feat: add productivity score for categories

[ErikBjare]

Rebased and salvaged #162

Shouldn't require any changes to backend code.

Tasks

• Review what would make the best UX from previous discussions
• How long you need to engage in a 1 point activity to get 1 point? (an hour?)
• Add computation of score for period

  • totalScore = 0
    for event in events:
      totalScore += event.duration * get_score(event.category, allCategories)
    return totalScore / (60 * 60)  # from score-seconds to score-hours

• Add visualization (just a number of the total score today?)
• Make sure score is inherited correctly
• What should scores be for the default categories?

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.32 ⚠️

Comparison is base (af12a54) 24.53% compared to head (ff9ecab) 24.22%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #258      +/-   ##
==========================================
- Coverage   24.53%   24.22%   -0.32%     
==========================================
  Files          27       27              
  Lines        1520     1540      +20     
  Branches      248      251       +3     
==========================================
  Hits          373      373              
- Misses       1122     1142      +20     
  Partials       25       25              

Impacted Files	Coverage Δ
src/main.js	0.00% <0.00%> (ø)
src/stores/activity.ts	30.24% <0.00%> (-0.78%)	⬇️
src/stores/categories.ts	50.00% <0.00%> (-5.56%)	⬇️
src/util/classes.ts	81.18% <ø> (ø)

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[johan-bjareholt]

How long you need to engage in a 1 point activity to get 1 point? (an hour?)

I never thought of it in that way at all.

Since you can do productive things outside of using your computer, to me it's more important to give a score of how productive you are on average rather than a sum of all your productive time.
So rather than to just say a number "Todays productivity score was 800", I had always imagined a scale from -1 to 1 which could in text say "Very productive" if it's for example above 0.7 or something.

[nicolae-stroncea]

@johan-bjareholt I think the current way is essentially identical to your way, except that the final value is unbounded. The current formula essentially returns a score-weighted average, where the scores can be both negative and positive depending on what the scores the user sets, so user more productive -> total score increases, user unproductive -> total score decreases.

If we want to bound the value, we can pass it through a tanh(total_score) function, which will map the values to [-1,1].

[ErikBjare]

I added a really quick-n-dirty visualization in the latest commit:

[ErikBjare]

Finally merging this. The remaining tasks will have to wait for another day.