Files
Europa/Nuvolari/README.md
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Alby96andClaude Opus 5 f3a0e3794a Narrow scope to radar, and put the app on a real OpenStreetMap base map
Drops forecasts, lightning, the home-screen widget and advertising. What
remains is radar on a map, the official ARPA alert bulletin, and rain
notifications.

The base map is now OpenFreeMap's Positron style: real OpenStreetMap vector
tiles with no API key, no registration, no request limits and commercial use
permitted. Every other free tier — MapTiler, Stadia, Jawg, Thunderforest —
needs a key, which is a secret to manage, a quota to outgrow and a signup to
complete before anyone can build the project, and the map is the one thing the
app cannot work without. Positron rather than Liberty or Bright because the
radar overlay has to be the loudest thing on screen, and a desaturated grey
base is built to sit under data.

Its style JSON carries no `attribution` field, so MapLibre displays no credits
by itself. The app renders them from the region config instead: the two
mandatory credits, OpenStreetMap and OpenMapTiles, go in the always-visible
bar, and OpenFreeMap's own credit — optional by their terms — is listed on the
Sources screen with the rest. The bundled offline style is still reachable with
MAP_STYLE_URL=offline, and still claims no base map attribution, because
crediting OpenStreetMap while showing it would be a false claim.

Radar-DPC stays the source. ARPA Piemonte's own radar remains a disabled stub
for two reasons that belong to the project owner, not to the code: the
real-time access link is only issued by email, and the open-data page states
the data is "gratuiti" and nothing else. Free of charge is not a licence, and
rendering those volumes into frames served from a CDN is redistribution. Both
questions go in the same email. An earlier draft of the docs recorded ARPA
radar as CC BY 4.0; the source page does not support that, so the claim is
removed rather than carried forward.

The documentation is updated throughout rather than annotated: CLAUDE.md gains
an explicit scope boundary, data-sources drops MET Norway and ISTAT and gains
the base map, licenses records that free of charge is not a licence, privacy
loses the whole advertising section, and the roadmap is renumbered so the
backend worker is next — until it exists, DpcRadarSource has nothing to read.

licenses.md keeps Open-Meteo and Blitzortung listed as excluded even though the
features that would have used them are gone: both are non-commercial-only, ads
are a plausible future, and neither should be adopted on the grounds that there
are none today.

Verified: analyze clean, 130 tests passing, and on the emulator the radar
overlay sits correctly over Piedmont on real OSM tiles with Turin, Milan and
Genoa labelled, the age reads "Aggiornato 4 minuti fa", and the Sources screen
lists all five credits with their licences.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-10 16:10:29 +02:00

110 lines
4.4 KiB
Markdown

# Nuvolari
Precipitation radar for Piedmont, Italy. Android first, iOS later, one Flutter codebase.
Radar imagery comes from the public **Radar-DPC** platform and weather alerts from the
**ARPA Piemonte** XML-CAP bulletin, drawn over an OpenStreetMap base map. The app is
free, with no advertising and no accounts.
**Scope**: radar, official alerts, rain notifications. No forecasts, no lightning, no
home-screen widget. See [CLAUDE.md](CLAUDE.md).
Nuvolari is an independent app. It is not affiliated with, endorsed by, or operated by
ARPA Piemonte or the Dipartimento della Protezione Civile. For civil-protection
purposes the official channels always prevail.
## Layout
```
app/ Flutter application (Dart package "nuvolari")
backend/ Python worker: fetches DPC rasters, crops, reprojects, renders PNG frames
docs/ architecture, data sources, licenses, stack decisions, roadmap, privacy
tool/ verification scripts
```
Start with [docs/architecture.md](docs/architecture.md), then
[docs/roadmap.md](docs/roadmap.md) for what is built and what is next.
## Toolchain
| Tool | Version |
|---|---|
| Flutter | 3.47.3 stable (Dart 3.13.3) |
| Android SDK | platform 36, build-tools 36.0.0, platform-tools |
| JDK | 21 |
| Python | 3.12+ (3.14 works; rasterio ships wheels for it) |
| Android NDK | 28.2.13676358 — pinned by `maplibre_gl`, not by this project |
A full toolchain plus a warm Gradle cache needs roughly **14 GB** of disk: Flutter
3 GB, Android SDK 2.5 GB (2 GB of which is the NDK the map plugin pins), the Gradle
cache 5 GB, and build output around 2 GB. `flutter clean` reclaims the last of those.
## Configuration
Secrets never enter the repository. Copy the template and fill it in:
```bash
cp env.example.json env.json # env.json is git-ignored
```
| Key | Purpose |
|---|---|
| `MAP_STYLE_URL` | MapLibre style URL. Empty uses the free OpenFreeMap style; `offline` forces the bundled no-network style. |
| `RADAR_MANIFEST_URL` | Base URL of the published `manifest.json`. |
| `RADAR_SOURCE` | `mock` (offline demo), `dpc` (live), `arpa` (disabled stub). |
| `REGION_ID` | Which region config to load. Defaults to `piemonte`. |
## Running
```bash
cd app
flutter run --dart-define-from-file=../env.json
```
With no `env.json` the app starts in demo mode: mock radar frames from assets on the
free OpenFreeMap base map. **No credentials are needed for anything** — OpenFreeMap has
no API key and no signup.
The radar frames work with no network at all. The base map needs one; run with
`--dart-define=MAP_STYLE_URL=offline` to drop it too and work entirely offline.
## Debugging in VS Code
Open the **`Nuvolari` folder** as the workspace root — the configurations in
`.vscode/` are relative to it. Then pick one in Run and Debug and press **F5**:
| Configuration | Use it for |
|---|---|
| **Nuvolari — debug (emulatore)** | Everyday work. Demo mode, no `env.json` needed, hot reload on save. |
| **Nuvolari — profile** | Judging animation smoothness. Debug builds run the Dart VM unoptimised, so the radar timeline always looks worse than it is — never assess it in debug. |
| **Nuvolari — debug con env.json** | Pointing the app at a live radar manifest or a different base map style. |
| **Nuvolari — debug su Windows** | Fast UI iteration with no emulator. The native map does not render here. |
| **Test — tutti** / **Test — file corrente** | Debugging tests with breakpoints. |
Every emulator configuration runs `tool/start_emulator.ps1` first, so F5 works from a
cold machine. The script exits immediately when a device is already attached, so
pressing F5 twice does not start two emulators.
`Ctrl+Shift+B` runs the full verification. Other tasks live under
**Terminal → Run Task**: quick verification, regenerating the demo radar frames, and
shutting the emulator down.
## Verifying
```powershell
.\tool\verify.ps1 # format, analyze, test, build, lint, pytest
.\tool\verify.ps1 -SkipBuild # fast inner loop
```
Stages whose target does not exist yet are skipped, so this runs from day one.
## Attribution
Radar-DPC (CC BY-SA) · Arpa Piemonte · © OpenStreetMap contributors (ODbL) ·
© OpenMapTiles · OpenFreeMap.
See [docs/licenses.md](docs/licenses.md) for the obligations these carry — in
particular, the rendered radar frames are a derived product of CC BY-SA data and inherit
share-alike, and the OpenFreeMap style ships no `attribution` field, so the app has to
render the map credits itself.