import base64
import hashlib
import hmac
import json
import logging
import time
from typing import Any, Dict, Iterator, List, Mapping, Optional, Type
from urllib.parse import urlparse

import requests
from langchain_core.callbacks import CallbackManagerForLLMRun
from langchain_core.language_models.chat_models import (
    BaseChatModel,
    generate_from_stream,
)
from langchain_core.messages import (
    AIMessage,
    AIMessageChunk,
    BaseMessage,
    BaseMessageChunk,
    ChatMessage,
    ChatMessageChunk,
    HumanMessage,
    HumanMessageChunk,
)
from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, ChatResult
from langchain_core.pydantic_v1 import Field, SecretStr, root_validator
from langchain_core.utils import (
    convert_to_secret_str,
    get_from_dict_or_env,
    get_pydantic_field_names,
)

logger = logging.getLogger(__name__)

DEFAULT_API_BASE = "https://hunyuan.cloud.tencent.com"
DEFAULT_PATH = "/hyllm/v1/chat/completions"


def _convert_message_to_dict(message: BaseMessage) -> dict:
    message_dict: Dict[str, Any]
    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}
    else:
        raise TypeError(f"Got unknown type {message}")

    return message_dict


def _convert_dict_to_message(_dict: Mapping[str, Any]) -> BaseMessage:
    role = _dict["role"]
    if role == "user":
        return HumanMessage(content=_dict["content"])
    elif role == "assistant":
        return AIMessage(content=_dict.get("content", "") or "")
    else:
        return ChatMessage(content=_dict["content"], role=role)


def _convert_delta_to_message_chunk(
    _dict: Mapping[str, Any], default_class: Type[BaseMessageChunk]
) -> BaseMessageChunk:
    role = _dict.get("role")
    content = _dict.get("content") or ""

    if role == "user" or default_class == HumanMessageChunk:
        return HumanMessageChunk(content=content)
    elif role == "assistant" or default_class == AIMessageChunk:
        return AIMessageChunk(content=content)
    elif role or default_class == ChatMessageChunk:
        return ChatMessageChunk(content=content, role=role)
    else:
        return default_class(content=content)


# signature generation
# https://cloud.tencent.com/document/product/1729/97732#532252ce-e960-48a7-8821-940a9ce2ccf3
def _signature(secret_key: SecretStr, url: str, payload: Dict[str, Any]) -> str:
    sorted_keys = sorted(payload.keys())

    url_info = urlparse(url)

    sign_str = url_info.netloc + url_info.path + "?"

    for key in sorted_keys:
        value = payload[key]

        if isinstance(value, list) or isinstance(value, dict):
            value = json.dumps(value, separators=(",", ":"))
        elif isinstance(value, float):
            value = "%g" % value

        sign_str = sign_str + key + "=" + str(value) + "&"

    sign_str = sign_str[:-1]

    hmacstr = hmac.new(
        key=secret_key.get_secret_value().encode("utf-8"),
        msg=sign_str.encode("utf-8"),
        digestmod=hashlib.sha1,
    ).digest()

    return base64.b64encode(hmacstr).decode("utf-8")


def _create_chat_result(response: Mapping[str, Any]) -> ChatResult:
    generations = []
    for choice in response["choices"]:
        message = _convert_dict_to_message(choice["messages"])
        generations.append(ChatGeneration(message=message))

    token_usage = response["usage"]
    llm_output = {"token_usage": token_usage}
    return ChatResult(generations=generations, llm_output=llm_output)


class ChatHunyuan(BaseChatModel):
    """Tencent Hunyuan chat models API by Tencent.

    For more information, see https://cloud.tencent.com/document/product/1729
    """

    @property
    def lc_secrets(self) -> Dict[str, str]:
        return {
            "hunyuan_app_id": "HUNYUAN_APP_ID",
            "hunyuan_secret_id": "HUNYUAN_SECRET_ID",
            "hunyuan_secret_key": "HUNYUAN_SECRET_KEY",
        }

    @property
    def lc_serializable(self) -> bool:
        return True

    hunyuan_api_base: str = Field(default=DEFAULT_API_BASE)
    """Hunyuan custom endpoints"""
    hunyuan_app_id: Optional[int] = None
    """Hunyuan App ID"""
    hunyuan_secret_id: Optional[str] = None
    """Hunyuan Secret ID"""
    hunyuan_secret_key: Optional[SecretStr] = None
    """Hunyuan Secret Key"""
    streaming: bool = False
    """Whether to stream the results or not."""
    request_timeout: int = 60
    """Timeout for requests to Hunyuan API. Default is 60 seconds."""

    query_id: Optional[str] = None
    """Query id for troubleshooting"""
    temperature: float = 1.0
    """What sampling temperature to use."""
    top_p: float = 1.0
    """What probability mass to use."""

    model_kwargs: Dict[str, Any] = Field(default_factory=dict)
    """Holds any model parameters valid for API call not explicitly specified."""

    class Config:
        """Configuration for this pydantic object."""

        allow_population_by_field_name = True

    @root_validator(pre=True)
    def build_extra(cls, values: Dict[str, Any]) -> Dict[str, Any]:
        """Build extra kwargs from additional params that were passed in."""
        all_required_field_names = get_pydantic_field_names(cls)
        extra = values.get("model_kwargs", {})
        for field_name in list(values):
            if field_name in extra:
                raise ValueError(f"Found {field_name} supplied twice.")
            if field_name not in all_required_field_names:
                logger.warning(
                    f"""WARNING! {field_name} is not default parameter.
                    {field_name} was transferred to model_kwargs.
                    Please confirm that {field_name} is what you intended."""
                )
                extra[field_name] = values.pop(field_name)

        invalid_model_kwargs = all_required_field_names.intersection(extra.keys())
        if invalid_model_kwargs:
            raise ValueError(
                f"Parameters {invalid_model_kwargs} should be specified explicitly. "
                f"Instead they were passed in as part of `model_kwargs` parameter."
            )

        values["model_kwargs"] = extra
        return values

    @root_validator()
    def validate_environment(cls, values: Dict) -> Dict:
        values["hunyuan_api_base"] = get_from_dict_or_env(
            values,
            "hunyuan_api_base",
            "HUNYUAN_API_BASE",
            DEFAULT_API_BASE,
        )
        values["hunyuan_app_id"] = get_from_dict_or_env(
            values,
            "hunyuan_app_id",
            "HUNYUAN_APP_ID",
        )
        values["hunyuan_secret_id"] = get_from_dict_or_env(
            values,
            "hunyuan_secret_id",
            "HUNYUAN_SECRET_ID",
        )
        values["hunyuan_secret_key"] = convert_to_secret_str(
            get_from_dict_or_env(
                values,
                "hunyuan_secret_key",
                "HUNYUAN_SECRET_KEY",
            )
        )

        return values

    @property
    def _default_params(self) -> Dict[str, Any]:
        """Get the default parameters for calling Hunyuan API."""
        normal_params = {
            "app_id": self.hunyuan_app_id,
            "secret_id": self.hunyuan_secret_id,
            "temperature": self.temperature,
            "top_p": self.top_p,
        }

        if self.query_id is not None:
            normal_params["query_id"] = self.query_id

        return {**normal_params, **self.model_kwargs}

    def _generate(
        self,
        messages: List[BaseMessage],
        stop: Optional[List[str]] = None,
        run_manager: Optional[CallbackManagerForLLMRun] = None,
        **kwargs: Any,
    ) -> ChatResult:
        if self.streaming:
            stream_iter = self._stream(
                messages=messages, stop=stop, run_manager=run_manager, **kwargs
            )
            return generate_from_stream(stream_iter)

        res = self._chat(messages, **kwargs)

        response = res.json()

        if "error" in response:
            raise ValueError(f"Error from Hunyuan api response: {response}")

        return _create_chat_result(response)

    def _stream(
        self,
        messages: List[BaseMessage],
        stop: Optional[List[str]] = None,
        run_manager: Optional[CallbackManagerForLLMRun] = None,
        **kwargs: Any,
    ) -> Iterator[ChatGenerationChunk]:
        res = self._chat(messages, **kwargs)

        default_chunk_class = AIMessageChunk
        for chunk in res.iter_lines():
            response = json.loads(chunk)
            if "error" in response:
                raise ValueError(f"Error from Hunyuan api response: {response}")

            for choice in response["choices"]:
                chunk = _convert_delta_to_message_chunk(
                    choice["delta"], default_chunk_class
                )
                default_chunk_class = chunk.__class__
                yield ChatGenerationChunk(message=chunk)
                if run_manager:
                    run_manager.on_llm_new_token(chunk.content)

    def _chat(self, messages: List[BaseMessage], **kwargs: Any) -> requests.Response:
        if self.hunyuan_secret_key is None:
            raise ValueError("Hunyuan secret key is not set.")

        parameters = {**self._default_params, **kwargs}

        headers = parameters.pop("headers", {})
        timestamp = parameters.pop("timestamp", int(time.time()))
        expired = parameters.pop("expired", timestamp + 24 * 60 * 60)

        payload = {
            "timestamp": timestamp,
            "expired": expired,
            "messages": [_convert_message_to_dict(m) for m in messages],
            **parameters,
        }

        if self.streaming:
            payload["stream"] = 1

        url = self.hunyuan_api_base + DEFAULT_PATH

        res = requests.post(
            url=url,
            timeout=self.request_timeout,
            headers={
                "Content-Type": "application/json",
                "Authorization": _signature(
                    secret_key=self.hunyuan_secret_key, url=url, payload=payload
                ),
                **headers,
            },
            json=payload,
            stream=self.streaming,
        )
        return res

    @property
    def _llm_type(self) -> str:
        return "hunyuan-chat"