const MAX_COLOUR_NAME_LEN = 20;
const MIN_COLOUR_NAME_LEN = 2;

/**
 * Validate colour name.
 * - Allowed characters: letters, numbers, spaces, underscores, and hyphens.
 * - Min length: 2 characters.
 * - Max length: 20 characters.
 *
 * @param colourName Colour name string to validate.
 * @getters getResult(), getColourName(), hasErrors(), getErrorsList()
 * @result string or null
 */
export default class ValidateOptionName {
  private result: string | null = null;
  private errors: boolean = false;
  private errmsg: string[] = [];
  private colourName: string = "";

  constructor(colourName: string) {
    this.colourName = colourName;

    if (this.isLenTooLong() || this.isLenTooShort()) {
      this.setErrorState();
      return;
    }

    const regex = /^[a-zA-Z0-9 _-]{2,20}$/;

    if (!regex.test(this.colourName)) {
      this.setErrorState();
      this.addError(
        "Colour name is not valid. Only letters, numbers, spaces, underscores, and hyphens are allowed. Between 2 and 20 characters long."
      );
      return;
    }

    this.result = this.colourName;
  }

  get getResult() {
    return this.result;
  }

  get getColourName() {
    return this.colourName;
  }

  get hasErrors() {
    return this.errors;
  }

  get getErrorsList() {
    return this.errmsg;
  }

  private addError(msg: string) {
    this.errmsg.push(msg);
  }

  private setErrorState() {
    this.errors = true;
  }

  private showErrors() {
    this.errmsg.forEach((msg) => {
      console.log(msg);
    });
  }

  private isLenTooLong() {
    if (this.colourName.length > MAX_COLOUR_NAME_LEN) {
      this.addError(`Colour name is too long. Max length is ${MAX_COLOUR_NAME_LEN}.`);
      return true;
    }
    return false;
  }

  private isLenTooShort() {
    if (this.colourName.length < MIN_COLOUR_NAME_LEN) {
      this.addError(`Colour name is too short. Min length is ${MIN_COLOUR_NAME_LEN}.`);
      return true;
    }
    return false;
  }
}