MySQL Advanced Ordering combining two queries

Question

I'm getting the following data using two queries which I'm then using a UNION ALL to combine:

• First part: All IN events are sorted using SideA then EventTime
• Second part: All OUT events are sorted the same way

However, I'd like the final result to be as follows:

• Insert the OUT events in the corresponding EventTime where out.SideB=in.SideA
• You'll notice that for each OUT event there's a correspodning IN event but sometimes it's not the case (case highlighted in orange).
• Also the timings might not be identical 100% so it can't be used for matching.

So the final result should be like this:

Please advise how to proceed.

PS: Please find the data used in my example in this GoogleSheet

Answer 1

I am thinking of an order by clause like:

order by 

    -- if event type is 1, order by SideA, else order by SideB        
    case when EventType = 'IN' then SideA else SideB end,

    -- then event time
    EventTime,

    -- `Out` goes before `IN` if there are several events at the same time
    EventType desc