"""
Filter paths found in a resource.

This plugin implements :func:`rp_filter`.
"""

from typing import Optional


def rp_filter(site, durl) -> Optional[str]:
    """
    Adjust or filter found paths (may depend on site).

    To filter out a path (i.e., not add it to table `site_path`)
    return None.
    """
    path = durl.pwa()
    # skip fetching images (linked from a tags; img tags are skipped anyway)
    if path.lower().endswith('.jpg') or path.lower().endswith('.png'):
        return None
    path = path.removesuffix('?amp=1')
    return path