Implement username search

backend/routes/account.py

@@ -222,4 +222,20 @@ def list_users(current_user: User = Depends(get_current_user), db: Session = Dep
 @router.get("/crypto/public-key/of/{user_id}")
 def get_public_key_of(user_id: int, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
     row = db.query(CryptoPublicKey).filter(CryptoPublicKey.user_id == user_id).first()
-    return {"publicKey": row.public_key_b64 if row else None}
+    return {"publicKey": row.public_key_b64 if row else None}
+
+
+@router.get("/users/search")
+def search_users(q: str, current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+    if len(q.strip()) < 2:
+        return {"users": []}
+    
+    # Case-insensitive partial match on username
+    users = db.query(User).filter(
+        User.username.ilike(f"%{q.strip()}%"),
+        User.id != current_user.id  # Exclude current user
+    ).order_by(User.username.asc()).limit(20).all()
+    
+    return {
+        "users": [convert_user(u) for u in users]
+    }

backend/routes/messaging.py

@@ -9,6 +9,7 @@ from fastapi.responses import FileResponse
 from fastapi.security import HTTPAuthorizationCredentials
 from sqlalchemy.orm import Session
 from dependencies import get_current_user, get_db
+from .account import convert_user
 from constants import OWNER_USERNAME
 from models import Message, SendMessageRequest, EditMessageRequest, User, DMEnvelope, MessageFile, DMFile, Reaction, ReactionRequest, ReactionResponse, DMReaction, DMReactionRequest, DMReactionResponse
 from push_service import push_service
@@ -448,6 +449,48 @@ async def dm_history(other_user_id: int, current_user: User = Depends(get_curren
     )
 
 
+@router.get("/dm/conversations")
+async def get_dm_conversations(current_user: User = Depends(get_current_user), db: Session = Depends(get_db)):
+    # Get all DM conversations where current user is involved
+    conversations_query = db.query(DMEnvelope).filter(
+        (DMEnvelope.sender_id == current_user.id) | (DMEnvelope.recipient_id == current_user.id)
+    ).order_by(DMEnvelope.timestamp.desc())
+    
+    # Group by the "other user" (not current user) and get latest message
+    conversations = {}
+    for envelope in conversations_query:
+        other_user_id = envelope.recipient_id if envelope.sender_id == current_user.id else envelope.sender_id
+        
+        if other_user_id not in conversations:
+            conversations[other_user_id] = envelope
+    
+    # Get user info for each conversation
+    result = []
+    for other_user_id, latest_message in conversations.items():
+        other_user = db.query(User).filter(User.id == other_user_id).first()
+        if other_user:
+            # Calculate unread count for this conversation
+            unread_count = db.query(DMEnvelope).filter(
+                DMEnvelope.sender_id == other_user_id,
+                DMEnvelope.recipient_id == current_user.id,
+                DMEnvelope.id > getattr(latest_message, 'last_read_id', 0)  # This would need to be stored somewhere
+            ).count()
+            
+            result.append({
+                "user": convert_user(other_user),
+                "lastMessage": convert_dm_envelope(latest_message),
+                "unreadCount": unread_count
+            })
+    
+    # Sort by latest message timestamp
+    result.sort(key=lambda x: x["lastMessage"]["timestamp"], reverse=True)
+    
+    return {
+        "status": "success",
+        "conversations": result
+    }
+
+
 @router.put("/edit_message/{message_id}")
 async def edit_message(
     message_id: int,