Presentation Core Location

BidViewController1

@property (strong, nonatomic) CLLocationManager *locationManager;
@property (strong, nonatomic) CLLocation *previousPoint;
@property (assign, nonatomic) CLLocationDistance totalMovementDistance;
@property (weak, nonatomic) IBOutlet UILabel *latitudeLabel;
@property (weak, nonatomic) IBOutlet UILabel *longitudeLabel;
@property (weak, nonatomic) IBOutlet UILabel *horizontalAccuracyLabel;
@property (weak, nonatomic) IBOutlet UILabel *altitudeLabel;
@property (weak, nonatomic) IBOutlet UILabel *verticalAccuracyLabel;
@property (weak, nonatomic) IBOutlet UILabel *distanceTraveledLabel;

BidViewController2

#pragma mark - CLLocationManagerDelegate Methods
- (void)locationManager:(CLLocationManager *)manager
     didUpdateLocations:(NSArray *)locations {
    CLLocation *newLocation = [locations lastObject];
    NSString *latitudeString = [NSString stringWithFormat:@"%g\u00B0",
                                newLocation.coordinate.latitude];
    self.latitudeLabel.text = latitudeString;
    
    NSString *longitudeString = [NSString stringWithFormat:@"%g\u00B0",
                                 newLocation.coordinate.longitude];
    self.longitudeLabel.text = longitudeString;
    
    NSString *horizontalAccuracyString = [NSString stringWithFormat:@"%gm",
                                          newLocation.horizontalAccuracy];
    self.horizontalAccuracyLabel.text = horizontalAccuracyString;
    
    NSString *altitudeString = [NSString stringWithFormat:@"%gm",
                                newLocation.altitude];
    self.altitudeLabel.text = altitudeString;
    
    NSString *verticalAccuracyString = [NSString stringWithFormat:@"%gm",
                                        newLocation.verticalAccuracy];
    self.verticalAccuracyLabel.text = verticalAccuracyString;
    
    if (newLocation.verticalAccuracy < 0 ||
        newLocation.horizontalAccuracy < 0) {
        // invalid accuracy
        return;
    }
    
    if (newLocation.horizontalAccuracy > 100 ||
        newLocation.verticalAccuracy > 50) {
        // accuracy radius is so large, we don't want to use it
        return;
    }
    
    if (self.previousPoint == nil) {
        self.totalMovementDistance = 0;
    } else {
        NSLog(@"movement distance: %f", [newLocation
                                             distanceFromLocation:self.previousPoint]);
        
        self.totalMovementDistance += [newLocation
                                  distanceFromLocation:self.previousPoint];
    }
    self.previousPoint = newLocation;
    
    NSString *distanceString = [NSString stringWithFormat:@"%gm",
                                self.totalMovementDistance];
    self.distanceTraveledLabel.text = distanceString;
    
}

BidViewController3

- (void)locationManager:(CLLocationManager *)manager
       didFailWithError:(NSError *)error {
    NSString *errorType = (error.code == kCLErrorDenied) ?
                          @"Access Denied" : @"Unknown Error";
    UIAlertView *alert = [[UIAlertView alloc]
                          initWithTitle:@"Error getting Location"
                          message:errorType
                          delegate:nil
                          cancelButtonTitle:@"Okay"
                          otherButtonTitles:nil];
    [alert show];
}

BIDViewController4

@property (strong, nonatomic) Firebase * timeRef;
@property (strong, nonatomic) Firebase * latRef;
@property (strong, nonatomic) Firebase * longRef;
@property (strong, nonatomic) CLLocation * coords;
@property (strong, nonatomic) Firebase *root;
@property (strong, nonatomic) NSMutableDictionary * others;
@property (assign, nonatomic) double oldTime;

BIDVIewController5

UIDevice *device = [UIDevice currentDevice];
    NSString  *currentDeviceId = [[device identifierForVendor]UUIDString];
    NSString * url = @"https://491presentation.firebaseio.com/";
    self.root = [[Firebase alloc] initWithUrl:url];
    url = [url stringByAppendingString: currentDeviceId];
    Firebase *myRootRef = [[Firebase alloc] initWithUrl:url];
    self.latRef = [myRootRef childByAppendingPath: @"/latitude"];
    self.longRef = [myRootRef childByAppendingPath: @"/longitude"];
    self.timeRef = [myRootRef childByAppendingPath:@"/velocity"];
    
    [self.root observeEventType:FEventTypeChildAdded withBlock:^(FDataSnapshot *snapshot) {
        [self displayData:snapshot];
    } withCancelBlock:^(NSError *error) {
        NSLog(@"%@", error.description);
    }];
    
    [self.root observeEventType:FEventTypeChildChanged withBlock:^(FDataSnapshot *snapshot) {
        [self changeChild:snapshot];
    } withCancelBlock:^(NSError *error) {
        NSLog(@"%@", error.description);
    }];
    self.others = [[NSMutableDictionary alloc] init];
    self.oldTime = [[NSDate date] timeIntervalSince1970];

BIDViewController6

       double now = [[NSDate date] timeIntervalSince1970];
       double difference = now - self.oldTime;
       double distance = [self.coords distanceFromLocation:newLocation];
       double velocity = distance/difference;
       self.coords = newLocation;
       self.oldTime = now;
       [self sendLocation:velocity];

BIDVIewController7

-(void)displayData:(FDataSnapshot*)snapshot
{
    CLLocationCoordinate2D coordinates;
    NSString * lat = snapshot.value[@"latitude"];
    NSString * lon = snapshot.value[@"longitude"];
    coordinates.latitude = [lat doubleValue];
    coordinates.longitude = [lon doubleValue];
    
    BIDPlace *start = [[BIDPlace alloc] init];
    start.coordinate = coordinates;
    start.title = snapshot.key;
    start.subtitle = @"This user is located here";
    [self.mapView addAnnotation:start];
    [self.others setObject:start forKey:snapshot.key];
}

-(void)changeChild:(FDataSnapshot*)snapshot
{
    BIDPlace * current = self.others[snapshot.key];
    CLLocationCoordinate2D coordinates;
    NSString * lat = snapshot.value[@"latitude"];
    NSString * lon = snapshot.value[@"longitude"];
    NSString * velocity = snapshot.value[@"velocity"];
    coordinates.latitude = [lat doubleValue];
    coordinates.longitude = [lon doubleValue];
    current.coordinate = coordinates;
    CLLocation * loc = [[CLLocation alloc] initWithLatitude:coordinates.latitude longitude:coordinates.longitude];
    NSString * distance = @"This user is ";
    double distValue = [self.coords distanceFromLocation:loc];
    NSNumber *myDoubleNumber = [NSNumber numberWithDouble:distValue];
    distance = [distance stringByAppendingString: [myDoubleNumber stringValue]];
    distance = [distance stringByAppendingString:@" m away"];
    current.title =[@"Velocity: " stringByAppendingString: velocity];
    current.subtitle = distance;
}

-(void) sendLocation:(double)velocity
{
    
    [self.latRef setValue:[NSString stringWithFormat:@"%f", self.coords.coordinate.latitude]];
    [self.longRef setValue:[NSString stringWithFormat:@"%f", self.coords.coordinate.longitude]];
    [self.timeRef setValue: @(velocity).stringValue];
}