local net = require "net"
local event = require "event"
local syslog = require "syslog"
local serial = require "serialization"

local cfgfile = "/etc/chatd.cfg"
local clients = {}
local cfg = {}
cfg.port = 194
cfg.topic = "Welcome to the "..os.getenv("HOSTNAME").." chat server."
local timer = false

local function saveconfig()
 local f = io.open(cfgfile,"wb")
 if f then
  f:write(serial.serialize(cfg))
  f:close()
 end
end
local function loadconfig()
 local f = io.open(cfgfile,"rb")
 if f then
  local newcfg = serial.unserialize(f:read("*a"))
  f:close()
  for k,v in pairs(newcfg) do
   cfg[k] = v
  end
 else
  saveconfig()
 end
end

local function log(msg,level)
 syslog(msg,level,"chatd")
end

local function sendToAll(data)
 for k,v in pairs(clients) do
  v:write(data)
 end
end
local function formatLine(...)
 local tA = {...}
 return string.format("%s"..("\t%s"):rep(#tA-1).."\n", ...)
end

local function clientLoop()
 for sn, socket in pairs(clients) do
  local line = socket.rbuffer:match("(.+)\n")
  if line then
   socket:read(line:len()+1)
   local tCmd = {}
   for w in line:gmatch("[^\t]+") do
    tCmd[#tCmd+1] = w
   end
   if tCmd[1] == "nick" then
    if socket.nick then
     sendToAll(formatLine("nick",socket.nick,tCmd[2]))
    else
     log(tostring(socket.addr)..":"..tostring(socket.port).." connected as "..tCmd[2])
     socket:write(formatLine("topic",cfg.topic))
     sendToAll(formatLine("join",tCmd[2]))
    end
    socket.nick = tCmd[2]
   elseif tCmd[1] == "msg" and socket.nick then
    sendToAll(formatLine("msg",socket.nick,tCmd[2]))
   end
  end
  if socket.state ~= "open" then
   log(tostring(socket.addr)..":"..tostring(socket.port).." ("..tostring(socket.nick)..") quit")
   clients[sn] = nil
   if socket.nick then
    sendToAll(formatLine("quit",socket.nick))
   end
  end
 end
end

local function handleSocket(s)
 clients[tostring(s.addr)..":"..tostring(s.port)] = s
end

function start()
 loadconfig()
 net.flisten(cfg.port,handleSocket)
 timer = event.timer(1,clientLoop,math.huge)
end
function stop()
 event.ignore("net_msg",handleSocket)
 event.cancel(timer)
 for k,v in pairs(clients) do
  v:close()
 end
end