pfUI:RegisterModule("updatenotify", function ()
  if pfUI.version.string == "dev" then return end

  local alreadyshown
  local localversion  = tonumber(pfUI.version.major*10000 + pfUI.version.minor*100 + pfUI.version.fix)
  local remoteversion = tonumber(pfUI_init.updateavailable) or 0
  local loginchannels = { "BATTLEGROUND", "RAID", "GUILD" }
  local groupchannels = { "BATTLEGROUND", "RAID" }

  local ADDON_PREFIX = "pfUI-brues"

  local localbranch = "main"
  local versionmsg  = "VERSION:" .. localversion .. ":" .. localbranch

  pfUI.events:RegisterFrameEventAndCallback("CHAT_MSG_ADDON", function(_, prefix, message)
    if prefix ~= ADDON_PREFIX then return end

    local v, rv, branch = pfUI.api.strsplit(":", message)
    rv = tonumber(rv)
    -- only process VERSION messages from the same branch
    -- messages without a branch tag (old versions) are ignored
    if v == "VERSION" and rv and branch == localbranch then
      if rv > localversion then
        pfUI_init.updateavailable = rv
      end
    end
  end)

  local group = 0
  pfUI.events:RegisterFrameEventAndCallback("PARTY_MEMBERS_CHANGED", function()
    local groupsize = IsInRaid() and GetNumRaidMembers() or IsInGroup() and GetNumPartyMembers() or 0
    if group < groupsize then
      for _, chan in pairs(groupchannels) do
        SendAddonMessage(ADDON_PREFIX, versionmsg, chan)
      end
    end
    group = groupsize
  end)

  pfUI.events:RegisterFrameEventAndCallback("PLAYER_ENTERING_WORLD", function()
    if not alreadyshown and localversion < remoteversion then
      DEFAULT_CHAT_FRAME:AddMessage(string.format(T["|cff33ffccpf|rUI: New version available! Get it at %s"], GetAddOnMetadata(pfUI.name, "X-Website") .. "/releases"))
      DEFAULT_CHAT_FRAME:AddMessage(T["|cffddddddIt's always safe to upgrade |cff33ffccpf|rUI. |cffddddddYou won't lose any of your configuration."])
      pfUI_init.updateavailable = localversion
      alreadyshown = true
    end

    for _, chan in pairs(loginchannels) do
      SendAddonMessage(ADDON_PREFIX, versionmsg, chan)
    end
  end)
end)