spawnerChild

-- Modem
local modem = peripheral.wrap("right")
local thisChannel = 3101
local mainHubChannel = 3000

-- Lua classes
local spawner = {}
local spawnerItems = {}
spawner.__index = spawner

function init()
  if ( checkErrors() ) then
    error('error found')
  end

  modem.open(thisChannel)

  spawner:create('cow', 'top')
  spawner:create('spider', 'bottom')
  spawner:create('blitz', 'front')
  spawner:create('basalz', 'back')

  while true do
    loop()
    sleep(1)
  end
end

function loop()
  local event, modemSide, senderChannel,
  replyChannel, message, senderDistance = os.pullEvent("modem_message")
  if ( replyChannel == mainHubChannel and type(message) == 'table' ) then
    local command, spawnerName, spawnerState = message[1], message[2], message[3]
    print(type(command), command)
    print(type(spawnerName), spawnerName)
    print(type(spawnerState), spawnerState)
    if ( type(command) == 'string' and type(spawnerName) == 'string' and type(spawnerState) == 'boolean' and command == "setState" ) then
      if ( spawnerName == 'all' ) then
        for index, value in pairs(spawnerItems) do
          local theSpawner = spawner:get(index)
          if ( theSpawner ) then
            theSpawner:setState(spawnerState)
          end
        end
        return
      else
        local theSpawner = spawner:get(spawnerName)
        if ( theSpawner ) then
          theSpawner:setState(spawnerState)
        end
      end
    end
  else
    error('message-received, not a table')
  end
end

function checkErrors()
  return false
end

function spawner:create(name, side)
  if ( not spawnerItems[name] ) then
    local spawnerAttr = {}
    setmetatable(spawnerAttr,spawner)
    spawnerAttr.name = name
    spawnerAttr.side = side
    spawnerItems[name] = spawnerAttr
    rs.setOutput(side, true)
    return spawnerAttr
  else
    return "already created"
  end
end

function spawner:get(name)
  return spawnerItems[name]
end

function spawner:setState(state)
  rs.setOutput(self.side, not state)
  self.state = state
  return true
end

init()