mattermost-push-plugin/README.md

# mattermost_push_plugin

Android-first Flutter plugin for Mattermost push notifications.

The plugin owns the push-notification domain that should not be duplicated in
each consuming app: native FCM handling, notification display, notification tap
events, inline replies, dismiss handling, ACK delivery, device-token storage,
auth-token storage, and Mattermost signing-key storage.

## Platform Status

| Platform | Status | Notes |
| --- | --- | --- |
| Android | Production target | Native FCM service, Room storage, JJWT verification, OkHttp ACK client, notification builder, inline reply receiver, dismiss receiver |
| iOS | Stub | Plugin scaffold exists, behavior is not implemented yet |
| macOS | Stub | Plugin scaffold exists, behavior is not implemented yet |

## Repository Layout

```text
mattermost-push-plugin/
  lib/                    # Public Dart API and Flutter-facing behavior
  android/                # Android native plugin implementation
  ios/                    # iOS plugin scaffold
  macos/                  # macOS plugin scaffold
  test/                   # Dart unit tests for the plugin contract
  example/                # Thin Flutter app used as the integration test harness
    test/                 # Widget tests for the harness app
    integration_test/     # Device/emulator integration tests
```

The `example/` app is the official independent consumer app for this repository.
Use it to validate plugin integration without coupling tests to any real product
app. Consuming apps should only test their own wiring, such as initialization,
credential handoff, and navigation callbacks.

## How It Works

```mermaid
graph TD
    A[Mattermost Server] -->|Secure JWT Push| B(Android FCM Service)
    B -->|Verify signing key| C{Valid?}
    C -->|Yes| D[Store payload and build notification]
    C -->|No| E[Drop push]
    D -->|Send ACK| A
    D -->|Display notification| F(Android status bar)
    F -->|Tap| G[Flutter opened event]
    F -->|Inline reply| H[Reply receiver]
    H -->|Send reply| A
    G -->|Stream and callbacks| I(Host app navigation)
```

## Host App Responsibilities

The plugin isolates push handling, but the host application still owns app-level
integration:

1. Configure Firebase for the host app, including `google-services.json` under
   `android/app/`.
2. Initialize Firebase as required by the host app before push registration.
3. Call `MattermostPushPlugin.instance.initialize()` during app startup.
4. Save auth tokens and signing keys after login.
5. Clear auth tokens on logout.
6. Send the formatted device token to the Mattermost server.
7. Connect notification-open callbacks to the host app router.

## Installation

For local development or another app in the same workspace, use a path
dependency:

```yaml
dependencies:
  mattermost_push_plugin:
    path: ../mattermost-push-plugin
```

For a private Git dependency, point the consuming app at the repository and pin
the branch, tag, or commit according to your release process.

## Dart Usage

Import the public API:

```dart
import 'package:mattermost_push_plugin/mattermost_push_plugin.dart';
```

Initialize the plugin:

```dart
await MattermostPushPlugin.instance.initialize();
```

Listen to raw notification events:

```dart
MattermostPushPlugin.instance.onNotification.listen((data) {
  // data includes the native payload plus a push type.
});
```

Listen to notification-open events:

```dart
MattermostPushPlugin.instance.onNotificationOpened.listen((event) {
  final serverUrl = event.serverUrl;
  final channelId = event.channelId;
  final rootId = event.rootId;
});
```

Register navigation callbacks:

```dart
MattermostPushPlugin.instance.onNavigateToChannel = (
  String serverUrl,
  String channelId,
) {
  // Navigate to the channel in the host app.
};

MattermostPushPlugin.instance.onNavigateToThread = (
  String serverUrl,
  String rootId,
) {
  // Navigate to the CRT thread in the host app.
};
```

Handle device-token registration:

```dart
MattermostPushPlugin.instance.onDeviceTokenReady = (String deviceToken) {
  // Example format: android_rn-v2:YOUR_FCM_TOKEN
  // Send this token to the Mattermost server.
};
```

Store credentials and signing keys:

```dart
await MattermostPushPlugin.instance.setAuthToken(
  'https://mattermost.example.com',
  'USER_AUTH_TOKEN',
  identifier: 'user_session_id',
);

await MattermostPushPlugin.instance.setSigningKey(
  'https://mattermost.example.com',
  'SERVER_PUBLIC_SIGNING_KEY',
);

await MattermostPushPlugin.instance.clearAuthToken(
  'https://mattermost.example.com',
);

final token = await MattermostPushPlugin.instance.getDeviceToken();
```

## Event Types

The Dart API currently recognizes these native event types:

| Type | Meaning |
| --- | --- |
| `message` | A Mattermost message notification |
| `clear` | Notification clear or dismiss event |
| `session` | Session-related event |
| `token_refresh` | Device-token refresh event |
| `opened` | User opened a notification |

`NotificationOpenedEvent` parses `server_url`, `channel_id`, `root_id`, and
`is_crt_enabled`. If CRT is enabled and `root_id` is present, the plugin calls
`onNavigateToThread`; otherwise it calls `onNavigateToChannel` when a channel is
available.

## Android Notes

The Android manifest declares the plugin's own
`MattermostFirebaseMessagingService` and removes the default FlutterFire
messaging components with `tools:node="remove"`. This avoids duplicate FCM
service registration when the host app also depends on `firebase_messaging`.

Host apps should not redeclare duplicate FCM services unless they intentionally
coordinate that behavior with this plugin.

Android Gradle tests require a configured Android SDK through `ANDROID_HOME` or
`example/android/local.properties`.

## Development Commands

Run Dart analysis and unit tests from the repository root:

```sh
flutter analyze
flutter test
```

Run harness-app checks:

```sh
cd example
flutter analyze
flutter test
flutter test integration_test
```

Run Android native unit tests:

```sh
cd example/android
./gradlew testDebugUnitTest
```

## Test Strategy

Use deterministic tests for repository-owned behavior. The example integration
test can inject a debug native event through the plugin method channel so the
EventChannel and opened-routing path can run without Firebase FCM.

Use the repository tests as the source of truth for plugin behavior:

1. Root `test/` covers Dart API behavior, event parsing, callback routing, and
   device-token formatting.
2. `android/src/test/` should cover native payload parsing, signing-key lookup,
   local storage, notification behavior, and ACK request behavior.
3. `example/test/` covers the thin Flutter harness app.
4. `example/integration_test/` covers real plugin registration,
   method-channel behavior, event-channel behavior, notification-open routing,
   and manifest integration on a device or emulator using the test/debug injection path.
5. Manual smoke tests cover true Firebase FCM delivery and real Mattermost ACK
   flows because they depend on external infrastructure.

## Manual Smoke Checklist

Use this checklist before promoting a plugin change to a consuming app:

- [ ] FCM payload wakes `MattermostFirebaseMessagingService`.
- [ ] Valid Mattermost push payload passes signing-key verification.
- [ ] Invalid or unsigned payload is dropped.
- [ ] System notification displays the expected title, message, avatar, and CRT
      threading behavior.
- [ ] ACK request is sent to the Mattermost server and receives a successful
      response.
- [ ] Tapping a notification launches or resumes the app and emits
      `onNotificationOpened`.
- [ ] Channel notifications call `onNavigateToChannel`.
- [ ] CRT thread notifications call `onNavigateToThread`.
- [ ] Inline reply action sends the reply through the native receiver.
- [ ] Dismiss action clears native notification records as expected.
- [ ] Device token is stored with the `android_rn-v2:` prefix.

## Current Limitations

- Android is the only implemented runtime target.
- iOS and macOS are scaffolded but no-op.
- Full FCM delivery cannot be reliably automated in a headless test runner.
- The `example/` app is intentionally small and should not grow into a product
  app.