import { ModelValidateOptions } from 'sequelize';

import { addAttributeOptions } from '../model/column/attribute-service';

/**
 * Adds custom validator
 * @param name Name of validator
 * @param validator Validator function
 */
export function Is(name: string, validator: (value: any) => any): Function;
/**
 * Adds custom validator
 * @param validator Validator function
 */
export function Is(validator: (value: any) => any): Function;
/**
 * Will only allow values, that match the string regex or real regex
 */
export function Is(
  arg:
    | string
    | (string | RegExp)[]
    | RegExp
    | { msg: string; args: string | (string | RegExp)[] | RegExp }
): Function;
export function Is(...args: any[]): Function {
  const options: ModelValidateOptions = {};
  const argIsFunction = typeof args[0] === 'function';

  if (argIsFunction || (typeof args[0] === 'string' && typeof args[1] === 'function')) {
    let validator: (value: any) => any;
    let name: string;

    if (argIsFunction) {
      validator = args[0] as (value: any) => any;
      name = validator.name;

      if (!name) throw new Error(`Passed validator function must have a name`);
    } else {
      name = args[0];
      validator = args[1];
    }

    options[`is${name.charAt(0).toUpperCase() + name.substr(1, name.length)}`] = validator;
  } else {
    options.is = args[0];
  }

  return (target: any, propertyName: string) =>
    addAttributeOptions(target, propertyName, {
      validate: options,
    });
}