop name -> geojson filename
             routes_val = from_station.get("routes", {})
             if isinstance(routes_val, str):
-                geo = routes_val
+                geo: str | None = routes_val
             else:
                 geo = routes_val.get(to_station.get("name"))
             if geo:
@@ -156,6 +126,24 @@ def load_buses(
     return items
 
 
+def load_coaches(
+    data_dir: str, route_distances: travel.RouteDistances | None = None
+) -> list[StrDict]:
+    """Load coaches."""
+    return load_road_transport(
+        "coach", "coaches", "coach_stations", data_dir, 0.027, route_distances
+    )
+
+
+def load_buses(
+    data_dir: str, route_distances: travel.RouteDistances | None = None
+) -> list[StrDict]:
+    """Load buses."""
+    return load_road_transport(
+        "bus", "buses", "bus_stops", data_dir, 0.1, route_distances
+    )
+
+
 def process_flight(
     flight: StrDict, by_iata: dict[str, Airline], airports: list[StrDict]
 ) -> None:
@@ -434,40 +422,22 @@ def get_trip_routes(trip: Trip, data_dir: str) -> list[StrDict]:
                 }
             )
             continue
-        if t["type"] == "coach":
+        if t["type"] in ("coach", "bus"):
-            coach_from, coach_to = t["from_station"], t["to_station"]
+            route_type = t["type"]
-            key = "_".join(["coach"] + sorted([coach_from["name"], coach_to["name"]]))
+            stop_from, stop_to = t["from_station"], t["to_station"]
-            # Use GeoJSON route when available, otherwise draw straight line
+            key = "_".join([route_type] + sorted([stop_from["name"], stop_to["name"]]))
             if t.get("geojson_filename"):
-                filename = os.path.join("coach_routes", t["geojson_filename"])
+                filename = os.path.join(f"{route_type}_routes", t["geojson_filename"])
                 routes.append(
-                    {"type": "coach", "key": key, "geojson_filename": filename}
+                    {"type": route_type, "key": key, "geojson_filename": filename}
                 )
             else:
                 routes.append(
                     {
-                        "type": "coach",
+                        "type": route_type,
                         "key": key,
-                        "from": latlon_tuple(coach_from),
+                        "from": latlon_tuple(stop_from),
-                        "to": latlon_tuple(coach_to),
+                        "to": latlon_tuple(stop_to),
-                    }
-                )
-            continue
-        if t["type"] == "bus":
-            bus_from, bus_to = t["from_station"], t["to_station"]
-            key = "_".join(["bus"] + sorted([bus_from["name"], bus_to["name"]]))
-            if t.get("geojson_filename"):
-                filename = os.path.join("bus_routes", t["geojson_filename"])
-                routes.append(
-                    {"type": "bus", "key": key, "geojson_filename": filename}
-                )
-            else:
-                routes.append(
-                    {
-                        "type": "bus",
-                        "key": key,
-                        "from": latlon_tuple(bus_from),
-                        "to": latlon_tuple(bus_to),
                     }
                 )
             continue

agenda/types.py

@@ -397,8 +397,7 @@ class Trip:
                         end_country=to_country,
                     )
                 )
-            if item["type"] == "coach":
+            if item["type"] in ("coach", "bus"):
-                # Include coach journeys in trip elements
                 from_country = agenda.get_country(item["from_station"]["country"])
                 to_country = agenda.get_country(item["to_station"]["country"])
                 name = f"{item['from']} → {item['to']}"
@@ -408,26 +407,7 @@ class Trip:
                         end_time=item.get("arrive"),
                         title=name,
                         detail=item,
-                        element_type="coach",
+                        element_type=item["type"],
-                        start_loc=item["from"],
-                        end_loc=item["to"],
-                        start_country=from_country,
-                        end_country=to_country,
-                    )
-                )
-
-            if item["type"] == "bus":
-                # Include bus journeys in trip elements
-                from_country = agenda.get_country(item["from_station"]["country"])
-                to_country = agenda.get_country(item["to_station"]["country"])
-                name = f"{item['from']} → {item['to']}"
-                elements.append(
-                    TripElement(
-                        start_time=item["depart"],
-                        end_time=item.get("arrive"),
-                        title=name,
-                        detail=item,
-                        element_type="bus",
                         start_loc=item["from"],
                         end_loc=item["to"],
                         start_country=from_country,