# Proposal: EQ Device Auto-Switch UX

## Intent

Device-specific EQ presets never apply at app startup because `cargarPersistido()` does not query the current audio device, leaving `_dispositivoActualId` null. Users must physically reconnect a device to trigger preset resolution. Additionally, the settings device list lacks connection indicators, rename capability, and inline EQ editing — making multi-device EQ management opaque and tedious.

## Scope

### In Scope
- Fix startup device query in `cargarPersistido()` to seed `_dispositivoActualId`
- Add `nombresDispositivos` persistence (`eq_nombres_dispositivos_v1` SharedPreferences key)
- Expose rename API in `EstadoEcualizador` (set/get custom device name)
- Connection status indicator (green dot) per device row in settings
- Device display name fallback chain: customName > platformName > deviceId
- Bottom sheet modal for device rename + embedded `EcualizadorWidget`
- Tests for all new/changed behavior

### Out of Scope
- Export schema v4 extension for device names (deferred)
- Changing Kotlin/platform-side audio device callback logic
- Modifying `EcualizadorWidget` internals
- Offline/background device switching behavior

## Capabilities

### New Capabilities
- `eq-device-rename`: Persist and manage custom device display names via SharedPreferences

### Modified Capabilities
- None (no existing specs)

## Approach

**Bug fix**: Call `obtenerDispositivoActual()` inside `cargarPersistido()` after `_configurarSuscripcionDispositivo()` when multi-device is enabled. Seed `_dispositivoActualId`, bootstrap preset if first-seen, re-resolve active preset.

**Rename persistence**: New `Map<String, String>` stored as JSON under `eq_nombres_dispositivos_v1` in `ServicioEcualizador`. `EstadoEcualizador` exposes `renombrarDispositivo(id, nombre)` and `obtenerNombreDispositivo(id)`.

**Settings UI**: Rewrite `_SeccionEcualizadorAvanzado` device rows with connection dot + display name fallback. Tap opens `showModalBottomSheet` (existing pattern: `showDragHandle: true`, `isScrollControlled: true`) containing rename TextField + embedded `EcualizadorWidget`.

## Affected Areas

| Area | Impact | Description |
|------|--------|-------------|
| `lib/estado/estado_ecualizador.dart` | Modified | Fix init + rename API + expose nombresDispositivos |
| `lib/servicios/servicio_ecualizador.dart` | Modified | New SP key for device names |
| `lib/pantallas/pantalla_ajustes.dart` | Modified | Rewrite device section + new modal widget |
| `test/` | New | Tests for bug fix, rename logic, display name fallback |

## Risks

| Risk | Likelihood | Mitigation |
|------|------------|------------|
| `obtenerDispositivoActual()` fails on edge devices | Low | Existing `builtin_speaker` fallback handles it |
| Bottom sheet clips EQ widget | Low | Use `isScrollControlled: true` (established pattern) |
| nombresDispositivos not in export schema | Med | Defer to v4; document omission |
| Platform `nombre` is null/empty | Med | Fallback chain: customName > platformName > deviceId |

## Rollback Plan

All changes are additive. Revert the commit(s). The new SP key (`eq_nombres_dispositivos_v1`) is ignored if code referencing it is removed. The startup device query is a single method call addition — removing it restores previous (broken) behavior without data loss.

## Dependencies

- None. All required APIs (`obtenerDispositivoActual`, `EcualizadorWidget`, `showModalBottomSheet` pattern) already exist.

## Success Criteria

- [ ] On app startup with multi-device enabled, the correct device preset is applied without user interaction
- [ ] Device list in settings shows connection status indicator for active device
- [ ] Users can rename devices; names persist across app restarts
- [ ] Tapping a device opens bottom sheet with rename + EQ editing
- [ ] Display name shows customName > platformName > deviceId fallback
- [ ] All new behavior has passing tests (Strict TDD)