add support for NVIDIA llm (#1645)

### What problem does this PR solve?

add support for NVIDIA llm
### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: Zhedong Cen <cenzhedong2@126.com>

rag/llm/chat_model.py

@@ -581,7 +581,6 @@ class MiniMaxChat(Base):
             response = requests.request(
                 "POST", url=self.base_url, headers=headers, data=payload
             )
-            print(response, flush=True)
             response = response.json()
             ans = response["choices"][0]["message"]["content"].strip()
             if response["choices"][0]["finish_reason"] == "length":
@@ -902,4 +901,79 @@ class StepFunChat(Base):
     def __init__(self, key, model_name, base_url="https://api.stepfun.com/v1/chat/completions"):
         if not base_url:
             base_url = "https://api.stepfun.com/v1/chat/completions"
-        super().__init__(key, model_name, base_url)
+        super().__init__(key, model_name, base_url)
+
+
+class NvidiaChat(Base):
+    def __init__(
+        self,
+        key,
+        model_name,
+        base_url="https://integrate.api.nvidia.com/v1/chat/completions",
+    ):
+        if not base_url:
+            base_url = "https://integrate.api.nvidia.com/v1/chat/completions"
+        self.base_url = base_url
+        self.model_name = model_name
+        self.api_key = key
+        self.headers = {
+            "accept": "application/json",
+            "Authorization": f"Bearer {self.api_key}",
+            "Content-Type": "application/json",
+        }
+
+    def chat(self, system, history, gen_conf):
+        if system:
+            history.insert(0, {"role": "system", "content": system})
+        for k in list(gen_conf.keys()):
+            if k not in ["temperature", "top_p", "max_tokens"]:
+                del gen_conf[k]
+        payload = {"model": self.model_name, "messages": history, **gen_conf}
+        try:
+            response = requests.post(
+                url=self.base_url, headers=self.headers, json=payload
+            )
+            response = response.json()
+            ans = response["choices"][0]["message"]["content"].strip()
+            return ans, response["usage"]["total_tokens"]
+        except Exception as e:
+            return "**ERROR**: " + str(e), 0
+
+    def chat_streamly(self, system, history, gen_conf):
+        if system:
+            history.insert(0, {"role": "system", "content": system})
+        for k in list(gen_conf.keys()):
+            if k not in ["temperature", "top_p", "max_tokens"]:
+                del gen_conf[k]
+        ans = ""
+        total_tokens = 0
+        payload = {
+            "model": self.model_name,
+            "messages": history,
+            "stream": True,
+            **gen_conf,
+        }
+
+        try:
+            response = requests.post(
+                url=self.base_url,
+                headers=self.headers,
+                json=payload,
+            )
+            for resp in response.text.split("\n\n"):
+                if "choices" not in resp:
+                    continue
+                resp = json.loads(resp[6:])
+                if "content" in resp["choices"][0]["delta"]:
+                    text = resp["choices"][0]["delta"]["content"]
+                else:
+                    continue
+                ans += text
+                if "usage" in resp:
+                    total_tokens = resp["usage"]["total_tokens"]
+                yield ans
+
+        except Exception as e:
+            yield ans + "\n**ERROR**: " + str(e)
+
+        yield total_tokens