[ComputerCraft] Basic Computer Locker

local diskLabel = "CC:Unlock"
local fileName = "default.code"
local password = "admin"

local useDefault = ...

term.setBackgroundColor(colors.cyan)
term.setTextColor(colors.black)

term.clear()
term.setCursorPos(1,1)

if not useDefault then
    print("Type disk label: (Default: '"..diskLabel.."')")

    local input = read()
    if (input == "") then input = diskLabel end

    diskLabel = input

    term.clear()
    term.setCursorPos(1,1)
    print("(Default: '"..fileName.."')")
    print("Type filename containing password:")

    local input = read()
    if (input == "") then input = fileName end

    fileName = input

    term.clear()
    term.setCursorPos(1,1)
    print("(Default: '"..password.."')")
    print("Type password to unlock computer:")

    local input = read()
    if (input == "") then input = password end

    password = input
end

local startup = [[
    local fileName = "]]..fileName..[["
    local password = "]]..password..[["

    local oldPullEvent = os.pullEvent
    os.pullEvent = os.pullEventRaw

    term.setBackgroundColor(colors.cyan)
    term.setTextColor(colors.black)

    term.clear()
    term.setCursorPos(1,1)

    print("This computer have been locked.")

    local drive
    while true do


        for _, device in pairs(peripheral.getNames()) do
            if peripheral.getType(device) == "monitor" then
                local monitor = peripheral.wrap(device)
                monitor.setBackgroundColor(colors.cyan)
                monitor.setTextColor(colors.black)
                monitor.setTextScale(0.5)

                monitor.clear()
                monitor.setCursorPos(1,1)

                monitor.write("Lockdown")
            end

            if peripheral.getType(device) == "drive" then
                drive = peripheral.wrap(device)

                if (drive.getDiskLabel() == "]]..diskLabel..[[") then
                    local file = drive.getMountPath().."/"..fileName

                    if fs.exists(file) then
                        local reader = fs.open(file, "r")
                        if reader then
                            local content = reader.readAll()
                            if content == password then
                                -- Unlock device

                                if fs.exists("startup") then fs.delete("startup") end

                                if fs.exists("startup_old.lua") then
                                    if fs.exists("startup.lua") then fs.delete("startup.lua") end
                                    fs.move("startup_old.lua", "startup.lua")
                                end

                                if fs.exists("diskName") then
                                    local reader = fs.open("diskName", "r")
                                    local content = reader.readAll()
                                    reader.close()

                                    os.setComputerLabel(content)

                                    fs.delete("diskName")
                                else
                                    os.setComputerLabel()
                                end

                                os.pullEvent = oldPullEvent

                                for _, device in pairs(peripheral.getNames()) do
                                    if peripheral.getType(device) == "monitor" then
                                        local monitor = peripheral.wrap(device)

                                        monitor.setBackgroundColor(colors.black)
                                        monitor.setTextColor(colors.white)
                                        monitor.setTextScale(1)

                                        monitor.clear()
                                        monitor.setCursorPos(1,1)
                                    end
                                end

                                os.reboot()

                            end
                        end
                    end
                end

            end
        end

        os.sleep(1)
    end
]]

if fs.exists("startup") then
    if fs.exists("startup_old") then fs.delete("startup_old") end
    fs.move("startup", "startup_old.lua")
end

if fs.exists("startup.lua") then
    if fs.exists("startup_old.lua") then fs.delete("startup_old.lua") end
    fs.move("startup.lua", "startup_old.lua")
end

if fs.exists("diskName") then
    fs.delete("diskName")
end

local h
local label = os.getComputerLabel()

if label then
    h = fs.open("diskName", "w")
    h.write(label)
    h.close()
end

h = fs.open("startup", "w")
h.write(startup)
h.close()

os.setComputerLabel("Lockdown") -- Makes sure you keep the files
os.reboot() -- Reboots into lockdown