#
#--
# Copyright (c) 2006, John Mettraux, OpenWFE.org
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without 
# modification, are permitted provided that the following conditions are met:
# 
# . Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.  
# 
# . Redistributions in binary form must reproduce the above copyright notice, 
#   this list of conditions and the following disclaimer in the documentation 
#   and/or other materials provided with the distribution.
# 
# . Neither the name of the "OpenWFE" nor the names of its contributors may be
#   used to endorse or promote products derived from this software without
#   specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
# POSSIBILITY OF SUCH DAMAGE.
#++
#
# $Id: definitions.rb 2725 2006-06-02 13:26:32Z jmettraux $
#

#
# "made in Japan"
#
# John Mettraux at openwfe.org
#

require 'workitem'
require 'ru/flowexpression'
require 'ru/fe_utils'


#
# base expressions like 'sequence' and 'concurrence'
#

module OpenWFEru

    class SequenceExpression < FlowExpression

        attr_accessor \
            :current_child_fei

        #
        # apply / reply

        def apply (workitem)

            reply(workitem)
        end

        def reply (workitem)

            @current_child_fei = next_fei()

            #ldebug { "reply() next_fei is #{@current_child_fei}" }

            if @current_child_fei
                store_itself()
                get_expression_pool().apply(@current_child_fei, workitem)
            else
                reply_to_parent(workitem)
            end
        end

        protected

            def next_fei ()
                if not @current_child_fei
                    return @children.each do |c|
                        return c if c.kind_of?(OpenWFE::FlowExpressionId)
                    end
                    return nil
                end
                found = false
                @children.each do |c|
                    #ldebug { "next_fei() considering #{c} (found ? #{found})" }
                    ldebug { "next_fei() considering #{c}" }
                    if found 
                        return c if c.kind_of?(OpenWFE::FlowExpressionId)
                        next
                    end
                    if c.kind_of?(OpenWFE::FlowExpressionId) and \
                       c == @current_child_fei

                        found = true
                    end
                end
                return nil
            end
    end

end