HealthKit

import HealthKit

class HealthKitManager {
    let healthStore = HKHealthStore()
    
    func requestAuthorization() {
        guard HKHealthStore.isHealthDataAvailable() else {
            print("HealthKit not available")
            return
        }
        
        let typesToRead: Set<HKObjectType> = [
            HKObjectType.quantityType(forIdentifier: .stepCount)!,
            HKObjectType.quantityType(forIdentifier: .heartRate)!
        ]
        
        let typesToWrite: Set<HKSampleType> = [
            HKObjectType.quantityType(forIdentifier: .stepCount)!
        ]
        
        healthStore.requestAuthorization(toShare: typesToWrite, read: typesToRead) { success, error in
            if success {
                print("HealthKit authorized")
            } else if let error = error {
                print("Error: \(error.localizedDescription)")
            }
        }
    }
}

import HealthKit

func queryStepCount(completion: @escaping (Double) -> Void) {
    guard let stepType = HKQuantityType.quantityType(forIdentifier: .stepCount) else { return }
    
    let now = Date()
    let startOfDay = Calendar.current.startOfDay(for: now)
    let predicate = HKQuery.predicateForSamples(withStart: startOfDay, end: now, options: .strictStartDate)
    
    let query = HKStatisticsQuery(quantityType: stepType, quantitySamplePredicate: predicate, options: .cumulativeSum) { _, result, error in
        guard let result = result, let sum = result.sumQuantity() else {
            completion(0)
            return
        }
        
        completion(sum.doubleValue(for: HKUnit.count()))
    }
    
    HKHealthStore().execute(query)
}