ATCP plugin for Achaea

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE muclient>

<muclient>
<plugin
   name="ATCP_NJG"
   author="Nick Gammon"
   id="85f72d0e263d75df7bde6f00"
   language="Lua"
   purpose="Nick Gammon's ATCP plugin"
   date_written="2010-03-09 10:04:32"
   requires="4.50"
   version="1.0"
   >
<description trim="y">
<![CDATA[
Install into IRE games to catch ATCP messages.

Other plugins can detect ATCP messages like this:

function OnPluginBroadcast (msg, id, name, text)
  if id == "85f72d0e263d75df7bde6f00" then
  
    if msg == 1 then
      do_ATCP_vitals (text)      -- eg. "H:496/496 M:412/412 E:1380/1380 W:960/960 NL:89/100 "
                                 --      health    mana      endurance   willpower experience
    elseif msg == 2 then
      do_ATCP_room_brief (text)  -- eg. "Continuing on the Parade of Zarathustra"
    elseif msg == 3 then
      do_ATCP_room_exit (text)   -- eg. "n,s"
    elseif msg == 4 then
      do_ATCP_room_number (text) -- eg. "401"
    end -- if   
 
  end -- if ATCP message
end

]]>
</description>

</plugin>


<!--  Script  -->


<script>
<![CDATA[

local CLIENT_ID = "MUSHclient " .. Version ()
local IAC, SB, SE, DO = 0xFF, 0xFA, 0xF0, 0xFD
local ATCP = 200


-- agree to use ATCP
function OnPluginTelnetRequest (type, data)
  
  if type == ATCP and data == "WILL" then
    return true
  end -- if
  
  if type == ATCP and data == "SENT_DO" then
    Note ("Enabling ATCP.")
    SendPkt (string.char (IAC, SB, ATCP) .. 
           "hello " .. CLIENT_ID .. "\n" ..
           "auth 1\n" ..
           "char_name 1\n" ..
           "char_vitals 1\n" ..
           "room_brief 1\n" ..
           "room_exits 1" ..
           string.char (IAC, SE)) 
     return true
  end -- if ATCP login needed (just sent DO)
  
  return false
  
end -- function OnPluginTelnetRequest

-- we got authorization request, eg. 
-- Auth.Request CH\n<identstr>
-- Auth.Request ON

function got_auth_request (s)
   
  -- calculate challenge response
  local function atcp_auth (seed)
    local a = 17
    local i = 0
    local n
    
    for letter in string.gmatch (seed, ".") do
      n = string.byte (letter) - 96
      if bit.band (i, 1) == 0 then  -- even/odd?
        a = a + n * bit.bor (i, 13)
      else
        a = a - n * bit.bor (i, 11)
      end -- if
      i = i + 1
    end -- for
    return a
  end

  if s:upper () == "ON" then
    Note ("ATCP authorization accepted.")
    return
  end -- if
    
  local identstr = string.match (s, "^CH\n(.+)$")
  
  if identstr then
    SendPkt (string.char (IAC, SB, ATCP) .. 
             "auth " .. 
             tostring (atcp_auth (identstr)) .. 
             " " .. CLIENT_ID .. 
             string.char (IAC, SE)) 
    return
  end -- if
  
end -- got_auth_request


function got_vitals (s)      -- eg. "H:496/496 M:412/412 E:1380/1380 W:960/960 NL:89/100"
  BroadcastPlugin (1, s)
end -- got_vitals

function got_room_brief (s)  -- eg. "Continuing on the Parade of Zarathustra"
  BroadcastPlugin (2, s)
end -- got_room_brief

function got_room_exits (s)  -- eg. "n,s"
  BroadcastPlugin (3, s)
end -- got_room_exits

function got_room_number (s)  -- eg. "441"
  BroadcastPlugin (4, s)
end -- got_room_number

handlers = {
  ['Auth.Request']  = got_auth_request,  -- handled here

  ['Room.Num']      = got_room_number,
  ['Room.Brief']    = got_room_brief,
  ['Room.Exits']    = got_room_exits,
  ['Char.Vitals']   = got_vitals,
  
  } -- end handlers
  
function OnPluginTelnetSubnegotiation (type, option)

  if type ~= ATCP then
    return
  end -- not Achaea subnegotiation

  local command, args = string.match (option, "^([%a.]+)%s+(.*)$")
  
  if not command then
    return
  end -- don't seem to have a command
  
  local f = handlers [command]
  
  if f then
    f (args)  -- call handler
  else
    BroadcastPlugin (0, option) -- other, just send whole message
  end -- handler
          
end -- function OnPluginTelnetSubnegotiation

]]>
</script>


</muclient>

OnPluginPacketReceived = function(packet)
  return parser.parse(packet)
end

OnPluginPacketReceived = function(packet)
  parser.parse(packet)
  return packet
end

-- agree to use ATCP
function OnPluginTelnetRequest (type, data)
  if type == 200 and data == "WILL" then
    return true
  end -- if
end -- function OnPluginTelnetRequest

function OnPluginTelnetSubnegotiation (type, option)

  if type ~= 200 then
    return
  end -- not Achaea subnegotiation

  local command, args = string.match (option, "^([%a.]+)%s+(.*)$")
  
  if command == "Room.Num" then
    handle_room_number (args)
  end -- if
          
end -- function OnPluginTelnetSubnegotiation

local codes = {
  IAC_DO_ATCP = "\255\253\200", -- enables ATCP communication
  IAC_SB_ATCP = "\255\250\200", -- begins an ATCP packet
  IAC_SE      = "\255\240",     -- ends an ATCP packet
  ATCP        = 200,            -- ATCP protocol number
}

local hello_msg = "hello MUSHclient " .. Version() .. "\n" ..
                  "auth 1\n" ..
                  "char_name 1\n" ..
                  "char_vitals 1\n" ..
                  "room_brief 1\n" ..
                  "room_exits 1\n" ..
                  "map_display 1\n" ..
                  "composer 1\n" ..
                  "keepalive 1\n" ..
                  "topvote 1\n" ..
                  "ping 1\n"

local callbacks = setmetatable({}, {
  __index = function(tbl, key)
    local group = {}
    rawset(tbl, key, group)
    return group
  end,
})


local Register = function(msg, callback)
  if type(msg) ~= "string" then
    error("Message name must be a string")
  elseif type(callback) ~= "function" then
    error("Callback must be a function")
  end
  table.insert(callbacks[msg], callback)
end

local Unregister = function(msg, callback)
  if type(msg) ~= "string" then
    error("Message name must be a string")
  elseif type(callback) ~= "function" then
    error("Callback must be a function")
  end
  
  for k,v in ipairs(callbacks[msg]) do
    if v == callback then
      table.remove(callbacks[msg], k)
      break
    end
  end
end

local Startup = function(type, data)
  if type == codes.ATCP then
    if data == "WILL" then
      return true
    elseif data == "SENT_DO" then
      SendPkt(codes.IAC_DO_ATCP .. codes.IAC_SB_ATCP .. hello_msg .. codes.IAC_SE)
      return true
    end
  end
  
  return false
end

local Handle = function(type, data)
  if type ~= codes.ATCP then
    return
  end

  local message, content
  local separator = data:find("%s")
  if separator then
    message, content = data:sub(1, separator-1), data:sub(separator+1)
  else
    message, content = data, ""
  end
  
  for _,callback in ipairs(callbacks[message]) do
    local ok, err = pcall(callback, message, content)
    if not ok then
      TraceOut("Error while executing ATCP callback " ..
               tostring(callback) .. " for message " .. message ..
              ":\n  " .. (err or ""))
    end
  end
  
  -- send to catch-all handlers as well
  for _,callback in ipairs(callbacks["*"]) do
    local ok, err = pcall(callback, message, content)
    if not ok then
      TraceOut("Error while executing ATCP callback " ..
               tostring(callback) .. " for message " .. message ..
              ":\n  " .. (err or ""))
    end
  end
end

return {
  Register = Register,
  Unregister = Unregister,
  Startup = Startup,
  Handle = Handle,
}

ATCP = require("atcp")

foo = function(message, content)
  -- ...
end,

bar = function(message, content)
  -- ...
end,

catchall = function(message, content)
  -- ...
end

OnPluginInstall = function()
  ATCP.Register("Char.Vitals", foo)
  ATCP.Register("Room.Name", bar)
  ATCP.Register("*", catchall) -- receives all messages
end

-- Set up ATCP handlers
OnPluginTelnetRequest = ATCP.Startup
OnPluginTelnetSubnegotiation = ATCP.Handle


-- Alternatively, if you want to handle these events yourself, too:

OnPluginTelnetRequest = function(type, data)
  ATCP.Startup(type, data)
  -- ...
end

OnPluginTelnetSubnegotiation = function(type, data)
  ATCP.Handle(type, data)
  -- ...
end

 IAC SB x blah blah IAC y