app.py

import os
import json
import numpy as np
import streamlit as st
from sentence_transformers import SentenceTransformer
from openai import OpenAI
import random
import prompts


# client = OpenAI(api_key=st.secrets["general"]["OpenAI_API"])
client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))

st.set_page_config(page_title="The AI Teaching Assistant")

def generate_YT_file_names(base_path, embedding_model_name, chunk_tokens, overlap_tokens):
    embedding_space_file_name = f'{base_path}/yt_embedding_space_{embedding_model_name}_tpc{chunk_tokens}_o{overlap_tokens}.json'
    with open(embedding_space_file_name, 'r') as json_file:
        loaded_data = json.load(json_file)
    
    embedding_space = np.array(loaded_data['embedding_space'])
    return loaded_data['chunks'], embedding_space

def generate_Latex_file_names(base_path, embedding_model_name, chunk_tokens, overlap_tokens):
    embedding_space_file_name = f'{base_path}/latex_embedding_space_by_sections_{embedding_model_name}_tpc{chunk_tokens}_o{overlap_tokens}.json'
    with open(embedding_space_file_name, 'r') as json_file:
        loaded_data = json.load(json_file)
    
    embedding_space = np.array(loaded_data['embedding_space'])
    return loaded_data['chunks'], embedding_space

@st.cache_resource
def load_text_data(json_file_name):
    with open(json_file_name, 'r') as f:
        data = json.load(f)
    return data


@st.cache_resource
def load_embeddings(npy_file_name):
    return np.load(npy_file_name)

@st.cache_resource
def load_model(model_name):
    return SentenceTransformer(model_name)

@st.cache_resource
def load_summary(file_path):
    with open(file_path, 'r') as file:
        transcripts = json.load(file)
    return transcripts


def embed_question_openai(texts, model="text-embedding-3-small"):
    response = client.embeddings.create(
        input=texts,
        model=model
    )
    return np.array(response.data[0].embedding)

def embed_question(question, embedding_model):
    if embedding_model == "text-embedding-3-small":
        return embed_question_openai(question, embedding_model)
    else:
        return embedding_model.encode(question, convert_to_numpy=True)
    
def fixed_knn_retrieval(question_embedding, context_embeddings, top_k=5, min_k=1):
    
    # Normalize 
    question_embedding = question_embedding / np.linalg.norm(question_embedding)
    context_embeddings = context_embeddings / np.linalg.norm(context_embeddings, axis=1, keepdims=True)
    
    # Calculate cosine similarities between the question embedding and all context embeddings.
    similarities = np.dot(context_embeddings, question_embedding)
    # Sort the similarities in descending order and get the corresponding indices.
    sorted_indices = np.argsort(similarities)[::-1]
    # Select the top_k most similar contexts, ensuring at least min_k contexts are selected.
    selected_indices = sorted_indices[:max(top_k, min_k)].tolist()
    return selected_indices

def sec_to_time(start_time):
    return f"{start_time // 60:02}:{start_time % 60:02}"

st.markdown("""
    <style>
    .video-wrapper {
        position: relative;
        padding-bottom: 56.25%;
        height: 0;
    }
    .video-wrapper iframe {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
    }
    </style>
    """, unsafe_allow_html=True)

def get_youtube_embed(video_id, start_time=0, autoplay=0):
    embed_code = f'''
    <div class="video-wrapper">
        <iframe src="https://www.youtube.com/embed/{video_id}?start={start_time}&autoplay={autoplay}&rel=0" 
        frameborder="0" allowfullscreen></iframe>
    </div>
    '''
    return embed_code


disclaimer_contact =""":gray[AI Teaching Assistant is developed at the University of Southern California by Mostafa Faghih Shojaei, Rahul Gulati, Benjamin Jasperson, Shangshang Wang, Simone Cimolato, Dangli Cao, Willie Neiswanger, and Krishna Garikipati.]

:gray[**Main Data Sources:**] [Introduction to Finite Element Methods (FEM) by Prof. Krishna Garikipati](https://www.youtube.com/playlist?list=PLJhG_d-Sp_JHKVRhfTgDqbic_4MHpltXZ) :gray[and] [The Finite Element Method: Linear Static and Dynamic Finite Element Analysis by Thomas J. R. Hughes](https://www.google.com/books/edition/_/cHH2n_qBK0IC?hl=en).

:gray[**Disclaimer and Copyright Notice:**] :gray[1. AI-Generated Responses: Answers are generated using AI and, while thorough, may not always be 100% accurate. Please verify the information independently. 2. Content Ownership: All video content and lecture material referenced belong to their original creators. We encourage users to view the original material on verified platforms to ensure authenticity and accuracy. 3. Educational Fair Use: This tool is intended solely for educational purposes and operates under the principles of fair use. It is not authorized for commercial applications.]

:gray[For any questions, concerns, or feedback about this application, please contact the development team directly.]
"""

# ---------------------------------------


base_path = "data/"

st.title(":red[AI Teaching Assistant]")
# st.markdown("### Finite Element Methods")
# st.markdown("### Based on Introduction to Finite Element Methods (FEM) by Prof. Krishna Garikipati")
# st.markdown("##### [YouTube playlist of the FEM lectures](https://www.youtube.com/playlist?list=PLJhG_d-Sp_JHKVRhfTgDqbic_4MHpltXZ)")

st.markdown(":gray[Welcome to] :red[AI Teaching Assistant]:gray[, developed at the] :red[University of Southern California]:gray[. This app leverages AI to provide expert answers to queries related to] :red[Finite Element Methods (FEM)]:gray[.]")

# As the content is AI-generated, we strongly recommend independently verifying the information provided. 

st.markdown(" ")
st.markdown(" ")
# st.divider()
# Sidebar for settings
with st.sidebar:
    st.header("Settings")
    # with st.container(border=True):
    # Embedding model

    model_name = st.selectbox("Choose content embedding model", [
        "text-embedding-3-small",
        # "text-embedding-3-large",
        # "all-MiniLM-L6-v2", 
        # "all-mpnet-base-v2"
    ], 
    # help="""
    # Select the embedding model to use for encoding the retrieved text data. 
    # Options include OpenAI's `text-embedding-3` models and two widely
    # used SentenceTransformers models.
    # """
    )
    
    with st.container(border=True):
        st.write('**Video lectures**')
        yt_token_choice = st.select_slider("Token per content", [256, 512, 1024], value=256, help="Larger values lead to an increase in the length of each retrieved piece of content", key="yt_token_len")
        yt_chunk_tokens = yt_token_choice
        yt_max_content = {128: 32, 256: 16, 512: 8, 1024: 4}[yt_chunk_tokens]
        top_k_YT = st.slider("Number of relevant content pieces to retrieve", 0, yt_max_content, 4, key="yt_token_num")
        yt_overlap_tokens = yt_chunk_tokens // 4

    # st.divider()
    with st.container(border=True):
        st.write('**Textbook**')
        show_textbook = False
        # show_textbook = st.toggle("Show Textbook Content", value=False)
        latex_token_choice = st.select_slider("Token per content", [128, 256, 512, 1024], value=256, help="Larger values lead to an increase in the length of each retrieved piece of content", key="latex_token_len")
        latex_chunk_tokens = latex_token_choice
        latex_max_content = {128: 32, 256: 16, 512: 8, 1024: 4}[latex_chunk_tokens]
        top_k_Latex = st.slider("Number of relevant content pieces to retrieve", 0, latex_max_content, 4, key="latex_token_num")
        # latex_overlap_tokens = latex_chunk_tokens // 4
        latex_overlap_tokens = 0

    st.write(' ')
    with st.expander('Expert model',expanded=False):
        # st.write('**Expert model**')
        # with st.container(border=True):
        # Choose the LLM model

        use_expert_answer = st.toggle("Use expert answer", value=True)
        show_expert_responce = st.toggle("Show initial expert answer", value=False)

        model = st.selectbox("Choose the LLM model", ["gpt-4o-mini", "gpt-3.5-turbo"], key='a1model')

        # Temperature
        expert_temperature = st.slider("Temperature", 0.0, 0.3, .2,  help="Defines the randomness in the next token prediction. Lower: More predictable and focused. Higher: More adventurous and diverse.", key='a1t')

        expert_top_p = st.slider("Top P", 0.1, 0.3, 0.1, help="Defines the range of token choices the model can consider in the next prediction. Lower: More focused and restricted to high-probability options. Higher: More creative, allowing consideration of less likely options.", key='a1p')
        

    with st.expander('Synthesis model',expanded=False):

        # with st.container(border=True):
        # Choose the LLM model
        model = st.selectbox("Choose the LLM model", ["gpt-4o-mini", "gpt-3.5-turbo"], key='a2model')

        # Temperature
        integration_temperature = st.slider("Temperature", 0.0, .3, .5, help="Defines the randomness in the next token prediction. Lower: More predictable and focused. Higher: More adventurous and diverse.", key='a2t')

        integration_top_p = st.slider("Top P", 0.1, 0.5, .3, help="Defines the range of token choices the model can consider in the next prediction. Lower: More focused and restricted to high-probability options. Higher: More creative, allowing consideration of less likely options.", key='a2p')

        

# Main content area
if "question" not in st.session_state:
    st.session_state.question = ""

def get_random_question():
    with open(base_path + "/questions.txt", "r") as file:
        questions = [line.strip() for line in file]
    return random.choice(questions)

text_area_placeholder = st.empty()
question_help = "Including details or instructions improves the answer."
st.session_state.question = text_area_placeholder.text_area(
    "**Enter your question/query about Finite Element Method**",
    height=120,
    value=st.session_state.question,
    help=question_help
)

_, col1, col2, _ = st.columns([4, 2, 4, 3]) 
with col1:
    submit_button_placeholder = st.empty()

with col2:
    if st.button("Random Question"):
        while True:
            random_question = get_random_question()
            if random_question != st.session_state.question:
                break
        st.session_state.question = random_question
        text_area_placeholder.text_area(
            "**Enter your question:**",
            height=120,
            value=st.session_state.question,
            help=question_help
        )

# Load YouTube and LaTeX data
text_data_YT, context_embeddings_YT = generate_YT_file_names(base_path, model_name, yt_chunk_tokens, yt_overlap_tokens)
text_data_Latex, context_embeddings_Latex = generate_Latex_file_names(base_path, model_name, latex_chunk_tokens, latex_overlap_tokens)

summary = load_summary('data/KG_FEM_summary.json')

if 'question_answered' not in st.session_state:
    st.session_state.question_answered = False
if 'context_by_video' not in st.session_state:
    st.session_state.context_by_video = {}
if 'context_by_section' not in st.session_state:
    st.session_state.context_by_section = {}
if 'answer' not in st.session_state:
    st.session_state.answer = ""
if 'playing_video_id' not in st.session_state:
    st.session_state.playing_video_id = None

if submit_button_placeholder.button("AI Answer", type="primary"): 
    if st.session_state.question != "":
        with st.spinner("Finding relevant contexts..."):
            question_embedding = embed_question(st.session_state.question, model_name)
            initial_max_k = int(0.1 * context_embeddings_YT.shape[0])
            idx_YT = fixed_knn_retrieval(question_embedding, context_embeddings_YT, top_k=top_k_YT, min_k=0)
            idx_Latex = fixed_knn_retrieval(question_embedding, context_embeddings_Latex, top_k=top_k_Latex, min_k=0)

        with st.spinner("Answering the question..."):
            relevant_contexts_YT = sorted([text_data_YT[i] for i in idx_YT], key=lambda x: x['order'])
            relevant_contexts_Latex = sorted([text_data_Latex[i] for i in idx_Latex], key=lambda x: x['order'])

            st.session_state.context_by_video = {}
            for context_item in relevant_contexts_YT:
                video_id = context_item['video_id']
                if video_id not in st.session_state.context_by_video:
                    st.session_state.context_by_video[video_id] = []
                st.session_state.context_by_video[video_id].append(context_item)

            st.session_state.context_by_section = {}
            for context_item in relevant_contexts_Latex:
                section_id = context_item['section']
                if section_id not in st.session_state.context_by_section:
                    st.session_state.context_by_section[section_id] = []
                st.session_state.context_by_section[section_id].append(context_item)

            context = ''
            for i, (video_id, contexts) in enumerate(st.session_state.context_by_video.items(), start=1):
                for context_item in contexts:
                    start_time = int(context_item['start'])
                    context += f'Video {i}, time: {sec_to_time(start_time)}:' + context_item['text'] + '\n\n'

            for i, (section_id, contexts) in enumerate(st.session_state.context_by_section.items(), start=1):
                context += f'Section {i} ({section_id}):\n'
                for context_item in contexts:
                    context += context_item['text'] + '\n\n'
            
            if use_expert_answer:
                st.session_state.expert_answer = prompts.openai_domain_specific_answer_generation("Finite Element Method", st.session_state.question, model=model, temperature=expert_temperature, top_p=expert_top_p)
            else:
                st.session_state.expert_answer = 'No Expert Answer. Only use the context.'
            answer = prompts.openai_context_integration("Finite Element Method", st.session_state.question, st.session_state.expert_answer, context, model=model, temperature=integration_temperature, top_p=integration_top_p)

        if answer.split()[0] == "NOT_ENOUGH_INFO":
            st.markdown("")
            st.markdown("#### Query:")
            st.markdown(prompts.fix_latex(st.session_state.question))
            if show_expert_responce:
                st.markdown("#### Initial Expert Answer:")
                st.markdown(st.session_state.expert_answer)
            st.markdown("#### Answer:")
            st.write(":smiling_face_with_tear:")
            st.markdown(answer.split('NOT_ENOUGH_INFO')[1])
            st.divider()
            st.caption(disclaimer_contact)
            # st.caption("The AI Teaching Assistant project")
            st.session_state.question_answered = False
            st.stop()   
        else:
            st.session_state.answer = answer

        st.session_state.question_answered = True

    else:
        st.markdown("")
        st.write("Please enter a question. :smirk:")
        st.session_state.question_answered = False

if st.session_state.question_answered:
    st.markdown("")
    st.markdown("#### Query:")
    st.markdown(prompts.fix_latex(st.session_state.question))
    if show_expert_responce:
        st.markdown("#### Initial Expert Answer:")
        st.markdown(st.session_state.expert_answer)
    st.markdown("#### Answer:")
    st.markdown(st.session_state.answer)
    
    if top_k_YT > 0:
        st.markdown("#### Retrieved content in lecture videos")
        for i, (video_id, contexts) in enumerate(st.session_state.context_by_video.items(), start=1):
            # with st.expander(f"**Video {i}** | {contexts[0]['title']}", expanded=True):
            with st.container(border=True):
                st.markdown(f"**Video {i} | {contexts[0]['title']}**")
                video_placeholder = st.empty()
                video_placeholder.markdown(get_youtube_embed(video_id, 0, 0), unsafe_allow_html=True)
                st.markdown('')
                with st.container(border=False):
                    st.markdown("Retrieved Times")
                    cols = st.columns([1 for i in range(len(contexts))] + [9 - len(contexts)])
                    for j, context_item in enumerate(contexts):
                        start_time = int(context_item['start'])
                        label = sec_to_time(start_time)
                        if cols[j].button(label, key=f"{video_id}_{start_time}"):
                            if st.session_state.playing_video_id is not None:
                                st.session_state.playing_video_id = None
                                video_placeholder.empty()
                            video_placeholder.markdown(get_youtube_embed(video_id, start_time, 1), unsafe_allow_html=True)
                            st.session_state.playing_video_id = video_id
                
                with st.expander("Video Summary", expanded=False):
                    # st.write("##### Video Overview:")
                    st.markdown(summary[video_id])

    if show_textbook and top_k_Latex > 0:
        st.markdown("#### Retrieved content in textbook",help="The Finite Element Method: Linear Static and Dynamic Finite Element Analysis")
        for i, (section_id, contexts) in enumerate(st.session_state.context_by_section.items(), start=1):
            # with st.expander(f"**Section {i} | {section_id}**", expanded=True):
            st.markdown(f"**Section {i} | {section_id}**")
            for context_item in contexts:
                st.markdown(context_item['text'])
                st.divider()

st.markdown(" ")
st.divider()
st.caption(disclaimer_contact)