from defusedxml import ElementTree as DefusedET
from fastapi import HTTPException, status

from app.core.config import settings


def inspect_svg_bytes(content: bytes) -> int:
    try:
        root = DefusedET.fromstring(content)
    except Exception as exc:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Invalid SVG XML: {exc.__class__.__name__}",
        ) from exc

    tag = root.tag or ""
    if not tag.endswith("svg"):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Root element is not <svg>",
        )

    element_count = sum(1 for _ in root.iter())

    if element_count > settings.svg_max_elements:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="SVG element count exceeds configured limit",
        )

    return element_count