Compare aggregate values of data grouped by date

Question

I've got a working code that transforms data from a MySQL database.

Currently, it's inefficient because it uses about loops, which you'll see at the bottom.

I get an array of objects from a database query. The rows look like this:

[
  {
    userId: 1,
    WorkoutId: 1,
    workoutTitle: 'Hustler',
    workoutDescription: 'Goes to jail a lot',
    exerciseId: 1,
    exerciseTitle: 'Forward Implementation Executive',
    exerciseDescription: 'directional',
    SetId: 1,
    setDate: 2021-07-05T23:00:00.000Z,
    restTime: 60,
    reps: 12,
    duration: 0,
    weight: 10
  },
DUPLICATE for more^^^^
]

The desired output looks like:

[
    {
        "date": "5-Jul",
        "reps": "up",
        "duration": "same",
        "weight": "up",
        "setDetails": [
            {
                "weight": 10,
                "reps": 12,
                "duration": 0
            }
        ]
    }
]

You'll notice some of the queried data is omitted from the final result; you can assume it's not needed/relevant to the question.

The objective is to:

• Group the data by the date property.
• Do comparisons between the weight, reps, duration properties that are grouped. (objects within setDetails)
• Append the comparison result to the grouped object. (GROUPED BY DATE)

Current code:

async function service(provider, token, exerciseId) {
    // Some validation
 
    const res = await GetTableAnalyticsTwo(id, exerciseId);
    const data = res[0];

    if (data.length < 1) {
        return {message: "We can't provide you with Analytics until you've recorded the workout."}
    }
    
    let analytics = {}
    
    data.map((exercise) => {
        const {setDate, weight, reps, duration} = exercise;
        const date = setDate.toISOString().substring(0, 10);
        const dateExists = analytics[date];
        
        if (dateExists) {
            let arr = analytics[date].setDetails;
            arr.push({
                weight,
                reps,
                duration
            });
        } else if (!dateExists) {
            analytics[date] = {
                setDetails: [{
                    weight,
                    reps,
                    duration
                }]  
            }
        }
    });

    Object.entries(analytics).forEach(([key, values]) => {
        let avgWeight = 0;
        let totalDuration = 0;
        let totalReps = 0;
        let length = values.setDetails.length;
        
        values.setDetails.forEach((sets) => {
            const {weight, reps, duration} = sets;
            avgWeight += weight;
            totalDuration += duration;
            totalReps += reps;

        });
        
        avgWeight /= length;

        analytics[key].avgWeight = avgWeight;
        analytics[key].totalDuration = totalDuration;
        analytics[key].totalReps = totalReps;
    });

    let response = [];

    let prevReps = 0, prevDuration = 0, prevWeight = 0;
    Object.entries(analytics).forEach(([date, exercises]) => {
        const {avgWeight, totalDuration, totalReps, setDetails} = exercises;
        let reps, duration, weight;

        prevReps < totalReps ? reps = "up" : reps = "down";
        prevDuration < totalDuration ? duration = "up" : duration = "down";
        prevWeight < avgWeight ? weight = "up" : weight = "down";

        if (prevReps === totalReps) {
            reps = "same";
        }
        if (prevDuration === totalDuration) {
            duration = "same";
        }
        if (prevWeight === avgWeight) {
            weight = "same";
        }
        
        const setDate = new Date(date);
        const month = toMonthString(date);

        const exercise = {
            date: setDate.getDate() + "-" + month,
            reps,
            duration,
            weight,
            setDetails
        }
        response.push(exercise);
        
        prevReps = totalReps;
        prevDuration = totalDuration;
        prevWeight = avgWeight;
    });
    
    return response;
}