# Hold2Send 🎙️ A private Android voice messaging app built with Flutter. **Hold to Record. Release to Send. No text. No calls. Just your voice.** --- ## Features | Feature | Details | |---|---| | 🔐 Auth | Google Sign-In via Firebase Authentication | | 🆔 Custom UID | User picks a unique handle (e.g. `alice_voice`) | | 👥 Friends | Add friends by their custom UID | | 🎙️ Voice Messaging | Hold-to-record, release-to-send (`.m4a` format) | | ☁️ Storage | Audio files stored in Appwrite Storage | | 🔔 Notifications | Firebase Cloud Messaging push to receiver | | 📥 Inbox | Play received voice messages in-app | --- ## Project Structure ``` lib/ ├── main.dart # Entry point, Firebase init, routing ├── firebase_options.dart # ⚠️ Replace with generated file │ ├── models/ │ ├── app_user.dart # User data model │ └── voice_message.dart # VoiceMessage data model │ ├── services/ │ ├── auth_service.dart # Firebase Auth + Google Sign-In │ ├── firestore_service.dart # Firestore CRUD (users, friends, messages) │ ├── appwrite_storage_service.dart # Appwrite file upload/delete/URL │ └── messaging_service.dart # FCM token management + push dispatch │ ├── screens/ │ ├── splash_screen.dart # Loading screen during auth resolution │ ├── auth/ │ │ └── login_screen.dart # Google Sign-In screen │ ├── setup_uid_screen.dart # Custom UID picker (first launch only) │ ├── home_screen.dart # Friends list + Inbox tabs │ ├── friend_search_screen.dart # Search by custom UID & add friend │ ├── voice_message_screen.dart # Hold-to-record screen │ └── inbox_screen.dart # Received messages with playback │ ├── widgets/ │ └── friend_tile.dart # Reusable friend list tile │ └── utils/ ├── app_theme.dart # Dark theme & color palette └── constants.dart # Appwrite config constants ``` --- ## Setup Instructions ### 1. Prerequisites - Flutter SDK ≥ 3.0.0 - Android Studio / VS Code - Firebase project - Appwrite project (cloud or self-hosted) --- ### 2. Firebase Setup 1. Go to [Firebase Console](https://console.firebase.google.com) and create a new project. 2. **Enable Authentication:** Authentication → Sign-in method → **Google** → Enable 3. **Enable Firestore:** Firestore Database → Create database → Start in **production mode** 4. **Enable Cloud Messaging:** Already enabled by default in Firebase projects. 5. **Add Android App:** - Package name: `com.hold2send.hold2send` - Download `google-services.json` - Place it at: `android/app/google-services.json` 6. **Generate `firebase_options.dart`:** ```bash dart pub global activate flutterfire_cli flutterfire configure --project= ``` This replaces the placeholder `lib/firebase_options.dart`. --- ### 3. Firestore Security Rules Go to **Firestore → Rules** and paste: ```js rules_version = '2'; service cloud.firestore { match /databases/{database}/documents { // Users can read/write their own profile match /users/{userId} { allow read: if request.auth != null; allow write: if request.auth.uid == userId; // Friends sub-collection match /friends/{friendId} { allow read, write: if request.auth.uid == userId; } } // Voice messages: sender can create, receiver can read/update (mark played) match /voiceMessages/{messageId} { allow create: if request.auth.uid == request.resource.data.senderId; allow read: if request.auth.uid == resource.data.receiverId || request.auth.uid == resource.data.senderId; allow update: if request.auth.uid == resource.data.receiverId; } } } ``` --- ### 4. Appwrite Setup 1. Go to your [Appwrite Console](https://cloud.appwrite.io) (or self-hosted). 2. **Create a project** with ID: `hold2send` *(Must match `AppwriteConfig.projectId` in `lib/utils/constants.dart`)* 3. **Create a Storage Bucket:** - Bucket ID: `voice-messages` - Permissions: `Any` can **create** (for authenticated users you can restrict by JWT) - Allowed file extensions: `m4a`, `aac` - Max file size: `25 MB` (recommended) 4. The endpoint is already configured: `https://nyc.cloud.appwrite.io/v1` --- ### 5. Firebase Cloud Messaging (Push Notifications) > **⚠️ Important:** FCM server keys must **never** be in your Flutter app. > Set up a Cloud Function (or any backend) to proxy FCM calls. **Option A — Firebase Cloud Functions (recommended):** ```javascript // functions/index.js const functions = require("firebase-functions"); const admin = require("firebase-admin"); admin.initializeApp(); exports.sendNotification = functions.https.onRequest(async (req, res) => { const { receiverToken, title, body } = req.body; await admin.messaging().send({ token: receiverToken, notification: { title, body }, }); res.json({ success: true }); }); ``` Deploy and set the URL in `lib/screens/voice_message_screen.dart`: ```dart const backendUrl = 'https://YOUR_REGION-YOUR_PROJECT.cloudfunctions.net/sendNotification'; ``` **Option B — Skip notifications for now:** Remove the `sendVoiceMessageNotification` call. Messages still save and receivers see them in the Inbox on next open. --- ### 6. Install Dependencies ```bash flutter pub get ``` --- ### 7. Run the App ```bash flutter run ``` For a release build: ```bash flutter build apk --release ``` The APK will be at: `build/app/outputs/flutter-apk/app-release.apk` --- ## Firestore Data Model ### `users/{userId}` ```json { "userId": "firebase_uid", "customUid": "alice_voice", "displayName": "Alice", "photoUrl": "https://...", "fcmToken": "fcm_registration_token", "createdAt": "Timestamp" } ``` ### `users/{userId}/friends/{friendUserId}` ```json { "addedAt": "Timestamp" } ``` ### `voiceMessages/{messageId}` ```json { "senderId": "firebase_uid", "receiverId": "firebase_uid", "appwriteFileId": "appwrite_file_id", "appwriteBucketId": "voice-messages", "audioUrl": "https://nyc.cloud.appwrite.io/v1/storage/...", "duration": 12, "createdAt": "Timestamp", "isPlayed": false } ``` --- ## Tech Stack | Layer | Technology | |---|---| | Framework | Flutter (Android) | | Auth | Firebase Authentication (Google) | | Database | Cloud Firestore | | File Storage | Appwrite Storage | | Push Notifications | Firebase Cloud Messaging | | Audio Recording | `record` package | | Audio Playback | `audioplayers` package | --- ## Important Notes - ❌ No text chat - ❌ No live calls - ❌ No live audio streaming - ✅ Voice messages only - ✅ Android first (iOS can be added later) --- ## License MIT # Yapi