/**
 * An error to be used when an object of the same type already exists
 */
export class AlreadyExistsError extends Error {
  /**
   * An array of strings identifying the resources that caused the error
   * @private
   * @type { string[] }
   * @ignore
   */
  private _conflicts: string[] = []

  public constructor(
    message?: string,
    ...conflicts: string[] | AlreadyExistsError[]
  ) {
    super(message ? message : 'Already exists')
    this.name = 'AlreadyExistsError'
    Object.setPrototypeOf(this, AlreadyExistsError.prototype)
    if (conflicts.length > 0) {
      if (this.isStringArray(conflicts)) {
        // set string array to provided string array
        this._conflicts = conflicts as string[]
      } else {
        // set string array to content of string arrays from provided error array
        const arrays = (conflicts as AlreadyExistsError[]).map(
          item => item.conflicts
        )
        this._conflicts = Array<string>().concat(...arrays)
      }
    }
  }

  /**
   * Returns an array of strings identifying the resources that caused the error
   */
  public get conflicts(): string[] {
    return this._conflicts
  }

  /**
   * Tests if an array is of type string[]
   * @param { [] } array The array to test
   */
  private isStringArray(array: any[]): boolean {
    return Array.isArray(array) && array.every(item => typeof item === 'string')
  }
}