---Reworked for support ticket 0013924 
-- Original code looked like it was meant to run in an event.
-- Or author thought UNITX was available in SA's for whatever reason, maybe it was at some point in past?
-- Reworked to be compatiable with at least CMO 112x.x forward. and to account for possible fuel type change.
-- Should also work on relatively recent cmano builds spring 2019+.

local function RefuelAllTanksByClassStringMatch(theSide,MatchingString)
    local s = VP_GetSide({side=theSide}) --get the side
    if(s~=nil) then -- sanity check we have valid side object.
        --Now get all ships, though with B1147.2 foward you could do this far more specifically and shorten the search.
        --But we'll leave it the old school way so it works on older builds as well for now.
        local shiplist = s:unitsBy('Ship'); 
        local fuel;
        local u;
        for k,v in ipairs(shiplist) do --loop through all ships. 
            u = ScenEdit_GetUnit({guid=v.guid}); -- get the unit.
            if ((u ~= nil) and u.type ~= 'Group') then --()make sure nil check goes first.
                --now we do the original code.
                if string.match(u.classname,MatchingString) then --test the string match.
                   fuel = u.fuel;
                   for i,j in pairs(fuel) do -- run through them all avoid error on a gas type change in db.
                      fuel[i].current = fuel[i].max;
                      u.fuel = fuel
                      print(string.format('MDK Refueling Script Used: refueled %s',tostring(u.name)));
                   end
                end
            end
            u=nil; fuel = nil; --release the old data before next iteration to ensure nil checking state.
        end
    else
        ScenEdit_MsgBox('The script could not obtain the side object with string ' .. tostring(theSide) .. '\r\nPlease pass this error on to the author.',1);
        ScenEdit_SetSpecialAction({ActionNameOrID="Refuel MDK",IsActive=true}); -- don't charge the user. 
    end
end 

RefuelAllTanksByClassStringMatch("WP","MDK")