"""Defines an interface to common OpenAI models."""

from abc import abstractmethod
from typing import Any, Generic, NoReturn, TypeVar

from kedro.io import AbstractDataset, DatasetError
from langchain_openai import ChatOpenAI, OpenAIEmbeddings

OPENAI_TYPE = TypeVar("OPENAI_TYPE")


class OpenAIDataset(AbstractDataset[None, OPENAI_TYPE], Generic[OPENAI_TYPE]):
    """OpenAI dataset used to access credentials at runtime."""

    @property
    @abstractmethod
    def constructor(self) -> OPENAI_TYPE:
        """Return the OpenAI class to construct in the _load method."""

    def __init__(self, credentials: dict[str, str], kwargs: dict[str, Any] = None):
        """Constructor.

        Args:
            credentials: must contain `openai_api_base` and `openai_api_key`.
            kwargs: keyword arguments passed to the underlying constructor.
        """
        self.openai_api_base = credentials["openai_api_base"]
        self.openai_api_key = credentials["openai_api_key"]
        self.kwargs = kwargs or {}

    def _describe(self) -> dict[str, Any]:
        return {**self.kwargs}

    def save(self, data: None) -> NoReturn:
        raise DatasetError(f"{self.__class__.__name__} is a read only dataset type")

    def load(self) -> OPENAI_TYPE:
        return self.constructor(
            openai_api_base=self.openai_api_base,
            openai_api_key=self.openai_api_key,
            **self.kwargs,
        )


class OpenAIEmbeddingsDataset(OpenAIDataset[OpenAIEmbeddings]):
    """
    `OpenAIEmbeddingsDataset` loads an OpenAIEmbeddings [langchain](https://python.langchain.com/) model.

    ### Example usage for the [YAML API](https://docs.kedro.org/en/stable/catalog-data/data_catalog_yaml_examples/)

    **catalog.yml**

    ```yaml
    text_embedding_ada_002:
        type: langchain.OpenAIEmbeddingsDataset
        kwargs:
            model: "text-embedding-ada-002"
        credentials: openai
    ```

    **credentials.yml**

    ```yaml
    openai:
        openai_api_base: <openai-api-base>
        openai_api_key: <openai-api-key>
    ```

    ### Example usage for the [Python API](https://docs.kedro.org/en/stable/catalog-data/advanced_data_catalog_usage/)

    ```python
    from kedro_datasets_experimental.langchain import OpenAIEmbeddingsDataset

    embeddings = OpenAIEmbeddingsDataset(
        credentials={
            "openai_api_base": "<openai-api-base>",
            "openai_api_key": "<openai-api-key>",
        },
        kwargs={
            "model": "text-embedding-ada-002",
        },
    ).load()

    # See: https://python.langchain.com/docs/integrations/text_embedding/openai
    embeddings.embed_query("Hello world!")
    ```

    """

    @property
    def constructor(self) -> type[OpenAIEmbeddings]:
        return OpenAIEmbeddings


class ChatOpenAIDataset(OpenAIDataset[ChatOpenAI]):
    """
    `ChatOpenAIDataset` loads a ChatOpenAI [langchain](https://python.langchain.com/) model.

    ### Example usage for the [YAML API](https://docs.kedro.org/en/stable/catalog-data/data_catalog_yaml_examples/)

    **catalog.yml**

    ```yaml
    gpt_3_5_turbo:
        type: langchain.ChatOpenAIDataset
        kwargs:
            model: "gpt-3.5-turbo"
            temperature: 0.0
        credentials: openai
    ```

    **credentials.yml**

    ```yaml
    openai:
        openai_api_base: <openai-api-base>
        openai_api_key: <openai-api-key>
    ```

    ### Example usage for the [Python API](https://docs.kedro.org/en/stable/catalog-data/advanced_data_catalog_usage/)

    ```python
    from kedro_datasets_experimental.langchain import ChatOpenAIDataset

    llm = ChatOpenAIDataset(
        credentials={
            "openai_api_base": "<openai-api-base>",
            "openai_api_key": "<openai-api-key>",
        },
        kwargs={
            "model": "gpt-3.5-turbo",
            "temperature": 0.0,
        },
    ).load()

    # See: https://python.langchain.com/docs/integrations/chat/openai
    llm.invoke("Hello world!")
    ```

    """

    @property
    def constructor(self) -> type[ChatOpenAI]:
        return ChatOpenAI
