app.py

from sentence_transformers import SentenceTransformer
from PyPDF2 import PdfReader
from uuid import uuid4
from uuid import UUID
import os
from astrapy.db import AstraDB
import gradio as gr
from dotenv import load_dotenv
load_dotenv() 
from openai import OpenAI
client = OpenAI()


# Initialization
db = AstraDB(
    token=os.environ["ASTRA_DB_APPLICATION_TOKEN"],
    api_endpoint=os.environ["ASTRA_DB_API_ENDPOINT"],
)

model = SentenceTransformer('BAAI/bge-base-en-v1.5')

def get_embeddings(text):
    embeddings_1 = model.encode(text, normalize_embeddings=True)
    return embeddings_1.tolist()
        
def query(ques, col):
    emb = get_embeddings(ques)
    results = col.vector_find(emb, limit=2, fields={"text", "$vector"})
    return results

def read_pdf(pdf_path):
    reader = PdfReader(pdf_path)
    pdf_content = ""
    for i in range(len(reader.pages)):
        pdf_content += reader.pages[i].extract_text()
    return pdf_content
    
def create_chunks(content):
    batch_size = 1000
    overlap_size = 100

    chunks = []

    for i in range(0, len(content), batch_size - overlap_size):
        chunk = content[i:i + batch_size]
        chunks.append(chunk)

    return chunks

def create_docs(chunks):
    documents = []
    for i in (range(len(chunks))) :
        mydict = {
            "_id" : i+1,
            "text" : chunks[i],
            "$vector" : get_embeddings(chunks[i])
            }
        documents.append(mydict)
    return documents

def create_and_insert_docs(docs):
    user_id = str(uuid4())
    col = db.create_collection(f"user_{UUID(user_id).hex}", dimension=768, metric="cosine")
    res = col.insert_many(docs, partial_failures_allowed=True)
    return col

def get_answer(context, query):
    response = client.chat.completions.create(
    model="gpt-3.5-turbo",
    messages=[
        {
        "role": "system",
        "content": "You are a document mining bot createed by Kanva Bhatia and Kanjika Singh. You will given a user query, and user context. You have to give the reply to the user's query if the query's answer is in the context. If it isn't you reply with \"I don't know\""
        },
        {
        "role": "user",
        "content": f"Below is a context and a query, reply from the context if the answer is there in the context, otherwise say I don't know.\nContext: {context}\nQuery: {query}"
        }
    ],
    temperature=0.3,
    max_tokens=2000,
    top_p=1,
    frequency_penalty=0,
    presence_penalty=0
    )
    return response.choices[0].message.content

def query(col, ques):
    q = get_embeddings(ques)
    results = col.vector_find(q, limit=2, fields={"text", "$vector"})
    context = ""
    for res in results:
        context += res['text'] + "\n"
    return get_answer(context, ques)

def delete_col(col):
    db.delete_collection(col.collection_name)

def pipeline(files, user_input):
    total_chunks = []
    for file in files:
        content = read_pdf(file.name)
        chunks = create_chunks(content)
        total_chunks.extend(chunks)
    docs = create_docs(total_chunks)
    try:
        col = create_and_insert_docs(docs)
        ans = query(col, user_input)
        delete_col(col)
    except Exception as e:
        print(e)
        return "Sorry, we can't query that document right now. Please try a different document."
    return ans 
chatbot_input = [gr.Files(label="Upload PDF Files"),gr.components.Textbox(label="User Input")]
chatbot_output = gr.components.Textbox(label="Chatbot Response")
article_mdx = """## About the bot
We created this bot using [DataStax AstraDB](https://www.datastax.com/products/datastax-astra) to store the vectors, and [BAAI/bge-base-en-v1.5](https://huggingface.co/BAAI/bge-base-en-v1.5) model to create embeddings, and [OpenAI's GPT-3.5-turbo](https://platform.openai.com/docs/models) for collecting the closest vectors and creating a human-friendly response.

## About the team
This product is created by [Kanjika Singh](https://www.linkedin.com/in/kanjika-singh/) and [Kanva Bhatia](https://www.linkedin.com/in/kanva-bhatia/).
"""
iface = gr.Interface(fn=pipeline, inputs=chatbot_input, outputs=chatbot_output, title="Chatbot Demo using DataStax AstraDB and OpenAI", description=article_mdx).queue()
iface.launch(debug=True, share = True)