QUICK_START.md

# Quick Start Guide - VQA Mobile App

This guide will help you get the VQA mobile app running quickly.

## Prerequisites Checklist

- [ ] Python 3.8+ installed
- [ ] Node.js 16+ installed
- [ ] VQA model checkpoints available
- [ ] Smartphone with Expo Go app installed
- [ ] Computer and phone on same WiFi network

## Step-by-Step Setup

### Step 1: Start the Backend Server

```bash
# Open terminal/PowerShell
cd c:\Users\rdeva\Downloads\vqa_coes

# Install backend dependencies (first time only)
pip install -r requirements_api.txt

# Start the server
python backend_api.py
```

**Expected output:**
```
🚀 INITIALIZING ENSEMBLE VQA SYSTEM
⚙️  Device: cuda
📥 Loading models...
✅ Ensemble ready!
```

**Important:** Keep this terminal window open! The server must keep running.

### Step 2: Find Your Local IP Address

**Windows:**
```bash
ipconfig
```
Look for "IPv4 Address" under your WiFi adapter (e.g., `192.168.1.100`)

**Mac/Linux:**
```bash
ifconfig
# or
ip addr
```

### Step 3: Configure the Mobile App

1. Open `ui/src/config/api.js`
2. Replace the IP address:
   ```javascript
   export const API_BASE_URL = 'http://YOUR_IP_HERE:8000';
   // Example: export const API_BASE_URL = 'http://192.168.1.100:8000';
   ```

### Step 4: Configure Google OAuth (Optional for Testing)

**For testing without Google login**, you can skip this and modify the app to bypass authentication.

**For full Google login:**

1. Go to [Google Cloud Console](https://console.cloud.google.com/)
2. Create a project
3. Enable Google+ API
4. Create OAuth 2.0 credentials
5. Update `ui/src/config/google.js` with your client IDs

### Step 5: Start the Mobile App

```bash
# Open a NEW terminal/PowerShell
cd c:\Users\rdeva\Downloads\vqa_coes\ui

# Start Expo
npm start
```

**Expected output:**
```
Metro waiting on exp://192.168.1.100:8081
› Scan the QR code above with Expo Go (Android) or the Camera app (iOS)
```

### Step 6: Run on Your Phone

1. **Install Expo Go** on your phone:
   - [Android - Play Store](https://play.google.com/store/apps/details?id=host.exp.exponent)
   - [iOS - App Store](https://apps.apple.com/app/expo-go/id982107779)

2. **Scan the QR code**:
   - Android: Open Expo Go app → Scan QR code
   - iOS: Open Camera app → Scan QR code → Tap notification

3. **Wait for app to load** (first time may take 1-2 minutes)

## Testing Without Google Login

If you want to test the VQA functionality without setting up Google OAuth:

1. Open `ui/App.js`
2. Temporarily modify the navigation to always show HomeScreen:

```javascript
// Replace this:
{user ? (
  <Stack.Screen name="Home" component={HomeScreen} />
) : (
  <Stack.Screen name="Login" component={LoginScreen} />
)}

// With this:
<Stack.Screen name="Home" component={HomeScreen} />
```

3. Restart the Expo server

## Testing the App

### Test 1: General Question (Base Model)
1. Tap "Gallery" and select an image
2. Enter question: "What color is the car?"
3. Tap "Ask Question"
4. Should show: 🔍 Base Model

### Test 2: Spatial Question (Spatial Model)
1. Select an image with multiple objects
2. Enter question: "What is to the right of the table?"
3. Tap "Ask Question"
4. Should show: 📍 Spatial Model

## Troubleshooting

### "Cannot connect to server"
- ✅ Check backend is running
- ✅ Verify IP address in `api.js` is correct
- ✅ Ensure phone and computer on same WiFi
- ✅ Check firewall isn't blocking port 8000

### "Model not loaded"
- ✅ Check checkpoint files are in project root
- ✅ Verify file names: `vqa_checkpoint.pt` and `vqa_spatial_checkpoint.pt`
- ✅ Check backend terminal for error messages

### App won't load on phone
- ✅ Ensure Expo Go is installed
- ✅ Check both devices on same network
- ✅ Try restarting Expo server (Ctrl+C, then `npm start`)
- ✅ Clear Expo cache: `npm start -- --clear`

### "Permission denied" for camera/gallery
- ✅ Grant permissions when prompted
- ✅ Check phone settings → App permissions

## Next Steps

Once everything works:

1. **Set up Google OAuth** for production use
2. **Customize the UI** in `src/styles/theme.js`
3. **Add custom icons** in `assets/` folder
4. **Build standalone app** with `eas build`

## Quick Commands Reference

```bash
# Start backend
cd c:\Users\rdeva\Downloads\vqa_coes
python backend_api.py

# Start mobile app
cd c:\Users\rdeva\Downloads\vqa_coes\ui
npm start

# Clear Expo cache
npm start -- --clear

# Install new package
npm install package-name

# Check backend health
curl http://localhost:8000/health
```

## Support

If you encounter issues:
1. Check the main README.md
2. Review backend terminal logs
3. Check Expo console for errors
4. Verify all prerequisites are met