local SERVER_IP = "192.168.1.1"  -- Replace with the actual server IP address
local SERVER_PORT = 5000
local MAX_ATTEMPTS = 3
local DOMAIN_FILE = "/disk/domain.txt"

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

    local windowWidth = maxLength + 4
    local windowHeight = #contentLines + 4
    local xStart = math.floor(w / 2 - windowWidth / 2)
    local yStart = math.floor(h / 2 - windowHeight / 2)

    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) .. "+")

    term.setCursorPos(xStart + 2, yStart + 1)
    term.write(headerText)

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

local function authenticate(computerID, username, password)
    local socket = require("socket")
    local tcp = socket.tcp()
    tcp:connect(SERVER_IP, SERVER_PORT)
    tcp:send(computerID .. "\n")
    tcp:send(username .. "\n")
    tcp:send(password .. "\n")
    local response = tcp:receive()
    tcp:close()
    return response == "OK"
end

local function readDomainID()
    local domainFile = fs.open(DOMAIN_FILE, "r")
    local domainID = domainFile.readLine()
    domainFile.close()
    return domainID
end

local function drawLoginScreen(username, attemptsLeft)
    local contentLines = {
        "Username: " .. username,
        "Attempts left: " .. attemptsLeft,
        "",
        "Enter password:"
    }
    drawPopupWindow("Login to Doggy OS", contentLines)
    term.setCursorPos(math.floor(term.getSize() / 2) - 2, math.floor(term.getSize() / 2) + 1)
end

local function checkCredentials(username)
    local computerID = readDomainID()
    local attempts = 0
    repeat
        drawLoginScreen(username, MAX_ATTEMPTS - attempts)
        local enteredPassword = read("*")
        attempts = attempts + 1
        if authenticate(computerID, username, enteredPassword) then
            return true
        else
            drawPopupWindow("Access Denied", {"Incorrect password or Computer ID. Please try again."})
            os.sleep(2)
        end
    until attempts > MAX_ATTEMPTS
    drawPopupWindow("Account Disabled", {"Too many incorrect attempts. User has been disabled."})
    os.sleep(2)
    return false
end

local function main()
    term.setTextColor(colors.white)
    term.setBackgroundColor(colors.black)
    term.clear()

    drawPopupWindow("Protected by Doggy OS Security", {"Enter username:"})
    local enteredUsername = read()

    if checkCredentials(enteredUsername) then
        drawPopupWindow("Welcome", {"Access granted. Welcome, " .. enteredUsername .. "!"})
        os.sleep(2)
        shell.run("/disk/os/gui")
    else
        drawPopupWindow("Access Denied", {"Access denied."})
        os.sleep(2)
        shell.run("/disk/os/lock.lua")
    end
end

main()