Added some comments

src/backend/database/core.py

@@ -10,6 +10,8 @@ from .mixins.job import JobMixin
 from .mixins.skill import SkillMixin
 from .mixins.ai import AIMixin  
 
+# RedisDatabase is the main class that combines all mixins for a 
+# comprehensive Redis database interface.
 class RedisDatabase(
     AIMixin,
     BaseMixin,

src/backend/database/mixins/user.py

@@ -11,8 +11,11 @@ from ..constants import KEY_PREFIXES
 logger = logging.getLogger(__name__)
 
 class UserMixin(DatabaseProtocol):
-    """Mixin for user and candidate operations"""
+    """Mixin for user operations"""
 
+    # ================
+    # Guests
+    # ================
     async def set_guest(self, guest_id: str, guest_data: Dict[str, Any]) -> None:
         """Store guest data with enhanced persistence"""
         try:
@@ -211,6 +214,56 @@ class UserMixin(DatabaseProtocol):
             logger.error(f"❌ Error getting guest statistics: {e}")
             return {}        
 
+    # ================
+    # Users
+    # ================
+    async def get_user_by_username(self, username: str) -> Optional[Dict]:
+        """Get user by username specifically"""
+        username_key = f"{KEY_PREFIXES['users']}{username.lower()}"
+        data = await self.redis.get(username_key)
+        return self._deserialize(data) if data else None
+    
+    async def get_user_rag_update_time(self, user_id: str) -> Optional[datetime]:
+        """Get the last time user's RAG data was updated (returns timezone-aware UTC)"""
+        try:
+            rag_update_key = f"user:{user_id}:rag_last_update"
+            timestamp_str = await self.redis.get(rag_update_key)
+            if timestamp_str:
+                dt = datetime.fromisoformat(timestamp_str)
+                # Ensure the datetime is timezone-aware (assume UTC if naive)
+                if dt.tzinfo is None:
+                    dt = dt.replace(tzinfo=timezone.utc)
+                else:
+                    # Convert to UTC if it's in a different timezone
+                    dt = dt.astimezone(timezone.utc)
+                return dt
+            logger.warning(f"⚠️ No RAG update time found for user {user_id}")
+            return None
+        except Exception as e:
+            logger.error(f"❌ Error getting user RAG update time: {e}")
+            return None    
+    
+    async def update_user_rag_timestamp(self, user_id: str) -> bool:
+        """Set the user's RAG data update time (stores as UTC ISO format)"""
+        try:
+            update_time = datetime.now(timezone.utc)
+            
+            # Ensure we're storing UTC timezone-aware format
+            if update_time.tzinfo is None:
+                update_time = update_time.replace(tzinfo=timezone.utc)
+            else:
+                update_time = update_time.astimezone(timezone.utc)
+            
+            rag_update_key = f"user:{user_id}:rag_last_update"
+            # Store as ISO format with timezone info
+            timestamp_str = update_time.isoformat()  # This includes timezone
+            await self.redis.set(rag_update_key, timestamp_str)
+            logger.info(f"✅ User RAG update time set for user {user_id}: {timestamp_str}")
+            return True
+        except Exception as e:
+            logger.error(f"❌ Error setting user RAG update time: {e}")
+            return False
+
     async def set_user_by_id(self, user_id: str, user_data: Dict[str, Any]) -> bool:
         """Store user data with ID as key for direct lookup"""
         try:
@@ -281,7 +334,40 @@ class UserMixin(DatabaseProtocol):
         """Delete user"""
         key = f"{KEY_PREFIXES['users']}{email}"
         await self.redis.delete(key)
-    
+
+    async def get_user(self, login: str) -> Optional[Dict[str, Any]]:
+        """Get user by email or username"""
+        try:
+            login = login.strip().lower()
+            key = f"users:{login}"
+            
+            data = await self.redis.get(key)
+            if data:
+                user_data = json.loads(data)
+                logger.info(f"👤 Retrieved user data for {login}")
+                return user_data
+            return None
+        except Exception as e:
+            logger.error(f"❌ Error retrieving user {login}: {e}")
+            return None
+
+    async def set_user(self, login: str, user_data: Dict[str, Any]) -> bool:
+        """Store user data by email or username"""
+        try:
+            login = login.strip().lower()
+            key = f"users:{login}"
+            
+            await self.redis.set(key, json.dumps(user_data, default=str))
+            logger.info(f"👤 Stored user data for {login}")
+            return True
+        except Exception as e:
+            logger.error(f"❌ Error storing user {login}: {e}")
+            return False
+
+
+    # ================
+    # Employers
+    # ================
     async def get_employer(self, employer_id: str) -> Optional[Dict]:
         """Get employer by ID"""
         key = f"{KEY_PREFIXES['employers']}{employer_id}"
@@ -319,36 +405,9 @@ class UserMixin(DatabaseProtocol):
         await self.redis.delete(key)
     
 
-    async def get_user(self, login: str) -> Optional[Dict[str, Any]]:
-        """Get user by email or username"""
-        try:
-            login = login.strip().lower()
-            key = f"users:{login}"
-            
-            data = await self.redis.get(key)
-            if data:
-                user_data = json.loads(data)
-                logger.info(f"👤 Retrieved user data for {login}")
-                return user_data
-            return None
-        except Exception as e:
-            logger.error(f"❌ Error retrieving user {login}: {e}")
-            return None
-
-    async def set_user(self, login: str, user_data: Dict[str, Any]) -> bool:
-        """Store user data by email or username"""
-        try:
-            login = login.strip().lower()
-            key = f"users:{login}"
-            
-            await self.redis.set(key, json.dumps(user_data, default=str))
-            logger.info(f"👤 Stored user data for {login}")
-            return True
-        except Exception as e:
-            logger.error(f"❌ Error storing user {login}: {e}")
-            return False
-
-    # Candidates operations
+    # ================
+    # Candidates
+    # ================
     async def get_candidate(self, candidate_id: str) -> Optional[Dict]:
         """Get candidate by ID"""
         key = f"{KEY_PREFIXES['candidates']}{candidate_id}"
@@ -723,13 +782,6 @@ class UserMixin(DatabaseProtocol):
             logger.error(f"❌ Critical error during batch candidate deletion: {e}")
             raise    
 
-    # User Operations
-    async def get_user_by_username(self, username: str) -> Optional[Dict]:
-        """Get user by username specifically"""
-        username_key = f"{KEY_PREFIXES['users']}{username.lower()}"
-        data = await self.redis.get(username_key)
-        return self._deserialize(data) if data else None
-    
     async def find_candidate_by_username(self, username: str) -> Optional[Dict]:
         """Find candidate by username"""
         all_candidates = await self.get_all_candidates()
@@ -741,7 +793,6 @@ class UserMixin(DatabaseProtocol):
         
         return None
 
-    # Batch Operations
     async def get_multiple_candidates_by_usernames(self, usernames: List[str]) -> Dict[str, Dict]:
         """Get multiple candidates by their usernames efficiently"""
         all_candidates = await self.get_all_candidates()
@@ -787,6 +838,9 @@ class UserMixin(DatabaseProtocol):
             "recent_sessions": sessions[:5]  # Last 5 sessions
         }
     
+    # ================
+    # Viewers
+    # ================
     async def get_viewer(self, viewer_id: str) -> Optional[Dict]:
         """Get viewer by ID"""
         key = f"{KEY_PREFIXES['viewers']}{viewer_id}"
@@ -824,44 +878,3 @@ class UserMixin(DatabaseProtocol):
         key = f"{KEY_PREFIXES['viewers']}{viewer_id}"
         await self.redis.delete(key)
 
-    async def get_user_rag_update_time(self, user_id: str) -> Optional[datetime]:
-        """Get the last time user's RAG data was updated (returns timezone-aware UTC)"""
-        try:
-            rag_update_key = f"user:{user_id}:rag_last_update"
-            timestamp_str = await self.redis.get(rag_update_key)
-            if timestamp_str:
-                dt = datetime.fromisoformat(timestamp_str)
-                # Ensure the datetime is timezone-aware (assume UTC if naive)
-                if dt.tzinfo is None:
-                    dt = dt.replace(tzinfo=timezone.utc)
-                else:
-                    # Convert to UTC if it's in a different timezone
-                    dt = dt.astimezone(timezone.utc)
-                return dt
-            logger.warning(f"⚠️ No RAG update time found for user {user_id}")
-            return None
-        except Exception as e:
-            logger.error(f"❌ Error getting user RAG update time: {e}")
-            return None    
-    
-    async def update_user_rag_timestamp(self, user_id: str) -> bool:
-        """Set the user's RAG data update time (stores as UTC ISO format)"""
-        try:
-            update_time = datetime.now(timezone.utc)
-            
-            # Ensure we're storing UTC timezone-aware format
-            if update_time.tzinfo is None:
-                update_time = update_time.replace(tzinfo=timezone.utc)
-            else:
-                update_time = update_time.astimezone(timezone.utc)
-            
-            rag_update_key = f"user:{user_id}:rag_last_update"
-            # Store as ISO format with timezone info
-            timestamp_str = update_time.isoformat()  # This includes timezone
-            await self.redis.set(rag_update_key, timestamp_str)
-            logger.info(f"✅ User RAG update time set for user {user_id}: {timestamp_str}")
-            return True
-        except Exception as e:
-            logger.error(f"❌ Error setting user RAG update time: {e}")
-            return False
-