thrillwiki_django_no_react/memory-bank/features/version-control/technical-guide.md

Version Control System Technical Implementation Guide

System Overview

The version control system implements full VCS capabilities with branching, merging, and collaboration features, building upon django-simple-history while adding robust versioning capabilities across the full stack.

Core VCS Features

1. Branching System

from vcs.models import VersionBranch, VersionTag, ChangeSet

class BranchManager:
    def create_branch(name: str, parent: Optional[VersionBranch] = None):
        """Create a new branch"""
        return VersionBranch.objects.create(
            name=name,
            parent=parent,
            metadata={'created_by': current_user}
        )
    
    def merge_branches(source: VersionBranch, target: VersionBranch):
        """Merge two branches with conflict resolution"""
        merger = MergeStrategy()
        return merger.merge(source, target)

    def list_branches():
        """Get all branches with their relationships"""
        return VersionBranch.objects.select_related('parent').all()

2. Change Tracking

class ChangeTracker:
    def record_change(model_instance, change_type, metadata=None):
        """Record a change in the system"""
        return ChangeSet.objects.create(
            instance=model_instance,
            change_type=change_type,
            metadata=metadata or {},
            branch=get_current_branch()
        )

    def get_changes(branch: VersionBranch):
        """Get all changes in a branch"""
        return ChangeSet.objects.filter(branch=branch).order_by('created_at')

3. Frontend Integration

State Management (React/TypeScript)

interface VCSState {
  currentBranch: Branch;
  branches: Branch[];
  changes: Change[];
  conflicts: Conflict[];
}

class VCSStore {
  private state: VCSState;
  
  async switchBranch(branchName: string): Promise<void> {
    // Implementation
  }
  
  async createBranch(name: string): Promise<void> {
    // Implementation
  }
  
  async mergeBranch(source: string, target: string): Promise<void> {
    // Implementation
  }
}

UI Components

// Branch Selector Component
const BranchSelector: React.FC = () => {
  const branches = useVCSStore(state => state.branches);
  
  return (
    <div className="branch-selector">
      {branches.map(branch => (
        <BranchItem key={branch.id} branch={branch} />
      ))}
    </div>
  );
};

// Change History Component
const ChangeHistory: React.FC = () => {
  const changes = useVCSStore(state => state.changes);
  
  return (
    <div className="change-history">
      {changes.map(change => (
        <ChangeItem key={change.id} change={change} />
      ))}
    </div>
  );
};

4. API Integration

Django REST Framework ViewSets

class VCSViewSet(viewsets.ModelViewSet):
    @action(detail=True, methods=['post'])
    def create_branch(self, request):
        name = request.data.get('name')
        parent = request.data.get('parent')
        
        branch = BranchManager().create_branch(name, parent)
        return Response(BranchSerializer(branch).data)

    @action(detail=True, methods=['post'])
    def merge(self, request):
        source = request.data.get('source')
        target = request.data.get('target')
        
        try:
            result = BranchManager().merge_branches(source, target)
            return Response(result)
        except MergeConflict as e:
            return Response({'conflicts': e.conflicts}, status=409)

5. Conflict Resolution

class ConflictResolver:
    def detect_conflicts(source: ChangeSet, target: ChangeSet) -> List[Conflict]:
        """Detect conflicts between changes"""
        conflicts = []
        # Implementation
        return conflicts

    def resolve_conflict(conflict: Conflict, resolution: Resolution):
        """Apply conflict resolution"""
        with transaction.atomic():
            # Implementation

6. Real-time Collaboration

class CollaborationConsumer(AsyncWebsocketConsumer):
    async def connect(self):
        await self.channel_layer.group_add(
            f"branch_{self.branch_id}",
            self.channel_name
        )

    async def receive_change(self, event):
        """Handle incoming changes"""
        change = event['change']
        await self.process_change(change)

Best Practices

1. Branch Management

• Create feature branches for isolated development
• Use meaningful branch names
• Clean up merged branches
• Regular synchronization with main branch

2. Change Management

• Atomic changes
• Clear change descriptions
• Related changes grouped in changesets
• Regular commits

3. Conflict Resolution

• Early conflict detection
• Clear conflict documentation
• Structured resolution process
• Team communication

4. Performance Optimization

• Efficient change tracking
• Optimized queries
• Caching strategy
• Background processing

5. Security

• Access control
• Audit logging
• Data validation
• Secure transmission

Implementation Examples

1. Creating a New Branch

branch_manager = BranchManager()
feature_branch = branch_manager.create_branch(
    name="feature/new-ui",
    parent=main_branch
)

2. Recording Changes

change_tracker = ChangeTracker()
change = change_tracker.record_change(
    instance=model_object,
    change_type="update",
    metadata={"field": "title", "reason": "Improvement"}
)

3. Merging Branches

try:
    result = branch_manager.merge_branches(
        source=feature_branch,
        target=main_branch
    )
except MergeConflict as e:
    conflicts = e.conflicts
    resolution = conflict_resolver.resolve_conflicts(conflicts)
    result = branch_manager.apply_resolution(resolution)

Error Handling

1. Branch Operations

try:
    branch = branch_manager.create_branch(name)
except BranchExistsError:
    # Handle duplicate branch
except InvalidBranchNameError:
    # Handle invalid name

2. Merge Operations

try:
    result = branch_manager.merge_branches(source, target)
except MergeConflictError as e:
    # Handle merge conflicts
except InvalidBranchError:
    # Handle invalid branch

Monitoring

1. Performance Monitoring

class VCSMonitor:
    def track_operation(operation_type, duration):
        """Track operation performance"""
        
    def check_system_health():
        """Verify system health"""

2. Error Tracking

class ErrorTracker:
    def log_error(error_type, details):
        """Log system errors"""
        
    def analyze_errors():
        """Analyze error patterns"""

Testing

1. Unit Tests

class BranchTests(TestCase):
    def test_branch_creation(self):
        """Test branch creation"""
        
    def test_branch_merge(self):
        """Test branch merging"""

2. Integration Tests

class VCSIntegrationTests(TestCase):
    def test_complete_workflow(self):
        """Test complete VCS workflow"""
        
    def test_conflict_resolution(self):
        """Test conflict resolution"""

Deployment Considerations

1. Database Migrations

• Create necessary tables
• Add indexes
• Handle existing data

2. Cache Setup

• Configure Redis
• Set up caching strategy
• Implement cache invalidation

3. Background Tasks

• Configure Celery
• Set up task queues
• Monitor task execution

Maintenance

1. Regular Tasks

• Clean up old branches
• Optimize database
• Update indexes
• Verify backups

2. Monitoring Tasks

• Check system health
• Monitor performance
• Track error rates
• Analyze usage patterns