import logging
import os

from llama_index.core import SimpleDirectoryReader, VectorStoreIndex, StorageContext, load_index_from_storage
from llama_index.core.node_parser import SentenceSplitter

logger = logging.getLogger(__name__)
DOCUMENT_PATH = './documents'


# remember to delete stored vectors when new documents are added to the data so the storage is recreated
def load_write_index_nodes(path):
    documents = []

    if not os.path.exists(path):
        documents = SimpleDirectoryReader(DOCUMENT_PATH, filename_as_id=True).load_data()
        logger.info(f'Indexing documents in {DOCUMENT_PATH}...')
        index = VectorStoreIndex.from_documents(documents)
        index.storage_context.persist(persist_dir=path)
        logger.info(f'{len(documents)} documents indexed.')
    else:
        logger.info(f'Loading index from {path}...')
        storage_context = StorageContext.from_defaults(persist_dir=path)
        index = load_index_from_storage(storage_context)

    parser = SentenceSplitter()
    nodes = parser.get_nodes_from_documents(documents)
    return index, nodes