docs/langchain/libs/experimental/langchain_experimental/llms/llamaapi.py

import json
import logging
from typing import (
    Any,
    Dict,
    List,
    Mapping,
    Optional,
    Tuple,
)

from langchain.schema import (
    ChatGeneration,
    ChatResult,
)
from langchain_core.callbacks.manager import CallbackManagerForLLMRun
from langchain_core.language_models import BaseChatModel
from langchain_core.messages import (
    AIMessage,
    BaseMessage,
    ChatMessage,
    FunctionMessage,
    HumanMessage,
    SystemMessage,
)

logger = logging.getLogger(__name__)


def _convert_dict_to_message(_dict: Mapping[str, Any]) -> BaseMessage:
    role = _dict["role"]
    if role == "user":
        return HumanMessage(content=_dict["content"])
    elif role == "assistant":
        # Fix for azure
        # Also OpenAI returns None for tool invocations
        content = _dict.get("content") or ""
        if _dict.get("function_call"):
            _dict["function_call"]["arguments"] = json.dumps(
                _dict["function_call"]["arguments"]
            )
            additional_kwargs = {"function_call": dict(_dict["function_call"])}
        else:
            additional_kwargs = {}
        return AIMessage(content=content, additional_kwargs=additional_kwargs)
    elif role == "system":
        return SystemMessage(content=_dict["content"])
    elif role == "function":
        return FunctionMessage(content=_dict["content"], name=_dict["name"])
    else:
        return ChatMessage(content=_dict["content"], role=role)


def _convert_message_to_dict(message: BaseMessage) -> dict:
    if isinstance(message, ChatMessage):
        message_dict = {"role": message.role, "content": message.content}
    elif isinstance(message, HumanMessage):
        message_dict = {"role": "user", "content": message.content}
    elif isinstance(message, AIMessage):
        message_dict = {"role": "assistant", "content": message.content}
        if "function_call" in message.additional_kwargs:
            message_dict["function_call"] = message.additional_kwargs["function_call"]
    elif isinstance(message, SystemMessage):
        message_dict = {"role": "system", "content": message.content}
    elif isinstance(message, FunctionMessage):
        message_dict = {
            "role": "function",
            "content": message.content,
            "name": message.name,
        }
    else:
        raise ValueError(f"Got unknown type {message}")
    if "name" in message.additional_kwargs:
        message_dict["name"] = message.additional_kwargs["name"]
    return message_dict


class ChatLlamaAPI(BaseChatModel):
    """Chat model using the Llama API."""

    client: Any  #: :meta private:

    def _generate(
        self,
        messages: List[BaseMessage],
        stop: Optional[List[str]] = None,
        run_manager: Optional[CallbackManagerForLLMRun] = None,
        **kwargs: Any,
    ) -> ChatResult:
        message_dicts, params = self._create_message_dicts(messages, stop)
        _params = {"messages": message_dicts}
        final_params = {**params, **kwargs, **_params}
        response = self.client.run(final_params).json()
        return self._create_chat_result(response)

    def _create_message_dicts(
        self, messages: List[BaseMessage], stop: Optional[List[str]]
    ) -> Tuple[List[Dict[str, Any]], Dict[str, Any]]:
        params = dict(self._client_params)
        if stop is not None:
            if "stop" in params:
                raise ValueError("`stop` found in both the input and default params.")
            params["stop"] = stop
        message_dicts = [_convert_message_to_dict(m) for m in messages]
        return message_dicts, params

    def _create_chat_result(self, response: Mapping[str, Any]) -> ChatResult:
        generations = []
        for res in response["choices"]:
            message = _convert_dict_to_message(res["message"])
            gen = ChatGeneration(
                message=message,
                generation_info=dict(finish_reason=res.get("finish_reason")),
            )
            generations.append(gen)
        return ChatResult(generations=generations)

    @property
    def _client_params(self) -> Mapping[str, Any]:
        """Get the parameters used for the client."""
        return {}

    @property
    def _llm_type(self) -> str:
        """Return type of chat model."""
        return "llama-api"