export const emailRegex = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/

export const combineValidators = (...validators: any) => (...value: any) => {
  for (let i = 0; i < validators.length; ++i) {
    const error_message = validators[i](...value)
    if (error_message) return error_message
  }
}

export function isFalsy(item: any) {
  try {
    if (
      !item || // handles most, like false, 0, null, etc
      (typeof item === 'object' &&
        Object.keys(item).length === 0 && // for empty objects, like {}, []
        !(typeof item.addEventListener === 'function')) // omit webpage elements
    ) {
      return true
    }
  } catch (err) {
    return true
  }

  return false
}

export const requiredValidator = (
  value?: string | number | Array<string> | boolean,
  message?: string
): string => {
  let errorMessage = ''

  if (isFalsy(typeof value === 'string' ? value.trim() : value)) {
    errorMessage = message || 'Required'
  }
  return errorMessage
}

export const emailValidator = (email: string) =>
  !emailRegex.test(email) ? 'Please enter a valid email address' : ''

export const passwordValidator = (password: string): string => {
  if (!password || password.length < 6) {
    return 'The password must be at least 6 characters.'
  }
  return ''
}

export const confirmPasswordValidator = (confirmPassword: string, password: string): string => {
  if (confirmPassword !== password) {
    return 'Passwords do not match.'
  }
  return ''
}

export const confirmEmailValidator = (confirmEmail: string, email: string): string => {
  if (confirmEmail !== email) {
    return 'Emails do not match.'
  }
  return ''
}