aura_env.update = function(overrideInterval)
    if not (overrideInterval or GetTime() - aura_env.lastCheck >= aura_env.config.interval) then
        return
    end

    aura_env.lastCheck = GetTime();

    if not aura_env.iconsInitialized then
        aura_env.initIcons();
    end

    local group;

    if IsInRaid() then
        group = "raid"
    elseif IsInGroup() then
        group = "party"
    else
        group = "player"
    end

    local groupSize = max(1, GetNumGroupMembers())

    aura_env.needsBuff = {};

    for i=1,#aura_env.spells do
        local spell = aura_env.spells[i];

        aura_env.needsBuff[spell] = {};
    end

    for unitId in WA_IterateGroupMembers() do
        if UnitIsFriend("player", unitId) and not UnitIsDeadOrGhost(unitId) and UnitIsConnected(unitId) then
            for i=1,#aura_env.spells do
                local spell = aura_env.spells[i];

                if IsSpellInRange(spell, unitId) == 1 then
                    if not WA_GetUnitAura(unitId, spell) then
                        --print(unitId.." missing "..spell)
                        local name = UnitName(unitId);
                        table.insert(aura_env.needsBuff[spell], name);
                    else
                        --print(unitId.." has "..spell)
                    end
                end
            end
        end
    end

    --DevTools_Dump(aura_env.needsBuff)

    WeakAuras.ScanEvents("RAID_BUFF_TSU");
    --print("updated")
end