class CreditCardValidator < ActiveModel::EachValidator

  def validate_each(record, attribute, value)
    unless valid?(value.to_s, options)
      record.errors[attribute] << (options.fetch(:message, false) || I18n.t('active_validation.errors.messages.credit_card'.freeze))
    end
  end

  private

  DEFAULT_LENGTHS = {
    american_express: [15],
    diners_club: [14, 16],
    discover: [16],
    jcb: [16],
    laser: [16, 17, 18, 19],
    maestro: [12, 13, 14, 15, 16, 17, 18, 19],
    mastercard: [16],
    solo: [16, 18, 19],
    unionpay: [16, 17, 18, 19],
    visa: [16]
  }.freeze

  DEFAULT_PREFIXES = {
    american_express: ['34', '37'],
    diners_club: ['300', '301', '302', '303', '304', '305', '36', '54', '55'],
    discover: [
      '6011', '622126', '622127', '622128', '622129', '62213',
      '62214', '62215', '62216', '62217', '62218', '62219',
      '6222', '6223', '6224', '6225', '6226', '6227', '6228',
      '62290', '62291', '622920', '622921', '622922', '622923',
      '622924', '622925', '644', '645', '646', '647', '648',
      '649', '65'
    ],
    jcb: ['3528', '3529', '353', '354', '355', '356', '357', '358'],
    laser: ['6304', '6706', '6771', '6709'],
    maestro: [
      '5018', '5020', '5038', '6304', '6759', '6761', '6762',
      '6763', '6764', '6765', '6766'
    ],
    mastercard: ['51', '52', '53', '54', '55'],
    solo: ['6334', '6767'],
    unionpay: [
      '622126', '622127', '622128', '622129', '62213', '62214',
      '62215', '62216', '62217', '62218', '62219', '6222', '6223',
      '6224', '6225', '6226', '6227', '6228', '62290', '62291',
      '622920', '622921', '622922', '622923', '622924', '622925'
    ],
    visa: ['4']
  }.freeze

  def valid_format?(value, options)
    value =~ (options.fetch(:strict, false) ? /^[0-9]+$/ : /^[0-9 -.]+$/)
  end

  def valid_length?(value, options)
    return(false) unless value.present?

    current_card = options.fetch(:card, :all).to_sym
    value_size   = value.size

    case current_card
    when :amex
      DEFAULT_LENGTHS.fetch(:american_express).include?(value_size)
    when :all
      value_size_range = DEFAULT_LENGTHS.values.flatten.uniq.sort
      value_size.between?(value_size_range.first, value_size_range.last)
    else
      DEFAULT_LENGTHS.fetch(current_card).include?(value_size)
    end
  end

  def valid_prefix?(value, options)
    current_card = options.fetch(:card, :all).to_sym

    case current_card
    when :amex
      DEFAULT_PREFIXES.fetch(:american_express).any? { |p| value.start_with?(p) }
    when :all
      result = false
      DEFAULT_LENGTHS.lazy.each do |key, values|
        break if result = DEFAULT_PREFIXES.fetch(key).any? { |p| value.start_with?(p) } if values.include?(value.size)
      end
      result
    else
      DEFAULT_PREFIXES.fetch(current_card).any? { |p| value.start_with?(p) }
    end
  end

  def valid?(value, options)
    striped_value = value.gsub(/\D/, ''.freeze)

    valid_format?(value, options) &&
    valid_length?(striped_value, options) &&
    valid_prefix?(striped_value, options)
  end

end