+
+def select_openweatherdata_grouped(cityid, begin, end):
+ # determine resolution (interval in seconds for data points)
+ resolution = calc_grouping_resolution(begin, end)
+
+ # Let the database do the grouping. Example in SQL (MySQL):
+ # select to_seconds(datetime) DIV (60*60*24) as interval_id, min(datetime), max(datetime), min(temp), avg(temp), max(temp), count(temp) from openweathermap group by interval_id order by interval_id;
+ query = db.session.query(func.to_seconds(OpenWeatherMap.datetime).op('div')(resolution).label('g'),
+ func.from_unixtime(func.avg(func.unix_timestamp(OpenWeatherMap.datetime))).label('datetime'),
+ func.avg(OpenWeatherMap.temp).label('temp'),
+ OpenWeatherMap.cityid)
+ OpenWeatherMap.query.filter(OpenWeatherMap.cityid == cityid)
+ query = query.filter(OpenWeatherMap.datetime >= begin)
+ query = query.filter(OpenWeatherMap.datetime <= end)
+ query = query.group_by('g', OpenWeatherMap.cityid)
+ return query.all()
+
+
+def convert_to_c3(result, id, field_x, field_y):
+ c3result = defaultdict(list)
+ for row in result:
+ c3result[str(getattr(row, id))].append(getattr(row, field_y))
+ dt = getattr(row, field_x).strftime('%Y-%m-%d %H:%M:%S')
+ c3result[str(getattr(row, id)) + '_x'].append(dt)
+ return c3result
+
+
+def request_arg(key, type, default=None):
+ """Returns the key from the request if available, otherwise the default value.
+ In case type is provided and the key is present, the value is converted by calling type.
+ In other words: Reimplement request.args.get but don't return default value if
+ type raises a ValueError."""
+ if key in request.args:
+ try:
+ return type(request.args[key])
+ except ValueError as e:
+ abort(Response(str(e), 400))
+ else:
+ return default
+
+
+def sensordata(sensor_id=None, sensor_type=None):
+ begin = request_arg('begin', parse_datetime)
+ end = request_arg('end', parse_datetime)
+ mode = request.args.get('mode', 'full')
+ format = request.args.get('format', 'default')
+
+ if mode == 'full':
+ result = select_sensordata(sensor_id, sensor_type, begin, end)
+ elif mode == 'consolidated':
+ if begin is None or end is None:
+ abort(Response('begin and end have to be set for mode==consolidated', 400))
+ result = select_sensordata_grouped(sensor_id, sensor_type, begin, end)
+ else:
+ abort(Response('unknown value for mode', 400))
+
+ if format == 'c3':
+ return convert_to_c3(result, 'sensor_id', 'timestamp', 'value')
+ return result
+
+
+def openweathermapdata(cityid):
+ begin = request_arg('begin', parse_datetime)
+ end = request_arg('end', parse_datetime)
+ mode = request.args.get('mode', 'full')
+ format = request.args.get('format', 'default')
+
+ if mode == 'full':
+ result = select_openweatherdata(cityid, begin, end)
+ elif mode == 'consolidated':
+ if begin is None or end is None:
+ abort(Response('begin and end have to be set for mode==consolidated', 400))
+ result = select_openweatherdata_grouped(cityid, begin, end)
+ else:
+ abort(Response('unknown value for mode', 400))
+
+ if format == 'c3':
+ return convert_to_c3(result, 'cityid', 'datetime', 'temp')
+ return result
+
+
+def currentairtemperature(cityid):
+ result = OpenWeatherMap.query.filter_by(cityid=cityid).order_by(OpenWeatherMap.datetime.desc()).first()
+ return result.temp, result.datetime
+
+
+def currentwatertemperature(sensorid):
+ result = Sensors.query.filter_by(sensor_id=sensorid).order_by(Sensors.timestamp.desc()).first()
+ return result.value, result.timestamp