Add (crappy) but functional interactive cqueues-based chat client

examples/client-cqchat.lua

@@ -0,0 +1,182 @@
+#! /usr/bin/env lua
+--
+-- client-cqchat.lua
+-- Copyright (C) 2016 Adrian Perez <aperez@igalia.com>
+--
+-- Distributed under terms of the MIT license.
+--
+
+local cqueues = require "cqueues"
+local posix   = require "posix"
+local bit     = require "bit32"
+local matrix  = require "matrix"
+
+local function xpcall_traceback(errmsg)
+   local tb = debug.traceback(nil, nil, 2)
+   return errmsg and (errmsg .. "\n" .. tb) or tb
+end
+
+--
+-- Wraps the controlling terminal into an object which can be polled
+-- with cqueues.poll() and uses O_NONBLOCK for input.
+--
+local tty = {
+   file = (function ()
+      local f = io.open(posix.ctermid(), "a+")
+      local fd = posix.fileno(f)
+      local flags = posix.fcntl(fd, posix.F_GETFL, 0)
+      flags = bit.bor(flags, assert(posix.O_NONBLOCK))
+      if posix.O_CLOEXEC then
+         flags = bit.bor(flags, posix.O_CLOEXEC)
+      else
+         io.stderr:write("no O_CLOEXEC, the TTY file descriptor might leak")
+         io.stderr:flush()
+      end
+      if posix.fcntl(fd, posix.F_SETFL, flags) ~= 0 then
+         error("cannot set O_NONBLOCK/O_CLOEXEC: " .. posix.errno())
+      end
+      return f
+   end)(),
+
+   -- Functions expected by cqueues
+   pollfd = function (self) return posix.fileno(self.file) end,
+   events = function () return "r" end,   -- Read only
+   timeout = function () return nil end,  -- Set in the call to cqueues.poll()
+
+   -- Wrappers for tcsetattr/tcgetattr
+   tcgetattr = function (self) return posix.tcgetattr(self:pollfd()) end,
+   tcsetattr = function (self, ...) return posix.tcsetattr(self:pollfd(), ...) end,
+
+   -- Obtain the terminal size using TIOCGWINSZ
+   _size_width = false,
+   _size_height = false,
+
+   size = function (self, force)
+      if force then
+         self._size_width = false
+         self._size_height = false
+      end
+      if self._size_width == false then
+         local p = io.popen("tput cols", "r")
+         self._size_width = p:read("*n")
+         p:close()
+      end
+      if self._size_height == false then
+         local p = io.popen("tput lines", "r")
+         self._size_height = p:read("*n")
+         p:close()
+      end
+      return self._size_width, self._size_height
+   end,
+
+   -- Saves terminal attributes, runs a function, and restores attributes
+   -- even if the function raises an error.
+   wrap = function (self, f, ...)
+      local saved_attr = self:tcgetattr()
+      local ok, err = xpcall(f, xpcall_traceback, self, ...)
+      self:tcsetattr(posix.TCSANOW, saved_attr)
+      if not ok then
+         error("tty:wrap: Error in wrapped function:\n" .. err)
+      end
+      return self
+   end
+}
+
+local command_pattern = "^%s*/(%a+)%s+(.*)$"
+
+local function main(tty, client, username, password)
+   do
+      local a = tty:tcgetattr()
+      a.cc[posix.VMIN] = 1
+      a.cc[posix.VTIME] = 0
+      a.lflag = bit.band(a.lflag, bit.bnot(bit.bor(posix.ECHO, posix.ICANON)))
+      a.iflag = bit.band(a.iflag, bit.bnot(bit.bor(posix.IXON, posix.ISTRIP)))
+      a.cflag = bit.band(a.cflag, bit.bnot(bit.bor(posix.CSIZE, posix.PARENB)))
+      a.cflag = bit.bor(a.cflag, posix.CS8)
+      a.oflag = bit.band(a.oflag, bit.bnot(posix.OPOST))
+      if tty:tcsetattr(posix.TCSANOW, a) ~= 0 then
+         error("tcsetattr: " .. posix.errno())
+      end
+   end
+
+   local cq = cqueues.new()
+   local ok, err, obj = cq:wrap(function ()
+      print(string.format("Terminal size: %dx%d", tty:size()))
+      client:login_with_password(username, password)
+      local clientqueue = cq:wrap(function ()
+         client:sync()
+      end)
+
+      local current_room
+      while true do
+         local line = ""
+         while true do
+            io.stdout:write(string.format("\r[%s] %s",
+               current_room and current_room.room_id or "*",
+               line))
+            io.stdout:flush()
+
+            local handle_tty = false
+            cqueues.poll(tty, 0.05)
+
+            local ch = tty.file:read(1)
+            if ch then
+               if ch == "\4" and #line == 0 then
+                  print("\r")
+                  cq:cancel()
+                  return
+               elseif ch == "\127" then
+                  line = line:sub(1, -2)
+               elseif ch == "\n" then
+                  break
+               else
+                  line = line .. ch
+               end
+            end
+         end
+
+         local command, params = line:match(command_pattern)
+         if command then
+            if command == "room" then
+               if client.rooms[params] then
+                  current_room = client.rooms[params]
+               else
+                  print("\r ! No such room")
+               end
+            end
+         else
+            if current_room then
+               current_room:send_text(line)
+            else
+               print("\r ! Choose a room using '/room <room_id>'")
+            end
+         end
+      end
+   end):loop()
+   if not ok then
+      error(err)
+   end
+end
+
+local function print_room_message(room, sender, message, event)
+   print(string.format("\rK[%s] <%s> %s", room.room_id, sender, message.body))
+end
+
+if #arg ~= 3 then
+   io.stderr:write(string.format("Usage: %s <homeserver> <username> <password>\n", arg[0]))
+   os.exit(1)
+end
+
+local client = matrix.client(arg[1])
+   :hook("logged-in", function (client)
+      print("\r * Logged in as " .. client.user_id)
+   end)
+   :hook("joined", function (client, room)
+      print("\r * Joined room " .. room.room_id)
+      room:hook("message", print_room_message)
+   end)
+   :hook("left", function (client, room)
+      print("\r * Left room " .. room.room_id)
+   end)
+
+tty:wrap(main, client, arg[2], arg[3])