memby/README.md

# Memby (Android TV)

An independent Android TV client for Emby, by **ponzischeme89**. Sign in to browse your
personalised home screen, resume titles, play recent movies, and choose audio or subtitle
tracks during playback. The screensaver (Dream) code remains isolated from the client work.

## Features

- **System screensaver** via `DreamService` — auto-starts on idle once selected in the
  TV's Screensaver settings. Also previewable from the app's home screen.
- Random, cross-fading **backdrops** of Movies and Series that have backdrop images.
- **Interactive**: OK reveals Play / Favorite actions; ◄ ► change the backdrop; Back exits.
- **In-app playback** with Media3/ExoPlayer (movies play directly; a series plays its
  next-up / first episode).
- **Favorites** managed through the Emby API and shown on the home screen.
- A dedicated **For You** destination, shaped by Tracearr completion/device history,
  Memby browsing signals and a viewer-selected 30/60/120-minute time window. Every pick
  says why it was chosen and whether it has direct-play evidence on that television.

## Tech stack

- Kotlin + Jetpack **Compose for TV** (`androidx.tv:tv-material`)
- **Media3 / ExoPlayer** for playback
- Retrofit + OkHttp + kotlinx.serialization for the Emby REST API
- DataStore for persisted connection/session
- Coil for backdrop image loading

## Project layout

```
app/src/main/java/com/ponzischeme89/memby/
  MembyApp.kt                    Application; initialises the ServiceLocator
  ServiceLocator.kt              Manual DI (settings + repository)
  data/
    SettingsStore.kt             DataStore-backed connection/session state
    ServerConfig.kt              Which backend this build talks to
    EmbyRepository.kt            Content, favorites, playback; dual gateway/direct paths
    analytics/RowAnalytics.kt    Row engagement buffering
    model/                       Emby + gateway DTOs (kotlinx.serialization)
    remote/EmbyApi.kt            Retrofit interface for Emby
    remote/GatewayApi.kt         Retrofit interface for the Memby gateway
  ui/
    MainActivity.kt              Setup, profiles, home
    HomeViewModel.kt             Home state, row analytics, refresh
    HomeComponents.kt            Navigation rail, rows, cards
    MaintenanceScreen.kt         Full-screen offline state
    settings/SettingsSheet.kt    Settings panel
    screensaver/                 Shared slideshow + in-app preview host
    player/PlayerActivity.kt     Media3 playback
  screensaver/MembyDreamService.kt  System screensaver (hosts ScreensaverContent)

server/                          The Memby gateway (Go) — see server/README.md
```

## Build & install

You need **JDK 17** and the **Android SDK** (Android Studio bundles both).

Open the folder in Android Studio (Giraffe/Koala or newer) and let it sync, **or** from a
terminal:

```powershell
# Android Studio writes local.properties automatically. If building from the CLI,
# point it at your SDK first:
"sdk.dir=C:\\Users\\<you>\\AppData\\Local\\Android\\Sdk" | Out-File -Encoding ascii local.properties

.\gradlew.bat assembleDebug            # build the APK
.\gradlew.bat installDebug             # install to a connected Android TV / emulator
# Preferred for a TV already showing the Dream: clears Memby, installs, then reopens
# it so the old render surface cannot remain black. Pass -Serial when more than one
# device is attached.
.\deploy-debug.ps1 -Serial 192.168.20.3:41479
```

The APK lands in `app/build/outputs/apk/debug/app-debug.apk`.

## Two ways to run

The client can talk to Emby directly, or through the **Memby gateway** — a Go service in
`server/` that runs in Docker alongside Postgres and Redis and owns auth, caching, search
and the shaping of TV screens. With a gateway the launcher is one request instead of four,
and the TV holds a revocable gateway token rather than a live Emby token.

```
direct:   TV ──────────────────────────────► Emby
gateway:  TV ──► Memby gateway ──► Emby      (metadata + artwork)
          TV ─────────────────────► Emby     (video, always direct-play)
```

Which one a build uses is decided by `memby.gatewayUrl` in `gradle.properties`: set it and
the app is a thin client; leave it blank and nothing changes from the direct path below.
See [`server/README.md`](server/README.md) to run the container.

The gateway also imports Emby's catalogue into Postgres (once manually, then hourly for
new episodes), composes the home rows — including "Recommended from your watching
history" — and has an admin page at `/admin/` for imports, an offline switch, and
per-row engagement.

For Tracearr-powered recommendations, create a read-only public API key in Tracearr and
set `MEMBY_TRACEARR_URL` plus `MEMBY_TRACEARR_API_KEY` on the gateway (and optionally
`MEMBY_TRACEARR_SERVER_ID` when Tracearr monitors several servers). Tracearr credentials
remain server-side; the Android app only receives ranked Emby items and short reasons.
The gateway imports compact session signals into Postgres every five minutes and prepares
an over-provisioned per-user pool, so opening For You normally performs one indexed
database read. The live on-demand path remains available for cold starts and failed
rebuilds.

## Server address

Memby is built for one Emby server, so the address is baked into the APK instead of being
typed on a TV remote. Set it in `gradle.properties`:

```properties
memby.serverUrl=http://192.168.1.10:8096
```

It can also come from `~/.gradle/gradle.properties` (keeps it out of the repo) or a single
build: `.\gradlew.bat assembleDebug -Pmemby.serverUrl=http://192.168.1.10:8096`.

The value becomes `BuildConfig.EMBY_SERVER_URL`, read through
`data/ServerConfig.kt`. When it is set, the setup screen only asks for a username and
password, and the address wins over whatever a saved session recorded — so moving the
server is a property change plus a reinstall, with no user action. Leaving the property
**blank** restores the original behaviour: users type the address themselves.

## First run

1. Launch **Memby** from the Android TV launcher.
2. Sign in with your Emby username and password. (If the build has no hardwired server,
   enter its address first, e.g. `http://192.168.1.10:8096`.)
3. **Preview screensaver** to test it, or **Set as system screensaver** to open the TV's
   screensaver settings and choose "Memby Screensaver".

## Distributing builds

Memby is handed out as an APK from your own web server or NAS, and updates itself from
the same folder.

### One-time: a signing key

Android identifies an app by `applicationId` **plus signing key**. Every update must be
signed with the *same* key, or the TV rejects it as a different app. Lose the key and
every user has to uninstall and reinstall.

```powershell
keytool -genkeypair -v -keystore memby-release.jks -alias memby `
  -keyalg RSA -keysize 4096 -validity 10000
```

Keep the `.jks` somewhere backed up and **outside the repo** (`*.jks` is gitignored), then
point `local.properties` at it — also gitignored:

```properties
memby.keystore=C:/keys/memby-release.jks
memby.keystorePassword=…
memby.keyAlias=memby
memby.keyPassword=…
```

Without these, `assembleRelease` still builds but the APK is unsigned and will not
install. The build prints a warning saying so.

### Each release

```powershell
.\release.ps1 -Version 0.1.54 -Notes "Faster home screen" -BaseUrl https://nas.example.com/memby
```

That bumps `versionName`/`versionCode`, runs the tests, builds a signed APK, and fills
`dist/out/` with:

```
index.html            the page people are sent to
latest.json           the update manifest the app polls
memby-0.1.54.apk      the build
```

Copy those to the folder the NAS serves. Old APKs can stay alongside — only `latest.json`
decides what the app offers, so rolling back is editing one file.

### How TVs update themselves

In Memby's Settings, set the update URL to `https://nas.example.com/memby/latest.json`.
**Check for updates** then downloads and installs on the TV, no computer involved. A URL
ending in `.json` is read as a static manifest; anything else is treated as a Gitea host
(`/api/v1/repos/{owner}/{repo}/releases/latest`), so either source works.

The manifest's `apkUrl` may be relative (`memby-0.1.54.apk`) and is resolved against the
manifest's own URL, so the folder keeps working if the NAS is reached by another name.

First install on each TV still has to be manual — the **Downloader** app pointed at the
landing page is the usual route, and the page explains it.

## Upgrading to v0.1.53

The package and install identity both became `com.ponzischeme89.memby` in this release
(previously `com.mattcohen.embyclientsname`). Android treats a new `applicationId` as a
different app, so on every TV:

1. Install v0.1.53 — it appears as a **second** Memby entry in the launcher.
2. Sign in again; the previous session does not carry over.
3. Uninstall the old app: `adb uninstall com.mattcohen.embyclientsname`.
4. Re-select Memby in the TV's Screensaver settings — the Dream's component name changed
   as well, so the old selection no longer resolves.

## Notes & limitations

- Playback uses Emby's direct stream (`/Videos/{id}/stream?static=true`). This direct-plays
  containers/codecs ExoPlayer supports (most MP4/H.264, many MKV). Server-side transcoding
  is not requested; unusual codecs may need it — a future enhancement is to call Emby's
  `PlaybackInfo` endpoint and use the returned HLS transcode URL (the `media3-exoplayer-hls`
  dependency is already included).
- Cleartext HTTP is enabled so local `http://` servers work out of the box. For an HTTPS-only
  server this is unnecessary but harmless.
- The device is remembered across sign-outs (stable `DeviceId`); credentials are cleared.
```