A Phone Number tiny type

phone_number.rb

# frozen_string_literal: true

class PhoneNumber
  EXACT_DIGITS = 10
  MAX_NON_DIGITS = 5

  delegate :present?, :blank?, :encoding, to: :@value
  delegate :hash, to: :strict

  def initialize(value)
    @value = value
  end

  # Format: +1112223333 or unaltered string
  def strict
    normalize(@value)
  end

  # Strict format or raise ArgumentError
  def strict!
    valid? ? strict : raise(ArgumentError, "Invalid strict phone number: #{@value}")
  end

  # In strict format already
  def valid?
    normalize(@value)&.match?(/\A\+\d{11}\z/)
  end

  def loose_valid?
    return false if @value.blank?

    digits = @value.to_s.gsub(/\D/, '')
    non_digits = @value.to_s.gsub(/\d/, '')

    digits.size == EXACT_DIGITS && non_digits.size <= MAX_NON_DIGITS
  end

  # 555-555-5555
  def display
    return @value unless valid?

    strict.to_s.delete_prefix('+1').insert(6, '-').insert(3, '-')
  end

  def ==(other)
    strict == if other.is_a?(PhoneNumber)
      other.strict
    else
      normalize(other)
    end
  end

  def presence
    present? ? self : nil
  end

  def to_s
    @value
  end

  # Allow comparison of "string" == PhoneNumber
  alias to_str to_s

  private

  # Turn into +1112223333, nil if blank, or unmodified value
  def normalize(string)
    return nil if string.blank?

    digits = string.to_s.strip.gsub(/\D/, '')
    if digits.size == 10
      "+1#{digits}"
    elsif digits.size == 11 && digits.start_with?('1')
      "+#{digits}"
    else
      string
    end
  end

  class Attribute < ActiveRecord::Type::Text
    def cast(value)
      return value if value.is_a?(PhoneNumber)
      return nil if value.nil?

      PhoneNumber.new(value)
    end

    def serialize(value)
      if value.present?
        value.is_a?(PhoneNumber) ? value.strict! : PhoneNumber.new(value).strict!
      end
    end

    def deserialize(value)
      value.nil? ? nil : PhoneNumber.new(value)
    end

    def changed_in_place?(raw_old_value, new_value)
      raw_old_value != serialize(new_value)
    end
  end
end