from asgiref.sync import sync_to_async
from django.utils import timezone


def messages_to_string(messages: list):
    """
    Converts message objects to a formatted string, showing custom_author if set.
    """
    message_texts = [
        f"[{msg.ts}] <{msg.custom_author if msg.custom_author else msg.session.identifier.person.name}> {msg.text}"
        for msg in messages
    ]
    return "\n".join(message_texts)

async def update_last_interaction(session):
    now = timezone.now()
    session.identifier.person.last_interaction = now
    session.last_interaction = now
    await sync_to_async(session.identifier.person.save)()
    await sync_to_async(session.save)()