Fix token list , stats in api app.py (#1896)

### What problem does this PR solve?

#1842 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/apps/api_app.py

         if not tenants:
             return get_data_error_result(retmsg="Tenant not found!")
 
-        objs = APITokenService.query(tenant_id=tenants[0].tenant_id, dialog_id=request.args["dialog_id"])
+        id = request.args.get("dialog_id", request.args["canvas_id"])
+        objs = APITokenService.query(tenant_id=tenants[0].tenant_id, dialog_id=id)
         return get_json_result(data=[o.to_dict() for o in objs])
     except Exception as e:
         return server_error_response(e)
                      days=7)).strftime("%Y-%m-%d 24:00:00")),
             request.args.get(
                 "to_date",
-                datetime.now().strftime("%Y-%m-%d %H:%M:%S")))
+                datetime.now().strftime("%Y-%m-%d %H:%M:%S")),
+            "agent" if request.args.get("canvas_id") else None)
         res = {
             "pv": [(o["dt"], o["pv"]) for o in objs],
             "uv": [(o["dt"], o["uv"]) for o in objs],

api/db/services/api_service.py

 
     @classmethod
     @DB.connection_context()
-    def stats(cls, tenant_id, from_date, to_date):
+    def stats(cls, tenant_id, from_date, to_date, source=None):
         return cls.model.select(
             cls.model.create_date.truncate("day").alias("dt"),
             peewee.fn.COUNT(
                 cls.model.thumb_up).alias("thumb_up")
         ).join(Dialog, on=(cls.model.dialog_id == Dialog.id & Dialog.tenant_id == tenant_id)).where(
             cls.model.create_date >= from_date,
-            cls.model.create_date <= to_date
+            cls.model.create_date <= to_date,
+            cls.model.source == source
         ).group_by(cls.model.create_date.truncate("day")).dicts()

rag/utils/__init__.py

 
 encoder = tiktoken.encoding_for_model("gpt-3.5-turbo")
 
+
 def num_tokens_from_string(string: str) -> int:
     """Returns the number of tokens in a text string."""
-    num_tokens = len(encoder.encode(string))
-    return num_tokens
+    try:
+        num_tokens = len(encoder.encode(string))
+        return num_tokens
+    except Exception as e:
+        pass
+    return 0
 
 
 def truncate(string: str, max_len: int) -> int: