redstone_server.lua

local ARGS = {...}
local SERVER_NAME = ARGS[3] or 'tydium_siren'
local CHANNEL = ARGS[1] or 'siren'
local OUTPUT_SIDE = ARGS[4] or 'left'
local PORT = ARGS[2] or 17234
local AUTHENTICATION = nil -- if specified, clients must include a password under message.auth

local repr = require('cc.pretty').pretty

local modem = peripheral.find('modem')
modem.open(PORT)

function handleEvent(message, senderPort, replyPort)

    if type(message) ~= 'table' or type(message.level) ~= 'number' then
        modem.transmit(replyPort,senderPort, {
            success = false,
            response = 'Invalid message "'..repr(message)..'"',
            channel = CHANNEL..'_response',
            author_name = SERVER_NAME,

            description = {
                received_message = message
            }
        })
        return
    end

    if not (message.channel == CHANNEL or message.channel == 'all') then
        return
    end

    if AUTHENTICATION and message.auth ~= AUTHENTICATION then
        print('Client "'..tostring(message.author_name)..'" sent unauthorized request (key: '..tostring(message.auth)..')')
        modem.transmit(replyPort, senderPort, {
            success = false,
            response = 'Unauthorized',
            channel = CHANNEL..'_response',
            author_name = SERVER_NAME,

            description = {
                received_auth = message.auth,
                device_name = message.author_name
            }
        })

    end

    redstone.setAnalogOutput(OUTPUT_SIDE, message.level)
    print('Request recieved from client "'..tostring(message.author_name)..'" (port '..senderPort..') to change redstone level to '..message.level)
    modem.transmit(replyPort, senderPort, {
        success = true,
        response = 'Setting redstone output level to '..message.level,
        channel = CHANNEL..'_response',
        author_name = SERVER_NAME,

        description = {
            output_level = message.level,
            output_side = OUTPUT_SIDE,
        }
    })
end

while true do

    local event, side, senderPort, replyPort, message, distance = os.pullEvent('modem_message')
    handleEvent(message, senderPort, replyPort)

end