Initial commit: Phase 1 & Phase 2 infrastructure complete

src/api/dependencies.py

@@ -0,0 +1,185 @@
+"""
+FastAPI Dependencies
+
+Shared dependencies for API endpoints
+"""
+
+from typing import Generator, Optional
+from fastapi import Depends, HTTPException, status, Security
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+from sqlalchemy.orm import Session
+
+from config.database import get_db_session
+from config.settings import settings
+from src.database.models import User
+
+
+# =============================================================================
+# DATABASE DEPENDENCY
+# =============================================================================
+
+def get_db() -> Generator[Session, None, None]:
+    """
+    Database session dependency
+
+    Yields database session and ensures it's closed after request
+    """
+    session = get_db_session()
+    try:
+        yield session
+    finally:
+        session.close()
+
+
+# =============================================================================
+# AUTHENTICATION DEPENDENCIES
+# =============================================================================
+
+# HTTP Bearer token scheme
+security = HTTPBearer(auto_error=False)
+
+
+def get_current_user(
+    credentials: Optional[HTTPAuthorizationCredentials] = Security(security),
+    db: Session = Depends(get_db)
+) -> Optional[User]:
+    """
+    Get current authenticated user from JWT token
+
+    Args:
+        credentials: Bearer token from Authorization header
+        db: Database session
+
+    Returns:
+        User object if authenticated, None if auth not required
+
+    Raises:
+        HTTPException: If authentication required but invalid
+    """
+
+    # If authentication not required (development mode)
+    if not settings.require_auth:
+        # Return anonymous user (ID 0)
+        return db.query(User).filter_by(id=0).first()
+
+    # Authentication required
+    if not credentials:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Authentication required",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    try:
+        # Decode JWT token (implementation in auth.py)
+        from src.api.auth import decode_access_token
+
+        payload = decode_access_token(credentials.credentials)
+        user_id = payload.get("sub")
+
+        if user_id is None:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Invalid authentication token"
+            )
+
+        # Get user from database
+        user = db.query(User).filter_by(id=int(user_id)).first()
+
+        if user is None:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="User not found"
+            )
+
+        return user
+
+    except Exception as e:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail=f"Authentication failed: {str(e)}"
+        )
+
+
+def require_auth(user: User = Depends(get_current_user)) -> User:
+    """
+    Require authentication (always)
+
+    Use this dependency when endpoint must have authentication
+    regardless of global settings
+
+    Args:
+        user: Current user from get_current_user
+
+    Returns:
+        Authenticated user
+
+    Raises:
+        HTTPException: If user not authenticated
+    """
+    if user is None or user.id == 0:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Authentication required for this endpoint"
+        )
+
+    return user
+
+
+def optional_auth(user: Optional[User] = Depends(get_current_user)) -> Optional[User]:
+    """
+    Optional authentication
+
+    Returns user if authenticated, None otherwise (no error)
+
+    Args:
+        user: Current user from get_current_user
+
+    Returns:
+        User if authenticated, None otherwise
+    """
+    return user
+
+
+# =============================================================================
+# PAGINATION DEPENDENCIES
+# =============================================================================
+
+def get_pagination(
+    skip: int = 0,
+    limit: int = 100
+) -> dict:
+    """
+    Pagination parameters
+
+    Args:
+        skip: Number of records to skip
+        limit: Maximum number of records to return
+
+    Returns:
+        Dictionary with skip and limit
+    """
+    # Enforce maximum limit
+    max_limit = 1000
+    if limit > max_limit:
+        limit = max_limit
+
+    return {
+        "skip": skip,
+        "limit": limit
+    }
+
+
+# =============================================================================
+# STORAGE DEPENDENCY
+# =============================================================================
+
+def get_storage():
+    """
+    Get storage backend
+
+    Returns:
+        Storage backend instance (LocalStorage or S3Storage)
+    """
+    from src.core.storage import get_storage
+    return get_storage()