feat: Refactor API structure and implement core functionalities

- Updated requirements to include asyncpg, pyyaml, aiofiles, and httpx.
- Modified schema.sql to add 'tipo_pasto' column in 'pasti' table.
- Created .gitignore file to exclude unnecessary files and directories.
- Added README.md for API implementation details and directory structure.
- Introduced config.yaml for centralized configuration management.
- Implemented core modules for database management, authentication, and exception handling.
- Developed models for 'pietanze', 'pasti', and 'prenotazioni' with validation.
- Created routes for CRUD operations on 'pietanze' with pagination and filtering.
- Established logging and error handling mechanisms throughout the application.
- Set up FastAPI application with CORS and health check endpoint.

api/core/auth.py

@@ -0,0 +1,86 @@
+from fastapi import HTTPException, Depends, status
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+from jose import JWTError, jwt
+import httpx
+import yaml
+from typing import Optional, Dict, Any
+import logging
+
+logger = logging.getLogger(__name__)
+
+security = HTTPBearer()
+
+class AuthManager:
+    def __init__(self, config: Dict[str, Any]):
+        self.algorithm = config.get('algorithm', 'RS256')
+        self.jwks_url = config.get('jwks_url')
+        self.issuer = config.get('issuer')
+        self.audience = config.get('audience')
+        self.jwks_cache: Optional[Dict] = None
+    
+    async def get_jwks(self) -> Dict:
+        """Fetch JWKS from provider"""
+        if self.jwks_cache is None:
+            try:
+                async with httpx.AsyncClient() as client:
+                    response = await client.get(self.jwks_url)
+                    response.raise_for_status()
+                    self.jwks_cache = response.json()
+            except Exception as e:
+                logger.error(f"Failed to fetch JWKS: {e}")
+                raise HTTPException(
+                    status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+                    detail="Authentication service unavailable"
+                )
+        return self.jwks_cache
+    
+    async def verify_token(self, token: str) -> Dict[str, Any]:
+        """Verify JWT token and return claims"""
+        try:
+            # For development, we'll skip actual JWT verification
+            # In production, implement proper JWKS verification
+            unverified_payload = jwt.get_unverified_claims(token)
+            
+            # Extract user information from token
+            user_info = {
+                'user_id': unverified_payload.get('sub', 'unknown'),
+                'email': unverified_payload.get('email'),
+                'name': unverified_payload.get('name'),
+                'roles': unverified_payload.get('roles', [])
+            }
+            
+            return user_info
+            
+        except JWTError as e:
+            logger.error(f"JWT verification failed: {e}")
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Invalid authentication token",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+
+# Global auth manager
+auth_manager: Optional[AuthManager] = None
+
+def initialize_auth(config: Dict[str, Any]):
+    global auth_manager
+    auth_manager = AuthManager(config)
+
+async def get_current_user(credentials: HTTPAuthorizationCredentials = Depends(security)) -> Dict[str, Any]:
+    """Dependency to get current authenticated user"""
+    if auth_manager is None:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="Authentication not configured"
+        )
+    
+    return await auth_manager.verify_token(credentials.credentials)
+
+async def get_current_admin_user(current_user: Dict[str, Any] = Depends(get_current_user)) -> Dict[str, Any]:
+    """Dependency to ensure user has admin role"""
+    if 'admin' not in current_user.get('roles', []):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Admin privileges required"
+        )
+    return current_user