#
#--
# Copyright (c) 2007-2008, 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"
#
# John Mettraux at openwfe.org
#

#
# this participant requires the twitter4r gem
#
# http://rubyforge.org/projects/twitter4r/
#
# atom-tools' license is X11/MIT
#

#require 'rubygems'
#gem 'twitter4r', '0.2.3'
require 'twitter' # gem 'twitter4r'

require 'openwfe/utils'
require 'openwfe/participants/participant'


module OpenWFE
module Extras

  #
  # Sometimes email is a bit too heavy for notification, this participant
  # emit messages via a twitter account.
  #
  # By default, the message emitted is the value of the field
  # "twitter_message", but this behaviour can be changed by overriding
  # the extract_message() method.
  #
  # If the extract_message doesn't find a message, the message will
  # be the result of the default_message method call, of course this
  # method is overridable as well.
  #
  class TwitterParticipant
    include OpenWFE::LocalParticipant

    #
    # The actual twitter4r client instance.
    #
    attr_accessor :client

    #
    # Keeping the initialization params at hand (if any)
    #
    attr_accessor :params

    #
    # This participant expects a login (twitter user name) and a password.
    #
    # The only optional param for now is :no_ssl, which you can set to
    # true if you want the connection to twitter to not use SSL.
    # (seems like the Twitter SSL service is available less often
    # than the plain http one).
    #
    def initialize (login, password, params={})

      super()

      Twitter::Client.configure do |conf|
        conf.protocol = :http
        conf.port = 80
      end if params[:no_ssl] == true

      @client = Twitter::Client.new(
        :login => login,
        :password => password)

      @params = params
    end

    #
    # The method called by the engine when a workitem for this
    # participant is available.
    #
    def consume (workitem)

      user, tmessage = extract_message workitem

      tmessage = default_message(workitem) unless tmessage

      begin

        if user
          #
          # direct message
          #
          tuser = @client.user user.to_s
          @client.message :post, tmessage, tuser
        else
          #
          # just the classical status
          #
          @client.status :post, tmessage
        end

      rescue Exception => e

        linfo do
          "consume() not emitted twitter, because of " +
          OpenWFE::exception_to_s(e)
        end
      end

      reply_to_engine(workitem) if @application_context
    end

    protected

      #
      # Returns a pair : the target user (twitter login name)
      # and the message (or status message if there is no target user) to
      # send to Twitter.
      #
      # This default implementation returns a pair composed with the
      # values of the field 'twitter_target' and of the field
      # 'twitter_message'.
      #
      def extract_message (workitem)

        [ workitem.attributes['twitter_target'],
          workitem.attributes['twitter_message'] ]
      end

      #
      # Returns the default message (called when the extract_message
      # returned nil as the second element of its pair).
      #
      # This default implementation simply returns the workitem
      # FlowExpressionId instance in its to_s() representation.
      #
      def default_message (workitem)

        workitem.fei.to_s
      end
  end

end
end