local MAX_ATTEMPTS = 3   -- Maximum number of 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"

-- Doggy OS branding and constants
local OS_NAME = "Doggy OS"
local OS_VERSION = "13.0"
local HEADER_COLOR = colors.blue
local HIGHLIGHT_COLOR = colors.blue  -- Set highlight color to blue

-- Utility function to draw a centered popup window with a text-based border
local function drawPopupWindow(headerText, contentLines)
    term.clear()  -- Clear the screen before drawing the popup window

    local w, h = term.getSize()
    local maxLength = #headerText
    for _, line in ipairs(contentLines) do
        maxLength = math.max(maxLength, #line)
    end

    local windowWidth = maxLength + 4  -- Width of the popup window
    local windowHeight = #contentLines + 4  -- Height of the popup window
    local xStart = math.floor(w / 2 - windowWidth / 2)
    local yStart = math.floor(h / 2 - windowHeight / 2)

    -- Draw border
    term.setCursorPos(xStart, yStart)
    term.write("+" .. string.rep("-", windowWidth - 2) .. "+")
    for i = 1, windowHeight - 2 do
        term.setCursorPos(xStart, yStart + i)
        term.write("|" .. string.rep(" ", windowWidth - 2) .. "|")
    end
    term.setCursorPos(xStart, yStart + windowHeight - 1)
    term.write("+" .. string.rep("-", windowWidth - 2) .. "+")

    -- Draw header
    term.setCursorPos(xStart + 2, yStart + 1)
    term.setTextColor(HEADER_COLOR)
    term.write(headerText)
    term.setTextColor(colors.white)

    -- Draw content
    for i, line in ipairs(contentLines) do
        term.setCursorPos(xStart + 2, yStart + 1 + i + 1)
        term.write(line)
    end
end

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)
    local contentLines = {
        "Username: " .. username,
        "Attempts left: " .. attemptsLeft,
        "",
        "Enter password:"
    }
    drawPopupWindow("Login", contentLines)
    term.setCursorPos(math.floor(term.getSize() / 2) - 2, math.floor(term.getSize() / 2) + 1)  -- Position cursor for password input
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
        drawPopupWindow("Access Denied", {"This user has been disabled due to security reasons.", "", "Contact your administrator for help."})
        os.sleep(5)  -- Display the disabled message for 5 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
            drawPopupWindow("Access Denied", {"Incorrect password. Please try again."})
            os.sleep(2)  -- Display the error message for 2 seconds
        end
    until attempts > MAX_ATTEMPTS

    drawPopupWindow("Account Disabled", {"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 checkDiskIDs()
    -- Get a list of all connected peripherals
    local peripherals = peripheral.getNames()

    -- Array to store disk IDs
    local diskIDs = {}

    -- Loop through all peripherals
    for _, name in ipairs(peripherals) do
        -- Check if the peripheral is a disk drive
        if peripheral.getType(name) == "drive" then
            -- Get the disk ID from the disk drive
            local diskID = disk.getID(name)

            -- If a disk is inserted, add its ID to the array
            if diskID then
                table.insert(diskIDs, {id = diskID, name = name})
            end
        end
    end

    -- Check if any disks were found
    if #diskIDs > 0 then
        return diskIDs
    else
        return nil
    end
end

local function drawSecurityCardPrompt()
    local contentLines = {
        "Please insert your security card.",
        "Press ENTER to use password instead."
    }
    drawPopupWindow("Insert Security Card", contentLines)
end

local function drawErrorMessage(message)
    drawPopupWindow("Error", {message})
end

local function drawMessage(header, message)
    drawPopupWindow(header, {message})
end

local function ejectDisk(diskName)
    peripheral.call(diskName, "ejectDisk")
end

local function insertSecurityCard(username)
    local idFolder = fs.combine(USERS_FOLDER .. username, "ID")
    if not fs.exists(idFolder) then
        return false
    end

    while true do
        drawSecurityCardPrompt()

        local event, key = os.pullEvent()

        if event == "key" and key == keys.enter then
            return false  -- Allow password login if enter is pressed
        elseif event == "disk" or event == "disk_insert" then
            local diskIDs = checkDiskIDs()
            if diskIDs then
                for _, disk in ipairs(diskIDs) do
                    ejectDisk(disk.name)  -- Eject the disk after checking
                    local idFile = fs.combine(idFolder, tostring(disk.id) .. ".file")
                    if fs.exists(idFile) then
                        return true  -- Allow access if a valid security ID is found
                    end
                end
                drawErrorMessage("Error: Unregistered security key.")
                os.sleep(2)
            end
        end
    end
end

local function selectUserFromList(users)
    local selectedIndex = 1
    local totalUsers = #users

    while true do
        local contentLines = {
            "Select your user account"
        }

        for i, user in ipairs(users) do
            if i == selectedIndex then
                term.setTextColor(HIGHLIGHT_COLOR)
                table.insert(contentLines, "> " .. user)
            else
                term.setTextColor(colors.white)
                table.insert(contentLines, "  " .. user)
            end
        end

        term.setTextColor(colors.white)  -- Reset color after loop
        drawPopupWindow("Select User", contentLines)

        local event, key = os.pullEvent()

        if event == "key" then
            if key == keys.down then
                selectedIndex = math.min(selectedIndex + 1, totalUsers)
            elseif key == keys.up then
                selectedIndex = math.max(selectedIndex - 1, 1)
            elseif key == keys.enter then
                return users[selectedIndex]
            end
        end
    end
end

local function main()
    -- Set the text color to white and the background color to black
    term.setTextColor(colors.white)
    term.setBackgroundColor(colors.black)
    term.clear()

    local users = fs.list(USERS_FOLDER)

    if not users or #users == 0 then
        -- No users detected, run the BSOD program
        shell.run(ERROR_FOLDER .. BSOD_PROGRAM)
    else
        -- Allow the user to select a username
        local selectedUser = selectUserFromList(users)
        if selectedUser then
            if insertSecurityCard(selectedUser) or checkCredentials(selectedUser) then
                drawMessage("Success", "Welcome back, " .. selectedUser .. "!")
                os.sleep(2)
                -- Proceed to the main Doggy OS interface
                shell.run("/disk/os/gui")
            else
                drawMessage("Login Failed", "Invalid username or password.")
                os.sleep(2)
                shell.run("/disk/os/gui")
            end
        end
    end
end

main()