dvbRetriever.py

import logging
import geojson
from helper.OsmDataQuery import OsmDataQuery
from helper.OsmObjectType import OsmObjectType
from helper.geoJsonHelper import groupBy, centerPoint
from helper.overPassHelper import OverPassHelper
import dvb
import time
import requests

logging.basicConfig(level=logging.INFO)


def getPublicStops():
    overpassFetcher = OverPassHelper()
    pieschenAreaId = overpassFetcher.getAreaId("Dresden, Germany")

    logging.info("Get stops from openstreetmap")
    stopsOsmQuery = OsmDataQuery("Public Transport stops", OsmObjectType.NODE, ['"public_transport"="stop_position"'])
    stops = next(overpassFetcher.directFetch(pieschenAreaId, [stopsOsmQuery]))
    stopsByName = []

    logging.info("Group stops by name")
    for name, group in groupBy(stops, "name").items():
        center = centerPoint(group)
        # TODO: more properties?
        # TODO: maybe draw line instead of just center point?
        properties = {
            "name": name,
            "stop_positions": len(group["features"])
        }
        stopByName = geojson.Feature(geometry=center, properties=properties)
        stopsByName.append(stopByName)
    return stopsByName


def callDvb(stopsByName):
    logging.info("Retrieve line info for each stop")

    # Problem: stop does not have to make sense for getting a result (tried "tst")
    # Problem: based on current time
    # better approach: https://github.com/kiliankoe/vvo/blob/master/documentation/webapi.md#lines (but need to get stopId using the pointFinder)
    changePoints = []
    countUniqueStops = len(stopsByName)
    for index, stop in enumerate(list(stopsByName)):
        if index % 3 == 0:
            logging.info("progress: {}/{}".format(index + 1, countUniqueStops))
        time.sleep(5)
        name = stop["properties"]["name"]
        # TODO:
        if name:
            try:
                dvbResponse = dvb.monitor(name)
            except requests.HTTPError:
                logging.error(
                    "dvb said no for {}, timeout for 30s".format(name))
                time.sleep(10)
                try:
                    # poor mans retry
                    dvbResponse = dvb.monitor(name)
                except requests.HTTPError:
                    continue
            if dvbResponse:
                lines = list(set([info.get("line", None)
                                  for info in dvbResponse if info]))
                stop["properties"]["lines"] = lines
                # TODO: show this based on color only? (could save lines for every stop)
                # if more than 1 line departes from this stop, it is a change point
                canChange = len(lines) > 1
                if canChange:
                    changePoints.append(stop)

    changePoints = geojson.FeatureCollection(changePoints)

    with open("out/data/dvbChangePoints.json", 'w', encoding='UTF-8') as outfile:
        geojson.dump(changePoints, outfile)

if __name__ == "__main__":
    stopsByName = getPublicStops()
    callDvb(stopsByName)