# WhatsApp Invitation Integration Guide

## Overview
Complete WhatsApp Cloud API integration for sending wedding invitation template messages to guests via Meta's WhatsApp Business Platform.

## Features Implemented

### Backend (FastAPI)
- ✅ WhatsApp service module with template message support
- ✅ Single guest invitation endpoint: `POST /events/{event_id}/guests/{guest_id}/whatsapp/invite`
- ✅ Bulk guest invitation endpoint: `POST /events/{event_id}/whatsapp/invite`
- ✅ Phone number normalization to E.164 format (international standard)
- ✅ Event data auto-mapping to template variables
- ✅ Rate limiting protection (0.5s delay between sends)
- ✅ Error handling and detailed response reporting
- ✅ Secure credential management via environment variables

### Database
- ✅ Event model extended with WhatsApp-specific fields:
  - `partner1_name` - First partner name (for template {{2}})
  - `partner2_name` - Second partner name (for template {{3}})
  - `venue` - Wedding venue/hall name (for template {{4}})
  - `event_time` - Event time in HH:mm format (for template {{6}})
  - `guest_link` - RSVP/guest link URL (for template {{7}})

### Frontend (React/Vite)
- ✅ `WhatsAppInviteModal` component with full Hebrew RTL support
- ✅ Guest selection checkboxes in guest list table
- ✅ "Send WhatsApp" button (💬 שלח בוואטסאפ) that appears when guests selected
- ✅ Modal form for event details input with message preview
- ✅ Results screen showing send success/failure details
- ✅ Dark/light theme support throughout
- ✅ API integration with error handling

## Setup Instructions

### 1. Environment Configuration (.env)

Add these variables to your `.env` file:

```env
# ============================================
# WhatsApp Cloud API Configuration
# ============================================
WHATSAPP_ACCESS_TOKEN=your_permanent_access_token_here
WHATSAPP_PHONE_NUMBER_ID=your_phone_number_id_here
WHATSAPP_API_VERSION=v20.0
WHATSAPP_TEMPLATE_NAME=wedding_invitation
WHATSAPP_LANGUAGE_CODE=he
WHATSAPP_VERIFY_TOKEN=your_webhook_verify_token_here  # Optional
```

**Where to get these credentials:**
1. Go to https://developers.facebook.com/
2. Select your WhatsApp Business Account
3. In "API Setup", find your Phone Number ID
4. Generate a permanent access token with `whatsapp_business_messaging` scope
5. Your template name must match the approved template in Meta (e.g., "wedding_invitation")

### 2. Database Migration

The database schema has been automatically updated with:
```sql
ALTER TABLE events ADD COLUMN partner1_name TEXT;
ALTER TABLE events ADD COLUMN partner2_name TEXT;
ALTER TABLE events ADD COLUMN venue TEXT;
ALTER TABLE events ADD COLUMN event_time TEXT;
ALTER TABLE events ADD COLUMN guest_link TEXT;
```

**If migration wasn't run automatically:**
```bash
cd backend
python run_migration.py
```

### 3. Start the Servers

**Backend:**
```bash
cd backend
python main.py
# Runs on http://localhost:8000
```

**Frontend:**
```bash
cd frontend
npm run dev
# Runs on http://localhost:5173
```

## Template Variables Mapping

The approved Meta template body (in Hebrew):
```
היי {{1}} 🤍

זה קורה! 🎉
{{2}} ו-{{3}} מתחתנים ונשמח שתהיה/י איתנו ברגע המיוחד הזה ✨

📍 האולם: "{{4}}"
📅 התאריך: {{5}}
🕒 השעה: {{6}}

לאישור הגעה ופרטים נוספים:
{{7}}

מתרגשים ומצפים לראותך 💞
```

**Auto-filled by system:**
- `{{1}}` = Guest first name (or "חבר" if empty)
- `{{2}}` = `event.partner1_name` (e.g., "דביר")
- `{{3}}` = `event.partner2_name` (e.g., "וורד")
- `{{4}}` = `event.venue` (e.g., "אולם כלות גן עדן")
- `{{5}}` = `event.date` formatted as DD/MM (e.g., "25/02")
- `{{6}}` = `event.event_time` in HH:mm (e.g., "19:00")
- `{{7}}` = `event.guest_link` or auto-generated RSVP URL

## Usage Flow

### 1. Create/Edit Event
When creating an event, fill in the wedding details:
- **Partner 1 Name**: חתן/ה ראשון/ה
- **Partner 2 Name**: חתן/ה שני/ה
- **Venue**: אולם/מקום
- **Date**: automatically formatted
- **Time**: HH:mm format
- **Guest Link**: Optional custom RSVP link (defaults to system URL)

### 2. Send Invitations
1. In guest list table, select guests with checkboxes
2. Click "💬 שלח בוואטסאפ" (Send WhatsApp) button
3. Modal opens with preview of message
4. Confirm details and click "שלח הזמנות" (Send Invitations)
5. View results: successful/failed deliveries

### 3. View Results
Results screen shows:
- ✅ Number of successful sends
- ❌ Number of failed sends
- Guest names and phone numbers
- Error reasons for failures

## API Endpoints

### Single Guest Invitation
```http
POST /events/{event_id}/guests/{guest_id}/whatsapp/invite
Content-Type: application/json

{
  "phone_override": "+972541234567"  # Optional
}

Response:
{
  "guest_id": "uuid",
  "guest_name": "דביר",
  "phone": "+972541234567",
  "status": "sent" | "failed",
  "message_id": "wamid.xxx...",
  "error": "error message if failed"
}
```

### Bulk Guest Invitations
```http
POST /events/{event_id}/whatsapp/invite
Content-Type: application/json

{
  "guest_ids": ["uuid1", "uuid2", "uuid3"],
  "phone_override": null
}

Response:
{
  "total": 3,
  "succeeded": 2,
  "failed": 1,
  "results": [
    { "guest_id": "uuid1", "status": "sent", ... },
    { "guest_id": "uuid2", "status": "failed", ... },
    ...
  ]
}
```

## Phone Number Format

The system automatically converts various phone formats to E.164 international format:

Examples:
- `05XXXXXXXX` (Israeli) → `+9725XXXXXXXX`
- `+9725XXXXXXXX` (already formatted) → unchanged
- `+1-555-123-4567` (US) → `+15551234567`

## Error Handling

Common errors and solutions:

| Error | Solution |
|-------|----------|
| `Invalid phone number` | Ensure phone has valid country code |
| `WhatsApp API error (400)` | Check template name and language code |
| `Not authenticated` | Admin must be logged in (localStorage userId set) |
| `Guest not found` | Verify guest exists in event and ID is correct |
| `Template pending review` | Template must be APPROVED in Meta Business Manager |

## Hebrew & RTL Support

✅ All text is in Hebrew
✅ RTL (right-to-left) layout throughout
✅ Component uses `direction: rtl` in CSS
✅ Form labels and buttons properly aligned for Arabic/Hebrew

## Security Considerations

1. **No secrets in code**: All credentials loaded from environment variables
2. **No token logging**: Access tokens never logged, even in errors
3. **Phone validation**: Invalid numbers rejected before API call
4. **Rate limiting**: 0.5s delay between sends to avoid throttling
5. **Authorization**: Only event members can send invitations
6. **HTTPS in production**: Ensure encrypted transmission of tokens

## Database Constraints

- Event fields are nullable for backward compatibility
- Phone numbers stored as-is, normalized only for sending
- Guest table still supports legacy `phone` field (use `phone_number`)
- No duplicate constraint on phone numbers (allows plus-ones)

## Logging & Monitoring

Events logged to console (can be extended):
```python
# In backend logs:
[INFO] Sending WhatsApp to guest: {guest_id} -> {phone_number}
[INFO] WhatsApp sent successfully: {message_id}
[ERROR] WhatsApp send failed: {error_reason}
```

## Testing Checklist

Before going to production:

- [ ] Meta template is APPROVED (not pending)
- [ ] Phone number ID correctly configured
- [ ] Access token has `whatsapp_business_messaging` scope
- [ ] Test with your own phone number first
- [ ] Verify phone normalization for your country
- [ ] Check message formatting in different languages
- [ ] Test with various phone number formats
- [ ] Verify event creation populates all new fields
- [ ] Test bulk send with 3+ guests
- [ ] Verify error handling (wrong phone, missing field)
- [ ] Check dark/light mode rendering

## Troubleshooting

### Backend Won't Start
```bash
# Check syntax
python -m py_compile main.py schemas.py crud.py whatsapp.py

# Check database connection
python << 'EOF'
import psycopg2
conn = psycopg2.connect("postgresql://wedding_admin:Aa123456@localhost:5432/wedding_guests")
print("✅ Database connected")
EOF
```

### Modal Not Appearing
1. Check browser console for JavaScript errors
2. Verify guests are selected (checkboxes checked)
3. Check that GuestList properly imports WhatsAppInviteModal
4. Clear browser cache and hard refresh

### Messages Not Sending
1. Check WHATSAPP_ACCESS_TOKEN in .env
2. Verify WHATSAPP_PHONE_NUMBER_ID matches your configured number
3. Confirm template is APPROVED (not pending/rejected)
4. Check guest phone numbers are complete and valid
5. Review backend logs for API errors

## Future Enhancements

- [ ] Webhook handling for message status updates (delivered/read)
- [ ] Message template versioning
- [ ] Scheduled sends (defer until specific time)
- [ ] Template variable presets per event
- [ ] Analytics: delivery rates, engagement metrics
- [ ] Support for local attachment messages
- [ ] Integration with CRM for follow-ups

## Support & References

- Meta WhatsApp API Docs: https://developers.facebook.com/docs/whatsapp/cloud-api
- Error Codes: https://developers.facebook.com/docs/whatsapp/cloud-api/support/error-codes
- Message Templates: https://developers.facebook.com/docs/whatsapp/business-management-api/message-templates
- Phone Number Formatting: https://en.wikipedia.org/wiki/E.164
