Add infrastructure for generating a "meta station" GTFS feed

Meta stations allow using e.g. "London" or "Paris" as destination while
referring to a set of (main) stations in the city. This affects
sufficiently few cities that we can maintain this mapping manually, as
this only really produces the result for multiple terminus stations with
limited connectivity between each other on long-distance modes.

Author: vkrause

metastations/metastations.yml

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+# SPDX-FileCopyrightText: Volker Krause <vkrause@kde.org>
+# SPDX-License-Identifier: CC0-1.0
+
+# London
+Q84:
+    - Q219867 # King's Cross
+    - Q720102 # St Pancras
+    - Q795691 # Waterloo Station
+    - Q800751 # Euston Station
+    - Q801124 # Liverpool Street

src/generate-metastations.py

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+#!/usr/bin/env python3
+# SPDX-FileCopyrightText: Volker Krause <vkrause@kde.org>
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+import argparse
+import csv
+from ruamel.yaml import YAML
+import pathlib
+import requests
+import os
+
+parser = argparse.ArgumentParser(description='Transitous meta-station GTFS feed generator.')
+parser.add_argument('--config', type=str, help="Configuration file describing the meta station mapping")
+parser.add_argument('--output', type=str, help="GTFS feed output folder")
+arguments = parser.parse_args()
+
+
+if __name__ == "__main__":
+
+    stops = []
+    stop_groups = []
+    translations = []
+    with open(arguments.config) as f:
+        yaml = YAML(typ="rt")
+        config = yaml.load(f)
+
+        headers = {"User-Agent": "org.transitous.metastation-generator"}
+        for metastation in config:
+            print(metastation)
+            metareq = requests.get(f"https://www.wikidata.org/w/rest.php/wikibase/v1/entities/items/{metastation}/labels", headers=headers)
+            metadata = metareq.json()
+            stop = {
+                "stop_id": metastation,
+                "stop_name": metadata["en"],
+                "stop_lat": 0,
+                "stop_lon": 0,
+                "location_type": 0
+            }
+            stops.append(stop)
+
+            for lang, name in metadata.items():
+                if lang == "en" or name == metadata["en"]:
+                    continue
+                translation = {
+                    "table_name": "stops",
+                    "field_name": "stop_name",
+                    "language": lang,
+                    "record_id": metastation,
+                    "translation": name
+                }
+                translations.append(translation)
+
+            for station in config[metastation]:
+                print(station)
+                stationreq = requests.get(f"https://www.wikidata.org/w/rest.php/wikibase/v1/entities/items/{station}", headers=headers)
+                stationdata = stationreq.json()
+                coord = stationdata["statements"]["P625"][0]["value"]["content"]
+                stop = {
+                    "stop_id": station,
+                    "stop_name": stationdata["labels"]["en"],
+                    "stop_lat": coord["latitude"],
+                    "stop_lon": coord["longitude"],
+                    "location_type": 0
+                }
+                stops.append(stop)
+                stop_group = {
+                    "stop_group_id": metastation,
+                    "stop_id": station,
+                }
+                stop_groups.append(stop_group)
+
+    os.makedirs(arguments.output, exist_ok=True)
+
+    # create dummy files we need for MOTIS to recognize this as a valid GTFS feed
+    pathlib.Path(os.path.join(arguments.output, "calendar_dates.txt")).touch(exist_ok=True)
+    pathlib.Path(os.path.join(arguments.output, "routes.txt")).touch(exist_ok=True)
+    pathlib.Path(os.path.join(arguments.output, "stop_times.txt")).touch(exist_ok=True)
+    pathlib.Path(os.path.join(arguments.output, "trips.txt")).touch(exist_ok=True)
+
+    # dummy agency data to define a timezone
+    agency = {
+        "agency_id": "transitous",
+        "agency_name": "Transitous",
+        "agency_url": "https://transitous.org",
+        "agency_timezone": "Etc/UTC",
+    }
+    with open(os.path.join(arguments.output, "agency.txt"), 'w') as f:
+        writer = csv.DictWriter(f, fieldnames=agency.keys())
+        writer.writeheader()
+        writer.writerow(agency)
+
+    # write stops
+    with open(os.path.join(arguments.output, "stops.txt"), 'w') as f:
+        writer = csv.DictWriter(f, fieldnames=["stop_id", "stop_name", "stop_lat", "stop_lon", "location_type"])
+        writer.writeheader()
+        for stop in stops:
+            writer.writerow(stop)
+
+    # write stop_group_elements
+    with open(os.path.join(arguments.output, "stop_group_elements.txt"), 'w') as f:
+        writer = csv.DictWriter(f, fieldnames=["stop_group_id", "stop_id"])
+        writer.writeheader()
+        for group in stop_groups:
+            writer.writerow(group)
+
+    # write translations
+    with open(os.path.join(arguments.output, "translations.txt"), 'w') as f:
+        writer = csv.DictWriter(f, fieldnames=["table_name", "field_name", "language", "record_id", "translation"])
+        writer.writeheader()
+        for t in translations:
+            writer.writerow(t)