search_agent_ui.py

import datetime
import os

import dotenv
import streamlit as st

from langchain_core.tracers.langchain import LangChainTracer
from langchain.callbacks.base import BaseCallbackHandler
from langsmith.client import Client

import web_rag as wr
import web_crawler as wc
import copywriter as cw

dotenv.load_dotenv()

ls_tracer = LangChainTracer(
    project_name=os.getenv("LANGSMITH_PROJECT_NAME"),
    client=Client()
)

class StreamHandler(BaseCallbackHandler):
    """Stream handler that appends tokens to container."""
    def __init__(self, container, initial_text=""):
        self.container = container
        self.text = initial_text

    def on_llm_new_token(self, token: str, **kwargs):
        self.text += token
        self.container.markdown(self.text)
        

def create_links_markdown(sources_list):
    """
    Create a markdown string for each source in the provided JSON.
    
    Args:
        sources_list (list): A list of dictionaries representing the sources.
                        Each dictionary should have 'title', 'link', and 'snippet' keys.
    
    Returns:
        str: A markdown string with a bullet point for each source,
             including the title linked to the URL and the snippet.
    """
    markdown_list = []
    for source in sources_list:
        title = source['title']
        link = source['link']
        snippet = source['snippet']
        markdown = f"- [{title}]({link})\n  {snippet}"
        markdown_list.append(markdown)
    return "\n".join(markdown_list)

st.set_page_config(layout="wide")
st.title("🔍 Simple Search Agent 💬")

if "providers" not in st.session_state:
    providers = []
    if os.getenv("FIREWORKS_API_KEY"):
        providers.append("fireworks")
    if os.getenv("COHERE_API_KEY"):
        providers.append("cohere")
    if os.getenv("OPENAI_API_KEY"):
        providers.append("openai")
    if os.getenv("GROQ_API_KEY"):
        providers.append("groq")
    if os.getenv("OLLAMA_API_KEY"):
        providers.append("ollama")
    if os.getenv("CREDENTIALS_PROFILE_NAME"):
        providers.append("bedrock")
    st.session_state["providers"] = providers

with st.sidebar.expander("Options", expanded=False):
    model_provider = st.selectbox("Model provider 🧠", st.session_state["providers"])
    temperature = st.slider("Model temperature 🌡️", 0.0, 1.0, 0.1, help="The higher the more creative")
    max_pages = st.slider("Max pages to retrieve 🔍", 1, 20, 15, help="How many web pages to retrive from the internet")
    top_k_documents = st.slider("Nbr of doc extracts to consider 📄", 1, 20, 5, help="How many of the top extracts to consider")
    reviewer_mode =  st.checkbox("Draft / Comment / Rewrite mode ✍️", value=False, help="First generate a write, then comments and then rewrite")

with st.sidebar.expander("Links", expanded=False):
    links_md = st.markdown("")

if reviewer_mode:
    with st.sidebar.expander("Answer review", expanded=False):
        st.caption("Draft")  
        draft_md = st.markdown("")
        st.divider()
        st.caption("Comments")
        comments_md = st.markdown("")
        st.divider()
        st.caption("Comparaison")
        comparaison_md = st.markdown("")   

if "messages" not in st.session_state:
    st.session_state["messages"] = [{"role": "assistant", "content": "How can I help you?"}]

for message in st.session_state.messages:
    st.chat_message(message["role"]).write(message["content"])
    if message["role"] == "assistant" and 'message_id' in message:
        st.download_button(
            label="Download",
            data=message["content"],
            file_name=f"{message['message_id']}.txt",
            mime="text/plain"
        )

if prompt := st.chat_input("Enter you instructions..." ):   
    st.chat_message("user").write(prompt)
    st.session_state.messages.append({"role": "user", "content": prompt})

    chat, embedding_model = wr.get_models(model_provider, temperature=temperature)

    with st.status("Thinking", expanded=True):
        st.write("I first need to do some research")
        
        optimize_search_query = wr.optimize_search_query(chat, query=prompt, callbacks=[ls_tracer])
        st.write(f"I should search the web for: {optimize_search_query}")
        
        sources = wc.get_sources(optimize_search_query, max_pages=max_pages)
        links_md.markdown(create_links_markdown(sources))
       
        st.write(f"I'll now retrieve the {len(sources)} webpages and documents I found")
        contents = wc.get_links_contents(sources)

        st.write( f"Reading through the {len(contents)} sources I managed to retrieve")
        vector_store = wc.vectorize(contents, embedding_model=embedding_model)
        st.write(f"I collected {vector_store.index.ntotal} chunk of data and I can now answer")
      
    
        if reviewer_mode:
            st.write("Creating a draft")
            draft_prompt = wr.build_rag_prompt(
                chat, prompt, optimize_search_query, 
                vector_store, top_k=top_k_documents, callbacks=[ls_tracer])
            draft = chat.invoke(draft_prompt, stream=False, config={ "callbacks": [ls_tracer]})
            draft_md.markdown(draft.content)
            st.write("Sending draft for review")
            comments = cw.generate_comments(chat, prompt, draft, callbacks=[ls_tracer])
            comments_md.markdown(comments)
            st.write("Reviewing comments and generating final answer")
            rag_prompt = cw.get_final_text_prompt(prompt, draft, comments)
        else:
            rag_prompt = wr.build_rag_prompt(
                chat, prompt, optimize_search_query, vector_store,
                top_k=top_k_documents, callbacks=[ls_tracer]
            )

    with st.chat_message("assistant"):
        st_cb = StreamHandler(st.empty())
        result = chat.invoke(rag_prompt, stream=True, config={ "callbacks": [st_cb, ls_tracer]})
        response = result.content.strip()
        message_id = f"{prompt}{datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')}"
        st.session_state.messages.append({"role": "assistant", "content": response})
        
    if st.session_state.messages[-1]["role"] == "assistant":
        st.download_button(
            label="Download",
            data=st.session_state.messages[-1]["content"],
            file_name=f"{message_id}.txt",
            mime="text/plain"
        )
        
    if reviewer_mode:
        compare_prompt = cw.get_compare_texts_prompts(prompt, draft_text=draft, final_text=response)
        result = chat.invoke(compare_prompt, stream=False, config={ "callbacks": [ls_tracer]})
        comparaison_md.markdown(result.content)