ZenXercise/docs/adr/0002-library-ui-and-player.md

ADR 0002 — Exercise library, mode design, Player cues

Status: Accepted (2026-10-28)

Decisions

1. Library source: free-exercise-db (Unlicense, 876 exercises). stretching → Stretching mode, everything else → Workout mode. No user-created exercises.
2. Images: Bundle both images per exercise, compressed to WebP (~400px, est. 15–20 MB). The start/end "flip" is the v1 animation; real animations are a future step.
3. Language: English only; UI strings centralised for later translation.
4. Plan Steps: Workout = sets, reps-or-duration, optional weight; no rest countdown. Stretching = hold, both-sides flag, rounds. Workout Steps can be grouped into Supersets.
5. Library browsing: search + muscle/equipment/level filters, reused as the Plan exercise picker.
6. Structure & design: Mode switch at top; per-mode tabs Plans · Library · History. Stretching = calm/light (sage/teal, rounded, slow). Workout = dark/energetic (orange/red, bold, snappy). Last-used mode is remembered.
7. Player cues: Visual cues (countdown ring, accent pulse, next cards, auto-advance, screen kept on) plus a gentle, non-annoying sound. No vibration.
8. History: Separate per Mode. The Streak is one shared, Duolingo-style daily Streak across both Modes; only complete Sessions count.
9. Units: kg only.