calculate total distance traveled

fgs/views.py

@@ -3,6 +3,7 @@ from .jwt import jwt_required
 from .model import *
 from flask import g, jsonify, request, abort
 from sqlalchemy import func
+import geopy.distance
 
 @app.route('/')
 def index():
@@ -37,6 +38,29 @@ def collars():
 
     return jsonify(active_collars)
 
+@app.route('/collars/stats/distance')
+@jwt_required
+def collars_distance():
+    active_collars = []
+    for collar in Collar.query.filter_by(active=True).all():
+        coords = DataPoint.query.filter_by(collar_id=collar.id).\
+                order_by(DataPoint.datetime.desc())
+  
+        distance_kilometers = 0
+        coords_pairs = list(map(lambda e : (e.longitude, e.latitude), coords))
+
+        coord_last = coords_pairs.pop()
+        for coord in coords_pairs:
+            distance_kilometers += geopy.distance.VincentyDistance(coord_last,coord).km
+            coord_last = coord
+         
+        active_collars.append(
+            {'id': collar.id, 'name': collar.name, 
+                'distance': distance_kilometers }
+        )
+
+    return jsonify(active_collars)
+
 @app.route('/collars/<int:id>/history')
 @jwt_required
 def collar_history(id):