#import <React/RCTBridgeModule.h>
#import <HealthKit/HealthKit.h>

@interface HealthKitBridge : NSObject <RCTBridgeModule>
@end

@implementation HealthKitBridge
{
  HKHealthStore *_store;
}

RCT_EXPORT_MODULE();

- (instancetype)init {
  self = [super init];
  if (self) {
    _store = [[HKHealthStore alloc] init];
  }
  return self;
}

+ (BOOL)requiresMainQueueSetup { return NO; }

RCT_EXPORT_METHOD(requestAuthorization:(RCTPromiseResolveBlock)resolve
                  rejecter:(RCTPromiseRejectBlock)reject)
{
  NSSet *readTypes = [NSSet setWithArray:@[
    [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate],
    [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount],
    [HKObjectType categoryTypeForIdentifier:HKCategoryTypeIdentifierSleepAnalysis],
  ]];
  [_store requestAuthorizationToShareTypes:nil readTypes:readTypes completion:^(BOOL success, NSError *error) {
    if (success) resolve(@YES);
    else reject(@"healthkit", error.localizedDescription, error);
  }];
}

RCT_EXPORT_METHOD(getLatestHeartRate:(RCTPromiseResolveBlock)resolve
                  rejecter:(RCTPromiseRejectBlock)reject)
{
  HKQuantityType *type = [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierHeartRate];
  NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:HKSampleSortIdentifierEndDate ascending:NO];
  HKSampleQuery *query = [[HKSampleQuery alloc] initWithSampleType:type predicate:nil limit:1 sortDescriptors:@[sort]
    resultsHandler:^(HKSampleQuery *q, NSArray *results, NSError *error) {
    if (error) { reject(@"healthkit", error.localizedDescription, error); return; }
    if (results.count == 0) { resolve(@{}); return; }
    HKQuantitySample *sample = results[0];
    double bpm = [sample.quantity doubleValueForUnit:[HKUnit unitFromString:@"count/min"]];
    resolve(@{@"bpm": @(bpm), @"time": @([sample.endDate timeIntervalSince1970] * 1000)});
  }];
  [_store executeQuery:query];
}

RCT_EXPORT_METHOD(getTodaySteps:(RCTPromiseResolveBlock)resolve
                  rejecter:(RCTPromiseRejectBlock)reject)
{
  HKQuantityType *type = [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount];
  NSCalendar *cal = [NSCalendar currentCalendar];
  NSDate *start = [cal startOfDayForDate:[NSDate date]];
  NSDate *end = [NSDate date];
  NSPredicate *pred = [HKQuery predicateForSamplesWithStartDate:start endDate:end options:HKQueryOptionStrictStartDate];
  HKStatisticsQuery *query = [[HKStatisticsQuery alloc] initWithQuantityType:type
    quantitySamplePredicate:pred options:HKStatisticsOptionCumulativeSum
    completionHandler:^(HKStatisticsQuery *q, HKStatistics *result, NSError *error) {
    if (error) { reject(@"healthkit", error.localizedDescription, error); return; }
    double steps = [result.sumQuantity doubleValueForUnit:[HKUnit countUnit]];
    resolve(@{@"steps": @(steps)});
  }];
  [_store executeQuery:query];
}

RCT_EXPORT_METHOD(getLastSleep:(RCTPromiseResolveBlock)resolve
                  rejecter:(RCTPromiseRejectBlock)reject)
{
  HKCategoryType *type = [HKObjectType categoryTypeForIdentifier:HKCategoryTypeIdentifierSleepAnalysis];
  NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:HKSampleSortIdentifierEndDate ascending:NO];
  HKSampleQuery *query = [[HKSampleQuery alloc] initWithSampleType:type predicate:nil limit:1 sortDescriptors:@[sort]
    resultsHandler:^(HKSampleQuery *q, NSArray *results, NSError *error) {
    if (error) { reject(@"healthkit", error.localizedDescription, error); return; }
    if (results.count == 0) { resolve(@{}); return; }
    HKCategorySample *sample = results[0];
    double hours = [sample.endDate timeIntervalSinceDate:sample.startDate] / 3600.0;
    resolve(@{@"hours": @(hours), @"start": @([sample.startDate timeIntervalSince1970] * 1000), @"end": @([sample.endDate timeIntervalSince1970] * 1000)});
  }];
  [_store executeQuery:query];
}

@end