feat: chat — suppression de post, messages privés, boîte compacte, link preview #191

backend/routers/file_chat.py

@@ -22,8 +22,9 @@ from fastapi.responses import FileResponse
 
 from backend import file_chat as _store
 from backend.auth.middleware import check_vault_access, require_auth
+from backend.auth.user_store import get_all_users, get_user
 from backend.indexer import get_vault_data
-from backend.schemas import ChatHistoryResponse, ChatMessageResponse
+from backend.schemas import ChatHistoryResponse, ChatMessageResponse, StatusResponse
 from backend.services.paths import resolve_safe_path
 from backend.sse import sse_manager
 
@@ -104,8 +105,10 @@ async def api_chat_post(
     text = str(body.get("text") or "")
     if not text.strip():
         raise HTTPException(400, "text is required")
+    # #191 — best-effort link preview: a dead/slow URL never blocks the post.
     msg = _store.add_global_message(
-        current_user.get("username", ""), text, _attachment(body)
+        current_user.get("username", ""), text, _attachment(body),
+        _store.build_preview(text),
     )
     await sse_manager.broadcast(
         "chat_message",
@@ -136,3 +139,105 @@ async def api_chat_attachment(name: str, current_user: dict[str, Any] = Depends(
         raise HTTPException(404, "Attachment not found")
     info = _store._MIME_BY_EXT.get(path.suffix.lower(), "application/octet-stream")
     return FileResponse(str(path), media_type=info)
+
+
+# --- #191 : suppression + messages privés -----------------------------------
+
+def _owner_or_admin(msg_user: str, current_user: dict[str, Any]) -> None:
+    """A post may be deleted by its author or by an admin."""
+    if current_user.get("role") != "admin" and current_user.get("username") != msg_user:
+        raise HTTPException(403, "Seul l'auteur ou un administrateur peut supprimer ce message")
+
+
+def _find_and_authorize(vault: str, path: str, message_id: str, current_user: dict[str, Any]) -> dict[str, Any]:
+    """Locate *message_id* in the conversation and check the delete right."""
+    for m in _store.get_messages(vault, path):
+        if m.get("id") == message_id:
+            _owner_or_admin(m.get("user", ""), current_user)
+            return m
+    raise HTTPException(404, "Message not found")
+
+
+@router.delete("/api/chat/{message_id}", response_model=StatusResponse)
+async def api_chat_delete(message_id: str, current_user: dict[str, Any] = Depends(require_auth)):
+    """Delete a message from the general chat (author or admin, #191)."""
+    _find_and_authorize(_store.GLOBAL_VAULT, _store.GLOBAL_PATH, message_id, current_user)
+    if not _store.delete_message(_store.GLOBAL_VAULT, _store.GLOBAL_PATH, message_id):
+        raise HTTPException(404, "Message not found")
+    await sse_manager.broadcast(
+        "chat_deleted",
+        {"vault": _store.GLOBAL_VAULT, "path": _store.GLOBAL_PATH, "id": message_id},
+    )
+    return {"status": "deleted"}
+
+
+@router.get("/api/chat/users", response_model=list[dict[str, Any]])
+async def api_chat_users(current_user: dict[str, Any] = Depends(require_auth)):
+    """Usernames available for a private conversation (chat DM picker, #191).
+
+    Every authenticated member may see who else is around — this is a
+    self-hosted portal, not a directory that needs hiding.
+    """
+    me = current_user.get("username", "")
+    return [
+        {"username": u.get("username", ""), "display_name": u.get("display_name") or u.get("username", "")}
+        for u in get_all_users()
+        if u.get("username") and u.get("username") != me
+    ]
+
+
+def _dm_peer(username: str, current_user: dict[str, Any]) -> str:
+    """Validate the DM peer exists and is not ourselves."""
+    if not username or username == current_user.get("username"):
+        raise HTTPException(400, "Destinataire invalide")
+    if not get_user(username):
+        raise HTTPException(404, "Utilisateur inconnu")
+    return username
+
+
+@router.get("/api/chat/dm/{username}", response_model=ChatHistoryResponse)
+async def api_chat_dm_history(username: str, current_user: dict[str, Any] = Depends(require_auth)):
+    """Private history with *username* (#191)."""
+    peer = _dm_peer(username, current_user)
+    return {"messages": _store.get_dm_messages(current_user["username"], peer)}
+
+
+@router.post("/api/chat/dm/{username}", response_model=ChatMessageResponse)
+async def api_chat_dm_post(
+    username: str,
+    body: dict[str, Any] = Body(...),
+    current_user: dict[str, Any] = Depends(require_auth),
+):
+    """Post a private message and broadcast it to both participants (#191)."""
+    peer = _dm_peer(username, current_user)
+    text = str(body.get("text") or "")
+    if not text.strip():
+        raise HTTPException(400, "text is required")
+    msg = _store.add_dm_message(
+        current_user["username"], peer, current_user.get("username", ""), text,
+        _attachment(body), _store.build_preview(text),
+    )
+    # Same shape as the general chat so the client routes on vault/path.
+    await sse_manager.broadcast(
+        "chat_message",
+        {"vault": _store.DM_VAULT, "path": _store.dm_path(current_user["username"], peer), "message": msg},
+    )
+    return {"message": msg, "status": "ok"}
+
+
+@router.delete("/api/chat/dm/{username}/{message_id}", response_model=StatusResponse)
+async def api_chat_dm_delete(
+    username: str,
+    message_id: str,
+    current_user: dict[str, Any] = Depends(require_auth),
+):
+    """Delete one private message (author or admin, #191)."""
+    peer = _dm_peer(username, current_user)
+    vault, path = _store.DM_VAULT, _store.dm_path(current_user["username"], peer)
+    _find_and_authorize(vault, path, message_id, current_user)
+    if not _store.delete_message(vault, path, message_id):
+        raise HTTPException(404, "Message not found")
+    await sse_manager.broadcast(
+        "chat_deleted", {"vault": vault, "path": path, "id": message_id}
+    )
+    return {"status": "deleted"}