# Improved Voter API Error Handling

## ✅ Enhanced Error Messages for Ration Card Validation

### Issue Fixed
When users provide a ration card number that doesn't exist, the system now provides clear, actionable error messages.

### Before (Old Error)
```json
{
    "status": 404,
    "message": "Ration card number does not exist"
}
```

### After (New Improved Error)
```json
{
    "status": 422,
    "message": "Ration card number \"RC123456789\" does not exist. Please verify the ration card number or create the ration card first."
}
```

## Error Scenarios

### 1. Single Voter Creation (`POST /api/voters/create`)
**Request with invalid ration card:**
```json
{
    "ration_card_number": "RC999999999",
    "voter_id_number": "ABC1234567890",
    "name": "John Doe",
    "gender": "Male"
}
```

**Response:**
```json
{
    "status": 422,
    "message": "Ration card number \"RC999999999\" does not exist. Please verify the ration card number or create the ration card first."
}
```

### 2. Voter Update (`PUT /api/voters/update/{id}`)
Same error format as creation.

### 3. Bulk Import (`POST /api/voters/import`)
**Response with multiple errors:**
```json
{
    "status": 422,
    "message": "CSV import completed with errors",
    "data": {
        "successful_imports": 5,
        "failed_imports": 2,
        "errors": [
            "Row 3: Ration card number 'RC111111111' does not exist. Please verify the ration card number or create the ration card first.",
            "Row 7: Ration card number 'RC222222222' does not exist. Please verify the ration card number or create the ration card first."
        ]
    }
}
```

## User Actions for This Error

When users receive this error, they can:

1. **Verify the ration card number** - Check for typos or incorrect numbers
2. **Create the ration card first** using:
   - `POST /api/rationCard/create` - Create with voters
   - `POST /api/rationCard/create-only` - Create without voters
3. **Create voter without ration card** - Simply omit the `ration_card_number` field

## Technical Details

### Status Code Changes
- **Old**: 404 (Not Found) 
- **New**: 422 (Unprocessable Entity) - More appropriate for validation errors

### Error Message Improvements
- ✅ Shows the exact ration card number that was not found
- ✅ Provides clear guidance on what to do next
- ✅ Consistent across all voter creation endpoints
- ✅ Helps users distinguish between typos and missing ration cards

### Affected Endpoints
- `POST /api/voters/create` - Single voter creation
- `POST /api/voters/create-with-image` - Voter with image upload
- `PUT /api/voters/update/{id}` - Voter update
- `POST /api/voters/import` - Bulk CSV import

## Example Frontend Alert Implementation

```javascript
// Frontend error handling example
if (response.status === 422 && response.message.includes('does not exist')) {
    // Show user-friendly alert
    alert('Ration Card Not Found!\n\n' + response.message);
    
    // Or show modal with options:
    showRationCardErrorModal({
        message: response.message,
        actions: [
            { label: 'Create Ration Card', action: 'create-ration-card' },
            { label: 'Verify Number', action: 'retry-input' },
            { label: 'Create Without Ration Card', action: 'create-standalone' }
        ]
    });
}
```

## Testing the Improved Errors

Use any non-existent ration card number to test:
- `RC000000000`
- `RC999999999`  
- `INVALID123`

The system will now provide clear, actionable feedback to help users resolve the issue quickly.