Mag-Card Utility

local reader = peripheral.wrap("left")

if not reader then
    error("No card reader found!")
end

reader.cancelWrite()

local cardBackup = "/card-data"

local function readCard()
    reader.setInsertCardLight(true)
    while true do
        local e, data, side = os.pullEvent()
        if e == "mag_swipe" then
            reader.setInsertCardLight(false)
            return data
        end
    end
end

local function writeCard(data, label)
    local success, err = reader.beginWrite(data, label)
    if success then
        while true do
            local e = os.pullEvent()
            if e == "mag_write_done" then
                reader.cancelWrite()
                return
            end
        end
    else
        error("Error while writing card: "..err)
    end
end

local args = {...}

local arg = args[1]

if not fs.exists(cardBackup) then
    print("A backup of your card is required")
    term.setTextColor(colors.yellow)
    print("Please insert your mag-card")

    cardData = readCard()

    local f = io.open(cardBackup, "w")
    f:write(cardData)
    f:close()
    print("Card data saved!")
end

if arg == "backup" then
    if fs.exists(cardBackup) then
        if fs.exists(cardBackup.."-old") then
            fs.delete(cardBackup.."-old")
        end
        fs.move(cardBackup, cardBackup.."-old")
    end

    term.setTextColor(colors.yellow)
    print("Insert the card you wish to backup")

    cardData = readCard()

    local f = io.open(cardBackup, "w")
    f:write(cardData)
    f:close()

    print("Card data saved!")
elseif arg == "pattern" then
    term.setTextColor(colors.yellow)
    print("Insert card to write")
    writeCard("[", "Pattern Exploit Card")
    term.setTextColor(colors.white)
    print("Card written!")
elseif arg == "exists" then
    term.setTextColor(colors.yellow)
    print("Insert card to write")
    writeCard("../rom/programs/help", "Exists Exploit Card")
    term.setTextColor(colors.white)
    print("Card written!")
elseif arg == "restore" then
    local readLocation = cardBackup
    if args[2] then
        readLocation = args[2]
    end

    if fs.exists(readLocation) and not fs.isDir(readLocation) then
        local f = io.open(readLocation)
        local cardData = f:read("*a")
        f:close()

        term.setTextColor(colors.yellow)
        print("Insert card to write")
        writeCard(cardData, "Restored Card")
        term.setTextColor(colors.white)
        print("Card written!")
    else
        print("No card data found!")
    end
elseif arg == "overwrite" then
    term.setTextColor(colors.yellow)
    print("Enter data to write")
    write("> ")
    local data = read()
    print("Insert card to write")
    writeCard(data, "Overwritten Card")
    term.setTextColor(colors.white)
    print("Card written!")
elseif arg == "read" then
    term.setTextColor(colors.yellow)
    print("Insert the card to read")
    local data = readCard()
    term.setTextColor(colors.white)
    print("The card reads:")
    print(data)
elseif arg == "label" then
    term.setTextColor(colors.yellow)
    write("Enter a label: ")
    local label = read()
    print("Insert the card you want to label twice")

    cardData = readCard()

    print("And again")

    writeCard(cardData, label)

    term.setTextColor(colors.white)
    print("Done! The new label has been written")
else
    term.setTextColor(colors.white)
    print("Run the program with an argument:")
    print("backup, pattern, exists, restore, overwrite, read")
end