InfluxDB 2.0: Group Periods and Sum Up Duration

Question

I have an InfluxDB (version 2), where an entry is written every second into my bucket, together with an identifier (uuid of the source) and a side value (some domain-specific measurement from 1 to 6). Instead of having a long list of such by-second logs:

2020-05-18T15:57:18 side=1
2020-05-18T15:57:19 side=1
2020-05-18T15:57:20 side=3
2020-05-18T15:57:21 side=3
2020-05-18T15:57:22 side=3
2020-05-18T15:57:23 side=2
2020-05-18T15:57:24 side=2

I'd like to condense those entries, so that I can calculate the duration, for how long side=x held true:

from 2020-05-18T15:57:18 to 2020-05-18T15:57:19 side=1 duration=2s
from 2020-05-18T15:57:20 to 2020-05-18T15:57:22 side=3 duration=3s
from 2020-05-18T15:57:23 to 2020-05-18T15:57:24 side=2 duration=2s

I also restrict the time period by a from/to range. This is my current query:

from(bucket: "mybucket")
    |>range(start:2020-01-01T00:00:00.000Z, stop:2020-12-31T00:00:00.000Z
    |>filter(fn:(r) => r.identifier == "3c583530-0152-4ed1-b15f-5bb0747e771e")

My approach is to read the raw data, and then iterate over it, detect changes of the side (something like current.side != last.side), and then report that as a new entry to my logbook. This approach is very inefficient, of course (JavaScript):

    const data = fetchFromInfluxDB(from, to):
    const terminator = { 'time': new Date(), 'identifier': '', 'side': -1 };
    data.push(terminator); // make sure last item is also reported
    const logbook = new Array();
    let lastSide = -1;
    let from = undefined;
    for (let e of data) {
        if (e.side != lastSide) {
            if (from != undefined) {
                let to = e.time;
                let diff = Math.floor((new Date(to) - new Date(from)) / 1000);
                if (diff > 0) {
                    logbook.push({'from': from, 'to': to, 'side': lastSide, 'seconds': diff});
                }
            }
            lastSide = e.side;
            from = e.time;
        }
    }

Is there a way to group and sum up that data using the InfluxDB query language?