api.py

import configparser
import sys
import json
from datetime import datetime

from flask import Flask, request

from DataObjects import LocationData
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

from collections import defaultdict

app = Flask(__name__)

ISO8601 = "%Y%m%dT%H%M%S"
ISO8601_O = "%Y-%m-%d %H:%M:%S"


def get_config():
	"""
		Get the configuration data for the application
	"""
	try:
		config = configparser.SafeConfigParser()
		config.read('config.ini')
		return config
	except Exception as e:
		print("No configuration file found.", e)
		sys.exit()

def get_session(config):
	"""
		Attempt to initialize the database session, quit if the
		program cannot find the database.
	"""
	try:
		# Collect Configuration
		dao_type = config.get('database', 'type').lower()
		username = config.get('database', 'username')
		password = config.get('database', 'pass')
		host = config.get('database', 'host')
		port = config.get('database', 'port')
		database = config.get('database', 'database')

		# Build URL
		if dao_type == 'sqlite':
			url = dao_type + ":///" + host
		else:
			url = dao_type + "://" + username +\
				  ":" + password + "@" + host + \
				  ":" + port + "/" + database

		# Create session
		engine = create_engine(url)
		Session = sessionmaker(bind=engine)
		session = Session()
		return session

	except Exception as e:
		print("Unable to configure database connection. Error:", e)
		sys.exit()
		
@app.route('/api')
def api():
	"""
		Returns the version for compatibility/availability checks"
	"""
	return 'v0.1'
	
@app.route('/api/locationdata', methods=('GET', 'POST'))
def location_data():
	"""
		Request or post location data
	"""
	session = get_session(get_config())
	if request.method == 'POST':
		if request.is_json:
			try:
				raw_location_data = request.get_json()
				location = raw_location_data["location"]
				coords = location["coords"]
				lat = coords["latitude"]
				lng = coords["longitude"]
				acc = coords["accuracy"]
				spd = coords["speed"]
				hed = coords["heading"]
				alt = coords["altitude"]
				tim = location["timestamp"]
				uuid = location["uuid"]
				uid = "1"
				locationData = LocationData(uuid = uuid,
											uid = uid,
											latitude = lat,
											longitude = lng,
											accuracy = acc,
											speed = spd,
											heading = hed,
											altitude = alt,
											timestamp = tim)
				session.add(locationData)
				session.commit()
				return "Success"
			except Exception as e:
				session.rollback()
				return ("Fail", str(e))
		else:
			return "NOT JSON"
	else:
		try:
			start = request.args.get('start')
			end = request.args.get('end')
			
			start = datetime.strptime(start, ISO8601)
			end = datetime.strptime(end, ISO8601)
			
			print(str([str(start), str(end)]))
			query_results = session.query(LocationData).filter(LocationData.timestamp > start, LocationData.timestamp < end).all()
			
			dataPoints = defaultdict(list)
			for result in query_results:
				dataPoints[result.uid].append(result)
				
			result = []
			for user in dataPoints:
				print(user)
				json_entry = json.loads('{}')
				json_entry['user_id'] = user
				json_entry['start_time'] = min(dataPoints[user], key=lambda x:x.timestamp).timestamp
				json_entry['end_time'] = max(dataPoints[user], key=lambda x:x.timestamp).timestamp
				json_entry['locations'] = []
				for location in dataPoints[user]:
					json_location = json.loads('{}')
					json_location['latitude'] = location.latitude
					json_location['longitude'] = location.longitude
					json_location['timestamp'] = location.timestamp
					json_entry['locations'].append(json_location)
				result.append(json_entry)
			
			return json.dumps(result)
		except Exception as e:	
			print(e)
			return json.dumps([[l.uuid, l.latitude, l.longitude, l.timestamp] for l in session.query(LocationData).all()])
	
if __name__ == '__main__':
	app.run(debug=True)