import AppleHealthKit, { HealthKitPermissions } from 'react-native-health';

const PERMISSIONS: HealthKitPermissions = {
  permissions: {
    read: [
      AppleHealthKit.Constants.Permissions.StepCount,
      AppleHealthKit.Constants.Permissions.ActiveEnergyBurned,
    ],
    write: [],
  },
};

export type TodayHealthData = {
  steps: number;
  activeEnergyBurned: number; // kilocalories
};

export async function ensureHealthPermissions(): Promise<boolean> {
  return new Promise((resolve) => {
    AppleHealthKit.initHealthKit(PERMISSIONS, (error) => {
      if (error) {
        console.warn('HealthKit init failed', error);
        resolve(false);
        return;
      }
      console.log('HealthKit init success');
      resolve(true);
    });
  });
}

export async function fetchTodayHealthData(): Promise<TodayHealthData> {
  const start = new Date();
  start.setHours(0, 0, 0, 0);
  const options = { startDate: start.toISOString() } as any;

  const steps = await new Promise<number>((resolve) => {
    AppleHealthKit.getStepCount(options, (err, res) => {
      if (err || !res) return resolve(0);
      resolve(res.value || 0);
    });
  });

  const calories = await new Promise<number>((resolve) => {
    AppleHealthKit.getActiveEnergyBurned(options, (err, res) => {
      if (err || !res) return resolve(0);
      // library returns value as number in kilocalories
      resolve(res[0].value || 0);
    });
  });

  return { steps, activeEnergyBurned: calories };
}