upgrade v2 graph

app.py

@@ -578,19 +578,78 @@ async def stream_agent_response(question: str, chat_history: List[List[str]]) ->
                     response_text += "\n\n⚠️ No se pudo conectar a la base de datos para ejecutar la consulta."
             elif sql_query and not looks_like_sql(sql_query):
                 logger.info("Detected code block but it does not look like SQL; skipping execution.")
+
+            # If we still have no chart but the user clearly wants one,
+            # try a second pass to get ONLY a SQL query from the agent and execute it.
+            if chart_fig is None:
+                q_lower = question.lower()
+                wants_chart = any(k in q_lower for k in ["gráfico", "grafico", "chart", "graph", "pastel", "pie"])
+                if wants_chart:
+                    try:
+                        logger.info("Second pass: asking agent for ONLY SQL query in fenced block.")
+                        sql_only_prompt = (
+                            "Devuelve SOLO la consulta SQL en un bloque ```sql``` para responder a: "
+                            f"{question}. No incluyas explicación ni texto adicional."
+                        )
+                        sql_only_resp = await agent.ainvoke({"input": sql_only_prompt})
+                        sql_only_text = str(sql_only_resp)
+                        sql_query2 = extract_sql_query(sql_only_text)
+                        if sql_query2 and looks_like_sql(sql_query2):
+                            logger.info(f"Second pass SQL detected: {sql_query2}")
+                            db_connection, _ = setup_database_connection()
+                            if db_connection:
+                                query_result = execute_sql_query(sql_query2, db_connection)
+                                # Try to parse table-like text into DataFrame if possible
+                                data = None
+                                if isinstance(query_result, str):
+                                    try:
+                                        import pandas as pd
+                                        df = pd.read_csv(io.StringIO(query_result), sep="|")
+                                        data = df
+                                    except Exception:
+                                        pass
+                                # As a fallback, don't rely on text table; just skip charting here
+                                if data is not None and hasattr(data, "empty") and not data.empty:
+                                    # Heuristics: choose first column as x and second as y if numeric
+                                    x_col = data.columns[0]
+                                    # pick first numeric column different to x
+                                    y_col = None
+                                    for col in data.columns[1:]:
+                                        try:
+                                            pd.to_numeric(data[col])
+                                            y_col = col
+                                            break
+                                        except Exception:
+                                            continue
+                                    if y_col:
+                                        desired_type = 'pie' if any(k in q_lower for k in ["gráfico circular", "grafico circular", "pie", "pastel"]) else 'bar'
+                                        chart_fig = generate_chart(
+                                            data=data,
+                                            chart_type=desired_type,
+                                            x=x_col,
+                                            y=y_col,
+                                            title=f"{y_col} por {x_col}"
+                                        )
+                                        if chart_fig is not None:
+                                            logger.info("Chart generated from second-pass SQL execution.")
+                            else:
+                                logger.info("No DB connection on second pass; skipping.")
+                    except Exception as e:
+                        logger.error(f"Second-pass SQL synthesis failed: {e}")
             
             # Fallback: if user asked for a chart (e.g., pie) and we didn't get SQL or chart yet,
             # parse the most recent assistant text for lines like "LABEL: NUMBER" (bulleted or plain).
             if chart_fig is None:
                 q_lower = question.lower()
                 wants_chart = any(k in q_lower for k in ["gráfico", "grafico", "chart", "graph", "pastel", "pie"])
-                if wants_chart and chat_history:
+                if wants_chart:
                     # Find the most recent assistant message with usable numeric pairs
                     candidate_text = ""
-                    for pair in reversed(chat_history):
-                        if len(pair) >= 2 and isinstance(pair[1], str) and pair[1].strip():
-                            candidate_text = pair[1]
-                            break
+                    if chat_history:
+                        for pair in reversed(chat_history):
+                            if len(pair) >= 2 and isinstance(pair[1], str) and pair[1].strip():
+                                candidate_text = pair[1]
+                                break
                     # Also consider current response_text as a data source
                     if not candidate_text and isinstance(response_text, str) and response_text.strip():
                         candidate_text = response_text