Encrypted security card manager

-- Encryption Functions

-- 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

-- Main Program Execution

-- Function to select and decrypt username
function selectAndDecryptUsername()
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter encrypted username:")
    local encryptedUsername = read("*")

    -- Load key from file in user's directory
    local keyFile = findKeyFile("/disk/users/<username>")  -- Replace <username> with actual username
    if not keyFile then
        print("Encryption key not found.")
        return nil
    end

    local key = loadKeyFromFile(keyFile)
    local decryptedUsername = decrypt(encryptedUsername, key)
    return decryptedUsername
end

-- Function to encrypt username and save key
function encryptAndSaveUsername(username)
    local key = generateKey()
    local encryptedUsername = encrypt(username, key)

    -- Save key to file in user's directory
    local keyFileName = saveKeyToFile(key, "/disk/users/" .. username)

    return { encryptedUsername = encryptedUsername, keyFileName = keyFileName }
end

-- Function to encrypt password
function encryptPassword(password, key)
    return encrypt(password, key)
end

-- Function to decrypt password
function decryptPassword(encryptedPassword, key)
    return decrypt(encryptedPassword, key)
end

-- Function to save encrypted password to file in user's directory
function saveEncryptedPassword(username, encryptedPassword)
    local userDir = "/disk/users/" .. username

    -- Create user directory if it doesn't exist
    if not fs.exists(userDir) then
        fs.makeDir(userDir)
    end

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

-- Function to load encrypted password from file in user's directory
function loadEncryptedPassword(username)
    local userDir = "/disk/users/" .. username
    local fileName = userDir .. "/password.txt"

    if not fs.exists(fileName) then
        print("Password file does not exist for user: " .. username)
        return nil
    end

    local file = fs.open(fileName, "r")
    local encryptedPassword = file.readAll()
    file.close()

    return encryptedPassword
end

-- Function for Security Card Login (insert or enter ID)
function securityCardLogin(username)
    while true do
        term.clear()
        term.setCursorPos(1, 1)
        print("Security Card Manager for User:", username)
        print("1. Add Card")
        print("2. Remove Cards")
        print("3. Show All Security Cards")
        print("4. Disable Security Card Login")
        print("5. Back to Main Menu")

        local choice = read()

        if choice == "1" then
            addCardMenu(username)
        elseif choice == "2" then
            removeCardsMenu(username)
        elseif choice == "3" then
            showAllSecurityCards(username)
        elseif choice == "4" then
            disableSecurityCardLogin(username)
        elseif choice == "5" then
            return  -- Back to main menu
        else
            print("Invalid choice. Try again.")
            sleep(2)
        end
    end
end

-- Function for Add Card submenu
function addCardMenu(username)
    while true do
        term.clear()
        term.setCursorPos(1, 1)
        print("Add Card")
        print("1. Insert Security Card")
        print("2. Enter Security Card ID")
        print("3. Back to Security Card Manager")

        local choice = read()

        if choice == "1" then
            grabAndSaveDiskID(username)
        elseif choice == "2" then
            saveDiskID(username)
        elseif choice == "3" then
            return  -- Back to Security Card Manager
        else
            print("Invalid choice. Try again.")
            sleep(2)
        end
    end
end

-- Function for Remove Cards submenu
function removeCardsMenu(username)
    while true do
        term.clear()
        term.setCursorPos(1, 1)
        print("Remove Cards")
        print("1. Insert Security Card to delete")
        print("2. Enter Security Card ID to delete")
        print("3. Back to Security Card Manager")

        local choice = read()

        if choice == "1" then
            grabAndDeleteDiskID(username)
        elseif choice == "2" then
            deleteSpecificCard(username)
        elseif choice == "3" then
            return  -- Back to Security Card Manager
        else
            print("Invalid choice. Try again.")
            sleep(2)
        end
    end
end

-- Function to delete a specific security card by ID
function deleteSpecificCard(username)
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter Card ID to delete:")
    local cardID = read()

    local filePath = "/disk/users/" .. username .. "/ID/" .. cardID .. ".file"

    if fs.exists(filePath) then
        fs.delete(filePath)
        print("Security Card deleted successfully.")
    else
        print("Security Card not found.")
    end

    sleep(2)
end

-- Function to grab disk ID and delete it for a user
function grabAndDeleteDiskID(username)
    term.clear()
    term.setCursorPos(1, 1)
    print("Insert Security Card to delete ID...")

    while true do
        local peripherals = peripheral.getNames()

        for _, name in ipairs(peripherals) do
            if peripheral.getType(name) == "drive" then
                local diskID = disk.getID(name)
                if diskID then
                    local filePath = "/disk/users/" .. username .. "/ID/" .. diskID .. ".file"

                    if fs.exists(filePath) then
                        fs.delete(filePath)
                        print("Security Card ID deleted successfully.")
                    else
                        print("Security Card ID not found.")
                    end

                    return  -- Exit function after deleting ID
                end
            end
        end

        sleep(1)  -- Check every second
    end
end

-- Function to save disk ID for a user
function saveDiskID(username)
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter Card ID:")
    local cardID = read()

    -- Create directory if it doesn't exist
    local idDir = "/disk/users/" .. username .. "/ID"
    if not fs.exists(idDir) then
        fs.makeDir(idDir)
    end

    -- Save disk ID as a file
    local filePath = idDir .. "/" .. cardID .. ".file"
    local file = fs.open(filePath, "w")
    file.writeLine("Disk ID: " .. cardID)
    file.close()

    print("Disk ID saved successfully.")
    sleep(2)
end

-- Function to disable Security Card Login (delete all IDs)
function disableSecurityCardLogin(username)
    term.clear()
    term.setCursorPos(1, 1)
    print("Are you sure you want to disable Security Card Login for user: " .. username .. "? (y/n)")
    local choice = read()

    if choice:lower() == "y" then
        local idDir = "/disk/users/" .. username .. "/ID"
        if fs.exists(idDir) then
            fs.delete(idDir)
            print("Security Card Login disabled successfully.")
        else
            print("No Security Cards found to disable.")
        end
    else
        print("Security Card Login disable operation cancelled.")
    end

    sleep(2)
end

-- Function to show all security cards for a user
function showAllSecurityCards(username)
    term.clear()
    term.setCursorPos(1, 1)
    print("Security Cards for User: " .. username)

    local idDir = "/disk/users/" .. username .. "/ID"
    if fs.exists(idDir) then
        local files = fs.list(idDir)
        for _, file in ipairs(files) do
            if fs.isDir(idDir .. "/" .. file) == false then
                print(file)
            end
        end
    else
        print("No security cards found.")
    end

    print("Press any key to continue...")
    read()
end

-- API Functions
function create(username, text)
    local userDir = "/disk/users/" .. username

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

    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()

    return { status = "success", encryptedText = encryptedText, keyFileName = keyFileName }
end

function delete(username)
    local userDir = "/disk/users/" .. username

    if fs.exists(userDir) then
        fs.delete(userDir)
        return { status = "success", message = "User directory deleted." }
    else
        return { status = "error", message = "User directory not found." }
    end
end

function authenticate(adminUsername, adminPassword)
    -- Replace with actual admin credential verification
    if adminUsername == "admin" and adminPassword == "password" then
        return { status = "success", message = "Authenticated successfully." }
    else
        return { status = "error", message = "Authentication failed." }
    end
end

-- Example Usage
local tArgs = {...}
if #tArgs < 1 then
    print("Usage: api <command> <args>")
    return
end

local command = tArgs[1]
if command == "create" then
    if #tArgs < 3 then
        print("Usage: api create <username> <text>")
        return
    end
    local username = tArgs[2]
    local text = table.concat(tArgs, " ", 3)
    local result = create(username, text)
    print(textutils.serialize(result))
elseif command == "delete" then
    if #tArgs < 2 then
        print("Usage: api delete <username>")
        return
    end
    local username = tArgs[2]
    local result = delete(username)
    print(textutils.serialize(result))
elseif command == "authenticate" then
    if #tArgs < 3 then
        print("Usage: api authenticate <adminUsername> <adminPassword>")
        return
    end
    local adminUsername = tArgs[2]
    local adminPassword = tArgs[3]
    local result = authenticate(adminUsername, adminPassword)
    print(textutils.serialize(result))
else
    print("Invalid command. Use 'create', 'delete', or 'authenticate'.")
end

-- Main Menu
while true do
    term.clear()
    term.setCursorPos(1, 1)
    print("Welcome to Security Card System")
    print("1. Login")
    print("2. Exit")

    local choice = read()

    if choice == "1" then
        local username = selectAndDecryptUsername()
        if username then
            term.clear()
            term.setCursorPos(1, 1)
            print("Enter password for user: " .. username)
            local password = read("*")

            if validateUserCredentials(username, password) then
                securityCardLogin(username)
            else
                print("Invalid password. Access denied.")
                sleep(2)
            end
        else
            print("Invalid username.")
            sleep(2)
        end
    elseif choice == "2" then
        print("Exiting...")
        break
    else
        print("Invalid choice. Try again.")
        sleep(2)
    end
end