relay.lua

vos.loadAPI('core.api')

local computers = { }
local messageTypes = { }

Message.addHandler('relay', function(h, id, msg)
  local relayMessage = msg.contents

  if relayMessage.toId then
    Logger.debug('direct send to %d: %s', relayMessage.toId, relayMessage.type)
    device.wireless_modem.transmit(relayMessage.toId, os.getComputerID(), relayMessage)
  else
    local listeners = messageTypes[relayMessage.type]
    if listeners then
      for k,computer in pairs(listeners) do
        if id ~= computer.id then
          Logger.debug('relaying from %d to %d: %s', id, computer.id, relayMessage.type)
          device.wireless_modem.transmit(computer.id, os.getComputerID(), relayMessage)
        end
      end
    end
  end
end)

local function getComputer(id)
  local computer = computers[id]
  if not computer then
    computer = {
      lastMessage = os.clock(),
      id = id
    }
    computers[id] = computer
    Logger.debug('relaying for %d', id)
  end
  return computer
end

Message.addHandler("listen", function(h, id, msg)
  local types = msg.contents
  for _,v in pairs(types) do
    local listener = messageTypes[v]
    if not listener then
      listener = { }
      messageTypes[v] = listener
    end
    for _,v in pairs(listener) do
      if v.id == id then
        return
      end
    end
    table.insert(listener, getComputer(id))
  end
end)

Message.addHandler("getRelayStation", function(h, id, msg)
  getComputer(id)
  Message.send(id, "relayStation", os.getComputerID())
end)

Logger.filter('event', 'modem_receive', 'modem_send')

Event.pullEvents()