HealthKitManager.m

+ (HealthKitManager *)sharedManager {
    static dispatch_once_t pred = 0;
    static HealthKitManager *instance = nil;
    dispatch_once(&pred, ^{
        instance = [[HealthKitManager alloc] init];
        instance.healthStore = [[HKHealthStore alloc] init];
        instance.connected = [[NSUserDefaults standardUserDefaults] boolForKey:APPLE_HEALTHKIT_CONNECTION];
    });
    return instance;
}

- (void)requestAuthorization:(void(^)(BOOL success, NSError *error))callback {
    
    if ([HKHealthStore isHealthDataAvailable] == NO) {
        // If our device doesn't support HealthKit -> return.
        return;
    }
    
    // Share body mass, height and body mass index
    NSSet *shareObjectTypes = [NSSet setWithObjects:
                               [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierActiveEnergyBurned],
                               [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierDistanceWalkingRunning],
                               [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate],
                               [HKObjectType workoutType],
                               nil];
    
    // Read date of birth, biological sex and step count
    NSSet *readObjectTypes  = [NSSet setWithObjects:
                               [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierBodyMass],
                               [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeight],
                               [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierBodyMassIndex],
                               nil];
    
    // Request access
    [self.healthStore requestAuthorizationToShareTypes:shareObjectTypes
                                        readTypes:readObjectTypes
                                       completion:^(BOOL success, NSError *error) {
                                           
                                           if(success == YES) {
                                               [[NSUserDefaults standardUserDefaults] setBool:YES forKey:APPLE_HEALTHKIT_CONNECTION];
                                               [[NSUserDefaults standardUserDefaults] synchronize];
                                               self.connected = YES;
                                           } else {
                                               NSLog(@"Apple HealthKit Connection Failed!");
                                           }
                                           
                                           if (callback)
                                               callback(success, error);
                                       }];
}

- (void)writeDistance:(NSNumber *)value startDate:(NSDate *)startDate endDate:(NSDate *)endDate{
    
    // Each quantity consists of a value and a unit.
    HKUnit *unit = [HKUnit meterUnit];
    HKQuantity *distanceQuantity = [HKQuantity quantityWithUnit:unit doubleValue:value.floatValue];
    
    HKQuantityType *distanceType = [HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierDistanceWalkingRunning];
    
    // For every sample, we need a sample type, quantity and a date.
    HKQuantitySample *hrObj = [HKQuantitySample quantitySampleWithType:distanceType quantity:distanceQuantity startDate:startDate endDate:endDate];
    
    [self.healthStore saveObject:hrObj withCompletion:^(BOOL success, NSError *error) {
        if (!success) {
            NSLog(@"Error while saving value (%f) to Health Store: %@.", value.floatValue, error);
        }
    }];
}


- (void)writeCalories:(NSNumber *)value startDate:(NSDate *)startDate endDate:(NSDate *)endDate{
    
    // Each quantity consists of a value and a unit.
    HKUnit *unit = [HKUnit kilocalorieUnit];
    HKQuantity *caloriesQuantity = [HKQuantity quantityWithUnit:unit doubleValue:value.floatValue];
    
    HKQuantityType *caloriesType = [HKQuantityType quantityTypeForIdentifier:HKQuantityTypeIdentifierActiveEnergyBurned];
    
    // For every sample, we need a sample type, quantity and a date.
    HKQuantitySample *hrObj = [HKQuantitySample quantitySampleWithType:caloriesType quantity:caloriesQuantity startDate:startDate endDate:endDate];
    
    [self.healthStore saveObject:hrObj withCompletion:^(BOOL success, NSError *error) {
        if (!success) {
            NSLog(@"Error while saving value (%f) to Health Store: %@.", value.floatValue, error);
        }
    }];
}

- (void)writeWorkoutWithEnergyBurned:(NSNumber *)energyBurned distance:(NSNumber *)distance startDate:(NSDate *)startDate endDate:(NSDate *)endDate{
    
    HKUnit *unit_cal = [HKUnit kilocalorieUnit];
    HKQuantity *caloriesQuantity = [HKQuantity quantityWithUnit:unit_cal doubleValue:energyBurned.floatValue];
    
    HKUnit *unit_dis = [HKUnit meterUnit];
    HKQuantity *distanceQuantity = [HKQuantity quantityWithUnit:unit_dis doubleValue:distance.floatValue];

    HKWorkout *workout = [HKWorkout workoutWithActivityType:HKWorkoutActivityTypeRowing
                                                  startDate:startDate
                                                    endDate:endDate
                                                   duration:[endDate timeIntervalSinceDate:startDate]
                                          totalEnergyBurned:caloriesQuantity
                                              totalDistance:distanceQuantity
                                                   metadata:nil];
    
    [self.healthStore saveObject:workout withCompletion:^(BOOL success, NSError *error) {
        if (!success) {
            NSLog(@"Error while saving value (%f), value (%f) to Health Store: %@.", distance.floatValue, energyBurned.floatValue, error);
        }
    }];
}