fix(search): use generated query for chat mode web search #4547 (#4557)

* fix(search): use generated query for chat mode web search #4547

* style(search): tidy query generation call

---------

Co-authored-by: Alexandre Teixeira <alexandremagteixeira@gmail.com>

src/chat_processor.py

@@ -280,10 +280,54 @@ class ChatProcessor:
         web_sources = []
         if use_web:
             try:
-                web_context, web_sources = comprehensive_web_search(
-                    message, time_filter=time_filter, return_sources=True
-                )
-                preface.append(untrusted_context_message("web search results", web_context))
+                from src.llm_core import llm_call
+
+                t_url, t_model, t_headers = session.endpoint_url, session.model, session.headers
+
+                # Default fallback is the first non-empty line of the original user message
+                fallback_query = next((line.strip() for line in message.split("\n") if line.strip()), "")
+                search_query = fallback_query
+
+                try:
+                    generated_query = llm_call(
+                        t_url,
+                        t_model,
+                        [
+                            {
+                                "role": "system",
+                                "content": (
+                                    "Extract a concise search query from the user's message. "
+                                    "Reply ONLY with the query."
+                                ),
+                            },
+                            {"role": "user", "content": message},
+                        ],
+                        headers=t_headers,
+                        temperature=0.1,
+                        max_tokens=50,
+                        timeout=15,
+                    ).strip()
+
+                    if generated_query:
+                        # LLM successfully generated a non-empty query -> use the generated query
+                        search_query = generated_query
+                    else:
+                        # LLM returned an empty or whitespace-only query -> fall back to original query
+                        logger.warning("LLM generated an empty search query, using fallback.")
+                except Exception as e:
+                    # LLM failed (exception/error) -> fall back to original user query
+                    logger.warning(f"Failed to generate search query via LLM, using fallback: {e}")
+
+                search_query = " ".join(search_query.split())
+                if len(search_query) > 150:
+                    search_query = search_query[:150].strip()
+
+                if search_query:
+                    # Execute web search using the final selected query
+                    web_context, web_sources = comprehensive_web_search(
+                        search_query, time_filter=time_filter, return_sources=True
+                    )
+                    preface.append(untrusted_context_message("web search results", web_context))
             except Exception as e:
                 logger.error(f"Web search failed: {e}")
                 preface.append({"role": "system", "content": "Web search encountered an error and could not retrieve results."})

tests/test_chat_processor_web_search.py

@@ -0,0 +1,95 @@
+from unittest.mock import MagicMock
+from types import SimpleNamespace
+from src.chat_processor import ChatProcessor
+
+def test_build_context_preface_web_search_success(monkeypatch):
+    """Test that LLM correctly extracts and uses a web search query."""
+    mock_llm_call = MagicMock(return_value="extracted query")
+    monkeypatch.setattr("src.llm_core.llm_call", mock_llm_call)
+
+    mock_web_search = MagicMock(return_value=("Search Results", [{"url": "http://mock.com"}]))
+    monkeypatch.setattr("src.chat_processor.comprehensive_web_search", mock_web_search)
+
+    processor = ChatProcessor(memory_manager=MagicMock(), personal_docs_manager=MagicMock())
+    session = SimpleNamespace(endpoint_url="http://local", model="test", headers={})
+
+    processor.build_context_preface(
+        message="Some text.\n\nSearch for LLMs.",
+        session=session,
+        use_web=True,
+        use_rag=False,
+        use_memory=False,
+        use_skills=False
+    )
+
+    mock_web_search.assert_called_with("extracted query", time_filter=None, return_sources=True)
+
+def test_build_context_preface_web_search_fallback_on_llm_failure(monkeypatch):
+    """Test fallback to original query if LLM fails."""
+    def failing_llm(*args, **kwargs):
+        raise ValueError("LLM down")
+    monkeypatch.setattr("src.llm_core.llm_call", failing_llm)
+
+    mock_web_search = MagicMock(return_value=("Search Results", []))
+    monkeypatch.setattr("src.chat_processor.comprehensive_web_search", mock_web_search)
+
+    processor = ChatProcessor(memory_manager=MagicMock(), personal_docs_manager=MagicMock())
+    session = SimpleNamespace(endpoint_url="http://local", model="test", headers={})
+
+    processor.build_context_preface(
+        message="First line\nSecond line",
+        session=session,
+        use_web=True,
+        use_rag=False,
+        use_memory=False,
+        use_skills=False
+    )
+
+    mock_web_search.assert_called_with("First line", time_filter=None, return_sources=True)
+
+def test_build_context_preface_web_search_fallback_on_empty_generation(monkeypatch):
+    """Test fallback to original query if LLM returns empty string."""
+    mock_llm_call = MagicMock(return_value="   \n  ")
+    monkeypatch.setattr("src.llm_core.llm_call", mock_llm_call)
+
+    mock_web_search = MagicMock(return_value=("Search Results", []))
+    monkeypatch.setattr("src.chat_processor.comprehensive_web_search", mock_web_search)
+
+    processor = ChatProcessor(memory_manager=MagicMock(), personal_docs_manager=MagicMock())
+    session = SimpleNamespace(endpoint_url="http://local", model="test", headers={})
+
+    processor.build_context_preface(
+        message="\n\nFallback line\nNext",
+        session=session,
+        use_web=True,
+        use_rag=False,
+        use_memory=False,
+        use_skills=False
+    )
+
+    mock_web_search.assert_called_with("Fallback line", time_filter=None, return_sources=True)
+
+def test_build_context_preface_web_search_query_sanitization(monkeypatch):
+    """Test that query is truncated and whitespace collapsed."""
+    long_query = "word  " * 50
+    mock_llm_call = MagicMock(return_value=long_query)
+    monkeypatch.setattr("src.llm_core.llm_call", mock_llm_call)
+
+    mock_web_search = MagicMock(return_value=("Search Results", []))
+    monkeypatch.setattr("src.chat_processor.comprehensive_web_search", mock_web_search)
+
+    processor = ChatProcessor(memory_manager=MagicMock(), personal_docs_manager=MagicMock())
+    session = SimpleNamespace(endpoint_url="http://local", model="test", headers={})
+
+    processor.build_context_preface(
+        message="Message",
+        session=session,
+        use_web=True,
+        use_rag=False,
+        use_memory=False,
+        use_skills=False
+    )
+
+    called_query = mock_web_search.call_args[0][0]
+    assert len(called_query) <= 150
+    assert "  " not in called_query