/*

File: MyCLController.m
Abstract: Singleton class used to talk to CoreLocation and send results back to
the app's view controllers.

Version: 1.1

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*/

#import "MyCLController.h"

// This is a singleton class, see below
static MyCLController *sharedCLDelegate = nil;

@implementation MyCLController

@synthesize delegate, locationManager, updating;

- (id) init {
	self = [super init];
	if (self != nil) {
		self.locationManager = [[[CLLocationManager alloc] init] autorelease];
		self.locationManager.delegate = self; // Tells the location manager to send updates to this object
	}
	return self;
}

-(void)startUpdatingLocation {
	self.updating = YES;
	[self.locationManager startUpdatingLocation];
}

-(void)stopUpdatingLocation {
	self.updating = NO;
	[self.locationManager stopUpdatingLocation];
}

// Called when the location is updated
- (void)locationManager:(CLLocationManager *)manager
	didUpdateToLocation:(CLLocation *)newLocation
		   fromLocation:(CLLocation *)oldLocation
{

	// Negative accuracy means an invalid or unavailable measurement
	if (signbit(newLocation.horizontalAccuracy)) {
		return;
	}
	
	// If location timestamp was ages ago, it's a cached one; ignore it
	NSTimeInterval howRecent = [newLocation.timestamp timeIntervalSinceNow];
	if (abs(howRecent) > 5.0) {
		return;
	}

	[self.delegate newLocationUpdate:newLocation];
}


// Called when there is an error getting the location
- (void)locationManager:(CLLocationManager *)manager
	   didFailWithError:(NSError *)error
{
	NSMutableString *errorString = [[[NSMutableString alloc] init] autorelease];

	if ([error domain] == kCLErrorDomain) {

		// We handle CoreLocation-related errors here

		switch ([error code]) {
			// This error code is usually returned whenever user taps "Don't Allow" in response to
			// being told your app wants to access the current location. Once this happens, you cannot
			// attempt to get the location again until the app has quit and relaunched.
			//
			// "Don't Allow" on two successive app launches is the same as saying "never allow". The user
			// can reset this for all apps by going to Settings > General > Reset > Reset Location Warnings.
			//
			case kCLErrorDenied:
				[self stopUpdatingLocation];
				[self.delegate newLocationError:@"FixMyStreet needs your location to know where your problem is."];
				break;

			// This error code is usually returned whenever the device has no data or WiFi connectivity,
			// or when the location cannot be determined for some other reason.
			//
			// CoreLocation will keep trying, so you can keep waiting, or prompt the user.
			//
			case kCLErrorLocationUnknown:
				[errorString appendFormat:@"%@\n", NSLocalizedString(@"LocationUnknown", nil)];
				break;

			// We shouldn't ever get an unknown error code, but just in case...
			//
			default:
				[errorString appendFormat:@"%@ %d\n", NSLocalizedString(@"GenericLocationError", nil), [error code]];
				break;
		}
	} else {
		// We handle all non-CoreLocation errors here
		// (we depend on localizedDescription for localization)
		[errorString appendFormat:@"Error domain: \"%@\"  Error code: %d\n", [error domain], [error code]];
		[errorString appendFormat:@"Description: \"%@\"\n", [error localizedDescription]];
	}

	self.updating = NO;
	
	// Send the update to our delegate
	// [self.delegate newLocationUpdate:errorString];
}

#pragma mark ---- singleton object methods ----

// See "Creating a Singleton Instance" in the Cocoa Fundamentals Guide for more info

+ (MyCLController *)sharedInstance {
    @synchronized(self) {
        if (sharedCLDelegate == nil) {
            [[self alloc] init]; // assignment not done here
        }
    }
    return sharedCLDelegate;
}

+ (id)allocWithZone:(NSZone *)zone {
    @synchronized(self) {
        if (sharedCLDelegate == nil) {
            sharedCLDelegate = [super allocWithZone:zone];
            return sharedCLDelegate;  // assignment and return on first allocation
        }
    }
    return nil; // on subsequent allocation attempts return nil
}

- (id)copyWithZone:(NSZone *)zone
{
    return self;
}

- (id)retain {
    return self;
}

- (unsigned)retainCount {
    return UINT_MAX;  // denotes an object that cannot be released
}

- (void)release {
    //do nothing
}

- (id)autorelease {
    return self;
}

@end