bambuddy/backend/app/services/print_control.py

"""Stopping a print on a user's behalf.

Every place a user can stop a print goes through here, so none can send the
stop without the "stopped by the user" mark: the printer card, the queue and
the webhook routes call stop_print_by_user; the HMS error dialog's "Stop
Printing" sends its own stop payload and calls mark_stopped_by_user. Without
the mark the printer's resulting "failed"/"aborted" status is taken at face
value: a "print failed" notification goes out, and on some printers the
cancel sequence's own error is reported as a fault such as a layer shift.
"""

import logging

from backend.app.services.printer_manager import printer_manager

logger = logging.getLogger(__name__)


def mark_stopped_by_user(printer_id: int) -> None:
    """Record that the user stopped the print on this printer (see module docstring)."""
    try:
        from backend.app.main import mark_printer_stopped_by_user

        mark_printer_stopped_by_user(printer_id)
    except Exception as e:
        logger.warning("Failed to mark printer %s as user-stopped: %s", printer_id, e)


def stop_print_by_user(printer_id: int, *, mark_when_unsent: bool = False) -> bool:
    """Send the stop command; returns whether it was sent.

    The printer is marked as stopped by the user when the command was sent,
    or always with ``mark_when_unsent`` (the queue, which closes the job even
    when the printer is offline, so a "failed" it reports later still reads
    as the user's cancel). Errors sending the command propagate to the caller.
    """
    try:
        sent = printer_manager.stop_print(printer_id)
    except Exception:
        if mark_when_unsent:
            mark_stopped_by_user(printer_id)
        raise
    if sent or mark_when_unsent:
        mark_stopped_by_user(printer_id)
    return sent