from src.utils import load_config
from dotenv import load_dotenv
from src.utils import get_pdf_from_url
from src.preprocess import Preprocessor
from src.embedding import EmbeddingModel
from src.utils import extract_text_from_pdf
from langchain.vectorstores import Chroma
from llm.answer_generator import GroqAnswerGenerator
from langchain.text_splitter import RecursiveCharacterTextSplitter
from llm.query_refiner import QueryRefiner


class ChatPipeline:
    def __init__(self, arxiv_id:str=None):

        self.arxiv_id = None
        self.config = load_config()
        self.chatbot_config = load_config("./configs/llm_producer.yaml")
        self.chunks = None
        self.retriever = None

    def _preprocess_docs(self, docs):
        """
        Preprocess the input text using the Preprocessor class.

        Args:
            text (str): The text to preprocess.

        Returns:
            str: The preprocessed text.
        """
        if not docs:
            raise ValueError("No documents provided for preprocessing.")
        if not isinstance(docs, list):
            raise TypeError("Expected a list of documents for preprocessing.")
        if not all(hasattr(doc, 'page_content') for doc in docs):
            raise ValueError("All documents must have a 'page_content' attribute.")
        

        preprocessor = Preprocessor()

        for i, doc in enumerate(docs):
            doc.page_content = preprocessor(doc.page_content)
        return docs
    
    def _create_chunks(self, docs):
        """
        Create chunks from the preprocessed documents.

        Args:
            docs (list): List of preprocessed documents.

        Returns:
            list: List of document chunks.
        """

        text_splitter = RecursiveCharacterTextSplitter(
            chunk_size=self.config["text_splitter"]["chunk_size"], 
            chunk_overlap=self.config["text_splitter"]["chunk_overlap"]
        )

        return text_splitter.split_documents(docs)
    
    def _create_vector_store(self, chunks):
        """
        Create a vector store from the document chunks.

        Args:
            chunks (list): List of document chunks.

        Returns:
            VectorStore: The created vector store.
        """
        embedding_model = EmbeddingModel(model_type=self.config['embedding']['model_type'],
                                         model_name=self.config['embedding']['model_name'])
        vector_store = Chroma.from_documents(
            documents=chunks,
            embedding=embedding_model.model,
            persist_directory=self.config['vector_db']['path']
        )
        vector_store.persist()
        self.retriever = vector_store.as_retriever(search_kwargs=self.config['vector_db']['search_kwargs'])
        
    def setup(self, arxiv_id:str):
        """
        Setup the pipeline by loading necessary configurations and resources.
        """
        self.arxiv_id = arxiv_id
        if not self.arxiv_id:
            raise ValueError("arxiv_id must be provided to setup the pipeline.")
        
        self.query_refiner = QueryRefiner()

        get_pdf_from_url(self.arxiv_id, self.config['storage']['save_pdf_path'])

        documents = extract_text_from_pdf(f"{self.config['storage']['save_pdf_path']}/{self.arxiv_id}.pdf")

        preprocessed_docs = self._preprocess_docs(documents)

        self.chunks = self._create_chunks(preprocessed_docs)

        self._create_vector_store(self.chunks)

        self.chatbot = GroqAnswerGenerator(
            model_name=self.chatbot_config['model_name'],
            temperature=self.chatbot_config['temperature'],
            max_tokens=self.chatbot_config['max_tokens'],
            retriever=self.retriever
        )
    
    def setup_from_pdf(self, pdf_path: str):
        """
        Setup the pipeline using a local PDF file.
        """
        if not pdf_path:
            raise ValueError("pdf_path must be provided to setup the pipeline.")

        self.query_refiner = QueryRefiner()

        documents = extract_text_from_pdf(pdf_path)

        preprocessed_docs = self._preprocess_docs(documents)

        self.chunks = self._create_chunks(preprocessed_docs)

        self._create_vector_store(self.chunks)

        self.chatbot = GroqAnswerGenerator(
            model_name=self.chatbot_config['model_name'],
            temperature=self.chatbot_config['temperature'],
            max_tokens=self.chatbot_config['max_tokens'],
            retriever=self.retriever
        )
        
    def query(self, prompt: str, refine_query: bool = True):
        """
        Query the chatbot with a prompt.

        Args:
            prompt (str): The prompt to query the chatbot with.

        Returns:
            str: The response from the chatbot.
        """
        if not self.chatbot:
            raise ValueError("Chatbot is not initialized. Call setup() method first.")
        
        if refine_query:
            refined_query = self.query_refiner.refine(prompt)
            return self.chatbot.generate_answer(refined_query)
        else:
            return self.chatbot.generate_answer(prompt)