import preferences from '@ohos.data.preferences';

export class PreferencesHelper {
  private constructor() {
  }

  public static async put(key: string, value: preferences.ValueType | undefined | null) {

    const pref = await preferences.getPreferences(getContext(), 'PreferencesHelper')
    // 写入数据
    if (value !== undefined && value !== null) {
      await pref.put(key, value)
    } else {
      await pref.delete(key)
    }
    // 刷盘
    await pref.flush()
  }

  public static async get(key: string): Promise<preferences.ValueType> {
    return new Promise(async (resolve, reject) => {

      const pref = await preferences.getPreferences(getContext(), 'PreferencesHelper')
      pref.get(key, undefined).then((r1: preferences.ValueType) => {
        resolve(r1)
      })
    })

  }

  public static async delete(key: string): Promise<void> {
    return new Promise(async (resolve, reject) => {

      const pref = await preferences.getPreferences(getContext(), 'PreferencesHelper')
      pref.delete(key).then(() => {
        resolve()
      })
    })

  }
}