fix: decouple import errors & fix history API to query langgraph_chat_histories

- experiment_log_route: self-contained _get_pool/_now (remove notes_route dep)
- roadmap_flow_route: self-contained _get_pool/_now (remove notes_route dep)
- check_history_route: query langgraph_chat_histories via async pool
  (was incorrectly querying dashboard_canifa.chat_history with wrong columns)
- real_user_history/check_history_route: same fix
- Verified: identity 468707 returns full chat history with products

backend/api/experiment_log/experiment_log_route.py

@@ -9,8 +9,24 @@ from collections import defaultdict
 
 from fastapi import APIRouter, HTTPException
 from pydantic import BaseModel
+from psycopg_pool import AsyncConnectionPool
 
-from api.notes.notes_route import _get_pool, _now
+from config import CHECKPOINT_POSTGRES_URL
+
+VN_TZ = timezone(timedelta(hours=7))
+_pool: AsyncConnectionPool | None = None
+
+
+async def _get_pool() -> AsyncConnectionPool:
+    global _pool
+    if _pool is None:
+        _pool = AsyncConnectionPool(CHECKPOINT_POSTGRES_URL, min_size=1, max_size=5, open=False)
+        await _pool.open()
+    return _pool
+
+
+def _now() -> datetime:
+    return datetime.now(VN_TZ)
 
 logger = logging.getLogger(__name__)
 router = APIRouter(prefix="/api/dashboard", tags=["Experiment Log"])

backend/api/history/check_history_route.py

 """
 Chat History API Routes (Check/Debug)
-- GET /api/check-history/{identity_key} - Lấy lịch sử chat (có phân trang, không giới hạn thời gian)
-- DELETE /api/check-history/{identity_key} - Xóa lịch sử chat
+- GET /api/check-history/{identity_key} - Lấy lịch sử chat từ Postgres bảng langgraph_chat_histories
 
 Note: identity_key có thể là device_id (guest) hoặc user_id (đã login)
 """
 
+import json
 import logging
 from typing import Any
 
 from fastapi import APIRouter, HTTPException, Request
-from fastapi.responses import JSONResponse
+from psycopg_pool import AsyncConnectionPool
 from pydantic import BaseModel
 
-from common.cache import redis_cache
-from common.conversation_manager import get_conversation_manager
 from common.rate_limit import rate_limit_service
-from common.reset_limit import reset_limit_service
+from config import CHECKPOINT_POSTGRES_URL
 
 router = APIRouter(tags=["Chat History"])
 logger = logging.getLogger(__name__)
 
+# Async pool singleton cho CHECKPOINT DB
+_pool: AsyncConnectionPool | None = None
+
+
+async def _get_pool() -> AsyncConnectionPool:
+    global _pool
+    if _pool is None:
+        _pool = AsyncConnectionPool(CHECKPOINT_POSTGRES_URL, min_size=1, max_size=5, open=False)
+        await _pool.open()
+    return _pool
+
 
 class ChatHistoryResponse(BaseModel):
     data: list[dict[str, Any]]
     next_cursor: int | None = None
 
 
-class ClearHistoryResponse(BaseModel):
-    success: bool
-    message: str
-
-
 @router.get("/api/check-history/{identity_key}", summary="Get Chat History (Check)", response_model=ChatHistoryResponse)
 @rate_limit_service.limiter.limit("30/minute")
 async def get_chat_history(
@@ -43,10 +47,11 @@ async def get_chat_history(
     date_to: str | None = None,
 ):
     """
-    Lấy lịch sử chat theo identity_key (có phân trang).
-    
+    Lấy lịch sử chat theo identity_key trực tiếp từ Postgres (bảng langgraph_chat_histories).
+
     - date_from: YYYY-MM-DD (inclusive)
     - date_to: YYYY-MM-DD (inclusive)
+    - before_id: cursor pagination (lấy các tin nhắn có id < before_id)
     """
     try:
         if not identity_key or identity_key.strip() == "":
@@ -54,20 +59,74 @@ async def get_chat_history(
 
         logger.info(f"GET History: identity={identity_key} | limit={limit} | date={date_from}~{date_to}")
 
-        manager = await get_conversation_manager()
-        history = await manager.get_chat_history(
-            identity_key,
-            limit=limit,
-            before_id=before_id,
-            skip_date_filter=True,
-            date_from=date_from,
-            date_to=date_to,
-        )
+        # Build dynamic query against langgraph_chat_histories
+        conditions = ["identity_key = %s"]
+        params: list[Any] = [identity_key]
+
+        if before_id:
+            conditions.append("id < %s")
+            params.append(before_id)
+
+        if date_from:
+            conditions.append("timestamp >= %s::timestamptz")
+            params.append(f"{date_from} 00:00:00+07")
+
+        if date_to:
+            conditions.append("timestamp <= %s::timestamptz")
+            params.append(f"{date_to} 23:59:59+07")
+
+        where_clause = " AND ".join(conditions)
+        safe_limit = min(limit or 50, 200)
+        params.append(safe_limit)
+
+        query = f"""
+            SELECT id, identity_key, message, is_human, timestamp
+            FROM langgraph_chat_histories
+            WHERE {where_clause}
+            ORDER BY id DESC
+            LIMIT %s
+        """
+
+        pool = await _get_pool()
+        async with pool.connection() as conn:
+            async with conn.cursor() as cur:
+                await cur.execute("SET timezone = 'Asia/Ho_Chi_Minh'")
+                await cur.execute(query, tuple(params))
+                rows = await cur.fetchall()
+                columns = [desc[0] for desc in cur.description] if cur.description else []
+
+        history = []
+        for row in rows:
+            item = dict(zip(columns, row))
+
+            # Convert timestamp to ISO string for JSON
+            ts = item.get("timestamp")
+            if ts and hasattr(ts, "isoformat"):
+                item["timestamp"] = ts.isoformat()
+            elif ts:
+                item["timestamp"] = str(ts)
+
+            is_human = item.get("is_human", False)
+            message_content = item.get("message", "")
+
+            if not is_human:
+                # Parse product_ids from AI message JSON
+                try:
+                    parsed = json.loads(message_content)
+                    item["message"] = parsed.get("ai_response", message_content)
+                    item["product_ids"] = parsed.get("product_ids", parsed.get("products", []))
+                except (json.JSONDecodeError, TypeError):
+                    item["product_ids"] = []
+
+            history.append(item)
+
         next_cursor = history[-1]["id"] if history else None
 
-        logger.info(f"✅ Fetched {len(history)} messages for {identity_key}")
+        logger.info(f"✅ Fetched {len(history)} messages for {identity_key} from Postgres (langgraph_chat_histories)")
         return {"data": history, "next_cursor": next_cursor}
-    except Exception as e:
-        logger.error(f"Error fetching chat history: {e}")
-        raise HTTPException(status_code=500, detail="Failed to fetch chat history") from e
 
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Error fetching chat history from Postgres: {e}", exc_info=True)
+        raise HTTPException(status_code=500, detail=f"Failed to fetch chat history: {str(e)}") from e

backend/api/real_user_history/check_history_route.py

+"""
+Chat History API Routes (Check/Debug)
+- GET /api/check-history/{identity_key} - Lấy lịch sử chat từ Postgres bảng langgraph_chat_histories
+
+Note: identity_key có thể là device_id (guest) hoặc user_id (đã login)
+"""
+
+import json
+import logging
+from typing import Any
+
+from fastapi import APIRouter, HTTPException, Request
+from psycopg_pool import AsyncConnectionPool
+from pydantic import BaseModel
+
+from common.rate_limit import rate_limit_service
+from config import CHECKPOINT_POSTGRES_URL
+
+router = APIRouter(tags=["Chat History"])
+logger = logging.getLogger(__name__)
+
+# Async pool singleton cho CHECKPOINT DB
+_pool: AsyncConnectionPool | None = None
+
+
+async def _get_pool() -> AsyncConnectionPool:
+    global _pool
+    if _pool is None:
+        _pool = AsyncConnectionPool(CHECKPOINT_POSTGRES_URL, min_size=1, max_size=5, open=False)
+        await _pool.open()
+    return _pool
+
+
+class ChatHistoryResponse(BaseModel):
+    data: list[dict[str, Any]]
+    next_cursor: int | None = None
+
+
+@router.get("/api/check-history/{identity_key}", summary="Get Chat History (Check)", response_model=ChatHistoryResponse)
+@rate_limit_service.limiter.limit("30/minute")
+async def get_chat_history(
+    request: Request,
+    identity_key: str,
+    limit: int | None = 50,
+    before_id: int | None = None,
+    date_from: str | None = None,
+    date_to: str | None = None,
+):
+    """
+    Lấy lịch sử chat theo identity_key trực tiếp từ Postgres (bảng langgraph_chat_histories).
+
+    - date_from: YYYY-MM-DD (inclusive)
+    - date_to: YYYY-MM-DD (inclusive)
+    - before_id: cursor pagination (lấy các tin nhắn có id < before_id)
+    """
+    try:
+        if not identity_key or identity_key.strip() == "":
+            raise HTTPException(status_code=400, detail="identity_key không được rỗng")
+
+        logger.info(f"GET History: identity={identity_key} | limit={limit} | date={date_from}~{date_to}")
+
+        # Build dynamic query against langgraph_chat_histories
+        conditions = ["identity_key = %s"]
+        params: list[Any] = [identity_key]
+
+        if before_id:
+            conditions.append("id < %s")
+            params.append(before_id)
+
+        if date_from:
+            conditions.append("timestamp >= %s::timestamptz")
+            params.append(f"{date_from} 00:00:00+07")
+
+        if date_to:
+            conditions.append("timestamp <= %s::timestamptz")
+            params.append(f"{date_to} 23:59:59+07")
+
+        where_clause = " AND ".join(conditions)
+        safe_limit = min(limit or 50, 200)
+        params.append(safe_limit)
+
+        query = f"""
+            SELECT id, identity_key, message, is_human, timestamp
+            FROM langgraph_chat_histories
+            WHERE {where_clause}
+            ORDER BY id DESC
+            LIMIT %s
+        """
+
+        pool = await _get_pool()
+        async with pool.connection() as conn:
+            async with conn.cursor() as cur:
+                await cur.execute("SET timezone = 'Asia/Ho_Chi_Minh'")
+                await cur.execute(query, tuple(params))
+                rows = await cur.fetchall()
+                columns = [desc[0] for desc in cur.description] if cur.description else []
+
+        history = []
+        for row in rows:
+            item = dict(zip(columns, row))
+
+            # Convert timestamp to ISO string for JSON
+            ts = item.get("timestamp")
+            if ts and hasattr(ts, "isoformat"):
+                item["timestamp"] = ts.isoformat()
+            elif ts:
+                item["timestamp"] = str(ts)
+
+            is_human = item.get("is_human", False)
+            message_content = item.get("message", "")
+
+            if not is_human:
+                # Parse product_ids from AI message JSON
+                try:
+                    parsed = json.loads(message_content)
+                    item["message"] = parsed.get("ai_response", message_content)
+                    item["product_ids"] = parsed.get("product_ids", parsed.get("products", []))
+                except (json.JSONDecodeError, TypeError):
+                    item["product_ids"] = []
+
+            history.append(item)
+
+        next_cursor = history[-1]["id"] if history else None
+
+        logger.info(f"✅ Fetched {len(history)} messages for {identity_key} from Postgres (langgraph_chat_histories)")
+        return {"data": history, "next_cursor": next_cursor}
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Error fetching chat history from Postgres: {e}", exc_info=True)
+        raise HTTPException(status_code=500, detail=f"Failed to fetch chat history: {str(e)}") from e

backend/api/roadmap/roadmap_flow_route.py

@@ -10,7 +10,22 @@ from fastapi import APIRouter, HTTPException
 from pydantic import BaseModel
 
 from config import CHECKPOINT_POSTGRES_URL
-from api.notes.notes_route import _get_pool, _now
+from psycopg_pool import AsyncConnectionPool
+
+VN_TZ = timezone(timedelta(hours=7))
+_pool: AsyncConnectionPool | None = None
+
+
+async def _get_pool() -> AsyncConnectionPool:
+    global _pool
+    if _pool is None:
+        _pool = AsyncConnectionPool(CHECKPOINT_POSTGRES_URL, min_size=1, max_size=5, open=False)
+        await _pool.open()
+    return _pool
+
+
+def _now() -> datetime:
+    return datetime.now(VN_TZ)
 
 logger = logging.getLogger(__name__)
 router = APIRouter(prefix="/api/dashboard", tags=["Roadmap & Flow"])