declare global {
  interface Navigator {
    getBattery: () => Promise<BatteryManager>;
  }
}
interface BatteryManager {
  /** 电池是否充电中 */
  readonly charging: boolean;
  /** 电池充满所需时间(秒)，为 0 则充电完毕 */
  readonly chargingTime: number;
  /** 电池剩余可用时间(秒) */
  readonly dischargingTime: number;
  /** 剩余电量，0.0-1.0 */
  readonly level: number;
  /** 电池充电状态改变时触发该监听函数 */
  onchargingchange: null | ((event: { target: BatteryManager }) => void);
  /** 电池充满所需时间改变时触发该监听函数 */
  onchargingtimechange: null | ((event: { target: BatteryManager }) => void);
  /** 电池剩余可用时间改变时触发该监听函数 */
  ondischargingtimechange: null | ((event: { target: BatteryManager }) => void);
  /** 电池电量改变时触发该监听函数 */
  onlevelchange: null | ((event: { target: BatteryManager }) => void);
}
/** 电池状态 */
interface Battery extends Pick<BatteryManager, 'charging' | 'chargingTime' | 'dischargingTime' | 'level'> {
  apiSupport: boolean;
}

/** 电池管理 */
export function useBattery() {
  const [battery, setBattery] = useSetState<Battery>({
    apiSupport: false,
    charging: true,
    chargingTime: Infinity,
    dischargingTime: Infinity,
    level: 1,
  });

  /** 更新电池使用状态 */
  const updateBattery = ({ charging, chargingTime, dischargingTime, level }: BatteryManager) => {
    setBattery({ apiSupport: true, charging, chargingTime, dischargingTime, level });
  };
  /** 计算电池充电状态 */
  const calcBatteryStatus = () => {
    if (battery.charging && battery.level >= 1) return '已充满';
    else if (battery.charging) return '充电中';
    else return '已断开电源';
  };
  /** 计算电池剩余可用时间 */
  const calcDischargingTime = () => {
    const hour = battery.dischargingTime / 3600;
    const minute = (battery.dischargingTime / 60) % 60;
    return battery.charging
      ? '电源已接通'
      : battery.dischargingTime === Infinity
      ? '计算中...'
      : `${~~hour}小时${~~minute}分钟`;
  };
  /** 计算电池充满剩余时间 */
  const calcChargingTime = () => {
    const hour = battery.chargingTime / 3600;
    const minute = (battery.chargingTime / 60) % 60;
    return `${~~hour}小时${~~minute}分钟`;
  };

  useAsyncEffect(async () => {
    const BatteryManager = await globalThis.navigator?.getBattery?.();

    if (BatteryManager) {
      updateBattery(BatteryManager);

      // 电池充电状态改变时触发该监听函数
      BatteryManager.onchargingchange = ({ target }) => {
        updateBattery(target);
      };
      // 电池充满所需时间改变时触发该监听函数
      BatteryManager.onchargingtimechange = ({ target }) => {
        updateBattery(target);
      };
      // 电池剩余可用时间改变时触发该监听函数
      BatteryManager.ondischargingtimechange = ({ target }) => {
        updateBattery(target);
      };
      // 电池电量改变时触发该监听函数
      BatteryManager.onlevelchange = ({ target }) => {
        updateBattery(target);
      };
    }
  }, []);

  return { battery, calcDischargingTime, calcChargingTime, calcBatteryStatus };
}