"""User-submitted listing reports + flag-count threshold auto-flag."""
from sqlalchemy.exc import IntegrityError
from app.extensions import db
from app.models.report import Report
from app.models.enums import ListingStatus, ReportReason
from app.services.settings import get_setting


class ReportError(ValueError):
    pass


def create_report(listing, reporter, reason: ReportReason, note=None):
    """Record a report, bump flag_count, auto-flag at threshold. Commits."""
    if listing.user_id == reporter.id:
        raise ReportError("cannot report your own listing")

    report = Report(listing_id=listing.id, reporter_id=reporter.id,
                    reason=reason, note=(note or "").strip() or None)
    db.session.add(report)
    try:
        db.session.flush()
    except IntegrityError:
        db.session.rollback()
        raise ReportError("you have already reported this listing")

    listing.flag_count = (listing.flag_count or 0) + 1
    threshold = get_setting("flag_threshold", 5)
    if listing.flag_count >= threshold and listing.status == ListingStatus.active:
        listing.status = ListingStatus.flagged
    db.session.commit()
    return report