local DELAY_MIN = 2
local DELAY_MAX = 5

local messages = {
    "hi",
    "o/",
    "o7",
    "yo",
    "hello",
}

local is_in_group = false
local has_greeted = false


local frame = CreateFrame("Frame")
frame:RegisterEvent("GROUP_ROSTER_UPDATE")


local function send_message(msg)
    if IsInGroup(LE_PARTY_CATEGORY_INSTANCE) then
        SendChatMessage(msg, "INSTANCE_CHAT")
    elseif IsInGroup() then
        SendChatMessage(msg, "PARTY")
    end
end

local function greet_group()
    local delay = math.random(DELAY_MIN, DELAY_MAX)
    C_Timer.After(delay, function()
        local msg = messages[ math.random(#messages) ]
        send_message(msg)
    end)
end

frame:SetScript("OnEvent", function()
    if IsInGroup() and not IsInRaid() then
        if not is_in_group then
            if not has_greeted then
                greet_group()
                has_greeted = true
            end
            is_in_group = true
        end
    else
        is_in_group = false
        has_greeted = false
    end
end)