# validate attributes have only alpha, numeric and whitespace
require 'rails/alpha_numeric_validator/version'

class AlphaNumericValidator < ActiveModel::EachValidator
  attr_accessor :string # :nodoc:

  PUNCTUATION_REGEXP = {
    default: /(?:[[:alpha:]]|[[:digit:]])+/,
    :true => /(?:[[:graph:]])+/,
    limited: /(?:[[:alpha:]]|[[:digit:]]|[_:\+\.\?,\-!'\/#])+/, # ' vim-color-syntax hack
    dns: /(?:[[:alpha:]]|[[:digit:]]|[\.\-])+/,
    fqdn: /(?:[[:alpha:]]|[[:digit:]]|-|\.)+/}

  WHITESPACE_EXCEPTIONS = [:dns, :fqdn]

  # == Creation
  # To use the AlphaNumericValidator, initialize it as any other class
  #
  #   class ExampleValidator < ActiveRecord::Base
  #     validates :attr1, alpha_numeric: true
  #     validates :attr2, alpha_numeric: {punctuation: true}
  #     validates :attr3, alpha_numeric: {punctuation: :limited}
  #     validates :attr4, alpha_numeric: {allow_whitespace: true}
  #     validates :attr4, alpha_numeric: {dns: true}
  #   end

  def initialize(*args) # :nodoc:
    @errors = []
    @record = nil
    super(*args)
  end

  # :call-seq:
  # validate_each :record, :attribute, :value
  #
  # <tt>:record</tt>:: AR instance
  # <tt>:attribute</tt>:: symbol for attribute
  # <tt>:value</tt>:: value to check validity

  def validate_each(record, attribute, value) #:nodoc:
    @record = record
    opts = {punctuation: :default}
    opts.merge! allow_whitespace: !WHITESPACE_EXCEPTIONS.member?(@options[:punctuation])
    @options = opts.merge @options

    # TODO: document why value[1]
    @string = value.is_a?(Array) ? value[1] : value
    unless @string.nil? || @string.class.ancestors.include?(Numeric) || is_valid?
      record.errors[attribute] << 'invalid characters'
    end
  end

  # :call-seq:
  # is_valid?
  #
  # alias for :is_valid_string?

  def is_valid?
    is_valid_string?
  end

  # :call-seq:
  # is_valid_string?
  #
  # returns true if the string only contains the requested character set
  #
  # TODO: support international DNS

  def is_valid_string?
    return false if !@options[:allow_whitespace] && has_whitespace?
    re = PUNCTUATION_REGEXP[@options[:punctuation].to_s.to_sym]
    @string.to_s.gsub(re, "").blank?
  end

  # :call-seq:
  # has_whitespace?
  #
  # returns true if the string contains whitespace

  def has_whitespace?
    @string.to_s.match /(?:\s)+/
  end
end