from typing import List, Tuple
from langchain_core.documents import Document


def combine_documents_without_losing_pagination(documents: list[Document]):
    combined_text = ""
    page_boundaries: List[Tuple[int, int, int]] = (
        []
    )  # (start_idx, end_idx, page_number)
    current_position = 0
    for document in documents:
        start = current_position
        combined_text += document.page_content
        end = current_position + len(document.page_content)
        page_number = document.metadata.get("page", len(page_boundaries) + 1)
        page_boundaries.append((start, end, page_number))

        current_position = end
    return page_boundaries, combined_text