app.py

import os
import io
import chromadb
import streamlit as st
import matplotlib.pyplot as plt
from langchain_openai import ChatOpenAI
from langchain.agents import AgentExecutor, create_openai_tools_agent
from langchain_core.messages import BaseMessage, HumanMessage
from langchain_community.tools.tavily_search import TavilySearchResults
from langchain_experimental.tools import PythonREPLTool
from langchain_community.document_loaders import DirectoryLoader, TextLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain_community.vectorstores import Chroma
from langchain.embeddings import HuggingFaceBgeEmbeddings
from langchain_core.output_parsers import StrOutputParser
from langchain_core.runnables import RunnablePassthrough
from langchain.output_parsers.openai_functions import JsonOutputFunctionsParser
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langgraph.graph import StateGraph, END
from langchain_core.documents import Document
from typing import Annotated, Sequence, TypedDict
import functools
import operator
from langchain_core.tools import tool
from glob import glob

# Clear ChromaDB cache
chromadb.api.client.SharedSystemClient.clear_system_cache()

# Load environment variables
OPENAI_API_KEY = os.getenv("OPENAI_API_KEY")
TAVILY_API_KEY = os.getenv("TAVILY_API_KEY")

if not OPENAI_API_KEY or not TAVILY_API_KEY:
    st.error("Please set OPENAI_API_KEY and TAVILY_API_KEY in your environment variables.")
    st.stop()

# Initialize LLM
llm = ChatOpenAI(model="gpt-4-1106-preview", openai_api_key=OPENAI_API_KEY)

# Utility Functions
def create_agent(llm: ChatOpenAI, tools: list, system_prompt: str):
    prompt = ChatPromptTemplate.from_messages([
        ("system", system_prompt),
        MessagesPlaceholder(variable_name="messages"),
        MessagesPlaceholder(variable_name="agent_scratchpad"),
    ])
    agent = create_openai_tools_agent(llm, tools, prompt)
    return AgentExecutor(agent=agent, tools=tools)

def agent_node(state, agent, name):
    # Run the agent and get its output
    result = agent.invoke(state)
    output_content = result["output"]
    
    # Check if Python code generates a graph
    if "matplotlib" in output_content or "plt." in output_content:
        exec_locals = {}
        try:
            exec(output_content, {}, exec_locals)
            fig = plt.gcf()
            buf = io.BytesIO()
            fig.savefig(buf, format="png")
            buf.seek(0)
            st.session_state.graph_image = buf
        except Exception as e:
            output_content += f"\nError: {str(e)}"
    
    return {"messages": [HumanMessage(content=output_content, name=name)]}

@tool
def RAG(state):
    """Use this tool to execute RAG. If the question is related to Japan or Sports, this tool retrieves the results."""
    st.session_state.outputs.append('-> Calling RAG ->')
    question = state
    template = """Answer the question based only on the following context:\n{context}\nQuestion: {question}"""
    prompt = ChatPromptTemplate.from_template(template)
    retrieval_chain = (
        {"context": retriever, "question": RunnablePassthrough()} |
        prompt |
        llm |
        StrOutputParser()
    )
    result = retrieval_chain.invoke(question)
    return result

# Tools Setup
tavily_tool = TavilySearchResults(max_results=5, tavily_api_key=TAVILY_API_KEY)
python_repl_tool = PythonREPLTool()

# Streamlit UI
# Sidebar with References
st.sidebar.title("References")
st.sidebar.markdown("1. [Multi-Agent with Supervisor](https://github.com/aritrasen87/LLM_RAG_Model_Deployment/blob/main/LangGraph_03_MultiAgent_With_Supervisor.ipynb)")
st.title("Multi-Agent with Supervisor")

example_questions = [
    "What is James McIlroy aiming for in sports?",
    "Fetch India's GDP over the past 5 years and draw a line graph.",
    "Fetch Japan's GDP over the past 4 years from RAG, then draw a line graph."
]

source_files = glob("sources/*.txt")
selected_files = st.multiselect("Select files from the source directory:", source_files, default=source_files[:2])
uploaded_files = st.file_uploader("Or upload your TXT files:", accept_multiple_files=True, type=['txt'])

# Document Handling
all_docs = []
if selected_files:
    for file_path in selected_files:
        loader = TextLoader(file_path)
        all_docs.extend(loader.load())

if uploaded_files:
    for uploaded_file in uploaded_files:
        content = uploaded_file.read().decode("utf-8")
        all_docs.append(Document(page_content=content, metadata={"name": uploaded_file.name}))

if not all_docs:
    st.warning("Please select files or upload TXT files.")
    st.stop()

# Document Splitting and Embedding
text_splitter = RecursiveCharacterTextSplitter(chunk_size=100, chunk_overlap=10)
split_docs = text_splitter.split_documents(all_docs)
embeddings = HuggingFaceBgeEmbeddings(model_name="BAAI/bge-base-en-v1.5", model_kwargs={'device': 'cpu'}, encode_kwargs={'normalize_embeddings': True})
db = Chroma.from_documents(split_docs, embeddings)
retriever = db.as_retriever(search_kwargs={"k": 4})

# Agents
research_agent = create_agent(llm, [tavily_tool], "You are a web researcher.")
code_agent = create_agent(llm, [python_repl_tool], "You may generate safe python code to analyze data and generate charts using matplotlib.")
RAG_agent = create_agent(llm, [RAG], "Use this tool when questions are related to Japan or Sports category.")

research_node = functools.partial(agent_node, agent=research_agent, name="Researcher")
code_node = functools.partial(agent_node, agent=code_agent, name="Coder")
rag_node = functools.partial(agent_node, agent=RAG_agent, name="RAG")

members = ["RAG", "Researcher", "Coder"]
system_prompt = "You are a supervisor managing these workers: {members}. Respond with the next worker or FINISH."
options = ["FINISH"] + members
function_def = {
    "name": "route", "description": "Select the next role.",
    "parameters": {"title": "routeSchema", "type": "object", "properties": {"next": {"anyOf": [{"enum": options}]}}, "required": ["next"]}
}
prompt = ChatPromptTemplate.from_messages([
    ("system", system_prompt),
    MessagesPlaceholder(variable_name="messages"),
    ("system", "Given the conversation above, who should act next? Select one of: {options}"),
]).partial(options=str(options), members=", ".join(members))
supervisor_chain = (prompt | llm.bind_functions(functions=[function_def], function_call="route") | JsonOutputFunctionsParser())

class AgentState(TypedDict):
    messages: Annotated[Sequence[BaseMessage], operator.add]
    next: str

workflow = StateGraph(AgentState)
workflow.add_node("Researcher", research_node)
workflow.add_node("Coder", code_node)
workflow.add_node("RAG", rag_node)
workflow.add_node("supervisor", supervisor_chain)

for member in members:
    workflow.add_edge(member, "supervisor")
conditional_map = {k: k for k in members}
conditional_map["FINISH"] = END
workflow.add_conditional_edges("supervisor", lambda x: x["next"], conditional_map)
workflow.set_entry_point("supervisor")
graph = workflow.compile()

# Workflow Execution
if 'outputs' not in st.session_state:
    st.session_state.outputs = []

user_input = st.text_area("Enter your task or question:", value=example_questions[0])

def run_workflow(task):
    st.session_state.outputs.clear()
    st.session_state.outputs.append(f"User Input: {task}")
    st.session_state.graph_image = None
    for state in graph.stream({"messages": [HumanMessage(content=task)]}):
        if "__end__" not in state:
            st.session_state.outputs.append(str(state))
            st.session_state.outputs.append("----")

if st.button("Run Workflow"):
    if user_input:
        run_workflow(user_input)
    else:
        st.warning("Please enter a task or question.")

st.subheader("Workflow Output:")
for output in st.session_state.outputs:
    st.text(output)

if "graph_image" in st.session_state and st.session_state.graph_image:
    st.subheader("Generated Graph:")
    st.image(st.session_state.graph_image, caption="Generated Line Graph", use_column_width=True)