Mapzen isochtrones integration

2016-11-29 12:57:23 +01:00
parent 4b714b3845
commit 77f4f3e7ff
10 changed files with 293 additions and 32 deletions
@@ -0,0 +1,128 @@
+import requests
+import json
+import re
+
+from exceptions import WrongParams, MalformedResult, ServiceException
+from qps import qps_retry
+
+
+class MapzenIsochrones:
+    'A Mapzen Isochrones wrapper for python'
+
+    BASE_URL = 'https://matrix.mapzen.com/isochrone'
+    READ_TIMEOUT = 60
+    CONNECT_TIMEOUT = 10
+
+    ACCEPTED_MODES = {
+        "walk": "pedestrian",
+        "car": "car"
+    }
+
+    def __init__(self, app_key, logger, base_url=BASE_URL):
+        self._app_key = app_key
+        self._url = base_url
+        self._logger = logger
+
+    @qps_retry
+    def isochrone(self, locations, costing, ranges):
+        request_params = self._parse_request_params(locations, costing,
+                                                    ranges)
+        try:
+            response = requests.get(self._url, params=request_params,
+                                    timeout=(self.CONNECT_TIMEOUT,
+                                            self.READ_TIMEOUT))
+
+            if response.status_code is requests.codes.ok:
+                return self._parse_response(response)
+            elif response.status_code == requests.codes.bad_request:
+                return []
+            else:
+                self._logger.error('Error trying to get isochrones from mapzen',
+                                data={"response_status": response.status_code,
+                                      "response_reason": response.reason,
+                                      "response_content": response.text,
+                                      "reponse_url": response.url,
+                                      "response_headers": response.headers,
+                                      "locations": locations,
+                                      "costing": costing})
+                raise ServiceException('Error trying to get isochrones from mapzen',
+                                       response)
+        except requests.Timeout as te:
+            # In case of timeout we want to stop the job because the server
+            # could be down
+            self._logger.error('Timeout connecting to Mapzen isochrones server', exception=te)
+            raise ServiceException('Error trying to calculate isochrones using mapzen',
+                                    None)
+        except requests.ConnectionError as e:
+            # Don't raise the exception to continue with the geocoding job
+            self._logger.error('Error connecting to Mapzen isochrones server',
+                               exception=e)
+            return []
+
+    def _parse_request_params(self, locations, costing, ranges):
+        if costing in self.ACCEPTED_MODES:
+            mode_source = self.ACCEPTED_MODES[costing]
+        else:
+            raise WrongParams("{0} is not an accepted mode".format(costing))
+
+        contours = []
+        for r in ranges:
+            # range is in seconds but mapzen uses minutes
+            range_minutes = r / 60
+            contours.append({"time": range_minutes, "color": 'tbd'})
+        request_params = {
+            'json': json.dumps({'locations': [locations],
+                                'costing': mode_source,
+                                'contours': contours}),
+            'api_key': self._app_key
+        }
+
+        return request_params
+
+    def _parse_response(self, response):
+        try:
+            json_response = response.json()
+            isochrones = []
+            for feature in json_response['features']:
+                # Coordinates could have more than one isochrone. For the
+                # moment we're getting the first polygon only
+                coordinates = feature['geometry']['coordinates']
+                duration = feature['properties']['contour']
+                mapzen_response = MapzenIsochronesResponse(coordinates,
+                                                           duration)
+                isochrones.append(mapzen_response)
+            return isochrones
+        except IndexError:
+            return []
+        except KeyError:
+            self._logger.error('Non existing key for mapzen isochrones response',
+                               data={"response_status": response.status_code,
+                                     "response_reason": response.reason,
+                                     "response_content": response.text,
+                                     "reponse_url": response.url,
+                                     "response_headers": response.headers})
+            raise MalformedResult()
+        except ValueError:
+            # JSON decode error
+            self._logger.error('JSON decode error for Mapzen isochrones',
+                               data={"response_status": response.status_code,
+                                     "response_reason": response.reason,
+                                     "response_content": response.text,
+                                     "reponse_url": response.url,
+                                     "response_headers": response.headers})
+            return []
+
+
+class MapzenIsochronesResponse:
+
+    def __init__(self, coordinates, duration):
+        self._coordinates = coordinates
+        self._duration = duration
+
+    @property
+    def coordinates(self):
+        return self._coordinates
+
+    @property
+    def duration(self):
+        return self._duration