class ActiveSupport::NumberHelper::NumberToPhoneConverter

def convert
  str = country_code(opts[:country_code]).dup
  str << convert_to_phone_number(number.to_s.strip)
  str << phone_ext(opts[:extension])
end

def convert_to_phone_number(number)
  if opts[:area_code]
    convert_with_area_code(number)
  else
    convert_without_area_code(number)
  end
end

def convert_with_area_code(number)
  default_pattern = /(\d{1,3})(\d{3})(\d{4}$)/
  number.gsub!(regexp_pattern(default_pattern),
               "(\\1) \\2#{delimiter}\\3")
  number
end

def convert_without_area_code(number)
  default_pattern = /(\d{0,3})(\d{3})(\d{4})$/
  number.gsub!(regexp_pattern(default_pattern),
               "\\1#{delimiter}\\2#{delimiter}\\3")
  number.slice!(0, 1) if start_with_delimiter?(number)
  number
end

def country_code(code)
  code.blank? ? "" : "+#{code}#{delimiter}"
end

def delimiter
  opts[:delimiter] || "-"
end

def phone_ext(ext)
  ext.blank? ? "" : " x #{ext}"
end

def regexp_pattern(default_pattern)
  opts.fetch :pattern, default_pattern
end

def start_with_delimiter?(number)
  delimiter.present? && number.start_with?(delimiter)
end