#-- vim:sw=2:et
#++
#
# :title: Shell Plugin for RBot
#
# Author:: Yaohan Chen <yaohan.chen@gmail.com>
# Copyright:: (C) 2008 Yaohan Chen
# License:: GPLv2


require 'treetop'

Treetop.load_string <<END_TREETOP_CODE

grammar Shell
  rule command
    interpolation /
    simple {
      def execute(&block)
        yield text_value
      end
   }
  end

  rule interpolation
    before:simple? "$(" command ")" after:simple? {
      def depth
        command.depth + 1
      end

      def execute(&block)
        yield before.text_value + command.execute(&block) + after.text_value
      end
    }
  end
  
  rule simple
    (!"$(" !")" .)+ {
      def depth
        0
      end
    }
  end
end
    
END_TREETOP_CODE


class ShellPlugin < Plugin
  def initialize
    super
    @parser = ShellParser.new
  end

  def shell(m, params)
    result = @parser.parse(params[:command].to_s).execute do |s|
      replies = []
      # FIXME currently all the interpolated commands are created with :from => m,
      # so they are considered depth 1. maybe we should calculate the depth using
      # the command parse tree, but having the parse tree implies finite depth
      new_m = fake_message(s, :from => m, :delegate => false)
      class << new_m
        self
      end.send(:define_method, :reply) do |s|
        replies << s
      end
      @bot.plugins.irc_delegate('privmsg', new_m)
      replies.join(' ')
    end
    m.reply result
  end

  def help(plugin, topic=nil)
    %{The "shell" command enables interpolation of commands. For example, "shell say #channel $(ping)" will say the response of the ping command, "pong", in #channel. Note that not all output of commands are considered response, only those using m.reply. It's recommended to interpolate only commands that respond quickly.}
  end
end


plugin = ShellPlugin.new
plugin.map 'shell *command'