Make `Categorize` see more chat hisotry. (#4538)

### What problem does this PR solve?

#4521

### Type of change
- [x] Performance Improvement

agent/component/base.py

@@ -482,11 +482,12 @@ class ComponentBase(ABC):
                         continue
 
                     if q["component_id"].lower().find("answer") == 0:
-                        for r, c in self._canvas.history[::-1]:
-                            if r == "user":
-                                self._param.inputs.append({"content": c, "component_id": q["component_id"]})
-                                outs.append(pd.DataFrame([{"content": c}]))
-                                break
+                        txt = []
+                        for r, c in self._canvas.history[::-1][:self._param.message_history_window_size]:
+                            txt.append(f"{r.upper()}: {c}")
+                        txt = "\n".join(txt)
+                        self._param.inputs.append({"content": txt, "component_id": q["component_id"]})
+                        outs.append(pd.DataFrame([{"content": txt}]))
                         continue
 
                     outs.append(self._canvas.get_component(q["component_id"])["obj"].output(allow_partial=False)[1])

agent/component/categorize.py

@@ -39,13 +39,13 @@ class CategorizeParam(GenerateParam):
             if not v.get("to"):
                 raise ValueError(f"[Categorize] 'To' of category {k} can not be empty!")
 
-    def get_prompt(self):
+    def get_prompt(self, chat_hist):
         cate_lines = []
         for c, desc in self.category_description.items():
             for line in desc.get("examples", "").split("\n"):
                 if not line:
                     continue
-                cate_lines.append("Question: {}\tCategory: {}".format(line, c))
+                cate_lines.append("USER: {}\nCategory: {}".format(line, c))
         descriptions = []
         for c, desc in self.category_description.items():
             if desc.get("description"):
@@ -62,11 +62,15 @@ class CategorizeParam(GenerateParam):
         {}
         You could learn from the above examples.
         Just mention the category names, no need for any additional words.
+        
+        ---- Real Data ----
+        {}
         """.format(
             len(self.category_description.keys()),
             "/".join(list(self.category_description.keys())),
             "\n".join(descriptions),
-            "- ".join(cate_lines)
+            "- ".join(cate_lines),
+            chat_hist
         )
         return self.prompt
 
@@ -76,9 +80,8 @@ class Categorize(Generate, ABC):
 
     def _run(self, history, **kwargs):
         input = self.get_input()
-        input = "Question: " + (list(input["content"])[-1] if "content" in input else "") + "\tCategory: "
         chat_mdl = LLMBundle(self._canvas.get_tenant_id(), LLMType.CHAT, self._param.llm_id)
-        ans = chat_mdl.chat(self._param.get_prompt(), [{"role": "user", "content": input}],
+        ans = chat_mdl.chat(self._param.get_prompt(input), [{"role": "user", "content": "\nCategory: "}],
                             self._param.gen_conf())
         logging.debug(f"input: {input}, answer: {str(ans)}")
         for c in self._param.category_description.keys():