app.py

import os, sys, json
import gradio as gr
import openai
from openai import OpenAI

from langchain.chains import LLMChain, RetrievalQA
from langchain.chat_models import ChatOpenAI
from langchain.document_loaders import PyPDFLoader, WebBaseLoader
from langchain.document_loaders.blob_loaders.youtube_audio import YoutubeAudioLoader
from langchain.document_loaders.generic import GenericLoader
from langchain.document_loaders.parsers import OpenAIWhisperParser

from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.prompts import PromptTemplate
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.vectorstores import Chroma
#from langchain.vectorstores import MongoDBAtlasVectorSearch

#from pymongo import MongoClient

from dotenv import load_dotenv, find_dotenv
_ = load_dotenv(find_dotenv())


# Schnittstellen hinzubinden und OpenAI Key holen aus den Secrets
#client = OpenAI(
  #api_key=os.getenv("OPENAI_API_KEY"),  
#)





#openai.api_key = os.getenv["OPENAI_API_KEY"]

#Für MongoDB statt Chroma als Vektorstore
#MONGODB_URI = os.environ["MONGODB_ATLAS_CLUSTER_URI"]
#client = MongoClient(MONGODB_URI)
#MONGODB_DB_NAME = "langchain_db"
#MONGODB_COLLECTION_NAME = "gpt-4"
#MONGODB_COLLECTION = client[MONGODB_DB_NAME][MONGODB_COLLECTION_NAME]
#MONGODB_INDEX_NAME = "default"

template = """If you don't know the answer, just say that you don't know, don't try to make up an answer. Keep the answer as concise as possible. Answer in german if not asked otherwise """

llm_template = "Answer the question at the end. " + template + "Question: {question} Helpful Answer: "
rag_template = "Use the following pieces of context to answer the question at the end. " + template + "{context} Question: {question} Helpful Answer: "

LLM_CHAIN_PROMPT = PromptTemplate(input_variables = ["question"], 
                                  template = llm_template)
RAG_CHAIN_PROMPT = PromptTemplate(input_variables = ["context", "question"], 
                                  template = rag_template)

OAI_API_KEY=os.getenv("OPENAI_API_KEY")
#Pfad, wo Docs abgelegt werden können - lokal, also hier im HF Space (sonst auf eigenem Rechner)
PATH_WORK = "."
CHROMA_DIR  = "/chroma"
YOUTUBE_DIR = "/youtube"

PDF_URL       = "https://arxiv.org/pdf/2303.08774.pdf"
WEB_URL       = "https://openai.com/research/gpt-4"
YOUTUBE_URL_1 = "https://www.youtube.com/watch?v=--khbXchTeE"
YOUTUBE_URL_2 = "https://www.youtube.com/watch?v=hdhZwyf24mE"
YOUTUBE_URL_3 = "https://www.youtube.com/watch?v=vw-KWfKwvTQ"

MODEL_NAME  = "gpt-3.5-turbo-16k"

def document_loading_splitting():
    # Document loading
    docs = []
    # Load PDF
    loader = PyPDFLoader(PDF_URL)
    docs.extend(loader.load())
    # Load Web
    loader = WebBaseLoader(WEB_URL)
    docs.extend(loader.load())
    # Load YouTube
    loader = GenericLoader(YoutubeAudioLoader([YOUTUBE_URL_1,
                                               YOUTUBE_URL_2,
                                               YOUTUBE_URL_3], PATH_WORK + YOUTUBE_DIR), 
                           OpenAIWhisperParser())
    docs.extend(loader.load())
    # Document splitting
    text_splitter = RecursiveCharacterTextSplitter(chunk_overlap = 150,
                                                   chunk_size = 1500)
    splits = text_splitter.split_documents(docs)
    return splits

def document_storage_chroma(splits):
    Chroma.from_documents(documents = splits, 
                          embedding = OpenAIEmbeddings(disallowed_special = ()), 
                          persist_directory = CHROMA_DIR)

def document_storage_mongodb(splits):
    MongoDBAtlasVectorSearch.from_documents(documents = splits,
                                            embedding = OpenAIEmbeddings(disallowed_special = ()),
                                            collection = MONGODB_COLLECTION,
                                            index_name = MONGODB_INDEX_NAME)

def document_retrieval_chroma(llm, prompt):      
    embeddings = OpenAIEmbeddings()
    #Alternative Embedding - für Vektorstore, um Ähnlichkeitsvektoren zu erzeugen
    #embeddings = HuggingFaceInstructEmbeddings(model_name="sentence-transformers/all-MiniLM-L6-v2", model_kwargs={"device": "cpu"})
    db = Chroma(embedding_function = embeddings,
                persist_directory = PATH_WORK + CHROMA_DIR)
    
    return db

def document_retrieval_mongodb(llm, prompt):
    db = MongoDBAtlasVectorSearch.from_connection_string(MONGODB_URI,
                                                         MONGODB_DB_NAME + "." + MONGODB_COLLECTION_NAME,
                                                         OpenAIEmbeddings(disallowed_special = ()),
                                                         index_name = MONGODB_INDEX_NAME)
    return db

def llm_chain(llm, prompt):
    llm_chain = LLMChain(llm = llm, prompt = LLM_CHAIN_PROMPT)
    result = llm_chain.run({"question": prompt})
    return result

def rag_chain(llm, prompt, db):
    rag_chain = RetrievalQA.from_chain_type(llm, 
                                            chain_type_kwargs = {"prompt": RAG_CHAIN_PROMPT}, 
                                            retriever = db.as_retriever(search_kwargs = {"k": 3}), 
                                            return_source_documents = True)
    result = rag_chain({"query": prompt})
    return result["result"]

def invoke(openai_api_key, rag_option, prompt):
    if (openai_api_key == "" or openai_api_key == "sk-"):
        #raise gr.Error("OpenAI API Key is required.")
        openai_api_key= OAI_API_KEY
    if (rag_option is None):
        raise gr.Error("Retrieval Augmented Generation is required.")
    if (prompt == ""):
        raise gr.Error("Prompt is required.")
    try:
        llm = ChatOpenAI(model_name = MODEL_NAME, 
                         openai_api_key = openai_api_key, 
                         temperature = 0)
        if (rag_option == "Chroma"):
            #splits = document_loading_splitting()
            #document_storage_chroma(splits)
            db = document_retrieval_chroma(llm, prompt)
            result = rag_chain(llm, prompt, db)
        elif (rag_option == "MongoDB"):
            #splits = document_loading_splitting()
            #document_storage_mongodb(splits)
            db = document_retrieval_mongodb(llm, prompt)
            result = rag_chain(llm, prompt, db)
        else:
            result = llm_chain(llm, prompt)
    except Exception as e:
        raise gr.Error(e)
    return result

description = """<strong>Überblick:</strong> Hier wird ein <strong>Large Language Model (LLM)</strong> mit 
                 <strong>Retrieval Augmented Generation (RAG)</strong> auf <strong>externen Daten</strong> demonstriert.\n\n
                 <strong>Genauer:</strong> Folgende externe Daten sind als Beispiel gegeben:
                 <a href='""" + YOUTUBE_URL_1 + """'>YouTube</a>, <a href='""" + PDF_URL + """'>PDF</a>, and <a href='""" + WEB_URL + """'>Web</a> 
                 Alle neueren Datums!.
                 <ul style="list-style-type:square;">
                 <li>Setze "Retrieval Augmented Generation" auf  "<strong>Off</strong>" und gib einen Prompt ein." Das entspricht <strong> ein LLM nutzen ohne RAG</strong></li>
                 <li>Setze "Retrieval Augmented Generation" to "<strong>Chroma</strong>"  und gib einen Prompt ein. Das <strong>LLM mit RAG</strong> weiß auch Antworten zu aktuellen Themen aus den angefügten Datenquellen</li>
                 <li>Experimentiere mit Prompts, z.B.  Answer in German, Arabic, Chinese, Hindi, and Russian." oder "Schreibe ein Python Programm, dass die GPT-4 API aufruft."</li>
                 </ul>\n\n
                 <strong>Verwendete Technology:</strong> <a href='https://www.gradio.app/'>Gradio</a> UI using the <a href='https://openai.com/'>OpenAI</a> API and 
                 AI-native <a href='https://www.trychroma.com/'>Chroma</a> embedding database / 
                 <a href='https://www.mongodb.com/blog/post/introducing-atlas-vector-search-build-intelligent-applications-semantic-search-ai'>MongoDB</a> vector search. 
                 <strong>Speech-to-text</strong> (STT) via <a href='https://openai.com/research/whisper'>whisper-1</a> model, <strong>text embedding</strong> via 
                 <a href='https://openai.com/blog/new-and-improved-embedding-model'>text-embedding-ada-002</a> model, and <strong>text generation</strong> via 
                 <a href='""" + WEB_URL + """'>gpt-4</a> model. Implementation via AI-first <a href='https://www.langchain.com/'>LangChain</a> toolkit.\n\n
                 In addition to the OpenAI API version, see also the <a href='https://aws.amazon.com/bedrock/'>Amazon Bedrock</a> API and 
                 <a href='https://cloud.google.com/vertex-ai'>Google Vertex AI</a> API versions on 
                 <a href='https://github.com/bstraehle/ai-ml-dl/tree/main/hugging-face'>GitHub</a>."""

gr.close_all()
demo = gr.Interface(fn=invoke, 
                    inputs = [gr.Textbox(label = "OpenAI API Key", value = "sk-", lines = 1), 
                              gr.Radio(["Off", "Chroma", "MongoDB"], label="Retrieval Augmented Generation", value = "Off"),
                              gr.Textbox(label = "Prompt", value = "What is GPT-4?", lines = 1)],
                    outputs = [gr.Textbox(label = "Completion", lines = 1)],
                    title = "Generative AI - LLM & RAG",
                    description = description)
demo.launch()