declare namespace C_AchivementInfo {
  /**
   * Returns any reward item for an achievement
   * @param achivementId
   * @returns rewardItemID
   * @see https://wow.gamepedia.com/API_C_AchievementInfo.GetRewardItemID
   * @since 8.1.0 (2018-12-11)
   */
  function GetRewardItemID(achivementId: number): number | null;

  /**
   * Returns the next achievement in a series
   * @param achivementId
   * @returns supercedingAchievements Only returns the next ID in a series even though it's in a table
   * @see https://wow.gamepedia.com/API_C_AchievementInfo.GetSupercedingAchievements
   * @since 8.1.0 (2018-12-11)
   */
  function GetSupercedingAchievements(achivementId: number): number[];

  /**
   * Needs summary
   * @param achivementId
   * @returns isValidAchievement
   * @see https://wow.gamepedia.com/API_C_AchievementInfo.IsValidAchievement
   * @since 9.0.1 (2020-10-13)
   */
  function IsValidAchievement(achivementId: number): boolean;

  /**
   * Sets a portrait texture for the unit being achievement compared
   * @param textureObject
   * @see https://wow.gamepedia.com/API_C_AchievementInfo.IsValidAchievement
   * @since 8.0.1 (2018-07-17)
   */
  function IsValidAchievement(textureObject: WoWAPI.Texture): void;
}