# ZenXercise

An offline Android app for stretching and working out, split into two fully separate Modes. The user
builds their own Plans from a large built-in Exercise Library and performs them in a guided Player.

## Modes

**Mode**:
One of the two top-level app states, **Stretching** or **Workout**. Switching Mode changes the whole
app: design, Exercise Library, Plans and History. The last-used Mode is remembered.
_Avoid_: Tab, section, category

**Stretching Mode**:
The calm Mode: light design, sage/teal, rounded shapes, slow transitions.

**Workout Mode**:
The energetic Mode: dark design, orange/red on near-black, bold type, snappy transitions.

## Exercises

**Exercise**:
A single movement from the Exercise Library, with name, Instructions, primary and secondary muscles,
equipment, level and a start and end image. Belongs to exactly one Mode. Users cannot create their own.
_Avoid_: Move, drill, activity

**Exercise Library**:
The read-only catalogue of Exercises bundled with the app, sourced from free-exercise-db (876
Exercises). Category `stretching` belongs to Stretching Mode (123); every other category to Workout
Mode (753). Browsed with text search and filters for muscle, equipment and level.
_Avoid_: Catalogue, database

**Flip Animation**:
Alternating an Exercise's start and end image about once a second, the v1 stand-in for real animation.

## Plans

**Plan**:
A user-created, ordered list of Steps (and Supersets) belonging to one Mode. The app ships no Plans.
_Avoid_: Routine, program, workout

**Step**:
One Exercise inside a Plan, with Mode-specific parameters:
- *Workout Step*: number of sets; reps **or** duration; optional target weight (kg).
- *Stretching Step*: hold duration; both-sides flag (left, then right); rounds.
_Avoid_: Item, entry

**Superset**:
Two or more adjacent Workout Steps grouped so they are performed alternately (A1 → B1 → A2 → B2 …).
It has one set count; each Step keeps its own reps or duration and weight. Rest between its Exercises
within a round is optional; the Rest Screen always follows the end of a round.
_Avoid_: Circuit, combo

**Rest Screen**:
In Workout Mode, the screen after "Set done": a count-up timer ("Resting 1:12") and a "Start next set"
button. Nothing counts down. Timed sets start only when the user taps Start.

**Transition**:
In Stretching Mode, a short card between rounds, sides ("Switch sides") and Exercises, after which the
next hold starts automatically. Length set per Plan, 5 s by default.

## Sessions

**Session**:
One run-through of a Plan in the Player. It stores a snapshot of the Plan, so later edits to the Plan
never change it. A Session is **complete** or **incomplete** (ended early).
_Avoid_: Workout, run

**Player**:
The guided, one-Exercise-at-a-time screen used to perform a Session. It shows a large countdown ring,
pulses the Mode's accent colour in the last three seconds, shows full-screen "next" cards, advances
automatically when a timer ends and keeps the screen awake. A single soft chime (singing bowl in
Stretching, muted "tok" in Workout) plays only when a timer ends or something new starts; it mixes
with the user's music and can be muted. No ticking, no vibration.

**Set Log**:
The reps and weight actually done for one Workout set, prefilled from the Step's targets and confirmed
with "Set done".

**History**:
The per-Mode list of Sessions with date, Plan, duration and Set Logs.

**Streak**:
A single, subtle, Duolingo-style daily streak shared by both Modes: consecutive days with at least one
complete Session in either Mode, however short. Incomplete Sessions do not count.