client side cache middleware created and added

Author: igorbenav

src/app/core/cache.py

@@ -8,9 +8,13 @@
 from fastapi import Request, Response
 from redis.asyncio import Redis, ConnectionPool
 from sqlalchemy.orm import class_mapper, DeclarativeBase
+from fastapi import FastAPI
+from starlette.middleware.base import BaseHTTPMiddleware, RequestResponseEndpoint
 
 from app.core.exceptions import CacheIdentificationInferenceError, InvalidRequestError
 
+# --------------- server side caching ---------------
+
 pool: ConnectionPool | None = None
 client: Redis | None = None
 
@@ -285,3 +289,59 @@ async def inner(request: Request, *args, **kwargs) -> Response:
         return inner
 
     return wrapper
+
+# --------------- client side caching ---------------
+
+class ClientCacheMiddleware(BaseHTTPMiddleware):
+    """
+    Middleware to set the `Cache-Control` header for client-side caching on all responses.
+    
+    Parameters
+    ----------
+    app: FastAPI 
+        The FastAPI application instance.
+    max_age: int, optional 
+        Duration (in seconds) for which the response should be cached. Defaults to 60 seconds.
+
+    Attributes
+    ----------
+    max_age: int
+        Duration (in seconds) for which the response should be cached.
+
+    Methods
+    -------
+    async def dispatch(self, request: Request, call_next: RequestResponseEndpoint) -> Response:
+        Process the request and set the `Cache-Control` header in the response.
+
+    Note
+    ----
+        - The `Cache-Control` header instructs clients (e.g., browsers) to cache the response for the specified duration.
+    """
+    
+    def __init__(self, app: FastAPI, max_age: int = 60) -> None:
+        super().__init__(app)
+        self.max_age = max_age
+
+    async def dispatch(self, request: Request, call_next: RequestResponseEndpoint) -> Response:
+        """
+        Process the request and set the `Cache-Control` header in the response.
+        
+        Parameters
+        ----------
+        request: Request
+            The incoming request.
+        call_next: RequestResponseEndpoint
+            The next middleware or route handler in the processing chain.
+            
+        Returns
+        -------
+        Response
+            The response object with the `Cache-Control` header set.
+
+        Note
+        ----
+            - This method is automatically called by Starlette for processing the request-response cycle.
+        """
+        response: Response = await call_next(request)
+        response.headers['Cache-Control'] = f"public, max-age={self.max_age}"
+        return response

src/app/core/config.py

@@ -72,13 +72,18 @@ class RedisCacheSettings(BaseSettings):
     REDIS_CACHE_URL: str = f"redis://{REDIS_CACHE_HOST}:{REDIS_CACHE_PORT}"
 
 
+class ClientSideCacheSettings(BaseSettings):
+    CLIENT_CACHE_MAX_AGE: int = config("CLIENT_CACHE_MAX_AGE", default=60)
+
+
 class Settings(
     AppSettings, 
     PostgresSettings, 
     CryptSettings, 
     FirstUserSettings,
     TestSettings,
-    RedisCacheSettings
+    RedisCacheSettings,
+    ClientSideCacheSettings
 ):
     pass
 

src/app/main.py

@@ -3,7 +3,7 @@
 
 from app.core.database import Base
 from app.core.database import async_engine as engine
-from app.core.config import settings, DatabaseSettings, RedisCacheSettings, AppSettings
+from app.core.config import settings, DatabaseSettings, RedisCacheSettings, AppSettings, ClientSideCacheSettings
 from app.api import router
 from app.core import cache
 
@@ -44,6 +44,9 @@ def create_application() -> FastAPI:
         application.add_event_handler("startup", create_redis_cache_pool)
         application.add_event_handler("shutdown", close_redis_cache_pool)
 
+    if isinstance(settings, ClientSideCacheSettings):
+        application.add_middleware(cache.ClientCacheMiddleware, max_age=60)
+
     return application