app.py

import gradio as gr
import datetime
import pytz

sentense_transformers_model = "sentence-transformers/paraphrase-multilingual-mpnet-base-v2"
ranker_model = 'hotchpotch/japanese-reranker-cross-encoder-base-v1' 

from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack.components.retrievers.in_memory import InMemoryBM25Retriever, InMemoryEmbeddingRetriever
from haystack.components.embedders import SentenceTransformersTextEmbedder
from haystack.components.joiners import DocumentJoiner
from haystack.components.rankers import TransformersSimilarityRanker
from haystack import Pipeline,component,Document
from haystack_integrations.components.generators.google_ai import GoogleAIGeminiChatGenerator
from haystack.components.builders import ChatPromptBuilder
from haystack_experimental.chat_message_stores.in_memory import InMemoryChatMessageStore
from haystack_experimental.components.retrievers import ChatMessageRetriever
from haystack_experimental.components.writers import ChatMessageWriter
from haystack.dataclasses import ChatMessage
from itertools import chain
from typing import Any,List
from haystack.core.component.types import Variadic

document_store = InMemoryDocumentStore.load_from_disk(path='./document_store.json')
print('document_store loaded' ,document_store.count_documents())

@component
class ListJoiner:
    def __init__(self, _type: Any):
        component.set_output_types(self, values=_type)
    def run(self, values: Variadic[Any]):
        result = list(chain(*values))
        return {"values": result}

class Niwa_rag :
    def __init__(self):
        self.createPipe()
    def createPipe(self):
        user_message_template = """
            チャット履歴と提供された資料に基づいて、質問に答えてください。
            資料はチャット履歴の一部ではないことに注意してください。
            質問が資料から回答できない場合は、その旨を述べてください。
        
            チャット履歴:
            {% for memory in memories %}
                {{ memory.content }}
            {% endfor %}
        
            資料:
            {% for document in documents %}
                {{ document.content }}
            {% endfor %}
        
            質問: {{query}}
            回答:
        """
        system_message = ChatMessage.from_system("あなたは、提供された資料とチャット履歴を使用して人間を支援するAIアシスタントです")
        user_message = ChatMessage.from_user(user_message_template)
        messages = [system_message, user_message]
        
        text_embedder = SentenceTransformersTextEmbedder(model=sentense_transformers_model)
        embedding_retriever = InMemoryEmbeddingRetriever(document_store)
        bm25_retriever = InMemoryBM25Retriever(document_store)
        document_joiner = DocumentJoiner()
        ranker = TransformersSimilarityRanker(model=ranker_model,top_k=8)
        prompt_builder = ChatPromptBuilder(template=messages,variables=["query", "documents", "memories"], required_variables=["query", "documents", "memories"])
        gemini = GoogleAIGeminiChatGenerator(model="models/gemini-1.5-flash")
        
        memory_store = InMemoryChatMessageStore()
        memory_joiner = ListJoiner(List[ChatMessage])
        memory_retriever = ChatMessageRetriever(memory_store)
        memory_writer = ChatMessageWriter(memory_store)
        
        pipe = Pipeline()
        pipe.add_component("text_embedder", text_embedder)
        pipe.add_component("embedding_retriever", embedding_retriever)
        pipe.add_component("bm25_retriever", bm25_retriever)
        pipe.add_component("document_joiner", document_joiner)
        pipe.add_component("ranker", ranker)
        pipe.add_component("prompt_builder", prompt_builder)
        pipe.add_component("llm", gemini)
        pipe.add_component("memory_retriever", memory_retriever)
        pipe.add_component("memory_writer", memory_writer)
        pipe.add_component("memory_joiner", memory_joiner)
        
        pipe.connect("text_embedder", "embedding_retriever")
        pipe.connect("bm25_retriever", "document_joiner")
        pipe.connect("embedding_retriever", "document_joiner")
        pipe.connect("document_joiner", "ranker")
        pipe.connect("ranker.documents", "prompt_builder.documents")
        pipe.connect("prompt_builder.prompt", "llm.messages")
        pipe.connect("llm.replies", "memory_joiner")
        pipe.connect("memory_joiner", "memory_writer")
        pipe.connect("memory_retriever", "prompt_builder.memories")
        
        self.pipe = pipe
    def run(self,q):
        now = datetime.datetime.now(pytz.timezone('Asia/Tokyo'))
        print('q:',q,now)
        if not q :
            return {'reply':'','sources':''}
        result = self.pipe.run({
            "text_embedder": {"text": q},
            "bm25_retriever": {"query": q},
            "ranker": {"query": q},
            "prompt_builder": { "query": q},
            "memory_joiner": {"values": [ChatMessage.from_user(q)]},
        },include_outputs_from=["llm",'ranker'])
        reply = result['llm']['replies'][0]
        docs = result['ranker']['documents']
        print('reply:',reply)
        html = '<div class="ref-title">参考記事</div><div class="ref">'
        for doc in docs :
            title = doc.meta['title']
            link = doc.meta['link']
            row = f'<div><a class="link" href="{link}" target="_blank">{title}</a></div>'
            html += row
            print('',title,link,doc.meta['type'],doc.score)
        html += '</div>'
        return {'reply':reply.content,'sources':html}

rag = Niwa_rag()

def fn(q,history):
    result = rag.run(q)
    return result['reply'] + result['sources']

app = gr.ChatInterface(
    fn, 
    type="messages",
    title='庭ファン　Chatbot',
    textbox=gr.Textbox(placeholder='質問を記入して下さい',submit_btn=True),
    css_paths = './app.css'
)


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