"""
app/utils/qr.py
---------------
Generic QR-code SVG helper (phase38).

Mirrors qr_svg() in app/utils/mfa.py (which is TOTP-specific and mirrored in
control/mfa.py — do not touch those; this is the general-purpose variant for
facility QR codes and any future QR needs).
"""

import io
import qrcode
import qrcode.image.svg


def qr_svg(data: str) -> str:
    """Return an inline SVG string encoding `data` (no Pillow needed).

    The SVG carries its own width/height attrs; size it via CSS on the
    containing element (svg { width:…; height:…; }) when embedding.
    """
    buf = io.BytesIO()
    qrcode.make(data, image_factory=qrcode.image.svg.SvgPathImage).save(buf)
    return buf.getvalue().decode('utf-8')