app.py

import gradio as gr
import json
from sentence_transformers import SentenceTransformer
from transformers import pipeline
from sklearn.metrics.pairwise import cosine_similarity
import numpy as np
import os

# === Custom PUP-themed CSS ===
PUP_Themed_css = """
html, body, .gradio-container, .gr-app {
    height: 100% !important;
    margin: 0 !important;
    padding: 0 !important;
    background: linear-gradient(to bottom right, #800000, #ff0000, #ffeb3b, #ffa500) !important;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif !important;
    color: #1b4332 !important;
}
"""

# === Load Models and Data ===
embedding_model = SentenceTransformer('paraphrase-mpnet-base-v2')
llm = pipeline("text2text-generation", model="google/flan-t5-small")

with open("dataset.json", "r") as f:
    dataset = json.load(f)

questions = [item["question"] for item in dataset]
answers = [item["answer"] for item in dataset]
question_embeddings = embedding_model.encode(questions, convert_to_tensor=True)

chat_history = []
feedback_data = []
feedback_questions = []
feedback_answers = []
feedback_embeddings = None

if os.path.exists("feedback.json") and os.path.getsize("feedback.json") > 0:
    with open("feedback.json", "r") as f:
        try:
            feedback_data = json.load(f)
            feedback_questions = [item["question"] for item in feedback_data]
            feedback_answers = [item["response"] for item in feedback_data]
            if feedback_questions:
                feedback_embeddings = embedding_model.encode(feedback_questions, convert_to_tensor=True)
        except json.JSONDecodeError:
            feedback_data = []

# === Chatbot Response Function ===
def chatbot_response(query, chat_history):
    query_embedding = embedding_model.encode([query], convert_to_tensor=True)

    # === Feedback Matching ===
    if feedback_embeddings is not None:
        feedback_scores = cosine_similarity(query_embedding.cpu().numpy(), feedback_embeddings.cpu().numpy())[0]
        best_idx = int(np.argmax(feedback_scores))
        best_score = feedback_scores[best_idx]
        matched_feedback = feedback_data[best_idx]

        base_threshold = 0.8
        upvotes = matched_feedback.get("upvotes", 0)
        downvotes = matched_feedback.get("downvotes", 0)
        adjusted_threshold = base_threshold - (0.01 * upvotes) + (0.01 * downvotes)
        dynamic_threshold = min(max(adjusted_threshold, 0.4), 1.0)

        if best_score >= dynamic_threshold:
            response = matched_feedback["response"]
            chat_history.append((query, response))
            return "", chat_history, gr.update(visible=True)

    # === Main Handbook Matching ===
    similarity_scores = cosine_similarity(query_embedding.cpu().numpy(), question_embeddings.cpu().numpy())[0]
    best_idx = int(np.argmax(similarity_scores))
    best_score = similarity_scores[best_idx]
    matched_q = questions[best_idx]
    matched_a = answers[best_idx]

    if best_score < 0.4:
        response = "Sorry, I couldn't find a relevant answer."
        chat_history.append((query, response))
        return "", chat_history, gr.update(visible=True)

    prompt = (
        f"The following is an official university handbook statement:\n"
        f"\"{matched_a}\"\n\n"
        f"Please explain this to a student in a short, natural, and easy-to-understand way. "
        f"Use simple words, and do not add new information."
    )

    llm_response = llm(prompt, max_length=200, do_sample=True, temperature=0.7, top_p=0.9)[0]["generated_text"].strip()
    if not llm_response:
        llm_response = "I'm sorry, I couldn't simplify that at the moment."

    a_embedding = embedding_model.encode([matched_a], convert_to_tensor=True)
    llm_embedding = embedding_model.encode([llm_response], convert_to_tensor=True)
    explanation_similarity = cosine_similarity(a_embedding.cpu().numpy(), llm_embedding.cpu().numpy())[0][0]

    if explanation_similarity >= 0.95:
        final_response = f"According to the university handbook, {matched_a}"
    else:
        final_response = f"According to the university handbook, {matched_a} In simpler terms, {llm_response}"

    chat_history.append((query, final_response))
    return "", chat_history, gr.update(visible=True)

# === Feedback Save & Upvote/Downvote Tracking ===
def record_feedback(feedback, chat_history):
    global feedback_embeddings
    if chat_history:
        last_query, last_response = chat_history[-1]
        matched = False

        for item in feedback_data:
            existing_embedding = embedding_model.encode([item["question"]], convert_to_tensor=True)
            new_embedding = embedding_model.encode([last_query], convert_to_tensor=True)
            similarity = cosine_similarity(existing_embedding.cpu().numpy(), new_embedding.cpu().numpy())[0][0]
            if similarity >= 0.8 and item["response"] == last_response:
                matched = True
                votes = {"positive": "upvotes", "negative": "downvotes"}
                item[votes[feedback]] = item.get(votes[feedback], 0) + 1
                break

        if not matched:
            entry = {
                "question": last_query,
                "response": last_response,
                "feedback": feedback,
                "upvotes": 1 if feedback == "positive" else 0,
                "downvotes": 1 if feedback == "negative" else 0
            }
            feedback_data.append(entry)

        with open("feedback.json", "w") as f:
            json.dump(feedback_data, f, indent=4)

        # Update feedback embeddings
        feedback_questions = [item["question"] for item in feedback_data]
        if feedback_questions:
            feedback_embeddings = embedding_model.encode(feedback_questions, convert_to_tensor=True)

    return gr.update(visible=False)

# === Gradio UI ===
with gr.Blocks(css=PUP_Themed_css, title="University Handbook AI Chatbot") as demo:
    gr.Markdown(
        "<div style='"
        "background-color: #ffffff; "
        "border-radius: 16px; "
        "padding: 24px 16px; "
        "margin-bottom: 24px; "
        "box-shadow: 0 6px 16px rgba(0, 0, 0, 0.15); "
        "max-width: 700px; "
        "margin-left: auto; "
        "margin-right: auto; "
        "text-align: center;'>"
        "<h1 style='font-size: 2.2rem; margin: 0;'>University Inquiries AI Chatbot</h1>"
        "</div>"
    )

    state = gr.State(chat_history)
    chatbot_ui = gr.Chatbot(label="Chat", show_label=False)

    with gr.Row():
        query_input = gr.Textbox(placeholder="Type your question here...", show_label=False)
        submit_btn = gr.Button("Submit")

    with gr.Row(visible=False) as feedback_row:
        gr.Markdown("Was this helpful?")
        thumbs_up = gr.Button("👍")
        thumbs_down = gr.Button("👎")

    def handle_submit(message, chat_state):
        return chatbot_response(message, chat_state)

    submit_btn.click(handle_submit, [query_input, state], [query_input, chatbot_ui, feedback_row])
    query_input.submit(handle_submit, [query_input, state], [query_input, chatbot_ui, feedback_row])

    thumbs_up.click(lambda state: record_feedback("positive", state), inputs=[state], outputs=[feedback_row])
    thumbs_down.click(lambda state: record_feedback("negative", state), inputs=[state], outputs=[feedback_row])

# === Launch App ===
if __name__ == "__main__":
    demo.launch()