Architecture Overview¶

class GitHubAPISync:
    """Facade coordinating specialized sync components."""

    def __init__(self, repo_url: str, local_path: str, token: Optional[str] = None):
        self.api_client = GitHubAPIClient(session_factory, repo_url)
        self.repo_manager = RepositoryManager(self.api_client, repo_url)
        self.file_sync = FileSynchronizer(self.api_client, local_path)
        self.progress = ProgressTracker()

    def sync(self, ref: str = "main") -> bool:
        """Coordinate components for complete sync."""
        # 1. Test connection
        # 2. Resolve reference
        # 3. Get repository tree
        # 4. Synchronize files
        # 5. Report progress
        # 6. Return success status

class GitHubAPIClient:
    """Low-level GitHub API client."""

    def __init__(self, session_factory, base_url):
        self.session = session_factory.create_session()
        self.base_url = base_url

    def make_request(self, endpoint, **kwargs):
        """Generic API request handling."""
        # Handle authentication
        # Manage rate limits
        # Retry on failure

class RepositoryManager:
    """Repository-specific operations."""

    def resolve_ref(self, ref: str) -> str:
        """Resolve branch/tag/commit to SHA."""

    def get_tree(self, ref: str) -> List[FileInfo]:
        """Get repository file tree."""

class FileSynchronizer:
    """File sync and incremental updates."""

    def sync_files(self, files: List[FileInfo]):
        """Synchronize files to local directory."""
        # Compare with cache
        # Download changed files
        # Update local files
        # Save metadata

class GitHubBrowserSync:
    """Playwright-based synchronization engine."""

    def sync(self) -> bool:
        """Perform browser-based sync."""
        # 1. Launch browser with Playwright
        # 2. Navigate to repository
        # 3. Download ZIP archive
        # 4. Extract and compare
        # 5. Update changed files

class SessionFactory:
    """Factory for creating configured HTTP sessions."""

    def create_session(self, config: Config) -> requests.Session:
        """Create session with proxy, SSL, and auth."""
        session = requests.Session()
        self.configure_ssl(session, config)
        self.configure_proxy(session, config)
        self.configure_auth(session, config)
        return session

class SyncProvider(ABC):
    """Interface for sync implementations."""
    def sync(self, ref: str) -> bool: ...
    def test_connection(self) -> bool: ...
    def get_status(self) -> Dict: ...

class ProxyProvider(ABC):
    """Interface for proxy configuration."""
    def get_proxy_config(self, url: str) -> Dict: ...
    def detect_proxy(self) -> bool: ...

class CertificateProvider(ABC):
    """Interface for certificate handling."""
    def get_certificates(self) -> List: ...
    def export_certificates(self) -> str: ...

class ConfigResolver:
    """Resolves configuration from multiple sources."""

    def resolve(self) -> Config:
        config = self.load_defaults()
        config.merge(self.load_file())
        config.merge(self.load_environment())
        config.merge(self.load_cli_args())
        return config

# Base exceptions
class GitBridgeError(Exception):
    """Base exception for all GitBridge errors."""

class ConfigurationError(GitBridgeError):
    """Configuration-related errors."""

# Network exceptions
class NetworkError(GitBridgeError):
    """Network and connectivity errors."""

class RateLimitError(NetworkError):
    """API rate limit exceeded."""

class ProxyError(NetworkError):
    """Proxy configuration errors."""

class SSLError(NetworkError):
    """SSL/TLS certificate errors."""

# Authentication exceptions
class AuthenticationError(GitBridgeError):
    """Authentication and authorization errors."""

class TokenError(AuthenticationError):
    """Invalid or expired token."""

# Repository exceptions
class RepositoryError(GitBridgeError):
    """Repository access errors."""

class InvalidRefError(RepositoryError):
    """Invalid branch, tag, or commit."""

# File system exceptions
class FileSystemError(GitBridgeError):
    """Local file system errors."""

class PermissionError(FileSystemError):
    """File permission errors."""

# Browser exceptions
class BrowserError(GitBridgeError):
    """Browser automation errors."""

class BrowserNotFoundError(BrowserError):
    """Browser executable not found."""

class RetryHandler:
    """Handles retry logic for transient failures."""

    def __init__(self, max_retries=3, backoff_factor=2):
        self.max_retries = max_retries
        self.backoff_factor = backoff_factor

    def execute_with_retry(self, func, *args, **kwargs):
        """Execute function with exponential backoff retry."""
        for attempt in range(self.max_retries):
            try:
                return func(*args, **kwargs)
            except TransientError as e:
                if attempt == self.max_retries - 1:
                    raise
                delay = self.backoff_factor ** attempt
                time.sleep(delay)

class ParallelDownloader:
    """Downloads multiple files concurrently."""

    def download_files(self, files: List[FileInfo], max_workers=5):
        """Download files in parallel."""
        with ThreadPoolExecutor(max_workers=max_workers) as executor:
            futures = {
                executor.submit(self.download_file, file): file
                for file in files
            }

            for future in as_completed(futures):
                file = futures[future]
                try:
                    result = future.result()
                    yield file, result
                except Exception as e:
                    self.handle_error(file, e)

class IncrementalSync:
    """Manages incremental synchronization."""

    def get_changes(self, remote_tree, local_cache):
        """Identify changed files."""
        changes = {
            'new': [],
            'modified': [],
            'deleted': [],
            'unchanged': []
        }

        for remote_file in remote_tree:
            local_file = local_cache.get(remote_file.path)

            if not local_file:
                changes['new'].append(remote_file)
            elif local_file.sha != remote_file.sha:
                changes['modified'].append(remote_file)
            else:
                changes['unchanged'].append(remote_file)

        # Check for deleted files
        for local_path in local_cache:
            if local_path not in remote_tree:
                changes['deleted'].append(local_path)

        return changes

class CustomSyncEngine(BaseSyncEngine):
    """Template for custom sync engines."""

    def sync(self) -> SyncResult:
        """Implement custom sync logic."""
        raise NotImplementedError

    def validate_config(self) -> bool:
        """Validate engine-specific configuration."""
        raise NotImplementedError

class PluginManager:
    """Manages GitBridge plugins."""

    def load_plugins(self, plugin_dir: str):
        """Load plugins from directory."""
        for plugin_file in Path(plugin_dir).glob("*.py"):
            spec = importlib.util.spec_from_file_location(
                plugin_file.stem, plugin_file
            )
            module = importlib.util.module_from_spec(spec)
            spec.loader.exec_module(module)

            # Register plugin
            if hasattr(module, 'register'):
                module.register(self)

class MetricsCollector:
    """Collects performance metrics."""

    def __init__(self):
        self.metrics = {
            'sync_duration': [],
            'files_processed': 0,
            'bytes_transferred': 0,
            'api_calls': 0,
            'errors': []
        }

    def record_sync(self, duration, files, bytes_transferred):
        """Record sync metrics."""
        self.metrics['sync_duration'].append(duration)
        self.metrics['files_processed'] += files
        self.metrics['bytes_transferred'] += bytes_transferred

class LogManager:
    """Manages logging configuration."""

    def setup_logging(self, config):
        """Configure logging based on config."""
        handlers = []

        # Console handler
        if config.logging.console:
            handlers.append(logging.StreamHandler())

        # File handler
        if config.logging.file:
            handlers.append(logging.FileHandler(config.logging.file))

        logging.basicConfig(
            level=config.logging.level,
            format=config.logging.format,
            handlers=handlers
        )