app.py

import os 
import gradio as gr

from langchain.document_loaders import PDFMinerLoader,CSVLoader ,UnstructuredWordDocumentLoader,TextLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.embeddings import SentenceTransformerEmbeddings
from langchain.vectorstores import FAISS
from langchain import HuggingFaceHub
from langchain.chains import RetrievalQA
from langchain.prompts import PromptTemplate

DEVICE = 'cpu'
FILE_EXT = ['pdf','text','csv','word','wav']


def loading_file():
    return "Loading..."


def get_openai_chat_model(API_key):
    try:
        from langchain.llms import OpenAI
    except ImportError as err:
        raise "{}, unable to load openAI. Please install openai and add OPENAIAPI_KEY"
    os.environ["OPENAI_API_KEY"] = API_key
    llm = OpenAI()
    return llm

def process_documents(documents,data_chunk=1000,chunk_overlap=50):
    text_splitter = RecursiveCharacterTextSplitter(chunk_size=data_chunk, chunk_overlap=chunk_overlap)
    texts = text_splitter.split_documents(documents[0])
    return texts

def get_hugging_face_model(model_id,API_key,temperature=0.1):
    chat_llm = HuggingFaceHub(huggingfacehub_api_token=API_key,
                                      repo_id=model_id,
                                      model_kwargs={"temperature": temperature, "max_new_tokens": 2048})
    return chat_llm

def chat_application(llm_service,key):
    if llm_model == 'HuggingFace':
        llm = get_hugging_face_model(model_id='tiiuae/falcon-7b-instruct',API_key=key)
    else:
        llm_model = get_openai_chat_model(API_key=key)


def document_loader(file_data,api_key,doc_type='pdf',llm='Huggingface'):
    embedding_model = SentenceTransformerEmbeddings(model_name='all-mpnet-base-v2',model_kwargs={"device": DEVICE})
    document = None
    if doc_type == 'pdf':
        document = process_pdf_document(document_file_name=file_data)
    elif doc_type == 'text':
        document = process_text_document(document_file_name=file_data)
    elif doc_type == 'csv':
        document = process_csv_document(document_file_name=file_data)
    elif doc_type == 'word':
        document = process_word_document(document_file_name=file_data)
    print(document)
    if document:
        texts = process_documents(documents=document)
        vector_db = FAISS.from_documents(documents=texts, embedding= embedding_model)
        global qa 
        qa = RetrievalQA.from_chain_type(llm=chat_application(llm_service=llm,key=api_key),
                                     chain_type='stuff',
                                     retriever=vector_db.as_retriever(),
                                    #  chain_type_kwargs=chain_type_kwargs,
                                     return_source_documents=True
                                     )
    else:
        return "Error in loading Documents "
    
    return "Ready..."

        
def process_text_document(document_file_name):
    loader = TextLoader(document_file_name)
    document = loader.load()
    return document


def process_csv_document(document_file_name):
    loader = CSVLoader(file_path=document_file_name)
    document = loader.load()
    return document


def process_word_document(document_file_name):
    loader = UnstructuredWordDocumentLoader(file_path=document_file_name)
    document = loader.load()
    return document


def process_pdf_document(document_file_name):
    loader = PDFMinerLoader(document_file_name)
    document = loader.load()[0]
    return document



css="""
#col-container {max-width: 700px; margin-left: auto; margin-right: auto;}
"""

title = """
<div style="text-align: center;max-width: 700px;">
    <h1>Chat with Data • OpenAI/HuggingFace</h1>
    <p style="text-align: center;">Upload a file from your computer, click the "Load data to LangChain" button, <br />
    when everything is ready, you can start asking questions about the data you uploaded ;) <br />
    This version is just for QA retrival so it will not use chat history, and uses Hugging face as LLM, 
    so you don't need any key</p>
</div>
"""

with gr.Blocks(css=css) as demo:
    with gr.Column(elem_id="col-container"):
        gr.HTML(title)
        
        with gr.Column():
            with gr.Box():
                LLM_option = gr.Dropdown(['HuggingFace','OpenAI'],label='Large Language Model Selection',info='LLM Service')
                API_key = gr.Textbox(label="Add {} API key".format(LLM_option), type="password")
            with gr.Column():
                with gr.Row():
                    file_extension = gr.Dropdown(FILE_EXT, label="File Extensions", info="Select your files extensions!")
                    pdf_doc = gr.File(label="Upload File to start QA", file_types=FILE_EXT, type="file")
                with gr.Row():
                    load_pdf = gr.Button("Load file to langchain")
                    langchain_status = gr.Textbox(label="Status", placeholder="", interactive=True)
        
        chatbot = gr.Chatbot()
        question = gr.Textbox(label="Question", placeholder="Type your question and hit Enter")
        submit_button = gr.Button("Send Message")
    load_pdf.click(loading_file, None, langchain_status, queue=False)    
    load_pdf.click(document_loader, inputs=[pdf_doc,file_extension,API_key], outputs=[langchain_status], queue=False)
    
    # question.submit(add_text, [chatbot, question], [chatbot, question]).then(
    #     bot, chatbot, chatbot
    # )

demo.launch()