Domain controller

local USERS_DB = "/domain/users.db" -- Path to user database

-- Simulated database: You can replace this with a more advanced implementation
local users = {
    ["user1"] = {password = "hashedPassword123", roles = {"admin"}},
    ["user2"] = {password = "hashedPassword456", roles = {"user"}},
}

-- Save the database to a file
local function saveDatabase()
    local file = fs.open(USERS_DB, "w")
    file.write(textutils.serialize(users))
    file.close()
end

-- Load the database from a file
local function loadDatabase()
    if fs.exists(USERS_DB) then
        local file = fs.open(USERS_DB, "r")
        users = textutils.unserialize(file.readAll())
        file.close()
    else
        saveDatabase()
    end
end

-- Validate user credentials
local function validateUser(username, password)
    local user = users[username]
    if user and user.password == password then -- Replace with hashing for real security
        return true, user.roles
    else
        return false
    end
end

-- Server loop
local function startDomainController()
    print("Domain Controller is running...")

    while true do
        print("Waiting for client requests...")
        local event, side, message, replyChannel = os.pullEvent("modem_message")
        local request = textutils.unserialize(message)

        if request and request.type == "authenticate" then
            local success, roles = validateUser(request.username, request.password)
            local response = {success = success, roles = roles}
            rednet.send(replyChannel, textutils.serialize(response))
        elseif request and request.type == "fetch_users" then
            local userData = {}
            for username, data in pairs(users) do
                userData[username] = {roles = data.roles} -- Exclude passwords
            end
            rednet.send(replyChannel, textutils.serialize(userData))
        end
    end
end

loadDatabase()
startDomainController()