//  Name:           Enums
//
//  Description:    Code for managing a more native Enum implementation
//
//  Credit:         dphilipson/typescript-string-enums
//                  https://github.com/dphilipson/typescript-string-enums/blob/master/src/index.ts
//
//  Requires:
//
//  ============================================================================

export function Enum<V extends string>(...values: V[]): { [K in V]: K };
export function Enum<T extends { [_: string]: V }, V extends string>(
  definition: T
): T;
export function Enum(...values: any[]): object {
  if (typeof values[0] === 'string') {
    const result: any = {};
    for (const value of values) {
      result[value] = value;
    }
    return result;
  } else {
    return values[0];
  }
}

export type Enum<T extends object> = T[keyof T];

export function ofEnumKeys<T extends { [_: string]: any }>(
  e: T
): { [K in keyof T]: K } {
  const result: any = {};
  for (const key of Object.keys(e)) {
    result[key] = key;
  }
  return result;
}

export function enumKeys<T extends { [_: string]: any }>(e: T): Array<keyof T> {
  return Object.keys(e) as Array<keyof T>;
}

export function enumValues<T extends { [_: string]: any }>(
  e: T
): Array<Enum<T>> {
  const result: Array<Enum<T>> = [];
  for (const key of Object.keys(e)) {
    result.push(e[key]);
  }
  return result;
}

export function isEnumType<T extends { [_: string]: any }>(
  e: T,
  value: any
): value is Enum<T> {
  return enumValues(e).indexOf(value) !== -1;
}