ledgrab/TODO.md

# LedGrab TODO

## Android — Restore Multi-ABI Wheels

During emulator testing, we switched the build to **x86 only** (see `android/app/build.gradle.kts` `abiFilters`) to avoid having to keep the arm64-v8a / x86_64 pydantic-core wheels current. Before shipping, restore all three ABIs:

- [x] Rebuild `pydantic-core` wheels for all three ABIs with the current SOABI + libpython linking settings (`android/build-scripts/build-pydantic-core.sh` — now supports `arm64`, `x86_64`, `x86` args; defaults to all three).
- [x] Verify wheels: all three now list `libpython3.11.so` in `NEEDED` (`llvm-readelf -d`), automated in the build script.
- [x] Restored `abiFilters += listOf("arm64-v8a", "x86_64", "x86")` in `build.gradle.kts`. Multi-ABI debug APK builds cleanly (~99 MB).
- [ ] Re-test on real ARM64 Android TV hardware (still pending — only emulator-verified build).

Build cache + scripts live in `android/build-scripts/` and `android/.build-cache/` (junction host + sysconfigdata for each ABI).

## Android CI Pipeline

Build the Android APK automatically on push/tag.

- [x] Generate Gradle wrapper (`gradlew`) and commit it
- [x] Create CI workflow (`.gitea/workflows/build-android.yml`)
  - JDK 17 + Android SDK + NDK setup
  - Python 3.11 for Chaquopy build
  - Recreate the directory junction via `ln -s` on Linux CI
  - `./gradlew assembleDebug` on master push, `assembleRelease` on `v*` tags (if signing secrets set)
  - Uploads APK as CI artifact; attaches to Gitea release on tag push
- [x] Commit pre-built pydantic-core wheels to `android/wheels/` (arm64, x86, x86_64)
- [x] APK signing for release builds — conditional signing config reads keystore from env vars (`ANDROID_KEYSTORE_PATH/_PASSWORD/_ALIAS/_KEY_PASSWORD`), falls back to debug signing locally
- [ ] Provision a real keystore and add the four CI secrets:
  - `ANDROID_KEYSTORE_BASE64` (base64-encoded .jks)
  - `ANDROID_KEYSTORE_PASSWORD`
  - `ANDROID_KEY_ALIAS`
  - `ANDROID_KEY_PASSWORD`
- [ ] Add `LedGrab-{tag}-android-release.apk` row to the release description table in `.gitea/workflows/release.yml` → `create-release` job
- [ ] Verify the CI workflow passes end-to-end with the now-restored multi-ABI build (larger APK, longer Android build step)

## Android Root Capture (No Permission Dialog, No System Indicator)

MediaProjection shows a mandatory system overlay/indicator while capturing — unavoidable on stock Android. Many cheap Android TV boxes ship pre-rooted, so an alternative root-only path would give much better UX.

- [ ] Detect root at runtime: check for `su` binary, `Superuser.apk`, etc.
- [ ] Implement `SurfaceControlCaptureEngine` (new capture engine) using hidden `SurfaceControl.screenshot()` API via reflection
  - No permission dialog
  - No system capture indicator
  - Direct bitmap output (no encoder/decoder roundtrip)
- [ ] Engine priority: higher than MediaProjection when root detected
- [ ] Fallback chain: `SurfaceControl` (root) → `MediaProjection` (stock) → `adb screencap` (last resort)
- [ ] Handle Android version differences in `SurfaceControl` API surface (renamed/moved across API 29, 30, 33)
- [ ] Alternative: shell out to `screenrecord --output-format=h264 -` as root (same H.264 decode as scrcpy_client_engine, but local instead of remote ADB)

Known projects using this approach for reference: scrcpy-hidden-api, shizuku, commercial scrcpy-derived apps.

## Android USB Serial Support

Drive USB LED controllers (APA102, WS2812) connected directly to the Android TV box via USB-to-serial adapters.

- [ ] Add [usb-serial-for-android](https://github.com/mik3y/usb-serial-for-android) dependency to `android/app/build.gradle.kts`
- [ ] Create Kotlin `UsbSerialBridge` class that:
  - Enumerates USB serial devices via Android USB Host API
  - Requests user permission for USB device access
  - Opens a serial connection (baud rate configurable)
  - Exposes a write method callable from Python via Chaquopy
- [ ] Create Python `AndroidSerialProvider` in `server/src/ledgrab/core/devices/` that:
  - Replaces `pyserial` on Android (which can't access USB ports)
  - Calls `UsbSerialBridge` via Chaquopy to send LED data
  - Registers as an alternative serial transport when `is_android()` is True
- [ ] Add USB device permission dialog to `MainActivity` (auto-triggered on device connect)
- [ ] Test with common USB-to-serial chips: CH340, CP2102, FTDI
- [ ] Document supported USB LED controllers in README

## Performance Metrics Abstraction

- [x] `MetricsProvider` protocol + dataclass DTOs (`MemorySnapshot`, `ProcessSnapshot`) live in `server/src/ledgrab/utils/metrics/types.py`. Each provider has its own module: `psutil_provider.py`, `null_provider.py`, `android_provider.py`.
- [x] Factory `get_metrics_provider()` in `utils/metrics/__init__.py` selects Android → psutil → Null. `psutil` import is now confined to one place.
- [x] `api/routes/system.py` and `core/processing/metrics_history.py` use the provider; no more `if psutil is not None` guards in the hot paths.
- [x] Android `/proc`-backed provider implemented (`/proc/stat`, `/proc/meminfo`, `/proc/self/stat`, `/proc/self/status`). Carries previous-sample state for delta-based CPU%; degrades to zeros if any `/proc` file is locked down. 12 unit tests cover both desktop and Android paths.

## Android Performance Metrics — Future Enhancements

Beyond the `/proc`-based AndroidMetricsProvider that's now in place:

- [ ] Optional: app-specific memory via `Debug.getMemoryInfo()` through a Kotlin → Python Chaquopy bridge (more accurate than `VmRSS` for split-app-process accounting)
- [ ] Consider: device battery/temperature readings for TV boxes (some have thermal throttling)
- [ ] Optional: GPU usage via `/sys/class/kgsl/kgsl-3d0/gpubusy` on Adreno, Mali-specific paths for Mali GPUs