oc-chat_pdf/langchain_tools/tools.py

from langchain_community.document_loaders.pdf import PyPDFLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain_openai import OpenAIEmbeddings
from langchain_community.vectorstores import Chroma
from langchain_community.llms import OpenAI
from langchain_community.chat_models import ChatOpenAI
from langchain import PromptTemplate
from langchain.chains import RetrievalQAWithSourcesChain, ConversationalRetrievalChain
import os
from dotenv import load_dotenv
import streamlit as st
from langchain.prompts import BasePromptTemplate
from langchain.memory.buffer import ConversationBufferMemory


def pdf_load(file_name: str):
    # Cargar el archivo PDF utilizando el modelo rápido de PDF
    pdf_path = os.path.join('documents/pdfs', file_name)

    loader = PyPDFLoader(
        pdf_path
    )

    # Cargar el contenido del PDF en una lista de documentos
    docs = loader.load()

    return docs


def split_docs(_data: list):
    chunk_size = 1000
    chunk_overlap = 200

    # Split the quote using RecursiveCharacterTextSplitter
    splitter = RecursiveCharacterTextSplitter(
        chunk_size=chunk_size,
        chunk_overlap=chunk_overlap)
    docs_split = splitter.split_documents(_data)

    # st.success('El pdf se ha dividido')

    return docs_split


def load_embedding_opnai():

    # Cargamos la variable que contiene la api_key de OpenAI
    load_dotenv()
    openai_api_key = os.getenv('api_key')
    # Define an OpenAI embeddings model
    embedding_model = OpenAIEmbeddings(openai_api_key=openai_api_key)
    # st.success('El modelo de embeddins de OpneAI se ha cargado')

    return embedding_model


# @st.cache_resource
def create_vector_strore(_docs_split, file_name):

    db_name = file_name.replace('.pdf', '').replace(' ', '_').lower()

    # Cargamos el modelo de embeddings
    embedding_model = load_embedding_opnai()

    # Verificamos si existe la vector strore
    persist_directory = f"./{db_name}"

    if os.path.exists(persist_directory):
        vectordb = Chroma(
            persist_directory=persist_directory,
            embedding_function=embedding_model)
    else:
        vectordb = Chroma.from_documents(
            persist_directory=persist_directory,
            documents=_docs_split,
            embedding=embedding_model)

        vectordb.persist()

    # vectordb.persist()

    return vectordb


# @st.cache_resource
def load_llm_openai():

    # Cargamos la variable que contiene la api_key de OpenAI
    load_dotenv()
    openai_api_key = os.getenv('api_key')

    # llm_openai = OpenAI(model_name="gpt-3.5-turbo-instruct",
    #                     temperature=0.0,
    #                     openai_api_key=openai_api_key,
    #                     max_tokens=1000)

    llm_openai = ChatOpenAI(model_name="gpt-3.5-turbo",
                            temperature=0.0,
                            openai_api_key=openai_api_key,
                            max_tokens=1000)

    # st.success('El modelo LLM de OpneAI se ha cargado')

    return llm_openai

# @st.cache_resource


def load_prompt_template():
    template = """Responde a la siguiente pregunta utilizando los documentos proporcionados y citando las fuentes relevantes entre corchetes []:

    Pregunta: {question}

    Respuesta:"""

    prompt_template = PromptTemplate(
        template=template, input_variables=["question"])

    return prompt_template


# def define_retrieval_qa(_llm, vectordb, file_name, embedding_model):
#
#     db_name = file_name.replace('.pdf', '').replace(' ', '_').lower()
#
#     # Verificamos si existe la vector strore
#     persist_directory = f"./{db_name}"
#
#     vectordb = Chroma(
#         persist_directory=persist_directory,
#         embedding_function=embedding_model)
#
#     memory = ConversationBufferMemory(
#         memory_key="chat_history", return_messages=True)
#
#     # Define the Retrieval QA Chain to integrate the database and LLM
#     qa = RetrievalQAWithSourcesChain.from_chain_type(
#         _llm,
#         memory=memory,
#         retriever=vectordb.as_retriever(),
#         return_source_documents=True,  # Devuelve los documentos fuente
#         max_tokens_limit=1000,  # Límite máximo de tokens para el LLM
#         reduce_k_below_max_tokens=True,  # Reduce k si los tokens exceden el límite
#         verbose=True,  # Modo verboso
#     )
#
#     return qa


def define_retrieval_qa(_llm, vectordb, file_name, embedding_model):

    db_name = file_name.replace('.pdf', '').replace(' ', '_').lower()

    # Verificamos si existe la vector strore
    persist_directory = f"./{db_name}"

    vectordb = Chroma(
        persist_directory=persist_directory,
        embedding_function=embedding_model)

    memory = ConversationBufferMemory(
        memory_key="chat_history", return_messages=True)

    # Define the Retrieval QA Chain to integrate the database and LLM
    qa = RetrievalQAWithSourcesChain.from_chain_type(
        _llm,
        retriever=vectordb.as_retriever(),
        return_source_documents=True,  # Devuelve los documentos fuente
        max_tokens_limit=1000,  # Límite máximo de tokens para el LLM
        reduce_k_below_max_tokens=True,  # Reduce k si los tokens exceden el límite
        verbose=True,  # Modo verboso
    )

    return qa


def define_retrieval_qa_memory(_llm, vectordb, file_name, embedding_model):

    db_name = file_name.replace('.pdf', '').replace(' ', '_').lower()

    # Verificamos si existe la vector strore
    persist_directory = f"./{db_name}"

    vectordb = Chroma(
        persist_directory=persist_directory,
        embedding_function=embedding_model)

    # Configura la memoria
    memory = ConversationBufferMemory(
        memory_key="chat_history", return_messages=True)

    # Define the Retrieval QA Chain to integrate the database and LLM
    conversation = ConversationalRetrievalChain.from_llm(
        _llm,
        retriever=vectordb.as_retriever(),
        memory=memory,
        verbose=True  # Modo verboso
    )

    # result = conversation({"query": query, "chat_history": chat_history})

    return conversation