Network scanner

-- Function to draw the header of Doggy OS Network Controller
function drawHeader()
    term.clear()
    term.setCursorPos(1, 1)
    print("====================================")
    print("     Doggy OS Network Controller    ")
    print("====================================")
    print("Monitoring network in real-time...")
    print("")
end

-- Function to automatically detect a modem and open rednet
function openModem()
    local modemSide
    for _, side in ipairs({"left", "right", "top", "bottom", "front", "back"}) do
        if peripheral.isPresent(side) and peripheral.getType(side) == "modem" then
            modemSide = side
            break
        end
    end

    if modemSide then
        rednet.open(modemSide)
        print("[INFO] Modem found and opened on side: " .. modemSide)
        return modemSide
    else
        return nil
    end
end

-- Function to display a styled error message
function showError(message)
    print("")
    print("====================================")
    print("             SYSTEM HALTED          ")
    print("====================================")
    print("ERROR: " .. message)
    print("====================================")
    print("")
end

-- Function to continuously monitor connected computers
function monitorConnectedComputers()
    drawHeader()

    local modemSide = openModem()  -- Automatically detect and open modem

    if modemSide then
        local knownComputers = {}  -- Table to keep track of known computers

        while true do
            local connectedComputers = {}  -- Fresh list each cycle
            for _, side in ipairs(peripheral.getNames()) do
                if peripheral.getType(side) == "computer" then
                    local computerID = peripheral.call(side, "getID")
                    local status, response = pcall(peripheral.call, side, "isOn")
                    local isOn = status and response and "On" or "Off"
                    connectedComputers[computerID] = {id = computerID, side = side, status = isOn}
                end
            end

            term.clear()
            drawHeader()

            if next(connectedComputers) then
                print("Connected Computers:")
                print("------------------------------------")
                for _, computer in pairs(connectedComputers) do
                    print("ID: " .. computer.id .. " | Side: " .. computer.side .. " | Status: " .. computer.status)
                end
                print("------------------------------------")
                print("[INFO] Monitoring in progress... Press Ctrl+T to stop.")
            else
                print("[INFO] No connected devices found.")
            end

            -- Update known computers for the next cycle
            knownComputers = connectedComputers

            sleep(5)  -- Wait for 5 seconds before refreshing the scan
        end

        rednet.close(modemSide)  -- Close the modem when done
    else
        showError("No Modem Found or Local Area Network Connection Failed.")
        handleError("No Modem Found or Local Area Network Connection Failed.")
    end
end

-- Function to handle errors with user options
function handleError(message)
    showError(message)
    print("Choose an option:")
    print("1. Retry")
    print("2. Shut Down")
    print("3. Reboot")
    print("====================================")
    io.write("Enter your choice: ")

    local choice = read()
    if choice == "1" then
        monitorConnectedComputers()
    elseif choice == "2" then
        os.shutdown()
    elseif choice == "3" then
        os.reboot()
    else
        print("[ERROR] Invalid choice. Rebooting...")
        sleep(2)
        os.reboot()
    end
end

-- Run the function to start real-time monitoring
monitorConnectedComputers()