#
#--
# Copyright (c) 2007, Alain Hoang and 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.
#++
#

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

require 'net/smtp'

require 'openwfe/participants/participant'


module OpenWFE

    #
    # MailParticipant is a simplification of EmailNotificationParticipant.
    #
    # It's initialized in this way :
    #
    #     p = MailParticipant.new(
    #         :smtp_server => "mailhost.ourcompany.co.jp",
    #         :from_address => "bpms@our.ourcompany.co.jp",
    #         :template => "Dear ${f:name}, you've got mail")
    #
    # or
    #
    #     p = MailParticipant.new(
    #         :smtp_server => "mailhost.ourcompany.co.jp",
    #         :smtp_port => 25,
    #         :from_address => "bpms@our.ourcompany.co.jp"
    #     ) do |workitem|
    #         s = ""
    #         s << "Dear #{workitem.name},\n"
    #         s << "\n"
    #         s << "it's #{Time.new.to_s} and you've got mail"
    #         s
    #     end
    #
    # As with EmailNotificationParticipant, the "to" address for your email
    # is taken from the workitem's <tt>email_target</tt> field. So, to have 
    # the email sent to "foo@nowhere.com", set your workitem's
    # <tt>email_target</tt> field to "foo@nowhere.com" prior to feeding it
    # to the mail participant.
    #
    # When passing the mail template as a block, you have 
    # four possible arities :
    #     { |workitem| ... }
    #     { |participant_expression, workitem| ... }
    #     { |participant_expression, participant_instance, workitem| ... }
    #     { ... }
    #
    # The smtp server and host default to "127.0.0.1" / 25.
    #
    class MailParticipant
        include LocalParticipant

        def initialize (params, &block)

            @smtp_server = params[:smtp_server]
            @smtp_port = params[:smtp_port]
            @from_address = params[:from_address]
            @template = params[:template]

            @block_template = block

            # some defaults

            @smtp_server = "127.0.0.1" unless @smtp_server
            @smtp_port = 25 unless @smtp_port
        end

        #
        # The method called each time a workitem reaches this participant
        #
        def consume (workitem)

            fe = get_flow_expression(workitem)
            to_address = workitem.email_target

            #
            # 1. Expand variables

            msg  = if @block_template
                #@block_template.call(fe, self, workitem)
                call_block @block_template, workitem
            elsif @template
                template = if @template.kind_of? File
                    @template.readlines
                else
                    @template.to_s
                end
                OpenWFE::dosub(template, fe, workitem)
            else
                "(no template given)"
            end

            puts "msg >>>\n#{msg}<<<"

            #
            # 2. Send message

            Net::SMTP.start(@smtp_server, @smtp_port) do |smtp|
                smtp.send_message(msg, @from_address, to_address)
            end

            #
            # 3. Reply to engine

            reply_to_engine(workitem)
        end
    end

    #
    # This participant is used to send an email notification.
    #
    # It's perhaps better to use MailParticipant which is simpler to 
    # initialize. This class is anyway an extension of MailParticipant.
    #
    #     @engine.register_participant(
    #         'eno', 
    #         EmailNotificationParticipant.new(
    #             "googlemail.l.google.com",
    #             25,
    #             "eno@outoftheblue.co.jp",
    #             """Subject: test 0
    #
    #     0 : ${r:Time.new}
    #     1 : ${f:customer_name}
    #             """))
    #
    # And then, from the process definition :
    #
    #     class TestDefinition0 < OpenWFE::ProcessDefinition
    #         def make
    #             process_definition :name => "test0", :revision => "0" do
    #                 sequence do
    #                     set :field => 'email_target' do
    #                         "whatever56x56@gmail.com"
    #                     end
    #                     set :field => 'customer_name' do
    #                         "Monsieur Toto"
    #                     end
    #                     participant :ref => 'eno'
    #                 end
    #             end
    #         end
    #     end
    #
    # The 'template' parameter may contain an instance of File instead of
    # an instance of String.
    #
    #     @engine.register_participant(
    #         'eno', 
    #         EmailNotificationParticipant.new(
    #             "googlemail.l.google.com",
    #             25,
    #             "eno@outoftheblue.co.jp",
    #             File.new("path/to/my/mail/template.txt")))
    #
    # You can also define the email template as a Ruby block :
    #
    #     p = EmailNotificationParticipant.new("googlemail.l.google.com", 25, "eno@co.co.jp") do | flowexpression, participant, workitem |
    #
    #         # generally, only the workitem is used within a template
    #
    #         s = ""
    #
    #         # the header of the message
    #
    #         s << "Subject: #{workitem.subject}\n\n"
    #
    #         # then, the body
    #
    #         workitem.attributes.each do |key, value|
    #             s << "- '#{k}' => '#{value}'\n"
    #         end
    #         s << "\ndone.\n"
    #     end
    #
    # Note that the template integrates the subject and requires then a double
    # newline before the message body.
    #
    class EmailNotificationParticipant < MailParticipant

        #
        # Create a new email notification participant.  Requires
        # a mail server, port, a from address, and a mail message template
        #
        def initialize (
            smtp_server, smtp_port, from_address, template=nil, &block)

            params = {}
            params[:smtp_server] = smtp_server
            params[:smtp_port] = smtp_port
            params[:from_address] = from_address

            params[:template] = template if template

            super(params, &block)
        end
    end
end