app.py

import os
import warnings
import gradio as gr
from dotenv import load_dotenv

from langchain.chains import ConversationalRetrievalChain
from langchain_community.vectorstores import FAISS
from langchain_openai import ChatOpenAI
from langchain_community.embeddings import OpenAIEmbeddings

# Patch Gradio bug (schema parsing issue)
import gradio_client.utils
gradio_client.utils.json_schema_to_python_type = lambda schema, defs=None: "string"



# Load environment variables
load_dotenv()
OPENAI_API_KEY = os.getenv("OPENAI_API_KEY_P") #or os.getenv("OPENAI_API_KEY_ROBO") 
if not OPENAI_API_KEY:
    raise ValueError("Missing OPENAI_API_KEY. Please set it in your environment variables.")


# Suppress warnings
warnings.filterwarnings("ignore")

# Initialize embedding model
embeddings = OpenAIEmbeddings(openai_api_key=OPENAI_API_KEY)

# Load FAISS vector store
vectorstore = FAISS.load_local(
    "faiss_index_sysml", embeddings, allow_dangerous_deserialization=True
)

# Load ChatOpenAI model
llm = ChatOpenAI(
    model_name="gpt-4", 
    temperature=0.5,
    openai_api_key=OPENAI_API_KEY
)

# Build conversational chain with history
qa = ConversationalRetrievalChain.from_llm(
    llm=llm,
    retriever=vectorstore.as_retriever(),
    return_source_documents=False
)

history = []

# Chatbot logic
def sysml_chatbot(message, history):
    result = qa({"question": message, "chat_history": history})
    answer = result["answer"]
    history.append((message, answer))
    return "", history

# Gradio UI
with gr.Blocks() as demo:
    gr.Markdown("## SysML Chatbot")
    chatbot = gr.Chatbot()
    msg = gr.Textbox(placeholder="Ask me about SysML diagrams or concepts...")
    clear = gr.Button("Clear")

    state = gr.State(history)

    msg.submit(sysml_chatbot, [msg, state], [msg, chatbot])
    clear.click(lambda: ([], ""), None, [chatbot, msg])

if __name__ == "__main__":
    demo.launch()