from operator import itemgetter
from typing import Optional
from uuid import UUID

from langchain.chains import ConversationalRetrievalChain
from langchain.embeddings.ollama import OllamaEmbeddings
from langchain.llms.base import BaseLLM
from langchain.schema import format_document
from langchain_community.chat_models import ChatLiteLLM
from langchain_core.messages import get_buffer_string
from langchain_core.output_parsers import StrOutputParser
from langchain_core.prompts import ChatPromptTemplate, PromptTemplate
from langchain_core.runnables import RunnableParallel, RunnablePassthrough
from langchain_openai import ChatOpenAI, OpenAIEmbeddings
from llm.utils.get_prompt_to_use import get_prompt_to_use
from logger import get_logger
from models import BrainSettings  # Importing settings related to the 'brain'
from modules.brain.service.brain_service import BrainService
from modules.chat.service.chat_service import ChatService
from pydantic import BaseModel, ConfigDict
from supabase.client import Client, create_client
from vectorstore.supabase import CustomSupabaseVectorStore

logger = get_logger(__name__)


# First step is to create the Rephrasing Prompt
_template = """Given the following conversation and a follow up question, rephrase the follow up question to be a standalone question, in its original language.

Chat History:
{chat_history}
Follow Up Input: {question}
Standalone question:"""
CONDENSE_QUESTION_PROMPT = PromptTemplate.from_template(_template)

# Next is the answering prompt

template = """Answer the question based only on the following context from files:
{context}

Question: {question}
"""
ANSWER_PROMPT = ChatPromptTemplate.from_template(template)

# How we format documents

DEFAULT_DOCUMENT_PROMPT = PromptTemplate.from_template(
    template="File {file_name}: {page_content}"
)


def is_valid_uuid(uuid_to_test, version=4):
    try:
        uuid_obj = UUID(uuid_to_test, version=version)
    except ValueError:
        return False

    return str(uuid_obj) == uuid_to_test


brain_service = BrainService()
chat_service = ChatService()


class QuivrRAG(BaseModel):
    """
    Quivr implementation of the RAGInterface.
    """

    model_config = ConfigDict(arbitrary_types_allowed=True)

    # Instantiate settings
    brain_settings = BrainSettings()  # type: ignore other parameters are optional

    # Default class attributes
    model: str = None  # pyright: ignore reportPrivateUsage=none
    temperature: float = 0.1
    chat_id: str = None  # pyright: ignore reportPrivateUsage=none
    brain_id: str = None  # pyright: ignore reportPrivateUsage=none
    max_tokens: int = 2000  # Output length
    max_input: int = 2000
    streaming: bool = False

    @property
    def embeddings(self):
        if self.brain_settings.ollama_api_base_url:
            return OllamaEmbeddings(
                base_url=self.brain_settings.ollama_api_base_url
            )  # pyright: ignore reportPrivateUsage=none
        else:
            return OpenAIEmbeddings()

    @property
    def prompt_to_use(self):
        if self.brain_id and is_valid_uuid(self.brain_id):
            return get_prompt_to_use(UUID(self.brain_id), self.prompt_id)
        else:
            return None

    supabase_client: Optional[Client] = None
    vector_store: Optional[CustomSupabaseVectorStore] = None
    qa: Optional[ConversationalRetrievalChain] = None
    prompt_id: Optional[UUID]

    def __init__(
        self,
        model: str,
        brain_id: str,
        chat_id: str,
        streaming: bool = False,
        prompt_id: Optional[UUID] = None,
        max_tokens: int = 2000,
        max_input: int = 2000,
        **kwargs,
    ):
        super().__init__(
            model=model,
            brain_id=brain_id,
            chat_id=chat_id,
            streaming=streaming,
            max_tokens=max_tokens,
            max_input=max_input,
            **kwargs,
        )
        self.supabase_client = self._create_supabase_client()
        self.vector_store = self._create_vector_store()
        self.prompt_id = prompt_id
        self.max_tokens = max_tokens
        self.max_input = max_input
        self.model = model
        self.brain_id = brain_id
        self.chat_id = chat_id
        self.streaming = streaming

        logger.info(f"QuivrRAG initialized with model {model} and brain {brain_id}")
        logger.info("Max input length: " + str(self.max_input))

    def _create_supabase_client(self) -> Client:
        return create_client(
            self.brain_settings.supabase_url, self.brain_settings.supabase_service_key
        )

    def _create_vector_store(self) -> CustomSupabaseVectorStore:
        return CustomSupabaseVectorStore(
            self.supabase_client,
            self.embeddings,
            table_name="vectors",
            brain_id=self.brain_id,
            max_input=self.max_input,
        )

    def _create_llm(
        self,
        callbacks,
        model,
        streaming=False,
        temperature=0,
    ) -> BaseLLM:
        """
        Create a LLM with the given parameters
        """
        if streaming and callbacks is None:
            raise ValueError(
                "Callbacks must be provided when using streaming language models"
            )

        api_base = None
        if self.brain_settings.ollama_api_base_url and model.startswith("ollama"):
            api_base = self.brain_settings.ollama_api_base_url

        return ChatLiteLLM(
            temperature=temperature,
            max_tokens=self.max_tokens,
            model=model,
            streaming=streaming,
            verbose=False,
            callbacks=callbacks,
            api_base=api_base,
        )

    def _combine_documents(
        docs, document_prompt=DEFAULT_DOCUMENT_PROMPT, document_separator="\n\n"
    ):
        doc_strings = [format_document(doc, document_prompt) for doc in docs]
        return document_separator.join(doc_strings)

    def get_retriever(self):
        return self.vector_store.as_retriever()

    def get_chain(self):
        retriever = self.get_retriever()

        _inputs = RunnableParallel(
            standalone_question=RunnablePassthrough.assign(
                chat_history=lambda x: get_buffer_string(x["chat_history"])
            )
            | CONDENSE_QUESTION_PROMPT
            | ChatOpenAI(temperature=0)
            | StrOutputParser(),
        )

        _context = {
            "context": itemgetter("standalone_question")
            | retriever
            | self._combine_documents,
            "question": lambda x: x["standalone_question"],
        }
        conversational_qa_chain = _inputs | _context | ANSWER_PROMPT | ChatOpenAI()

        return conversational_qa_chain