require "active_model/validations/clusivity"

module ActiveModel

  # == Active Model Exclusion Validator
  module Validations
    class ExclusionValidator < EachValidator #:nodoc:
      include Clusivity

      def validate_each(record, attribute, value)
        if include?(record, value)
          record.errors.add(attribute, :exclusion, options.except(:in).merge!(:value => value))
        end
      end
    end

    module HelperMethods
      # Validates that the value of the specified attribute is not in a
      # particular enumerable object.
      #
      #   class Person < ActiveRecord::Base
      #     validates_exclusion_of :username, in: %w( admin superuser ), message: "You don't belong here"
      #     validates_exclusion_of :age, in: 30..60, message: 'This site is only for under 30 and over 60'
      #     validates_exclusion_of :format, in: %w( mov avi ), message: "extension %{value} is not allowed"
      #     validates_exclusion_of :password, in: ->{ |p| [p.username, p.first_name] },
      #                            message: 'should not be the same as your username or first name'
      #   end
      #
      # Configuration options:
      # * <tt>:in</tt> - An enumerable object of items that the value shouldn't
      #   be part of. This can be supplied as a proc or lambda which returns an
      #   enumerable. If the enumerable is a range the test is performed with
      #   <tt>Range#cover?</tt>, otherwise with <tt>include?</tt>.
      # * <tt>:message</tt> - Specifies a custom error message (default is: "is
      #   reserved").
      # * <tt>:allow_nil</tt> - If set to true, skips this validation if the
      #   attribute is +nil+ (default is +false+).
      # * <tt>:allow_blank</tt> - If set to true, skips this validation if the
      #   attribute is blank(default is +false+).
      # * <tt>:on</tt> - Specifies when this validation is active. Runs in all
      #   validation contexts by default (+nil+), other options are <tt>:create</tt>
      #   and <tt>:update</tt>.
      # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if
      #   the validation should occur (e.g. <tt>if: :allow_validation</tt>, or
      #   <tt>if: Proc.new { |user| user.signup_step > 2 }</tt>). The method,
      #   proc or string should return or evaluate to a +true+ or +false+ value.
      # * <tt>:unless</tt> - Specifies a method, proc or string to call to determine
      #   if the validation should not occur (e.g. <tt>unless: :skip_validation</tt>,
      #   or <tt>unless: Proc.new { |user| user.signup_step <= 2 }</tt>). The
      #   method, proc or string should return or evaluate to a +true+ or
      #   +false+ value.
      # * <tt>:strict</tt> - Specifies whether validation should be strict.
      #   See <tt>ActiveModel::Validation#validates!</tt> for more information.
      def validates_exclusion_of(*attr_names)
        validates_with ExclusionValidator, _merge_attributes(attr_names)
      end
    end
  end
end