-- 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 save encrypted password to a file
function saveEncryptedPassword(username, encryptedPassword)
    local userDir = "/disk/users/" .. username
    local passwordFile = fs.open(userDir .. "/password.txt", "w")
    passwordFile.write(encryptedPassword)
    passwordFile.close()
end

-- Function to load encrypted password from a file
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.")
        return nil
    end
    local file = fs.open(fileName, "r")
    local encryptedPassword = file.readAll()
    file.close()
    return encryptedPassword
end

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

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

-- Function to select and encrypt username
function selectAndEncryptUsername()
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter username:")
    local username = read()

    local key = generateKey()
    local encryptedUsername = encrypt(username, key)
    local keyFileName = saveKeyToFile(key, "/disk/users/" .. username)

    return {
        encryptedUsername = encryptedUsername,
        keyFileName = keyFileName
    }
end

-- Function to decrypt username
function decryptUsername(encryptedUsername, keyFileName)
    local key = loadKeyFromFile(keyFileName)
    if not key then
        print("Encryption key not found.")
        return nil
    end
    return decrypt(encryptedUsername, key)
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 grab disk ID and save it for a user
function grabAndSaveDiskID(username)
    term.clear()
    term.setCursorPos(1, 1)
    print("Insert Security Card to grab 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
                    -- 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 .. "/" .. diskID .. ".file"
                    local file = fs.open(filePath, "w")
                    file.writeLine("Disk ID: " .. diskID)
                    file.close()

                    print("Disk ID grabbed and saved successfully.")
                    return  -- Exit function after saving
                end
            end
        end

        sleep(1)  -- Check every second
    end
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? (y/n)")
    local confirm = read()
    if confirm: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 delete.")
        end
    else
        print("Operation canceled.")
    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

-- Main function to manage user selection and login
function main()
    term.clear()
    term.setCursorPos(1, 1)
    print("Enter encrypted username:")
    local encryptedUsername = read()

    term.clear()
    term.setCursorPos(1, 1)
    print("Enter encrypted password:")
    local encryptedPassword = read()

    -- Assume key for decrypting username and password is stored in the user directory
    local keyFileName = "/disk/users/" .. decryptedUsername .. "/key.txt"

    local username = decryptUsername(encryptedUsername, keyFileName)
    local password = decryptPassword(encryptedPassword, keyFileName)

    if username and password then
        print("Authenticated as:", username)
        -- Proceed with security card manager or other functionalities
        securityCardLogin(username)
    else
        print("Authentication failed.")
    end
end

-- Run the main function
main()