User creation for Doggy OS

-- 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

-- 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

-- Function to create a new user
function createUser()
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter new username:")
    local username = read()

    -- Check if the username already exists
    if fs.exists("/disk/users/" .. username) then
        print("Username already exists. Try again.")
        sleep(2)
        return
    end

    -- Create a directory for the new user
    fs.makeDir("/disk/users/" .. username)

    -- Prompt for password
    local password
    repeat
        term.clear()
        term.setCursorPos(1, 1)
        print("Enter password:")
        password = read("*")

        print("Confirm password:")
        local confirmPassword = read("*")

        if password ~= confirmPassword then
            print("Passwords do not match. Try again.")
            sleep(2)
        end
    until password == confirmPassword

    -- Encrypt the password before storing
    local key = generateKey()
    local encryptedPassword = encrypt(password, key)

    -- Store the encrypted password in a text file
    local file = fs.open("/disk/users/" .. username .. "/password.txt", "w")
    file.write(encryptedPassword)
    file.close()

    -- Save the encryption key to a file
    saveKeyToFile(key, "/disk/users/" .. username)

    print("User created successfully.")
    sleep(2)
end

-- Function to delete a user
function deleteUser()
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter username to delete:")
    local username = read()

    -- Check if the username exists
    if not fs.exists("/disk/users/" .. username) then
        print("User not found. Try again.")
        sleep(2)
        return
    end

    -- Prompt for password to confirm deletion
    print("Enter password to confirm deletion:")
    local inputPassword = read("*")

    -- Read encryption key from file
    local keyFileName = findKeyFile("/disk/users/" .. username)
    if not keyFileName then
        print("Encryption key not found. Deletion failed.")
        sleep(2)
        return
    end
    local key = loadKeyFromFile(keyFileName)

    -- Read stored encrypted password from the file
    local file = fs.open("/disk/users/" .. username .. "/password.txt", "r")
    local encryptedPassword = file.readAll()
    file.close()

    -- Decrypt stored password and compare with input password
    local storedPassword = decrypt(encryptedPassword, key)
    if inputPassword == storedPassword then
        -- Delete the user directory
        fs.delete("/disk/users/" .. username)
        print("User deleted successfully.")
    else
        print("Incorrect password. Deletion failed.")
    end

    sleep(2)
end

-- Function for password recovery by admin
function passwordRecovery()
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter admin username:")
    local adminUsername = read()

    -- Check if the entered user has admin privileges
    if not fs.exists("/disk/users/" .. adminUsername .. "/admin.txt") then
        print("Permission denied. Admin access required.")
        sleep(2)
        return
    end

    -- Prompt for admin password
    print("Enter admin password:")
    local adminPassword = read("*")

    -- Read stored admin password from the file
    local adminFile = fs.open("/disk/users/" .. adminUsername .. "/password.txt", "r")
    local storedAdminPassword = adminFile.readAll()
    adminFile.close()

    -- Decrypt stored admin password and compare with input admin password
    local keyFileName = findKeyFile("/disk/users/" .. adminUsername)
    if not keyFileName then
        print("Encryption key not found. Password reset failed.")
        sleep(2)
        return
    end
    local key = loadKeyFromFile(keyFileName)
    local decryptedAdminPassword = decrypt(storedAdminPassword, key)

    if adminPassword == decryptedAdminPassword then
        print("Enter username for password reset:")
        local username = read()

        -- Check if the username exists
        if not fs.exists("/disk/users/" .. username) then
            print("User not found. Try again.")
            sleep(2)
            return
        end

        -- Confirm password reset
        print("Are you sure you want to reset the password for " .. username .. "? (y/n)")
        local confirm = read()
        if confirm:lower() ~= "y" then
            print("Password reset canceled.")
            sleep(2)
            return
        end

        -- Prompt for new password
        term.clear()
        term.setCursorPos(1, 1)
        print("Enter new password for " .. username .. ":")
        local newPassword = read("*")

        -- Encrypt the new password before storing
        local newKey = generateKey()
        local encryptedNewPassword = encrypt(newPassword, newKey)

        -- Store the encrypted new password in the text file
        local file = fs.open("/disk/users/" .. username .. "/password.txt", "w")
        file.write(encryptedNewPassword)
        file.close()

        -- Save the encryption key for the new password
        saveKeyToFile(newKey, "/disk/users/" .. username)

        print("Password reset successfully.")
    else
        print("Incorrect admin password. Password reset failed.")
    end

    sleep(2)
end

-- Function to exit the program
function exitProgram()
    term.clear()
    term.setCursorPos(1, 1)
    print("Exiting...")
    sleep(2)
    term.clear()
    term.setCursorPos(1, 1)
    os.shutdown()
end

-- Function to list all users (directories) in /disk/users
function viewAllUsers()
    term.clear()
    term.setCursorPos(1, 1)
    print("List of Users:")
    local users = fs.list("/disk/users")
    for _, user in ipairs(users) do
        print("- " .. user)
    end
    print("\nPress any key to return to the main menu.")
    os.pullEvent("key")
end

-- Function to run Security Card Setup
function runSecurityCardSetup()
    term.clear()
    term.setCursorPos(1, 1)
    shell.run("/disk/security/CardSetup")
    print("Security Card Setup completed. Press any key to continue.")
    os.pullEvent("key")
end

-- Function to display the main menu
function mainMenu()
    while true do
        term.clear()
        term.setCursorPos(1, 1)
        print("Main Menu:")
        print("1. Create User")
        print("2. Delete User")
        print("3. Password Recovery")
        print("4. View All Users")
        print("5. Security Card Login")
        print("6. Exit")

        local choice = read()

        if choice == "1" then
            createUser()
        elseif choice == "2" then
            deleteUser()
        elseif choice == "3" then
            passwordRecovery()
        elseif choice == "4" then
            viewAllUsers()
        elseif choice == "5" then
            runSecurityCardSetup()
        elseif choice == "6" then
            exitProgram()
        else
            print("Invalid choice. Try again.")
            sleep(2)
        end
    end
end

-- Main program entry point
mainMenu()