--
--  gcsd
--
--  gcsd the generic command sequencer daemon can be used to serialize 
--  commands sent over various paralell communication channels to a
--  single command output. It can be seen as a multiplexer for any
--  kind of communication between a single resource and various clients
--  which want to submit commands to it or query information from it.
--  gcsd is written in C and Lua. The goal is to provide an easy to 
--  understand high level API based on Lua which can be used to
--  implement the business logic of the so formed multiplexer daemon.
--  
--
--  Copyright (C) 2009-2010 Markus Grueneis <gimpf@spreadspace.org>
--                          Christian Pointner <equinox@spreadspace.org>
--
--  This file is part of gcsd.
--
--  gcsd is free software: you can redistribute it and/or modify
--  it under the terms of the GNU General Public License as published by
--  the Free Software Foundation, either version 3 of the License, or
--  any later version.
--
--  gcsd is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License
--  along with gcsd. If not, see <http://www.gnu.org/licenses/>.
--

dispatch_table = {}
dispatch_table.regex_to_handler = {
   ["%w+%s*\n"] = function(match)
                     command_queue:enqueue(string.match(match , "(%w+)%s*"))
                  end,
   [".*\n"] = function(match) end
}

function dispatch_table:load_handler_table_file(filename)
   local defines = require('defines')
   if (type(filename) ~= "nil") then
      if (type(filename) ~= "string") then
         log.printf(log.ERROR, "filename must be of type 'string' and denote a valid path")
         return defines.KILL_DAEMON
      end
      local chunk, err = loadfile(filename)
      if (not chunk) then
         log.printf(log.ERROR, "failed to load dispatch table: %s", err)
         return defines.KILL_DAEMON
      end
      self:register_handler_table(chunk())
      log.printf(log.NOTICE, "loaded dispatch table from file %s", filename)
   end
   return defines.OK
end

function dispatch_table:register_handler_table(handler_table)
   if (type(handler_table) ~= "table") then
      error("handler_table must be of type 'table'")
   end
   self.regex_to_handler = handler_table
end

function dispatch_table:dispatch(command_buffer)
   local init = 1
   repeat
      local had_match = false
      for regex, handler in pairs(self.regex_to_handler) do
         local match = string.match(command_buffer, "^" .. regex, init)
         if match then
            handler(match)
            had_match = true
            init = init + string.len(match)
            break
         end
      end
   until (not had_match)
   
   return string.sub(command_buffer, init + 1)
end