app.py

#================imports==============

import uuid
import requests
import os
os.environ["USER_AGENT"] = "RAG-App/1.0"
from typing import Dict, List, Any
from dotenv import load_dotenv

from bs4 import BeautifulSoup
from langchain_core.globals import set_llm_cache
from langchain_core.caches import InMemoryCache

from langchain_community.document_loaders import WebBaseLoader
from langchain_text_splitters import RecursiveCharacterTextSplitter

from langchain_huggingface import HuggingFaceEmbeddings
from langchain_community.vectorstores import Weaviate
from langchain_community.vectorstores import FAISS
from langchain_groq import ChatGroq
from langchain_core.prompts import ChatPromptTemplate,MessagesPlaceholder

from langchain_classic.chains.combine_documents import create_stuff_documents_chain
from langchain_classic.chains import create_retrieval_chain

from langchain_core.runnables.history import RunnableWithMessageHistory
from langchain_community.chat_message_histories import ChatMessageHistory
from langchain_core.chat_history import BaseChatMessageHistory

#================== CONFIG==================

load_dotenv()

set_llm_cache(InMemoryCache())
api_key=os.environ["GROQ_API_KEY"]
#os.environ["HF_API_KEY"]
print("api chargée:" if api_key else "y'a probleme!!")

#========== charger et decouper documents=================

urls=[
    "https://fr.wikipedia.org/wiki/%C3%89levage",
    "https://fr.wikipedia.org/wiki/La_P%C3%AAche"
]

loader = WebBaseLoader(urls,
                      requests_kwargs={
                          "headers":{
                              "User-Agent":"RAG-App/1.0"
                          }
                      }
)
docs =loader.load()

splitter = RecursiveCharacterTextSplitter(chunk_size= 1000, chunk_overlap=200)
chunks= splitter.split_documents(docs)

#============embeding et indexation vers faiss_db================

embeddings= HuggingFaceEmbeddings(model_name="sentence-transformers/all-MiniLM-L6-v2")

faiss_db=FAISS.from_documents(
    documents=chunks,
    embedding=embeddings
    )

retriever=faiss_db.as_retriever(search_type="similarity", search_kwargs={"k":3})

#=============== LLM et Prompt=================

llm = ChatGroq(
    model="llama-3.3-70b-versatile",
    temperature=0.0,
    max_tokens=1200
    )

prompt = ChatPromptTemplate.from_messages([
    ("system", """Tu es un assistant expert en dans le domaine de l'elevage et la pêche. Réponds clairement.
Si tu ne connais pas, n'invente pas. Garde un ton amical.

Contexte :
{context}"""),
    MessagesPlaceholder(variable_name="chat_history"),
    ("human", "{input}"),
])

#============= CHAINE DE RECUPERATION=======

stuff_chain= create_stuff_documents_chain(llm, prompt)
rag_chain=create_retrieval_chain(retriever, stuff_chain)

import gradio as gr

store = {}

def get_session_history(session_id:str)->BaseChatMessageHistory:
    if session_id not in store:
        store[session_id] = ChatMessageHistory()
    return store[session_id]

# ======== CHAIN AVEC MÉMOIRE ===========

convers_chain = RunnableWithMessageHistory(
    rag_chain,
    get_session_history,
    input_messages_key="input",
    history_messages_key="chat_history",
    output_messages_key="answer"
)

# =============FONCTION CHAT ================

SESSION_ID = str(uuid.uuid4())  # session globale

def chat_fn(message, history):
    result = convers_chain.invoke(
        {"input": message},
        config={"configurable": {"session_id": SESSION_ID}}
    )
    return result.get("answer", str(result))




# ================= GRADIO ====================

demo = gr.ChatInterface(
    fn=chat_fn,
    title="🤖 RAG:Specialist en Science Animale 👌",
    description="Posez vos questions sur l'élévage et la pêche",
    examples=[
        "C'est quoi la pêche ?",
        "Explique l'élévage",
        "Quelle est la différence entre l'élévage et pêche ?"
    ]
)


# ===================LANCEMENT ================

demo.launch()