feat: Implement session management with middleware and update authentication flow

dependencies.py

@@ -2,8 +2,18 @@ from __future__ import annotations
 
 from collections.abc import Generator
 
+from fastapi import Depends, HTTPException, Request, status
+
 from config.settings import Settings, get_settings
+from models import User
 from services.security import JWTSettings
+from services.session import (
+    AuthSession,
+    SessionStrategy,
+    SessionTokens,
+    build_session_strategy,
+    extract_session_tokens,
+)
 from services.unit_of_work import UnitOfWork
 
 
@@ -24,3 +34,65 @@ def get_jwt_settings() -> JWTSettings:
     """Provide JWT runtime configuration derived from settings."""
 
     return get_settings().jwt_settings()
+
+
+def get_session_strategy(
+    settings: Settings = Depends(get_application_settings),
+) -> SessionStrategy:
+    """Yield configured session transport strategy."""
+
+    return build_session_strategy(settings.session_settings())
+
+
+def get_session_tokens(
+    request: Request,
+    strategy: SessionStrategy = Depends(get_session_strategy),
+) -> SessionTokens:
+    """Extract raw session tokens from the incoming request."""
+
+    existing = getattr(request.state, "auth_session", None)
+    if isinstance(existing, AuthSession):
+        return existing.tokens
+
+    tokens = extract_session_tokens(request, strategy)
+    request.state.auth_session = AuthSession(tokens=tokens)
+    return tokens
+
+
+def get_auth_session(
+    request: Request,
+    tokens: SessionTokens = Depends(get_session_tokens),
+) -> AuthSession:
+    """Provide authentication session context for the current request."""
+
+    existing = getattr(request.state, "auth_session", None)
+    if isinstance(existing, AuthSession):
+        return existing
+
+    if tokens.is_empty:
+        session = AuthSession.anonymous()
+    else:
+        session = AuthSession(tokens=tokens)
+    request.state.auth_session = session
+    return session
+
+
+def get_current_user(
+    session: AuthSession = Depends(get_auth_session),
+) -> User | None:
+    """Return the current authenticated user if present."""
+
+    return session.user
+
+
+def require_current_user(
+    session: AuthSession = Depends(get_auth_session),
+) -> User:
+    """Ensure that a request is authenticated and return the user context."""
+
+    if session.user is None:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Authentication required.",
+        )
+    return session.user