GChat 5000

if not process.info "chatbox" then process.spawn(chatbox.run, "chatbox") end

local messages = {
    "Ah, %s. I have been expecting you.",
    "Welcome back!",
    "Hi.",
    "Hello!",
    "Hey %s!",
    "Hi %s.",
    "WELCOME" .. ("!"):rep(10),
    "Good morning!",
    "Good evening, %s.",
    "Beneficent salutations.",
    "Good morrow, good %s."
}

local data = persistence "gchat"
data.players = data.players or {}

local function set_optin(player, thing, yesno)
    if not data.players[player] then data.players[player] = {} end
    local playerdata = data.players[player]
    if not playerdata.optin then playerdata.optin = {} end
    playerdata.optin[thing] = yesno
    chatbox.tell(player, ("Optin status for %s: %s"):format(thing, tostring(yesno)))
    data:save()
end

local function get_optin(player, thing)
    return data.players[player] and data.players[player].optin and data.players[player].optin[thing]
end

while true do
    local event, player, command, arguments = os.pullEvent ()
    if event == "join" and get_optin(player, "hi") then
        local x = messages[math.random(1, #messages)]
        if type(x) == "string" then x = x:format(player)
        elseif type(x) == "function" then x = x(player, messages) end
        print(player, x)
        sleep(1)
        chatbox.tell(player, x)
    elseif event == "command" then
        print(player, command, textutils.serialise(arguments))
        if command == "hi" then
            local sub = arguments[1]
            if sub == "optin" then
                set_optin(player, "hi", true)
            elseif sub == "optout" then
                set_optin(player, "hi", false)
            else
                chatbox.tell(player, "Command not found.")
            end
        end
    end
end