auto take screenshot when bg/arena finished

[devilArt]

i took these code from shestakui, it could auto take a screenshot when you earned a achievement, but I want it auto take a screenshot when bg/arena finished too, is there anyone know how to modify it?

local function TakeScreen(delay, func, ...)
    local waitTable = {}
    local waitFrame = CreateFrame("Frame", "WaitFrame", UIParent)
    waitFrame:SetScript("onUpdate", function (self, elapse)
        local count = #waitTable
        local i = 1
        while (i <= count) do
            local waitRecord = tremove(waitTable, i)
            local d = tremove(waitRecord, 1)
            local f = tremove(waitRecord, 1)
            local p = tremove(waitRecord, 1)
            if d > elapse then
                tinsert(waitTable, i, {d-elapse, f, p})
                i = i + 1
            else
                count = count - 1
                f(unpack(p))
            end
        end
    end)
    tinsert(waitTable, {delay, func, {...} })
end
 
local function OnEvent(...)
    TakeScreen(1, Screenshot)
end
 
local frame = CreateFrame("Frame")
frame:RegisterEvent("ACHIEVEMENT_EARNED")
frame:SetScript("OnEvent", OnEvent)