sulphurClient

modem = peripheral.wrap("top")

local function clear(x,y)
  term.clear()
  term.setCursorPos(x,y)
end

local function listen(modem,chans)
  if chans[1] == "all" then
    local senderId, message, protocol = rednet.receive()
    return senderId, message, protocol
  else
    for i=1, #chans do -- open queued channels
      modem.open(chans[i])
    end
    -- Listen for message on those channels
    event, modemSide, senderChannel, replyChannel, message, senderDistance = os.pullEvent("modem_message")

    modem.closeAll()
  end

  return event, modemSide, senderChannel, replyChannel, message, senderDistance
end

local channel = 20
local replyChannel = 11

while true do
  clear(1,1)
  term.write("Input a command. Type 'commands' for help")
  term.setCursorPos(1,2)
  input = read()

  if input == "commands" then

    clear(1,1)
    print("'request file' requests a file from the cloud server.")
    print("'send file' sends a file to the cloud server.")
	print("Press any key to continue")
	local event, key = os.pullEvent("key")

  elseif input == "send file" then

    clear(1,1)
    print("Input file name")
    term.setCursorPos(1,2)
    name = read()

	clear(1,1)
    print("Input name to send file as")
    term.setCursorPos(1,2)
	sendName = read()

	sleep(1)
    if fs.exists(name) then
      local cFile = fs.open(name, "r")
  	  fileTable = {name=sendName,content=cFile.readAll()}
  	  modem.transmit(channel,replyChannel,fileTable)
	else
	  clear(1,1)
	  print("File not found")
	  sleep(1)
    end

  elseif input == "request file" then

    clear(1,1)
    print("Input file name")
    term.setCursorPos(1,2)
    input = read()
    fileTable = {request=input} --create table to send
    modem.transmit(channel,replyChannel,fileTable) --send request table
	chans = {replyChannel}
	local event, modemSide, senderChannel, replyChannel, message, senderDistance = listen(modem,chans) --listen for response

	fileName = nil
	fileContent = nil
	for k,v in pairs(message) do
	  if k == "name" then
	    if fs.exists(v) then
		  print("file "..v.." already exists")
		  os.reboot()
		else
          fileName = v
		end
      elseif k == "content" then
	    fileContent = v
	  end
	end

    if fileName then
	  local h = fs.open(fileName, fs.exists(fileName) and "a" or "w")
	  h.write(fileContent)
      h.flush()
	  print("Saved file "..fileName)
	end
  end

end