module AfterCommit
  module ActiveRecord
    def self.included(base)
      base.class_eval do
        class << self
          def establish_connection_with_after_commit(spec = nil)
            establish_connection_without_after_commit spec
            include_after_commit_extensions
          end
          alias_method_chain :establish_connection, :after_commit
          
          def include_after_commit_extensions
            base = ::ActiveRecord::ConnectionAdapters::AbstractAdapter
            Object.subclasses_of(base).each do |klass|
              include_after_commit_extension klass
            end
            
            if defined?(JRUBY_VERSION) and defined?(JdbcSpec::MySQL)
              include_after_commit_extension JdbcSpec::MySQL
            end
          end
          
          private
          
          def include_after_commit_extension(adapter)
            additions = AfterCommit::ConnectionAdapters
            unless adapter.included_modules.include?(additions)
              adapter.send :include, additions
            end
          end
        end
        
        # The define_callbacks method was added post Rails 2.0.2 - if it
        # doesn't exist, we define the callback manually
        if respond_to?(:define_callbacks)
          define_callbacks  :after_commit,
                            :after_commit_on_create,
                            :after_commit_on_update,
                            :after_commit_on_destroy,
                            :after_rollback,
                            :before_commit,
                            :before_commit_on_create,
                            :before_commit_on_update,
                            :before_commit_on_destroy,
                            :before_rollback
        else
          class << self
            # Handle after_commit callbacks - call all the registered callbacks.
            def after_commit(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:after_commit, callbacks)
            end
            
            def after_commit_on_create(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:after_commit_on_create, callbacks)
            end
            
            def after_commit_on_update(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:after_commit_on_update, callbacks)
            end
            
            def after_commit_on_destroy(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:after_commit_on_destroy, callbacks)
            end

            def after_rollback(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:after_commit, callbacks)
            end

            def before_commit(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:before_commit, callbacks)
            end
            
            def before_commit_on_create(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:before_commit_on_create, callbacks)
            end
            
            def before_commit_on_update(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:before_commit_on_update, callbacks)
            end
            
            def before_commit_on_destroy(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:before_commit_on_destroy, callbacks)
            end

            def before_rollback(*callbacks, &block)
              callbacks << block if block_given?
              write_inheritable_array(:before_commit, callbacks)
            end
          end
        end

        after_create  :add_committed_record_on_create
        after_update  :add_committed_record_on_update
        after_destroy :add_committed_record_on_destroy
        
        def add_committed_record_on_create
          AfterCommit.record(self.class.connection, self)
          AfterCommit.record_created(self.class.connection, self)
        end
        
        def add_committed_record_on_update
          AfterCommit.record(self.class.connection, self)
          AfterCommit.record_updated(self.class.connection, self)
        end
        
        def add_committed_record_on_destroy
          AfterCommit.record(self.class.connection, self)
          AfterCommit.record_destroyed(self.class.connection, self)
        end
      end
    end
  end
end