// !!!! HELPER FUNCTIONS !!!!
public List<PointOfInterest> getPlaces(Location start, int timeInMinutes)
{
//create query
//build ("https://maps.googleapis.com/maps/api/place/nearbysearch/output?" + parameters)
//OR (less data)
string URI = "https://maps.googleapis.com/maps/api/place/radarsearch/json?";
//add parameters
//key
URI += "key=" + (new Secrets()).GoogleAPIServerKey + "&";
//location
URI += "location=" + start.latitude.ToString() + "," + start.longitude.ToString() + "&";
//radius; estimate 1 meter per second walking speed
URI += "radius=" + (timeInMinutes * 60 / 2).ToString() + "&";
//types; start with "park" and possibly add more later
//see https://developers.google.com/places/supported_types for list of types
URI += "types=park";
//create a new, empty list of Points Of Interest
List<PointOfInterest> candidatePoIs = new List<PointOfInterest>();
//request processing
var googleRadarObject = JToken.Parse(callAPIgetJSon(URI));
var status = googleRadarObject.Children<JProperty>().FirstOrDefault(x => x.Name == "status").Value;
if (status.ToString() == "OK")
{
var resultsArray = googleRadarObject.Children<JProperty>().FirstOrDefault(x => x.Name == "results").Value;
//iterate over the json and parse into PointsOfInterest, placing each in the list
foreach (var item in resultsArray)
{
//extract the google place id
string GooglePlaceId = item.Children<JProperty>().FirstOrDefault(x => x.Name == "place_id").Value.ToString();
//extract the lattitude from JSon structuret
decimal lat = decimal.Parse(
item.Children<JProperty>().FirstOrDefault(x => x.Name == "geometry").Value.
Children<JProperty>().FirstOrDefault(x => x.Name == "location").Value.
Children<JProperty>().FirstOrDefault(x => x.Name == "lat").Value.ToString());
//extract the longitude from JSon structure
decimal lng = decimal.Parse(
item.Children<JProperty>().FirstOrDefault(x => x.Name == "geometry").Value.
Children<JProperty>().FirstOrDefault(x => x.Name == "location").Value.
Children<JProperty>().FirstOrDefault(x => x.Name == "lng").Value.ToString());
//create new PoI with above properties
PointOfInterest point = new PointOfInterest(lat, lng, GooglePlaceId);
//add it to the list of candidates
candidatePoIs.Add(point);
}
}
//return processed list
return candidatePoIs;
}
public ActionResult Walk(FormCollection collection)
{
Location start = new Location(decimal.Parse(collection["startLatitude"]), decimal.Parse(collection["startLongitude"]));
int time = int.Parse(collection["timeInput"]);
List<PointOfInterest> radarList = getPlaces(start, time);
List<PointOfInterest> goldilocks = screenPlaces(radarList, start, time);
PointOfInterest chosen = null;
if (goldilocks.Count() > 0)
{
chosen = goldilocks[0];
}
else if (radarList.Count() > 0)
{
chosen = radarList[radarList.Count() - 1];
}
if (chosen != null)
{
ViewBag.GoogleId = chosen.GooglePlaceId;
ViewBag.Latitude = chosen.location.latitude;
ViewBag.Longitude = chosen.location.longitude;
ViewBag.OriginLat = start.latitude;
ViewBag.OriginLon = start.longitude;
ViewBag.NoneInRange = false;
}
else
{
ViewBag.NoneInRange = true;
}
ViewBag.time = time;
if (chosen != null){
ViewBag.GoogleId = chosen.GooglePlaceId;
ViewBag.Latitude = chosen.location.latitude;
ViewBag.Longitude = chosen.location.longitude;
ViewBag.NoneInRange = false;
string poiURL = "http://maps.google.com/maps?q=";
poiURL += chosen.location.latitude + "," + chosen.location.longitude;
ViewBag.PoIMapLink = poiURL;
}
else
{
ViewBag.NoneInRange = true;
}
ViewBag.time = time;
return View();
}
List<PointOfInterest> screenPlaces(List<PointOfInterest> candidates, Location start, int timeInMinutes)
{
//if the candidates list is empty, return the/an empty list
if (!(candidates.Any<PointOfInterest>()))
{
return candidates;
}
//create distance matrix query
string URI = "https://maps.googleapis.com/maps/api/distancematrix/json?";
//add parameters
//key
URI += "key=" + (new Secrets()).GoogleAPIServerKey + "&";
//specifiy walking
URI += "mode=walking&";
//origin location
URI += "origins=" + start.latitude.ToString() + "," + start.longitude.ToString() + "&";
//list all candidate points of interest by lat/lon as destinations
URI += "destinations=";
//iterate over candidate destinations, and add each location, separated by a pipe |
int count = candidates.Count();
for (int i = 0; i < count; i++)
{
URI += candidates[i].getLatitude().ToString() + "," + candidates[i].getLongitude().ToString();
if (i < count - 1) // if not the last item in the list
{
URI += "|"; //add a pipe to separate destinations
}
}
List<PointOfInterest> viable = new List<PointOfInterest>(); //create a new empty list
//calculate Goldilocks range (not too far but also not too close) in seconds
//use 90-100% of available one-way time to start
//may need to iterate or otherwise process & if so, should probably save the times instead of make decisions in loop
//note that these use integer math
int ceiling = (timeInMinutes * 60) / 2; //max length of each leg of round trip
int floor = (ceiling * 9) / 10; //min length of each leg of round trip
var client = new WebClient();
var values = System.Web.HttpUtility.ParseQueryString(string.Empty);
var result = client.DownloadData(URI.ToString());
var json = Encoding.UTF8.GetString(result);
var serializer = new JavaScriptSerializer();
var distanceResponse = serializer.Deserialize<DistanceResponse>(json);
//extract elements' travel times
//remember there is only one destination, so the elements list the times to destinations in order
if (string.Equals("OK", distanceResponse.Status, StringComparison.OrdinalIgnoreCase))
{
var elements = (distanceResponse.Rows[0]).Elements;
for (int i = 0; i < count; i++)
{
//extract the time in seconds from origin to the current (i'th) destination
if (string.Equals("OK", distanceResponse.Status, StringComparison.OrdinalIgnoreCase))
{
// making a new int value to be able to better understand what the actual value is.
int value = elements[i].Duration.Value;
//compare to Goldilocks zone to evaluate and add to list if in the range
if (value > floor && value <= ceiling)
{
viable.Add(candidates[i]);
}
}
}
}
Console.WriteLine(candidates);
return viable;
}
