placerequest.py

import urllib, json
from kmeans import kmean

AUTH_KEY = 'AIzaSyAG0fCOK8Qh9iODUjcK2TexVWVEBcw3MO4'
class FindRestaurants():

	def __init__(self, origin, destination):
		self.origin = origin
		self.destination = destination
		# get parameters to use Google Places
		jsonData = FindDir(self)
		if (jsonData == "No Walking Path Found"):
			print(jsonData)
			return

		distance = jsonData["routes"][0]["legs"][0]["distance"]["value"]
		decodedPoly = decode(jsonData["routes"][0]["overview_polyline"]["points"])
		midPoint = decodedPoly[(int)(len(decodedPoly)/2)]
		radius = distance*(3/2)
		lat = midPoint[1]
		lng = midPoint[0]

		# run Google Places
		open_restaurants = GoogPlac(lat, lng, radius)
		latlong = []
		
		for restaurant in open_restaurants["results"]:
			latlong.append(PlaceDetails(restaurant["place_id"]))

		# doing k means clustering
		waypoints_limit = 23
		k = min(int(len(latlong)/3), waypoints_limit)
		centroids, clusters = kmean(latlong, k)
		centroidString = ""
		for centroid in centroids:
			centroidString += str(centroid)+"|"
		newDirection = NewDir(self, centroidString)



# find the shortest path between two points
def FindDir(self):
		MyUrl = ('https://maps.googleapis.com/maps/api/directions/json'
	           '?origin=%s'
	           '&destination=%s'
	           '&mode=walking'
	           '&key=%s') % (self.origin, self.destination, AUTH_KEY)
		#grabbing the JSON result
	  	response = urllib.urlopen(MyUrl)
	  	jsonRaw = response.read()
	  	jsonData = json.loads(jsonRaw)
	  	status = str((jsonData["status"]))
	  	no_results = "ZERO_RESULTS"
	  	if (status == no_results):
	  		return ("No Walking Path Found")
	  	return jsonData

# decode polyline
def decode(point_str):
    '''Decodes a polyline that has been encoded using Google's algorithm
    http://code.google.com/apis/maps/documentation/polylinealgorithm.html
    
    This is a generic method that returns a list of (latitude, longitude) 
    tuples.
    
    :param point_str: Encoded polyline string.
    :type point_str: string
    :returns: List of 2-tuples where each tuple is (latitude, longitude)
    :rtype: list
    
    '''
            
    # sone coordinate offset is represented by 4 to 5 binary chunks
    coord_chunks = [[]]
    for char in point_str:
        
        # convert each character to decimal from ascii
        value = ord(char) - 63
        
        # values that have a chunk following have an extra 1 on the left
        split_after = not (value & 0x20)         
        value &= 0x1F
        
        coord_chunks[-1].append(value)
        
        if split_after:
                coord_chunks.append([])
        
    del coord_chunks[-1]
    
    coords = []
    
    for coord_chunk in coord_chunks:
        coord = 0
        
        for i, chunk in enumerate(coord_chunk):                    
            coord |= chunk << (i * 5) 
        
        #there is a 1 on the right if the coord is negative
        if coord & 0x1:
            coord = ~coord #invert
        coord >>= 1
        coord /= 100000.0
                    
        coords.append(coord)
    
    # convert the 1 dimensional list to a 2 dimensional list and offsets to 
    # actual values
    points = []
    prev_x = 0
    prev_y = 0
    for i in xrange(0, len(coords) - 1, 2):
        if coords[i] == 0 and coords[i + 1] == 0:
            continue
        
        prev_x += coords[i + 1]
        prev_y += coords[i]
        # a round to 6 digits ensures that the floats are the same as when 
        # they were encoded
        points.append((round(prev_x, 6), round(prev_y, 6)))
    
    return points    

# Get all the restaurants currently open within specified radius
def GoogPlac(lat,lng,radius):
	  LOCATION = str(lat) + "," + str(lng)
	  RADIUS = radius
	  MyUrl = ('https://maps.googleapis.com/maps/api/place/nearbysearch/json'
	           '?location=%s'
	           '&radius=%s'
	           '&types=restaurant'
	           '&opennow=true'
	           '&key=%s') % (LOCATION, RADIUS, AUTH_KEY)
	  
	  #grabbing the JSON result
	  response = urllib.urlopen(MyUrl)
	  jsonRaw = response.read()
	  jsonData = json.loads(jsonRaw)
	  return jsonData

# get place details
def PlaceDetails(placeid):
		PLACEID = placeid
		MyUrl = ('https://maps.googleapis.com/maps/api/place/details/json'
				'?placeid=%s'
				'&key=%s') % (PLACEID, AUTH_KEY)
		#grabbing the JSON result
	  	response = urllib.urlopen(MyUrl)
	  	jsonRaw = response.read()
	  	jsonData = json.loads(jsonRaw)
	  	return jsonData["result"]["geometry"]["location"]["lat"], jsonData["result"]["geometry"]["location"]["lng"]

# calculate new directions with waypoints
def NewDir(self, centroidString):
	MyUrl = ('https://maps.googleapis.com/maps/api/directions/json'
	           '?origin=%s'
	           '&destination=%s'
	           '&mode=walking'
	           '&waypoint=optimize:true|%s'
	           '&key=%s') % (self.origin, self.destination, centroidString, AUTH_KEY)
	#grabbing the JSON result
  	response = urllib.urlopen(MyUrl)
  	jsonRaw = response.read()
  	jsonData = json.loads(jsonRaw)
  	status = str((jsonData["status"]))
  	no_results = "ZERO_RESULTS"
  	if (status == no_results):
  		return ("No Walking Path Found")
  	return jsonData


FindRestaurants('Georgetown University', 'Union Station')