# Copyright (C) 2009  Kouhei Sutou <kou@clear-code.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License version 2.1 as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

# This library includes ActiveRecord based codes temporary.
# Here is their copyright and license:
#
#   Copyright (c) 2004-2009 David Heinemeier Hansson
#
#   Permission is hereby granted, free of charge, to any person obtaining
#   a copy of this software and associated documentation files (the
#   "Software"), to deal in the Software without restriction, including
#   without limitation the rights to use, copy, modify, merge, publish,
#   distribute, sublicense, and/or sell copies of the Software, and to
#   permit persons to whom the Software is furnished to do so, subject to
#   the following conditions:
#
#   The above copyright notice and this permission notice shall be
#   included in all copies or substantial portions of the Software.
#
#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
#   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
#   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
#   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
#   LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
#   OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
#   WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

module ActiveGroonga
  module Associations
    class << self
      def included(base)
        base.class_eval do
          include(ActiveRecord::Associations)
          extend(ClassMethods)
        end
      end
    end

    autoload :BelongsToAssociation, 'active_groonga/associations/belongs_to_association'

    module ClassMethods
      # from ActiveRecord
      def belongs_to(association_id, options = {})
        reflection = create_belongs_to_reflection(association_id, options)

        if reflection.options[:polymorphic]
          association_accessor_methods(reflection, BelongsToPolymorphicAssociation)
        else
          association_accessor_methods(reflection, BelongsToAssociation)
          association_constructor_method(:build,  reflection, BelongsToAssociation)
          association_constructor_method(:create, reflection, BelongsToAssociation)
        end

        # Create the callbacks to update counter cache
        if options[:counter_cache]
          cache_column = reflection.counter_cache_column

          method_name = "belongs_to_counter_cache_after_create_for_#{reflection.name}".to_sym
          define_method(method_name) do
            association = send(reflection.name)
            association.class.increment_counter(cache_column, send(reflection.primary_key_name)) unless association.nil?
          end
          after_create method_name

          method_name = "belongs_to_counter_cache_before_destroy_for_#{reflection.name}".to_sym
          define_method(method_name) do
            association = send(reflection.name)
            association.class.decrement_counter(cache_column, send(reflection.primary_key_name)) unless association.nil?
          end
          before_destroy method_name

          module_eval(
            "#{reflection.class_name}.send(:attr_readonly,\"#{cache_column}\".intern) if defined?(#{reflection.class_name}) && #{reflection.class_name}.respond_to?(:attr_readonly)"
          )
        end

        configure_dependency_for_belongs_to(reflection)
      end
    end
  end
end