utils.py

from langchain_community.document_loaders import TextLoader
from langchain_community.docstore.document import Document
from langchain.text_splitter import CharacterTextSplitter, RecursiveCharacterTextSplitter
from langchain_community.vectorstores import Chroma
from langchain_community.embeddings import HuggingFaceEmbeddings
from langchain_community.retrievers import BM25Retriever
from langchain_community.llms import OpenAI
from langchain_openai import ChatOpenAI
from langchain.chains import RetrievalQA
from langchain.schema import AIMessage, HumanMessage
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
import os

def split_with_source(text, source):
    splitter = CharacterTextSplitter(
        separator = "\n",
        chunk_size = 512,
        chunk_overlap  = 128,
        add_start_index = True,
    )
    documents = splitter.create_documents([text])
    # print(documents)
    for doc in documents:
        doc.metadata["source"] = source
        # print(doc.metadata)

    return documents


def count_files_in_folder(folder_path):
    # Kiểm tra xem đường dẫn thư mục có tồn tại không
    if not os.path.isdir(folder_path):
        print("Đường dẫn không hợp lệ.")
        return None

    # Sử dụng os.listdir() để lấy danh sách các tập tin và thư mục trong thư mục
    files = os.listdir(folder_path)

    # Đếm số lượng tập tin trong danh sách
    file_count = len(files)

    return file_count

def get_document_from_raw_text():
    documents = [Document(page_content="", metadata={'source': 0})]
    files = os.listdir(os.path.join(os.getcwd(), "raw_data"))
    # print(files)
    for i in files:
        file_path = i
        with open(os.path.join(os.path.join(os.getcwd(), "raw_data"),file_path), 'r', encoding="utf-8") as file:
            # Xử lý bằng text_spliter
            # Tiền xử lý văn bản
            content = file.read().replace('\n\n', "\n")
            # content = ''.join(content.split('.'))
            new_doc = content
            texts = split_with_source(new_doc, i)
            documents = documents + texts

            ##Xử lý mỗi khi xuống dòng
            # for line in file:
            #     # Loại bỏ khoảng trắng thừa và ký tự xuống dòng ở đầu và cuối mỗi dòng
            #     line = line.strip()
            #     documents.append(Document(page_content=line, metadata={"source": i}))
    # print(documents)
    return documents

def load_the_embedding_retrieve(is_ready = False, k = 3, model= 'sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2'):
    embeddings = HuggingFaceEmbeddings(model_name=model)
    if is_ready:
        retriever = Chroma(persist_directory=os.path.join(os.getcwd(), "Data"), embedding_function=embeddings).as_retriever(
            search_kwargs={"k": k}
        )
    else:
        documents = get_document_from_raw_text()
        print(type(documents))
        retriever = Chroma.from_documents(documents, embeddings).as_retriever(
            search_kwargs={"k": k}
        )


    return retriever

def load_the_bm25_retrieve(k = 3):
    documents = get_document_from_raw_text()
    bm25_retriever = BM25Retriever.from_documents(documents)
    bm25_retriever.k = k

    return bm25_retriever

def get_qachain(llm_name = "gpt-3.5-turbo-0125", chain_type = "stuff", retriever = None, return_source_documents = True):
    llm = ChatOpenAI(temperature=0,
                     model_name=llm_name)
    return RetrievalQA.from_chain_type(llm=llm,
                                  chain_type=chain_type,
                                  retriever=retriever,
                                  return_source_documents=return_source_documents)


def summarize_messages(demo_ephemeral_chat_history, llm):
    stored_messages = demo_ephemeral_chat_history.messages
    if len(stored_messages) == 0:
        return False
    summarization_prompt = ChatPromptTemplate.from_messages(
        [
            MessagesPlaceholder(variable_name="chat_history"),
            (
                "user", os.environ['SUMARY_MESSAGE_PROMPT'],
            ),
        ]
    )
    summarization_chain = summarization_prompt | llm

    summary_message = summarization_chain.invoke({"chat_history": stored_messages})

    demo_ephemeral_chat_history.clear()

    demo_ephemeral_chat_history.add_message(summary_message)

    return demo_ephemeral_chat_history

def get_question_from_summarize(summary, question, llm):
    new_qa_prompt = ChatPromptTemplate.from_messages([
        ("system", os.environ['NEW_QUESTION_PROMPT']),
        ("human",
         '''
         Sumary: {summary}
         Question: {question}
         Output:
         '''
         )
    ]
    )

    new_qa_chain = new_qa_prompt | llm
    return new_qa_chain.invoke({'summary': summary, 'question': question}).content

def get_final_answer(question, context, prompt, llm):
    qa_prompt = ChatPromptTemplate.from_messages(
        [
            ("system", prompt),
            ("human", '''
            Context: {context}
            Question: {question}
            Output:
            '''),
        ]
    )

    answer_chain = qa_prompt | llm

    answer = answer_chain.invoke({'question': question, 'context': context})

    return answer.content

def process_llm_response(llm_response):
    print(llm_response['result'])
    print('\n\nSources:')
    for source in llm_response["source_documents"]:
        print(source.metadata['source'])