# subwave-nowplaying

Tronbyt/Tidbyt app showing the current track on a [SUB/WAVE](https://github.com/perminder-klair/subwave)
internet radio station: album art, track title, artist, the current show
and host, and a progress bar for the track pinned to the bottom, with
title/artist/show scrolling if they don't fit. Color scheme (cyan
title/artist, gray label, white show name, magenta host/progress bar) is
loosely modeled on SUB/WAVE's own web now-playing display.

Not tied to any specific station — set your own station's base URL in the
app's config when adding it to a device.

## Configuration

- **Station URL** — the base URL of your SUB/WAVE instance, e.g.
  `https://radio.example.com`. No trailing slash needed (stripped
  automatically). No auth required — SUB/WAVE's now-playing and cover-art
  endpoints are public.

## How it works

- `GET {station_url}/api/now-playing` — track title, artist, `subsonic_id`,
  DJ/station name, and stream online status. Cached 20s.
- `GET {station_url}/api/cover/{subsonic_id}` — album art JPEG, proxied by
  SUB/WAVE itself (no Navidrome credentials needed). Cached 300s.
- If the station reports `streamOnline: false`, shows "<station> offline"
  instead of stale track info.
- If a track has no `subsonic_id`, or the cover fetch fails, falls back to a
  full-width layout with no art rather than a broken image.
- Shows a "-- Show --" label, the current show name
  (`context.activeShow.name`), and host name (`dj.name`) below the artist,
  and a track progress bar pinned to the very bottom.

**Progress bar caveat:** the now-playing API reports track `duration` but
not elapsed/remaining time, so the app tracks playback position itself —
the first time it sees a given `subsonic_id`, it stamps the current
wall-clock time in pixlet's cache, then diffs against that stamp on later
renders to compute elapsed seconds. This only works correctly on a
long-lived server process with a persistent cache (true for
`tronbyt/server`'s in-memory cache) — a one-shot `pixlet render` CLI
invocation always starts a fresh process with an empty cache, so the bar
will always show 0% when testing locally. This is expected, not a bug.

**Note on unreachable hosts:** if the station URL is wrong or the host is
completely unreachable (DNS failure, connection refused), `http.get` raises
a hard error and the render fails for that cycle — this is normal pixlet/
Starlark behavior (no try/except in the language), not a bug. Only
HTTP-level errors (404, 500, etc.) are something the app can catch and
display a message for, which it does.

## Dev/test

```
pixlet render subwave_nowplaying.star station_url=https://your-station.example.com
pixlet serve subwave_nowplaying.star
```

## Deploy

Upload `subwave_nowplaying.star` directly through your Tronbyt server's
"Upload app" button on a device's Add App page (single file, no bundled
assets — no need to zip). Configure the Station URL field when adding it to
your device's schedule.