📱 Calorie Compass

Calorie Compass is a mobile health companion app that helps users track their meals, monitor calorie intake, and stay informed with helpful health tips — all powered by AI!

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✨ Features

• 🔐 Firebase-based authentication
• 🧠 AI-powered meal analysis using Gemini (estimates calories + provides contextual advice)
• 🎯 Daily goal setting and smart progress tracking
• 📈 Visual progress bar with color-coded calorie zones
• 📅 Recent meals and 7-day goal history
• 🔁 Seamless backend integration via Express.js

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🧠 Tech Stack

Layer	Technology
Frontend	React Native + Expo Dev Client
Backend	Node.js + Express
Auth	Firebase Authentication (via REST API)
Storage	Firebase Firestore (via REST API)
AI	Gemini API (for tips & calorie estimates)

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🧰 Prerequisites

To run this project locally, ensure you have the following:

1. Node.js – Latest LTS version recommended.
2. Expo CLI – Install globally (npm install -g expo-cli) or use via npx.
3. Git – For cloning the repository.
4. Firebase Project:
   • Enable Email/Password Authentication
   • Set up Cloud Firestore
   • Generate a Service Account Key (used in backend)
5. Gemini API Key – Obtain from Google AI Studio.
6. Android Studio or Xcode – Required for building and installing the custom Expo Dev Client on your device.
7. Expo Dev Client (Custom Build) – See instructions below.

📌 Note: This app now uses a custom Expo Dev Client, not Expo Go. You’ll need to build the development client once using eas build.

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🚀 Setup Instructions

📌 Note: This current build is compatible with Android only. For iOS devices, check Expo Docs

1. Clone the Repository

git clone https://github.com/rustyBot31/Calorie-Compass.git
cd Calorie-Compass

2. Install Dependencies

npm install

3. Set Up Environment Variables

envVar.ts (root)

export const FIREBASE_API_KEY = 'your-firebase-api-key';
export const PROJECT_ID = 'your-firebase-project-id';
export const BASE_URL = 'https://identitytoolkit.googleapis.com/v1/accounts';
export const FIRESTORE_URL =  `https://firestore.googleapis.com/v1/projects/${PROJECT_ID}/databases/(default)/documents`;
export const BACKEND_URL = 'http://your-local-ip:4000';

envVarBackend.js (inside backend/)

const GEMINI_API_KEY = 'your-gemini-api-key';
module.exports = { GEMINI_API_KEY };

4. Add Firebase Service Account

Download your service account key JSON from Firebase and place it in the backend/ folder as serviceAccountKey.json.

5. Start the Backend Server

cd backend
node index.js

6. Build & Install Expo Dev Client

This app requires a custom development build.

If not already built:

npx expo install expo-dev-client
npx eas build --profile development --platform android

💡 After the build completes, install the generated .apk on your device manually or use eas build:run.

7. Start the App

Once the Dev Client is installed:

npx expo start --dev-client

Scan the QR code from your terminal with the custom Dev Client installed on your device.

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🚢 Releases

Version	Description	Notes
1.0.0	Expo Go Initial Release	Deprecated
1.1.0	Switched to Expo Dev Build (Android only (for now))	Deprecated
1.1.1	Minor bug fixes	Custom Dev Client required

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🔑 How to Generate serviceAccountKey.json

1. Go to Firebase Console
2. Select your project
3. Click ⚙️ → Project Settings
4. Navigate to Service Accounts
5. Click “Generate new private key”
6. Save it as serviceAccountKey.json inside backend/

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🤝 Contributions

Contributions and feedback are welcome!
Feel free to open issues or submit pull requests.

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📝 License

This project is licensed under the MIT License.

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