app.py

import tempfile
import os
import tiktoken
import streamlit as st

from llama_index.llms.gemini import Gemini
from llama_index.llms.huggingface import HuggingFaceLLM
from llama_index.llms.mistralai import MistralAI
from llama_index.llms.openai import OpenAI

from llama_index.embeddings.openai import OpenAIEmbedding

from llama_index.core import (
    VectorStoreIndex,
    Settings,
)

from llama_parse import LlamaParse

from streamlit_pdf_viewer import pdf_viewer

def main():
    with st.sidebar:
        st.title('Document Summarization and QA System')
        # st.markdown('''
        # ## About this application
        # Upload a pdf to ask questions about it. This retrieval-augmented generation (RAG) workflow uses:
        # - [Streamlit](https://streamlit.io/)
        # - [LlamaIndex](https://docs.llamaindex.ai/en/stable/)
        # - [OpenAI](https://platform.openai.com/docs/models)
        # ''')

        # st.write('Made by ***Nate Mahynski***')
        # st.write('nathan.mahynski@nist.gov')

        # Select Provider
        provider = st.selectbox(
            label="Select LLM Provider",
            options=['google', 'huggingface', 'mistralai', 'openai'],
            index=3
        )

        # Select LLM
        if provider == 'google':
            llm_list = ['gemini']
        elif provider == 'huggingface':
            llm_list = []
        elif provider == 'mistralai':
            llm_list =[]
        elif provider == 'openai':
            llm_list = ['gpt-3.5-turbo', 'gpt-4', 'gpt-4-turbo', 'gpt-4o', 'gpt-4o-mini']
        else:
            llm_list = []

        llm_name = st.selectbox(
            label="Select LLM Model",
            options=llm_list,
            index=0
        )

        # Temperature
        temperature = st.slider(
            "Temperature",
            min_value=0.0, 
            max_value=1.0, 
            value=0.0, 
            step=0.05, 
        )

        max_output_tokens = 2048  

        # Enter LLM API Key
        llm_key = st.text_input(
            "Enter your LLM API Key",
            value=None,
        )

        # Create LLM
        # Global tokenization needs to be consistent with LLM for token counting
        # https://docs.llamaindex.ai/en/stable/module_guides/models/llms/
        if llm_key is not None:
            if provider == 'openai':
                os.environ["OPENAI_API_KEY"] = str(llm_key)
                Settings.llm = OpenAI(
                    model=llm_name, 
                    temperature=temperature,
                    max_tokens=max_output_tokens
                )
                Settings.tokenizer = tiktoken.encoding_for_model(llm_name).encode
                Settings.num_output = max_output_tokens
                Settings.context_window = 4096 # max possible
                Settings.embed_model = OpenAIEmbedding()
            elif provider == 'huggingface':
                os.environ['HFTOKEN'] = str(llm_key)

        # Enter Parsing API Key
        parse_key = st.text_input(
            "Enter your LlamaParse API Key",
            value=None,
        )

        uploaded_file = st.file_uploader(
            "Choose a PDF file to upload", 
            type=['pdf'], 
            accept_multiple_files=False
        )

        parsed_document = None
        if uploaded_file is not None:
            # Parse the file
            parser = LlamaParse(
                api_key=parse_key,  # Can also be set in your env as LLAMA_CLOUD_API_KEY
                result_type="text"  # "markdown" and "text" are available
            )

            # Create a temporary directory to save the file then load and parse it
            temp_dir = tempfile.TemporaryDirectory()
            temp_filename = os.path.join(temp_dir.name, uploaded_file.name)
            with open(temp_filename, "wb") as f:
                f.write(uploaded_file.getvalue())
            parsed_document = parser.load_data(temp_filename)
            temp_dir.cleanup()

    col1, col2 = st.columns(2)

    with col1:
        st.markdown(
            """
            # Instructions

            1. Obtain an [API Key](https://cloud.llamaindex.ai/api-key) from LlamaParse to parse your document. 
            2. Obtain a similar API Key from your preferred LLM provider.
            3. Make selections at the left and upload a document to use a context.
            4. Begin asking questions below!
            """
        )

        st.divider()

        prompt_txt = 'Summarize this document in a 3-5 sentences.'
        prompt = st.text_area(
            label="Enter your query.",
            key="prompt_widget",
            value=prompt_txt
        )

        if parsed_document is not None:
            index = VectorStoreIndex.from_documents(parsed_document)
            query_engine = index.as_query_engine()
            response = query_engine.query(prompt)
            st.write(response.response)

    with col2:
        tab1, tab2 = st.tabs(["Uploaded File", "Parsed File",])

        with tab1:
            if uploaded_file is not None: # Display the pdf
                bytes_data = uploaded_file.getvalue()
                pdf_viewer(input=bytes_data, width=700)    
        
        with tab2:
            if parsed_document is not None: # Showed the raw parsing result
                st.write(parsed_document)

if __name__ == '__main__':
    # Global configurations
    from llama_index.core import set_global_handler
    set_global_handler("langfuse")
    st.set_page_config(layout="wide")

    main()