Experimental repository to provide glue for seamlessly integrating cargo build
with flutter plugins and packages.

See https://matejknopp.com/post/flutter_plugin_in_rust_with_no_prebuilt_binaries/
for a tutorial on how to use Cargokit.

Example plugin available at https://github.com/irondash/hello_rust_ffi_plugin.

## Local build caching
Build caching has been added as an optional feature in order to reduce build times as a Quality of Life feature for developers.  Rust build artifacts from the first build are reused on subsequent builds.  Cached builds are invalidated when source code changes, effectively automatically rebuilding as needed.

### Enabling local build caching
Add to `cargokit_options.yaml` in your project root:
```yaml
cache_local_builds: true
```

### Cache location
Cached artifacts are stored under `CARGOKIT_TARGET_TEMP_DIR/precompiled/<hash>/<config>/<target>/`:

- **Gradle** (Android): `${project.buildDir}/cargokit/` (e.g., `android/app/build/cargokit/`)
- **CocoaPods** (iOS/macOS): `$TARGET_TEMP_DIR` (under Xcode DerivedData)
- **CMake** (Linux/Windows): `${CMAKE_CURRENT_BINARY_DIR}/cargokit_build/`

The cache is cleared when you run:
- `flutter clean`
- `gradle clean` (Android)
- `xcodebuild clean` (iOS/macOS)

## Precompiled binaries
The [silence-laboratories' precompiled binaries PR](irondash#91), adapting work from flutter_rust_bridge, is included in this repository as a non-default option.  To use it, follow these steps:

1. Create local precompiled binaries using command `precompile-local-binaries`
```sh
flutter pub run bin/build_tool.dart precompile-local-binaries -v --manifest-dir ../../rust --android-sdk-location=/Users/asdf/Library/Android/sdk --android-ndk-version=28.0.12674087 --android-min-sdk-version=23 --temp-dir tempDir
```

2. Update `cargokit_options.yaml`
```yaml
use_local_precompiled_binaries: true
use_precompiled_binaries: true
```

3. Commit and/or publish precompiled binaries for a build-free usage option.