Backend for ogg-live

app/ogn_backend_app.py

@@ -0,0 +1,81 @@
+from datetime import datetime, timedelta, date
+
+from flask import Flask
+from flask import Response
+
+from ogn.db import session
+
+from sqlalchemy import func, and_, case, between
+from ogn.model import ReceiverBeacon
+from ogn.model import AircraftBeacon
+from ogn.model import Flarm
+
+from flask import request
+
+app = Flask(__name__)
+
+
+@app.route("/rec.php")
+def index():
+    sq = session.query(ReceiverBeacon.name, func.max(ReceiverBeacon.timestamp).label('lastseen')) \
+        .group_by(ReceiverBeacon.name) \
+        .subquery()
+
+    last_10_minutes = datetime.utcnow() - timedelta(minutes=10)
+    receiver_query = session.query(ReceiverBeacon.name, ReceiverBeacon.latitude, ReceiverBeacon.longitude, case([(sq.c.lastseen>last_10_minutes, True)], else_=False).label('is_online')) \
+        .filter(and_(ReceiverBeacon.name == sq.c.name, ReceiverBeacon.timestamp == sq.c.lastseen)) \
+        .order_by(ReceiverBeacon.name)
+
+    lines = list()
+    lines.append('<?xml version="1.0" encoding="UTF-8"?>')
+    lines.append('<markers>')
+    lines.append('<m e="0"/>')
+    for [name, latitude, longitude, is_online] in receiver_query.all():
+        lines.append('<m a="{0}" b="{1:.7f}" c="{2:.7f}" d="{3:1d}"/>'.format(name, latitude, longitude, is_online))
+
+    lines.append('</markers>')
+    xml = '\n'.join(lines)
+    return Response(xml, mimetype='text/xml')
+
+
+@app.route('/lxml.php', methods=['GET', 'POST'])
+def live():
+    show_offline = request.args.get('a', False)
+    lat_max = request.args.get('b', 90)
+    lat_min = request.args.get('c', -90)
+    lon_max = request.args.get('d', 180)
+    lon_min = request.args.get('e', -180)
+
+    if show_offline:
+        start_observation = date.today()
+    else:
+        start_observation = datetime.utcnow - timedelta(minutes=5)
+
+    sq = session.query(AircraftBeacon.address, func.max(AircraftBeacon.timestamp).label('lastseen')) \
+        .filter(and_(between(AircraftBeacon.latitude, lat_max, lat_min), between(AircraftBeacon.longitude, lon_max, lon_min))) \
+        .filter(AircraftBeacon.timestamp > start_observation) \
+        .group_by(AircraftBeacon.address) \
+        .subquery()
+
+    position_query = session.query(AircraftBeacon, Flarm) \
+        .outerjoin(Flarm, AircraftBeacon.address == Flarm.address) \
+        .filter(and_(AircraftBeacon.address == sq.c.address, AircraftBeacon.timestamp == sq.c.lastseen))
+
+    lines = list()
+    lines.append('<?xml version="1.0" encoding="UTF-8"?>')
+    lines.append('<markers>')
+
+    hashcode = '4711abcd'
+    flarm_competition = lambda flarm_object: '_' + hashcode[6:7] if flarm_object is None else flarm_object.competition
+    flarm_registration = lambda flarm_object: hashcode if flarm_object is None else flarm_object.registration
+    flarm_address = lambda flarm_object: 0 if flarm_object is None else flarm_object.address
+    for [ab, flarm] in position_query.all():
+        lines.append('<m a="{0:.7f},{1:.7f},{2},{3},{4},{5},{6},{7},{8},{9},{10},{11},{12}"/>'.format(ab.latitude, ab.longitude, flarm_competition(flarm), flarm_registration(flarm), ab.altitude, ab.timestamp, ab.track, ab.ground_speed, ab.climb_rate, ab.aircraft_type, ab.receiver_name, flarm_address(flarm), flarm_registration(flarm)))
+
+    lines.append('</markers>')
+    xml = '\n'.join(lines)
+    return Response(xml, mimetype='text/xml')
+
+
+if __name__ == "__main__":
+    app.run(debug=True)