# MOC Auto-Generation Feature

## Overview

The LEGO Instructions Manager now includes automatic MOC (My Own Creation) set number generation, making it easier to track and organize your custom LEGO builds without manually managing set numbers.

**Default Behavior: Global Numbering** - All users share the same MOC number sequence, ensuring system-wide unique MOC numbers.

## Features

### 🤖 Automatic Number Generation
- **Sequential Numbering**: Automatically generates MOC numbers in sequence (MOC-10000, MOC-10001, MOC-10002, etc.)
- **Global by Default**: All users share the same sequence for system-wide uniqueness
- **Conflict-Free**: Ensures no duplicate MOC numbers across the entire system
- **Customizable Prefix**: Default is "MOC" but can be changed
- **Optional User-Scoping**: Can scope to individual users if needed

### 🔌 API Endpoints

#### 1. Generate Next MOC Number
```
GET /api/moc/generate
```

**Query Parameters:**
- `prefix` (optional): MOC prefix, default is 'MOC'
- `user_scoped` (optional): Scope to current user, default is **'false'** (GLOBAL)

**Response:**
```json
{
  "success": true,
  "moc_number": "MOC-10001",
  "prefix": "MOC",
  "user_scoped": false
}
```

**Example Usage:**
```javascript
// Get next global MOC number (default)
fetch('/api/moc/generate')
  .then(response => response.json())
  .then(data => {
    console.log('Next MOC number:', data.moc_number);
  });

// Get next user-scoped MOC number (optional)
fetch('/api/moc/generate?user_scoped=true')
  .then(response => response.json())
  .then(data => {
    console.log('Next user MOC number:', data.moc_number);
  });
```

#### 2. Validate MOC Number
```
POST /api/moc/validate
```

**Request Body:**
```json
{
  "set_number": "MOC-12345",
  "user_scoped": false
}
```

**Response:**
```json
{
  "success": true,
  "available": true,
  "set_number": "MOC-12345"
}
```

#### 3. Check MOC Format
```
GET /api/moc/check-format?set_number=MOC-10001&prefix=MOC
```

**Response:**
```json
{
  "is_moc": true,
  "set_number": "MOC-10001",
  "prefix": "MOC"
}
```

## Database Schema

The `Set` model includes MOC support fields:

```python
is_moc = db.Column(db.Boolean, default=False, nullable=False, index=True)
moc_designer = db.Column(db.String(100), nullable=True)  # Designer/creator name
moc_description = db.Column(db.Text, nullable=True)      # Detailed description
```

## Frontend Integration

### HTML Form Example

When creating a new set, users can toggle MOC mode:

```html
<div class="form-check form-switch mb-3">
    <input class="form-check-input" type="checkbox" id="is_moc" name="is_moc">
    <label class="form-check-label" for="is_moc">
        <strong>This is a MOC (My Own Creation)</strong>
    </label>
</div>

<div id="mocSection" style="display: none;">
    <div class="alert alert-success">
        <i class="bi bi-lightbulb"></i> 
        MOC set number will be auto-generated: 
        <strong id="mocNumberPreview">Loading...</strong>
    </div>
</div>

<div id="officialSection">
    <label for="set_number">Set Number</label>
    <input type="text" id="set_number" name="set_number" required>
</div>
```

### JavaScript Integration

```javascript
// Handle MOC toggle
document.getElementById('is_moc').addEventListener('change', function() {
    const mocSection = document.getElementById('mocSection');
    const officialSection = document.getElementById('officialSection');
    const setNumberInput = document.getElementById('set_number');
    
    if (this.checked) {
        // Show MOC section, hide official section
        mocSection.style.display = 'block';
        officialSection.style.display = 'none';
        setNumberInput.removeAttribute('required');
        
        // Fetch next MOC number (global by default)
        fetchNextMocNumber();
    } else {
        // Show official section, hide MOC section
        mocSection.style.display = 'none';
        officialSection.style.display = 'block';
        setNumberInput.setAttribute('required', 'required');
    }
});

// Fetch next MOC number from API
function fetchNextMocNumber() {
    fetch('/api/moc/generate')
        .then(response => response.json())
        .then(data => {
            if (data.success) {
                document.getElementById('mocNumberPreview').textContent = data.moc_number;
                // Optionally store in hidden field
                document.getElementById('moc_number_hidden').value = data.moc_number;
            }
        })
        .catch(error => {
            console.error('Error fetching MOC number:', error);
            document.getElementById('mocNumberPreview').textContent = 'Error generating number';
        });
}
```

## Backend Implementation

### Service Layer

The `MOCNumberGenerator` service handles all MOC number logic:

```python
from app.services.moc_generator import MOCNumberGenerator

# Generate next GLOBAL MOC number (default)
moc_number = MOCNumberGenerator.generate_next_number(
    prefix='MOC',
    user_id=None  # None = global numbering
)

# Generate next USER-SCOPED MOC number (optional)
moc_number = MOCNumberGenerator.generate_next_number(
    prefix='MOC',
    user_id=current_user.id  # Scope to specific user
)

# Validate MOC number availability (global)
is_available = MOCNumberGenerator.validate_moc_number(
    'MOC-12345',
    user_id=None  # Check globally
)

# Check if number follows MOC format
is_moc = MOCNumberGenerator.is_moc_number('MOC-10001')
```

### Route Layer

MOC routes are organized in `app/routes/moc.py`:

```python
from flask import Blueprint, jsonify
from flask_login import login_required, current_user
from app.services.moc_generator import MOCNumberGenerator

bp = Blueprint('moc', __name__, url_prefix='/api/moc')

@bp.route('/generate', methods=['GET'])
@login_required
def generate_moc_number():
    # Default: user_scoped=false (global numbering)
    user_scoped = request.args.get('user_scoped', 'false').lower() == 'true'
    user_id = current_user.id if user_scoped else None
    
    moc_number = MOCNumberGenerator.generate_next_number(
        user_id=user_id
    )
    return jsonify({
        'success': True,
        'moc_number': moc_number
    })
```

## Configuration

### Customizing MOC Prefix

Edit `app/services/moc_generator.py`:

```python
class MOCNumberGenerator:
    DEFAULT_PREFIX = 'MOC'      # Change to 'CUSTOM' or any prefix
    DEFAULT_START = 10000        # Starting number for MOCs
```

### Numbering Modes

**Global Numbering** (Default - **RECOMMENDED**):
- All users share the same MOC number sequence
- Ensures system-wide unique MOC numbers
- MOC-10000 is unique across the entire system
- **API**: `user_scoped=false` or omit parameter
- **Use Case**: Single household, organization, or when you want guaranteed unique IDs

**Per-User Numbering** (Optional):
- Each user has their own MOC number sequence
- MOC-10000 can exist for multiple users
- **API**: `user_scoped=true`
- **Use Case**: Multi-tenant systems where users want isolated numbering

## Use Cases

### Creating a New MOC

1. User clicks "Add New Set"
2. User toggles "This is a MOC" checkbox
3. System automatically generates next global MOC number (e.g., MOC-10000)
4. User fills in MOC designer, description, and other details
5. System saves set with is_moc=True

### Importing Multiple MOCs

```python
from app.services.moc_generator import MOCNumberGenerator

for moc_data in moc_import_list:
    # Global numbering - user_id=None
    moc_number = MOCNumberGenerator.generate_next_number()
    new_set = Set(
        set_number=moc_number,
        set_name=moc_data['name'],
        is_moc=True,
        moc_designer=moc_data['designer'],
        theme='MOC',
        year_released=moc_data['year']
    )
    db.session.add(new_set)

db.session.commit()
```

### Filtering MOCs

```python
# Get all MOCs
mocs = Set.query.filter_by(is_moc=True).all()

# Get MOCs by designer
designer_mocs = Set.query.filter_by(
    is_moc=True,
    moc_designer='John Doe'
).all()

# Get MOCs by number range
mocs_range = Set.query.filter(
    Set.is_moc == True,
    Set.set_number.like('MOC-10%')
).all()
```

## Troubleshooting

### MOC Number Not Generating

**Issue**: API returns error or "Error generating number"

**Solutions**:
1. Check that user is logged in (endpoint requires authentication)
2. Verify database connection
3. Check browser console for JavaScript errors
4. Ensure `moc_bp` is registered in `app/__init__.py`

### Duplicate MOC Numbers

**Issue**: Same MOC number assigned to multiple sets

**Solutions**:
1. Verify you're using global numbering (default `user_scoped=false`)
2. Check database constraints on `set_number` field (should be unique)
3. Run database migration to add unique constraint if missing

### MOC Toggle Not Working

**Issue**: Toggle switch doesn't show/hide sections

**Solutions**:
1. Check JavaScript console for errors
2. Verify element IDs match between HTML and JavaScript
3. Ensure Bootstrap JavaScript is loaded (for styling)

## Future Enhancements

Potential improvements for the MOC feature:

- [ ] Bulk MOC number generation API
- [ ] MOC number recycling (reuse deleted MOC numbers)
- [ ] Custom number formats (e.g., MOC-YYYY-NNNN for year-based)
- [ ] MOC templates for common builds
- [ ] MOC sharing/export functionality
- [ ] Integration with MOC platforms like Rebrickable

## Related Documentation

- [Main README](../README.md) - General application documentation
- [Setup Guide](../SETUP_GUIDE.md) - Installation and configuration
- [Feature Update Summary](../FEATURE_UPDATE_SUMMARY.md) - Recent changes

## Support

For issues or questions about MOC auto-generation:

1. Check existing issues on Gitea
2. Review this documentation
3. Check application logs for errors
4. Create a new issue with:
   - Steps to reproduce
   - Expected vs actual behavior
   - Browser console logs
   - Server logs (if applicable)

---

**Last Updated**: December 2024  
**Feature Version**: 1.1 (Global Numbering Default)  
**Compatibility**: LEGO Instructions Manager v1.3.0+