Create Doggy OS encryped user accounts

-- Function to generate a key for encryption and decryption
function generateKey()
    local chars = {}
    for i = 32, 126 do -- ASCII range for printable characters
        table.insert(chars, string.char(i))
    end

    local key = {}
    while #chars > 0 do
        local index = math.random(#chars)
        table.insert(key, table.remove(chars, index))
    end

    return table.concat(key)
end

-- Function to create a map from a key
function createMap(key)
    local map = {}
    for i = 32, 126 do
        map[string.char(i)] = key:sub(i - 31, i - 31)
    end
    return map
end

-- Function to invert a map
function invertMap(map)
    local invMap = {}
    for k, v in pairs(map) do
        invMap[v] = k
    end
    return invMap
end

-- Function to encrypt text using a key
function encrypt(text, key)
    local map = createMap(key)
    local encrypted = {}
    for i = 1, #text do
        local char = text:sub(i, i)
        table.insert(encrypted, map[char] or char)
    end
    return table.concat(encrypted)
end

-- Function to decrypt text using a key
function decrypt(text, key)
    local map = invertMap(createMap(key))
    local decrypted = {}
    for i = 1, #text do
        local char = text:sub(i, i)
        table.insert(decrypted, map[char] or char)
    end
    return table.concat(decrypted)
end

-- Function to save the key to a file
function saveKeyToFile(key, dir)
    local randomNumber = math.random(1, 1000)
    local fileName = dir .. "/key" .. randomNumber .. ".txt"
    local file = fs.open(fileName, "w")
    file.write(key)
    file.close()
    return fileName
end

-- Function to load the key from a file
function loadKeyFromFile(fileName)
    local file = fs.open(fileName, "r")
    local key = file.readAll()
    file.close()
    return key
end

-- Function to find the key file in a directory
function findKeyFile(dir)
    local files = fs.list(dir)
    for _, file in ipairs(files) do
        if file:match("^key%d+%.txt$") then
            return dir .. "/" .. file
        end
    end
    return nil
end

-- Function to load the encrypted text from the password file
function loadEncryptedText(userDir)
    local fileName = userDir .. "/password.txt"
    if not fs.exists(fileName) then
        print("Password file does not exist.")
        return nil
    end
    local file = fs.open(fileName, "r")
    local encryptedText = file.readAll()
    file.close()
    return encryptedText
end

-- Main Program
local tArgs = {...}
if #tArgs < 2 then
    print("Usage: jambler <encrypt|decrypt> <username> <text> [keyfile (for decrypt)]")
    return
end

local mode = tArgs[1]
local username = tArgs[2]
local userDir = "/disk/users/" .. username

if not fs.exists(userDir) then
    fs.makeDir(userDir)
end

if mode == "encrypt" then
    local text = table.concat(tArgs, " ", 3)
    local key = generateKey()
    local encryptedText = encrypt(text, key)
    local keyFileName = saveKeyToFile(key, userDir)

    local passwordFile = fs.open(userDir .. "/password.txt", "w")
    passwordFile.write(encryptedText)
    passwordFile.close()

    print("Encrypted Text: " .. encryptedText)
    print("Key saved to file: " .. keyFileName)
elseif mode == "decrypt" then
    local encryptedText = loadEncryptedText(userDir)
    if not encryptedText then return end

    local keyFileName = findKeyFile(userDir)
    if not keyFileName then
        print("No key file found in the user's directory.")
        return
    end

    local key = loadKeyFromFile(keyFileName)
    local decryptedText = decrypt(encryptedText, key)

    print("Decrypted Text: " .. decryptedText)
else
    print("Invalid mode. Use 'encrypt' or 'decrypt'.")
end