import os
from langchain.document_loaders import PyPDFLoader
from langchain.embeddings import HuggingFaceEmbeddings  # Updated import per deprecation notice
from langchain.schema import Document
from langchain_community.vectorstores import FAISS
from langchain_text_splitters import CharacterTextSplitter
import re

# Path to folder containing PDFs
folder_path = "normativa" 
pdf_files = [f for f in os.listdir(folder_path) if f.endswith(".pdf")]

# Load docs in folder and split text
text_splitter = CharacterTextSplitter(chunk_size = 500, chunk_overlap = 0)
documents = []
for pdf in pdf_files:
    print("Loading file:", pdf)
    loader = PyPDFLoader(os.path.join(folder_path, pdf))
    docs = loader.load()
    documents = text_splitter.split_documents(docs)

# Load the embedding model
embedding_model = HuggingFaceEmbeddings(model_name="sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2")

# Create a FAISS index with chunk-level embeddings
faiss_index = FAISS.from_documents(documents, embedding_model)

# Save (persist) the index to disk
faiss_index.save_local("faiss_index")

print("FAISS index built and saved successfully!")