#  Copyright (c) "Neo4j"
#  Neo4j Sweden AB [https://neo4j.com]
#  #
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#  #
#      https://www.apache.org/licenses/LICENSE-2.0
#  #
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

from __future__ import annotations

from typing import Any, Optional

from neo4j_graphrag.embeddings.base import Embedder
from neo4j_graphrag.exceptions import EmbeddingsGenerationError
from neo4j_graphrag.utils.rate_limit import (
    RateLimitHandler,
    rate_limit_handler,
    async_rate_limit_handler,
)


class OllamaEmbeddings(Embedder):
    """
    Ollama embeddings class.
    This class uses the ollama Python client to generate vector embeddings for text data.

    Args:
        model (str): The name of the Mistral AI text embedding model to use. Defaults to "mistral-embed".
    """

    def __init__(
        self,
        model: str,
        rate_limit_handler: Optional[RateLimitHandler] = None,
        **kwargs: Any,
    ) -> None:
        try:
            import ollama
        except ImportError:
            raise ImportError(
                """Could not import ollama python client.
                Please install it with `pip install "neo4j_graphrag[ollama]"`."""
            )
        super().__init__(rate_limit_handler)
        self.model = model
        self.client = ollama.Client(**kwargs)
        self.async_client = ollama.AsyncClient(**kwargs)

    @rate_limit_handler
    def embed_query(self, text: str, **kwargs: Any) -> list[float]:
        """
        Generate embeddings for a given query using an Ollama text embedding model.

        Args:
            text (str): The text to generate an embedding for.
            **kwargs (Any): Additional keyword arguments to pass to the Ollama client.
        """
        embeddings_response = self.client.embed(
            model=self.model,
            input=text,
            **kwargs,
        )

        if embeddings_response is None or not embeddings_response.embeddings:
            raise EmbeddingsGenerationError("Failed to retrieve embeddings.")

        embeddings = embeddings_response.embeddings
        # client always returns a sequence of sequences
        embedding = embeddings[0]
        if not isinstance(embedding, list):
            raise EmbeddingsGenerationError("Embedding is not a list of floats.")

        return embedding

    @async_rate_limit_handler
    async def async_embed_query(self, text: str, **kwargs: Any) -> list[float]:
        """
        Asynchronously generate embeddings for a given query using an Ollama text embedding model.

        Args:
            text (str): The text to generate an embedding for.
            **kwargs (Any): Additional keyword arguments to pass to the Ollama client.
        """
        embeddings_response = await self.async_client.embed(
            model=self.model,
            input=text,
            **kwargs,
        )

        if embeddings_response is None or not embeddings_response.embeddings:
            raise EmbeddingsGenerationError("Failed to retrieve embeddings.")

        embeddings = embeddings_response.embeddings
        # client always returns a sequence of sequences
        embedding = embeddings[0]
        if not isinstance(embedding, list):
            raise EmbeddingsGenerationError("Embedding is not a list of floats.")

        return embedding