"""Append-only audit trail writer for admin actions."""
from app.extensions import db
from app.models.audit import AuditLog


def log_action(actor, action: str, target_type: str, target_id, meta: dict | None = None):
    """Append an AuditLog row. Caller commits."""
    db.session.add(AuditLog(
        actor_id=actor.id if actor else None,
        action=action,
        target_type=target_type,
        target_id=target_id,
        meta=meta,
    ))