local minitel = require "minitel"
local shell = require "shell"
local port = 22

local function sread(self, len)
 while true do
  local d=self.sock:read(len)
  if d then
   return d
  end
  coroutine.yield()
 end
end
local function swrite(self, data)
 while self.flushing do
  coroutine.yield()
 end
 if data and data:len() > 0 then
  self.wb = self.wb .. (data or "")
 end
end
local function sclose(self)
 self.sock:close()
end
local function sflush(self)
 self.flushing = true
 self.sock:write(self.wb)
 self.wb = ""
 self.flushing = false
end

function start()
 return os.spawn(function()
 local oout = io.output()
 local pname = os.taskInfo(os.pid()).name
 while true do
  local sock = minitel.listen(port)
  print(string.format("Connection from %s:%d",sock.addr,sock.port))
  os.spawn(function() _G.worked = {pcall(function()
   local fh = {}
   fh.sock = sock
   fh.read = sread
   fh.write = swrite
   fh.close = sclose
   fh.flush = sflush
   fh.wb = ""
   io.input(fh)
   io.output(fh)
   print(_OSVERSION.." - "..tostring(math.floor(computer.totalMemory()/1024)).."K RAM")
   local pid = os.spawn(shell.interactive,string.format(pname.." shell [%s:%d]",sock.addr,sock.port))
   repeat
    coroutine.yield()
    if fh.wb:len() > 0 then
     fh:flush()
    end
   until sock.state ~= "open" or not os.taskInfo(pid)
   sock:close()
   os.kill(pid)
   oout:write(string.format("Session %s:%d ended",sock.addr,sock.port))
  end)} end,string.format(pname.." [%s:%d]",sock.addr,sock.port))
 end
 end,"termsrv")
end