app.py

import subprocess

subprocess.run(["pip", "install", "--upgrade", "transformers[torch,sentencepiece]==4.34.1"])

import logging
from pathlib import Path
from time import perf_counter

import gradio as gr
from jinja2 import Environment, FileSystemLoader

from backend.query_llm import generate_hf, generate_openai
from backend.semantic_search import table, retriever, ranker

proj_dir = Path(__file__).parent
# Setting up the logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Set up the template environment with the templates directory
env = Environment(loader=FileSystemLoader(proj_dir / 'templates'))

# Load the templates directly from the environment
template = env.get_template('template.j2')
template_html = env.get_template('template_html.j2')

# Examples
examples = ['What is the capital of China?',
            'Why is the sky blue?',
            'Who won the mens world cup in 2014?', ]


def add_text(history, text):
    history = [] if history is None else history
    history = history + [(text, None)]
    return history, gr.Textbox(value="", interactive=False)


def bot(history, use_ranker, api_kind):
    top_k_rank = 4
    top_k_retrieve = 40
    query = history[-1][0]

    if not query:
         gr.Warning("Please submit a non-empty string as a prompt")
         raise ValueError("Empty string was submitted")

    logger.warning('Retrieving documents...')
    # Retrieve documents relevant to query
    document_start = perf_counter()
    if use_ranker:
        query_vec = retriever.encode(query)
        documents = table.search(query_vec, vector_column_name="embedding").limit(top_k_retrieve).to_list()
        documents = [doc["text"] for doc in documents]
        pairs = [(query, doc) for doc in documents]
        scores = ranker.predict(pairs, batch_size=8)
        documents = [doc for _, doc in sorted(zip(scores, documents))[-top_k_rank:]]
    else:
        query_vec = retriever.encode(query)
        documents = table.search(query_vec, vector_column_name="embedding").limit(top_k_rank).to_list()
        documents = [doc["text"] for doc in documents]

    document_time = perf_counter() - document_start
    logger.warning(f'Finished Retrieving documents in {round(document_time, 2)} seconds...')

    # Create Prompt
    prompt = template.render(documents=documents, query=query)
    prompt_html = template_html.render(documents=documents, query=query)

    if api_kind == "HuggingFace":
         generate_fn = generate_hf
    elif api_kind == "OpenAI":
         generate_fn = generate_openai
    elif api_kind is None:
         gr.Warning("API name was not provided")
         raise ValueError("API name was not provided")
    else:
         gr.Warning(f"API {api_kind} is not supported")
         raise ValueError(f"API {api_kind} is not supported")

    history[-1][1] = ""
    for character in generate_fn(prompt, history[:-1]):
        history[-1][1] = character
        yield history, prompt_html


with gr.Blocks() as demo:
    # with gr.Tab("RAGDemo"):
        chatbot = gr.Chatbot(
                [],
                elem_id="chatbot",
                avatar_images=('https://aui.atlassian.com/aui/8.8/docs/images/avatar-person.svg',
                               'https://huggingface.co/datasets/huggingface/brand-assets/resolve/main/hf-logo.svg'),
                bubble_full_width=False,
                show_copy_button=True,
                show_share_button=True,
                )

        with gr.Row():
            txt = gr.Textbox(
                    scale=3,
                    show_label=False,
                    placeholder="Enter text and press enter",
                    container=False,
                    )
            txt_btn = gr.Button(value="Submit text", scale=1)

        cb = gr.Checkbox(label="Use cross-encoder", info="Rerank after retrieval?")
        api_kind = gr.Radio(choices=["HuggingFace", "OpenAI"], value="HuggingFace")

        prompt_html = gr.HTML()
        # Turn off interactivity while generating if you click
        txt_msg = txt_btn.click(add_text, [chatbot, txt], [chatbot, txt], queue=False).then(
                bot, [chatbot, cb, api_kind], [chatbot, prompt_html])

        # Turn it back on
        txt_msg.then(lambda: gr.Textbox(interactive=True), None, [txt], queue=False)

        # Turn off interactivity while generating if you hit enter
        txt_msg = txt.submit(add_text, [chatbot, txt], [chatbot, txt], queue=False).then(
                bot, [chatbot, cb, api_kind], [chatbot, prompt_html])

        # Turn it back on
        txt_msg.then(lambda: gr.Textbox(interactive=True), None, [txt], queue=False)

        # Examples
        gr.Examples(examples, txt)

demo.queue()
demo.launch(debug=True)