choose user

local MAX_ATTEMPTS = 3   -- Maximum incorrect password attempts allowed
local LOCKOUT_TIME = 30  -- Lockout time in seconds after reaching maximum attempts

local USERS_FOLDER = "/disk/users/"
local ERROR_FOLDER = "/disk/error/"
local BSOD_PROGRAM = "BSOD.lua"

local function getUserCredentials(username)
    local passwordFile = fs.combine(USERS_FOLDER .. username, "password.txt")

    if fs.exists(passwordFile) then
        local file = fs.open(passwordFile, "r")
        local storedPassword = file.readLine()
        file.close()
        return storedPassword
    else
        return nil  -- User does not exist
    end
end

local function drawLoginScreen(username, attemptsLeft)
    term.clear()
    term.setCursorPos(1, 1)

    term.setTextColor(colors.cyan)
    print("Doggy OS Login")
    print("--------------")

    term.setTextColor(colors.yellow)
    print("User: " .. username)
    print("Attempts Left: " .. attemptsLeft)

    term.setTextColor(colors.white)
    print("Enter Password:")
end

local function lockoutUser(username)
    local disabledFile = fs.combine(USERS_FOLDER .. username, "disabled.txt")
    local file = fs.open(disabledFile, "w")
    file.close()
end

local function checkDisabled(username)
    local disabledFile = fs.combine(USERS_FOLDER .. username, "disabled.txt")
    return fs.exists(disabledFile)
end

local function checkCredentials(username)
    if checkDisabled(username) then
        term.clear()
        term.setCursorPos(1, 1)
        term.setTextColor(colors.red)
        print("This user has been disabled for security reasons.")
        os.sleep(3)  -- Display the disabled message for 3 seconds
        print("Contact your administrator for assistance.")
        os.sleep(2)  -- Display the contact administrator message for 2 seconds
        shell.run("/disk/os/lock.lua")  -- Run the lock.lua program
        return false
    end

    local storedPassword = getUserCredentials(username)

    if not storedPassword then
        return false  -- User does not exist
    end

    local attempts = 0

    repeat
        drawLoginScreen(username, MAX_ATTEMPTS - attempts)

        local enteredPassword = read("*")
        attempts = attempts + 1

        if enteredPassword == storedPassword then
            return true
        else
            term.setTextColor(colors.red)
            print("Incorrect password. Please try again.")
            os.sleep(2)  -- Display the error message for 2 seconds
        end
    until attempts > MAX_ATTEMPTS

    print("Too many incorrect attempts. User has been disabled.")
    lockoutUser(username)
    os.sleep(2)  -- Display the lockout message for 2 seconds

    return false
end

local function getUserList()
    local users = fs.list(USERS_FOLDER)
    local validUsers = {}

    for _, user in ipairs(users) do
        local blockFile = fs.combine(USERS_FOLDER .. user, "block.txt")
        if not fs.exists(blockFile) then
            table.insert(validUsers, user)
        end
    end

    return validUsers
end

local function displayUserMenu()
    term.clear()
    term.setCursorPos(1, 1)

    term.setTextColor(colors.green)
    print("Welcome to Doggy OS")
    print("--------------------")

    print("Select a user to log in:\n")

    local userList = getUserList()

    for i, user in ipairs(userList) do
        print(i .. ". " .. user)
    end

    term.setTextColor(colors.white)
    write("\nEnter the number corresponding to the user: ")
    local choice = tonumber(read())

    if choice and userList[choice] then
        return userList[choice]
    else
        return nil
    end
end

local function main()
    term.clear()
    term.setCursorPos(1, 1)

    term.setTextColor(colors.green)
    print("Secured by Doggy OS")
    print("--------------------")

    local enteredUsername = displayUserMenu()

    if not enteredUsername then
        term.clear()
        term.setCursorPos(1, 1)

        term.setTextColor(colors.red)
        print("Invalid user selection.")
        os.sleep(2)  -- Display the invalid selection message for 2 seconds
        return
    end

    if checkDisabled(enteredUsername) then
        term.clear()
        term.setCursorPos(1, 1)
        term.setTextColor(colors.red)
        print("This user is temporarily disabled for security reasons.")
        os.sleep(3)  -- Display the disabled message for 3 seconds
        print("Contact your administrator for assistance.")
        os.sleep(2)  -- Display the contact administrator message for 2 seconds
        shell.run("/disk/os/lock.lua")  -- Run the lock.lua program
        return
    end

    if not checkCredentials(enteredUsername) then
        term.clear()
        term.setCursorPos(1, 1)

        term.setTextColor(colors.red)
        print("Access denied.")
        os.sleep(2)  -- Display the access denied message for 2 seconds
        return
    end

    term.clear()
    term.setCursorPos(1, 1)

    term.setTextColor(colors.lime)
    print("Access granted. Welcome, " .. enteredUsername .. "!")
    os.sleep(2)  -- Display the success message for 2 seconds

    -- Your main OS code goes here
end

main()