app.py

import gradio as gr
from langchain_community.document_loaders import WebBaseLoader
from langchain_community.document_loaders import PyPDFLoader
from langchain_community.vectorstores import Chroma
from langchain_community import embeddings
from langchain_community.chat_models import ChatOllama
from langchain_core.runnables import RunnablePassthrough
from langchain_core.output_parsers import StrOutputParser
from langchain_core.prompts import ChatPromptTemplate
from langchain.output_parsers import PydanticOutputParser
from langchain.text_splitter import CharacterTextSplitter
from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.embeddings import HuggingFaceEmbeddings
from langchain.vectorstores import Chroma
from langchain_community.llms import HuggingFaceHub
from getpass import getpass
import os 

HUGGINGFACEHUB_API_TOKEN = os.getenv("hf_api")
os.environ["HUGGINGFACEHUB_API_TOKEN"] = HUGGINGFACEHUB_API_TOKEN

def process_input(urls, question):
    # model_local = ChatOllama(model="mistral")
    
    repo_id = "mistralai/Mistral-7B-Instruct-v0.2" 
    llm = HuggingFaceHub(
        repo_id=repo_id, 
    )
    model_local = llm
    # Convert string of URLs to list
    # urls_list = urls.split("\n")
    if urls:
        urls_list = urls.split("\n")
    else:
        urls_list = [
    "https://ollama.com/",
    "https://ollama.com/blog/windows-preview",
    "https://ollama.com/blog/openai-compatibility",
    ]

    link_list_path = "./shef_extracted_links.txt"
    with open(link_list_path, "r") as f:
        link_list = [l.strip() for l in f.readlines()]
    urls_list += link_list

    docs = [WebBaseLoader(url).load() for url in urls_list]
    docs_list = [item for sublist in docs for item in sublist]
    
    # print(docs_list)
    loader = PyPDFLoader("./doc.pdf")

    pages = loader.load_and_split()

    text_splitter = CharacterTextSplitter.from_tiktoken_encoder(chunk_size=7500, chunk_overlap=100)
    doc_init = text_splitter.split_documents(pages)
    doc_splits = text_splitter.split_documents(docs_list)

    doc_new = doc_init + doc_splits
    # doc_new = doc_splits


    vectorstore = Chroma.from_documents(
        documents=doc_new,
        collection_name="rag-chroma",
        embedding=embeddings.ollama.OllamaEmbeddings(model='nomic-embed-text'),
    )
    retriever = vectorstore.as_retriever()

    # after_rag_template = """Answer the question based only on the following context:
    # {context}
    # Question: {question}
    # """

    after_rag_template = """ Using the contexts below, answer the question.
    contexts:
    {context}
    Question: {question}
    """

    after_rag_prompt = ChatPromptTemplate.from_template(after_rag_template)
    after_rag_chain = (
        {"context": lambda x:retriever, "question": RunnablePassthrough()}
        | after_rag_prompt
        | model_local
        | StrOutputParser()
    )
    return after_rag_chain.invoke(question).split(f'Question: {question}')[1]

# Define Gradio interface
iface = gr.Interface(fn=process_input,
                     inputs=[gr.Textbox(label="Enter URLs separated by new lines"), gr.Textbox(label="Question")],
                     outputs="text",
                     title="ChatAcadamy with Mistral",
                     description="Enter URLs and a question to query the documents.")
iface.launch()