bikemap/tracking/management/commands/import_gpx.py

__author__ = 'tyrel'
from django.core.management.base import BaseCommand, CommandError
from django.contrib.auth.models import User
from tracking.models import Track, Segment, Point
import xmltodict

import os


class Command(BaseCommand):
    help = 'Import a gpx file'

    def add_arguments(self, parser):
        parser.add_argument('username', help="Username to import to.")
        parser.add_argument('filepath', help="File or directory to import a gpx file.")

    def handle(self, *args, **options):
        self.username = options['username']
        filepath = options['filepath']

        try:
            self.user = User.objects.get(username=self.username)
        except User.DoesNotExist:
            raise CommandError("User {0} does not exist".format(self.username))

        if os.path.isdir(filepath):
            self.import_directory(filepath)
        elif os.path.isfile(filepath):
            self.import_file(filepath)

        else:
            raise CommandError("{0} is neither an existing file, nor a path.".format(filepath))

    def import_directory(self, directory):
        pass

    def import_file(self, filename):
        with open(filename) as fd:
            obj = dict(xmltodict.parse(fd.read()))['gpx']

        metadata = obj['metadata']
        tracks = obj['trk']

        start_time = metadata['time']

        name = tracks['name']
        segments = tracks['trkseg']
        if isinstance(segments, list):
            raise NotImplemented(
                "Haven't run across one that has multiple segments. "
                "Contribute a patch if you have.")
        elif isinstance(segments, dict):
            track = Track.objects.create(user=self.user,
                                         start=start_time,
                                         name=name)
            points = segments['trkpt']
            segment = Segment(track=track, time=points[0]['time'])
            segment.save()
            for pt in points:
                Point.objects.create(segment=segment,
                                     time=pt['time'],
                                     elevation=pt['ele'],
                                     latitude=pt['@lat'],
                                     longitude=pt['@lon'])
        print "created Track <{0}> start: {1}, stop: {2}".format(
            track.name,
            track.start,
            track.finish
        )


def etree_to_dict(t):
    d = {t.tag: map(etree_to_dict, t.getchildren())}
    d.update(('@' + k, v) for k, v in t.attrib.iteritems())
    d['text'] = t.text
    return d