Meeting with James 04/26 about fashion-shopping-assistant HOT 2 OPEN

import neo4j
import langchain.embeddings
import langchain.chat_models
import langchain.prompts.chat

emb = OpenAIEmbeddings() # VertexAIEmbeddings() or BedrockEmbeddings() or ...
llm = ChatOpenAI() # ChatVertexAI() or BedrockChat() or ChatOllama() ...

vector = emb.embed_query(user_input)

vectory_query = """
// find products by similarity search in vector index
CALL db.index.vector.queryNodes('products', 5, $embedding) yield node as product, score

// enrich with additional explicit relationships from the knowledge graph
MATCH (product)-[:HAS_CATEGORY]->(cat), (product)-[:BY_BRAND]->(brand)
MATCH (product)-[:HAS_REVIEW]->(review {rating:5})<-[:WROTE]-(customer) 

// return relevant contextual information
RETURN product.Name, product.Description, brand.Name, cat.Name, 
       collect(review { .Date, .Text })[0..5] as reviews, score
"""

records = neo4j.driver.execute_query(vectory_query, embedding = vector)
context = format_context(records)

template = """
You are a helpful assistant that helps users find information for their shopping needs.
Only use the context provided, do not add any additional information.
Context:  {context}
User question: {question}
"""

chain = prompt(template) | llm

answer = chain.invoke({"question":user_input, "context":context}).content