storage

-- Storage host
local keepAlive = true
local manager

function doHello()
  print("Sending Hello")

  local message = {command="helo"}
  rednet.broadcast(textutils.serialize(message))
end

function doRegister(resource)
  print(("Registering storage for %s"):format(resource))

  local message = {command = "storage", resource = resource}
  rednet.send(manager, textutils.serialize(message))
end

function handleCommunications()
  local sender, message = rednet.receive()
  print(("Received message from %d: %s"):format(sender, message))

  local actualMessage = textutils.unserialize(message)

  if actualMessage.command == "request" then
    handleRequest(actualMessage.amount)
  elseif actualMessage.command == "hello" then
    handleHello(sender)
  end
end

function handleHello(sender)
  print(("Received hello from %d"):format(sender))

  manager = sender
  local message = {command = "ack"}
  rednet.send(manager, textutils.serialize(message))
end

function handleRequest(amount)
  print(("Handle request for %d"):format(amount))

  for i = 1, amount-1, 1 do
    redstone.setOutput("top", true)
    os.sleep(0.2)
    redstone.setOutput("top", false)
  end

  local message = {command = "ack"}
  rednet.send(manager, textutils.serialize(message))
end

function handleTerminate()
  local event, key, is_held = os.pullEvent("key")
  if keys.getName(key) ~= "f12" then
    return
  end

  redstone.setOutput("top", false)

  local message = {command="bye"}
  rednet.send(manager, textutils.serialize(message))
  keepAlive = false
end

function main(...)
  resource = ...
  if not resource then
    print("Please specify a resource: storage cobblestone")
    return
  end

  peripheral.find("modem", rednet.open)

  doHello()
  handleCommunications()
  doRegister(resource)

  while keepAlive do
    parallel.waitForAny(handleCommunications, handleTerminate)
  end
end

main(...)