Initial commit

.env.example

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+FLASK_ENV=development
+FLASK_APP=index.py
+ZOMATO_API_KEY=
+OPENCAGEDATA_API_KEY=

.gitignore

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+.env
+.pytest_cache
+.next
+node_modules

.nowignore

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+.vscode
+.env
+.pytest_cache

.pre-commit-config.yaml

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+repos:
+-   repo: https://github.com/ambv/black
+    rev: stable
+    hooks:
+    - id: black

Pipfile

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+[[source]]
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+flask = "*"
+"rfc3339" = "*"
+ansicolors = "*"
+requests = "*"
+psycopg2-binary = "*"
+
+[dev-packages]
+pytest = "*"
+black = "==19.3b0"
+pre-commit = "*"
+
+[scripts]
+dev = "flask run"

README.md

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+# Prague public transport departures
+
+Next.js app which uses flask lambda function to query PostGIS for departures from stops near me.

api/departures.py

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+import os
+from flask import request, jsonify
+import psycopg2
+from app_generator import create_app
+
+app = create_app()
+
+database_url = os.getenv('DATABASE_URL')
+
+QUERY = """
+set timezone TO 'Europe/Prague';
+WITH stops_nearby AS (
+    SELECT stops.stop_id
+    FROM gtfs.stops
+    ORDER BY gtfs.stops.the_geom <-> ST_GeomFromText(%(location)s, 4326)
+    LIMIT 10
+)
+SELECT r.route_short_name, trip_headsign, departure_time, s.stop_name
+FROM gtfs.stops s
+left join gtfs.stop_times st on s.stop_id = st.stop_id
+left join gtfs.trips t on t.trip_id = st.trip_id
+left join gtfs.calendar c on c.service_id = t.service_id
+left join gtfs.routes r on r.route_id = t.route_id
+WHERE departure_time::time > current_time and departure_time::time < current_time + interval '15 minutes'
+and c.start_date <= current_date
+and c.end_date >= current_date
+and s.stop_id in (select * from stops_nearby)
+and (
+CASE
+    WHEN extract(dow from current_date) = 1 THEN c.monday::boolean = true
+    WHEN extract(dow from current_date) = 2 THEN c.tuesday::boolean = true
+    WHEN extract(dow from current_date) = 3 THEN c.wednesday::boolean = true
+    WHEN extract(dow from current_date) = 4 THEN c.thursday::boolean = true
+    WHEN extract(dow from current_date) = 5 THEN c.friday::boolean = true
+    WHEN extract(dow from current_date) = 6 THEN c.saturday::boolean = true
+    WHEN extract(dow from current_date) = 0 THEN c.sunday::boolean = true
+END
+)
+order by departure_time;
+"""
+
+def convert(item):
+    return (item[0], item[1], str(item[2]), item[3])
+
+@app.route("/api/departures", methods=["GET"])
+def api():
+    latitude = request.args.get('latitude')
+    longitude = request.args.get('longitude')
+
+    connection = psycopg2.connect(database_url)
+    cursor = connection.cursor()
+    try:
+        cursor.execute(QUERY, {"location": f"POINT({longitude} {latitude})"})
+        data = cursor.fetchall()
+    finally:
+        cursor.close()
+        connection.close()
+    data = [convert(item) for item in data]
+    return jsonify(data)

app_generator.py

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+import logging
+from flask import Flask
+from request_logger import attach_logger
+
+
+def create_app():
+    app = Flask(__name__)
+
+    logger = logging.getLogger()
+    logger.setLevel(logging.DEBUG)
+
+    attach_logger(app)
+    return app

now.json

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+{
+    "version": 2,
+    "name": "departures",
+    "alias": "departures",
+    "env": {
+        "DATABASE_URL": "@departures-database-url"
+    }
+}