Aniworld/src/server/middleware/application_flow_middleware.py
2025-10-12 18:05:31 +02:00

248 lines
8.7 KiB
Python

"""
Application Flow Middleware for FastAPI.
This middleware enforces the application flow priorities:
1. Setup page (if setup is not complete)
2. Authentication page (if user is not authenticated)
3. Main application (for authenticated users with completed setup)
The middleware redirects users to the appropriate page based on their current state
and the state of the application setup.
"""
import logging
from typing import Optional
from fastapi import Request
from fastapi.responses import RedirectResponse
from starlette.middleware.base import BaseHTTPMiddleware
# Import the setup service
try:
from ...core.application.services.setup_service import SetupService
except ImportError:
# Handle case where service is not available
class SetupService:
def is_setup_complete(self):
return True
logger = logging.getLogger(__name__)
class ApplicationFlowMiddleware(BaseHTTPMiddleware):
"""
Middleware to enforce application flow: setup → auth → main application.
This middleware:
1. Checks if setup is complete
2. Validates authentication status
3. Redirects to appropriate page based on state
4. Allows API endpoints and static files to pass through
"""
def __init__(self, app, setup_service: Optional[SetupService] = None):
"""
Initialize the application flow middleware.
Args:
app: FastAPI application instance
setup_service: Setup service instance (optional, will create if not provided)
"""
super().__init__(app)
self.setup_service = setup_service or SetupService()
# Define paths that should bypass flow enforcement
self.bypass_paths = {
"/static", # Static files
"/favicon.ico", # Browser favicon requests
"/robots.txt", # Robots.txt
"/health", # Health check endpoints
"/docs", # OpenAPI documentation
"/redoc", # ReDoc documentation
"/openapi.json" # OpenAPI spec
}
# API paths that should bypass flow but may require auth
self.api_paths = {
"/api",
"/auth"
}
# Pages that are part of the flow and should be accessible
self.flow_pages = {
"/setup",
"/login",
"/app"
}
async def dispatch(self, request: Request, call_next):
"""
Process the request and enforce application flow.
Args:
request: Incoming HTTP request
call_next: Next middleware/handler in chain
Returns:
Response: Either a redirect response or the result of call_next
"""
try:
# Get the request path
path = request.url.path
# Skip flow enforcement for certain paths
if self._should_bypass_flow(path):
return await call_next(request)
# Check application setup status
setup_complete = self.setup_service.is_setup_complete()
# Check authentication status
is_authenticated = await self._is_user_authenticated(request)
# Determine the appropriate action
redirect_response = self._determine_redirect(path, setup_complete, is_authenticated)
if redirect_response:
logger.info(f"Redirecting {path} to {redirect_response.headers.get('location')}")
return redirect_response
# Continue with the request
return await call_next(request)
except Exception as e:
logger.error(f"Error in ApplicationFlowMiddleware: {e}", exc_info=True)
# In case of error, allow the request to continue
return await call_next(request)
def _should_bypass_flow(self, path: str) -> bool:
"""
Check if the given path should bypass flow enforcement.
Args:
path: Request path
Returns:
bool: True if path should bypass flow enforcement
"""
# Check exact bypass paths
for bypass_path in self.bypass_paths:
if path.startswith(bypass_path):
return True
# API paths bypass flow enforcement (but may have their own auth)
for api_path in self.api_paths:
if path.startswith(api_path):
return True
return False
async def _is_user_authenticated(self, request: Request) -> bool:
"""
Check if the user is authenticated by validating JWT token.
Args:
request: HTTP request object
Returns:
bool: True if user is authenticated, False otherwise
"""
try:
# Check for Authorization header
auth_header = request.headers.get("authorization")
if not auth_header or not auth_header.startswith("Bearer "):
return False
# Extract and validate token
token = auth_header.split(" ")[1]
# Import JWT validation function (avoid circular imports)
try:
from ..fastapi_app import verify_jwt_token
payload = verify_jwt_token(token)
return payload is not None
except ImportError:
# Fallback if import fails
logger.warning("Could not import JWT verification function")
return False
except Exception as e:
logger.error(f"Error checking authentication: {e}")
return False
def _determine_redirect(self, path: str, setup_complete: bool, is_authenticated: bool) -> Optional[RedirectResponse]:
"""
Determine if a redirect is needed based on current state.
Args:
path: Current request path
setup_complete: Whether application setup is complete
is_authenticated: Whether user is authenticated
Returns:
Optional[RedirectResponse]: Redirect response if needed, None otherwise
"""
# If setup is not complete
if not setup_complete:
# Allow access to setup page
if path == "/setup":
return None
# Redirect everything else to setup
return RedirectResponse(url="/setup", status_code=302)
# Setup is complete, check authentication
if not is_authenticated:
# Allow access to login page
if path == "/login":
return None
# Redirect unauthenticated users to login (except for specific pages)
if path in self.flow_pages or path == "/":
return RedirectResponse(url="/login", status_code=302)
# User is authenticated and setup is complete
else:
# Redirect from setup/login pages to main app
if path in ["/setup", "/login", "/"]:
return RedirectResponse(url="/app", status_code=302)
# No redirect needed
return None
def get_flow_status(self, request: Request) -> dict:
"""
Get current flow status for debugging/monitoring.
Args:
request: HTTP request object
Returns:
dict: Current flow status information
"""
try:
setup_complete = self.setup_service.is_setup_complete()
is_authenticated = self._is_user_authenticated(request)
return {
"setup_complete": setup_complete,
"authenticated": is_authenticated,
"path": request.url.path,
"should_bypass": self._should_bypass_flow(request.url.path)
}
except Exception as e:
return {
"error": str(e),
"path": request.url.path
}
def create_application_flow_middleware(setup_service: Optional[SetupService] = None) -> ApplicationFlowMiddleware:
"""
Factory function to create application flow middleware.
Args:
setup_service: Setup service instance (optional)
Returns:
ApplicationFlowMiddleware: Configured middleware instance
"""
return ApplicationFlowMiddleware(app=None, setup_service=setup_service)