/**
 * This is represented as an object instead of an enum due to limitations with TypeScript enums. (We
 * want this type to be a child of the `BitFlag` type.)
 *
 * @enum
 * @notExported
 * @rename TargetFlag
 */
const TargetFlagInternal = {
  /**
   * Allow switching to a better target even if we already have one.
   *
   * 1 << 0 (1)
   */
  ALLOW_SWITCHING: 1 << 0,

  /**
   * Do not prioritize enemies that are close to the familiar's owner.
   *
   * 1 << 1 (2)
   */
  DONT_PRIORITIZE_ENEMIES_CLOSE_TO_PLAYER: 1 << 1,

  /**
   * Prioritize enemies with higher HP.
   *
   * 1 << 2 (4)
   */
  PRIORITIZE_ENEMIES_WITH_HIGH_HP: 1 << 2,

  /**
   * Prioritize enemies with higher HP.
   *
   * 1 << 3 (8)
   */
  PRIORITIZE_ENEMIES_WITH_LOW_HP: 1 << 3,

  /**
   * Give a lower priority to our current target. (This makes it more likely for the familiar to
   * switch between targets.)
   *
   * 1 << 4 (16)
   */
  GIVE_LOWER_PRIORITY_TO_CURRENT_TARGET: 1 << 4,
} as const;

type TargetFlagValue = BitFlag & {
  readonly __targetFlagBrand: symbol;
};
type TargetFlagType = {
  readonly [K in keyof typeof TargetFlagInternal]: TargetFlagValue;
};

export const TargetFlag = TargetFlagInternal as TargetFlagType;
export type TargetFlag = TargetFlagType[keyof TargetFlagType];

export const TargetFlagZero = 0 as BitFlags<TargetFlag>;