module ActiveLdap
  module Validations
    extend ActiveSupport::Concern
    include ActiveModel::Validations

    module ClassMethods
      def attribute_method?(attribute)
        normalized_attribute = entry_attribute.normalize(attribute)
        normalized_attribute and normalized_attribute != "objectClass"
      end

      private
      def entry_attribute
        @entry_attribute ||=
          connection.entry_attribute(classes.collect(&:name))
      end
    end

    included do
      alias_method :new_record?, :new_entry?
      class << self
        unless method_defined?(:human_attribute_name_with_gettext)
          def human_attribute_name_with_gettext(attribute_key_name, options={})
            logger.warn("options was ignored.") unless options.empty?
            s_("#{self}|#{attribute_key_name.to_s.humanize}")
          end
        end
      end

      class_local_attr_accessor true, :validation_skip_attributes
      remove_method :validation_skip_attributes
      self.validation_skip_attributes = []

      validate :validate_duplicated_dn_creation, :on => :create
      validate :validate_duplicated_dn_rename, :on => :update
      validate :validate_dn
      validate :validate_excluded_classes
      validate :validate_required_ldap_values
      validate :validate_ldap_values
    end

    def validation_skip_attributes
      @validation_skip_attributes ||= []
    end

    def validation_skip_attributes=(attributes)
      @validation_skip_attributes = attributes
    end

    def valid?(context = nil)
      context ||= (new_entry? ? :create : :update)
      output = super(context)
      errors.empty? && output
    end

    def save(**options)
      perform_validations(options) ? super : false
    end

    def save!(**options)
      perform_validations(options) ? super : raise(EntryInvalid.new(self))
    end

    private
    def perform_validations(options)
      if options[:validate] == false
        true
      else
        valid?(options[:context])
      end
    end

    def format_validation_message(format, parameters)
      format % parameters
    end

    def validate_duplicated_dn_creation
      _dn = nil
      begin
        _dn = dn
      rescue DistinguishedNameInvalid, DistinguishedNameNotSetError
        return
      end
      if _dn and exist?
        format = _("is duplicated: %s")
        message = format_validation_message(format, _dn)
        errors.add("distinguishedName", message)
      end
    end

    def validate_duplicated_dn_rename
      _dn_attribute = dn_attribute_with_fallback
      original_dn_value = @ldap_data[_dn_attribute]
      current_dn_value = @data[_dn_attribute]
      return if original_dn_value == current_dn_value
      return if original_dn_value == [current_dn_value]

      _dn = nil
      begin
        _dn = dn
      rescue DistinguishedNameInvalid, DistinguishedNameNotSetError
        return
      end
      if _dn and exist?
        format = _("is duplicated: %s")
        message = format_validation_message(format, _dn)
        errors.add("distinguishedName", message)
      end
    end

    def validate_dn
      dn
    rescue DistinguishedNameInvalid
      format = _("is invalid: %s")
      message = format_validation_message(format, $!.message)
      errors.add("distinguishedName", message)
    rescue DistinguishedNameNotSetError
      format = _("isn't set: %s")
      message = format_validation_message(format, $!.message)
      errors.add("distinguishedName", message)
    end

    def validate_excluded_classes
      excluded_classes = self.class.excluded_classes
      return if excluded_classes.empty?

      _schema = schema
      _classes = classes.collect do |name|
        _schema.object_class(name)
      end
      unexpected_classes = excluded_classes.inject([]) do |classes, name|
        excluded_class = _schema.object_class(name)
        if _classes.include?(excluded_class)
          classes << excluded_class
        end
        classes
      end
      return if unexpected_classes.empty?

      names = unexpected_classes.collect do |object_class|
        self.class.human_object_class_name(object_class)
      end
      format = n_("has excluded value: %s",
                  "has excluded values: %s",
                  names.size)
      message = format_validation_message(format, names.join(", "))
      errors.add("objectClass", message)
    end

    # validate_required_ldap_values
    #
    # Basic validation:
    # - Verify that every 'MUST' specified in the schema has a value defined
    def validate_required_ldap_values
      _schema = nil
      @validation_skip_attributes ||= []
      _validation_skip_attributes =
        @validation_skip_attributes +
        (self.class.validation_skip_attributes || [])
      # Make sure all MUST attributes have a value
      entry_attribute.object_classes.each do |object_class|
        object_class.must.each do |required_attribute|
          # Normalize to ensure we catch schema problems
          # needed?
          real_name = to_real_attribute_name(required_attribute.name, true)
          raise UnknownAttribute.new(required_attribute) if real_name.nil?

          next if required_attribute.read_only?
          next if _validation_skip_attributes.include?(real_name)

          value = @data[real_name]
          next unless self.class.blank_value?(value)

          _schema ||= schema
          aliases = required_attribute.aliases.collect do |name|
            self.class.human_attribute_name(name)
          end
          args = [self.class.human_object_class_name(object_class)]
          if aliases.empty?
            format = _("is required attribute by objectClass '%s'")
          else
            format = _("is required attribute by objectClass " \
                       "'%s': aliases: %s")
            args << aliases.join(', ')
          end
          message = format_validation_message(format, args)
          errors.add(real_name, message)
        end
      end
    end

    def validate_ldap_values
      entry_attribute.schemata.each do |name, attribute|
        value = self[name]
        # Is it really proper location for setting encoding?
        attribute.apply_encoding(value)
        next if self.class.blank_value?(value)
        validate_ldap_value(attribute, name, value)
      end
    end

    def validate_ldap_value(attribute, name, value)
      failed_reason, option = attribute.validate(value)
      return if failed_reason.nil?
      if attribute.binary?
        inspected_value = _("<binary-value>")
      else
        inspected_value = self.class.human_readable_format(value)
      end
      params = [inspected_value,
                self.class.human_syntax_description(attribute.syntax),
                failed_reason]
      if option
        format = _("(%s) has invalid format: %s: required syntax: %s: %s")
      else
        format = _("has invalid format: %s: required syntax: %s: %s")
      end
      params.unshift(option) if option
      message = format_validation_message(format, params)
      errors.add(name, message)
    end
  end
end