wirelessSwitch

rednet.open("right")

local args = {...}

if args[3] == nill then
  print("usage: " .. shell.getRunningProgram() .. " <watcherID> <side> <defaultState> [invert]")
  error()
end

local wid   = tonumber(args[1])
local side  = args[2]
local state = args[3]
local invert = args[4] == "invert"

function xor(a, b)
  return not a ~= not b
end

redstone.setOutput(side, xor(state == "on", invert))
print("initial " .. state)

rednet.send(wid, "stateplease")
while true do
  local id, msg = rednet.receive()
  if id == wid and msg == "on" then
    redstone.setOutput(side, xor(true, invert))
    print(os.clock() .. " on")
  end
  if id == wid and msg == "off" then
    redstone.setOutput(side, xor(false, invert))
    print(os.clock() .. " off")
  end
end