import logging
from typing import Any, Dict, List, Mapping, Optional

from pydantic_v1 import Extra, Field, root_validator

from langchain.callbacks.manager import CallbackManagerForLLMRun
from langchain.llms.base import LLM
from langchain.llms.utils import enforce_stop_tokens
from langchain.utils import get_from_dict_or_env

logger = logging.getLogger(__name__)


class Banana(LLM):
    """Banana large language models.

    To use, you should have the ``banana-dev`` python package installed,
    and the environment variable ``BANANA_API_KEY`` set with your API key.

    Any parameters that are valid to be passed to the call can be passed
    in, even if not explicitly saved on this class.

    Example:
        .. code-block:: python

            from langchain.llms import Banana
            banana = Banana(model_key="")
    """

    model_key: str = ""
    """model endpoint to use"""

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

    banana_api_key: Optional[str] = None

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

        extra = Extra.forbid

    @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 = {field.alias for field in cls.__fields__.values()}

        extra = values.get("model_kwargs", {})
        for field_name in list(values):
            if field_name not in all_required_field_names:
                if field_name in extra:
                    raise ValueError(f"Found {field_name} supplied twice.")
                logger.warning(
                    f"""{field_name} was transferred to model_kwargs.
                    Please confirm that {field_name} is what you intended."""
                )
                extra[field_name] = values.pop(field_name)
        values["model_kwargs"] = extra
        return values

    @root_validator()
    def validate_environment(cls, values: Dict) -> Dict:
        """Validate that api key and python package exists in environment."""
        banana_api_key = get_from_dict_or_env(
            values, "banana_api_key", "BANANA_API_KEY"
        )
        values["banana_api_key"] = banana_api_key
        return values

    @property
    def _identifying_params(self) -> Mapping[str, Any]:
        """Get the identifying parameters."""
        return {
            **{"model_key": self.model_key},
            **{"model_kwargs": self.model_kwargs},
        }

    @property
    def _llm_type(self) -> str:
        """Return type of llm."""
        return "bananadev"

    def _call(
        self,
        prompt: str,
        stop: Optional[List[str]] = None,
        run_manager: Optional[CallbackManagerForLLMRun] = None,
        **kwargs: Any,
    ) -> str:
        """Call to Banana endpoint."""
        try:
            import banana_dev as banana
        except ImportError:
            raise ImportError(
                "Could not import banana-dev python package. "
                "Please install it with `pip install banana-dev`."
            )
        params = self.model_kwargs or {}
        params = {**params, **kwargs}
        api_key = self.banana_api_key
        model_key = self.model_key
        model_inputs = {
            # a json specific to your model.
            "prompt": prompt,
            **params,
        }
        response = banana.run(api_key, model_key, model_inputs)
        try:
            text = response["modelOutputs"][0]["output"]
        except (KeyError, TypeError):
            returned = response["modelOutputs"][0]
            raise ValueError(
                "Response should be of schema: {'output': 'text'}."
                f"\nResponse was: {returned}"
                "\nTo fix this:"
                "\n- fork the source repo of the Banana model"
                "\n- modify app.py to return the above schema"
                "\n- deploy that as a custom repo"
            )
        if stop is not None:
            # I believe this is required since the stop tokens
            # are not enforced by the model parameters
            text = enforce_stop_tokens(text, stop)
        return text
