imprv: Styling: Introduce URI scheme whitelisting

Fixes #11266

Co-authored-by: Philipp Hörist <philipp@hoerist.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/scripts/get_iana_data.py b/scripts/get_iana_data.py
new file mode 100755
index 000000000..ec0e62a29
--- /dev/null
+++ b/scripts/get_iana_data.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+
+import argparse
+from datetime import datetime
+from urllib.request import urlopen
+import csv
+import io
+import logging
+from pathlib import Path
+import re
+import sys
+
+
+SCHEMES_URL = 'https://www.iana.org/assignments/uri-schemes/uri-schemes-1.csv'
+
+logging.basicConfig(level='INFO', format='%(levelname)s: %(message)s')
+
+
+def download_file(url: str) -> str:
+    logging.info('Download: %s', url)
+    with urlopen(url) as f:
+        content = f.read()
+    return content.decode()
+
+
+def parse_uri_schemes(content: str) -> list[str]:
+    logging.info('Parse uri schemes')
+    schemes: list[str] = []
+
+    reader = csv.reader(io.StringIO(content), delimiter=',')
+    next(reader)  # Skip header row
+    for line in reader:
+        scheme = line[0].lower().removesuffix(' (obsolete)')
+        if not re.fullmatch('[a-z0-9+.-]+', scheme):
+            logging.warning('unexpected scheme field contents: %s', scheme)
+            continue
+
+        schemes.append(scheme)
+
+    return schemes
+
+
+def generate_output(schemes: list[str],
+                    out_path: Path):
+
+    logging.info('Generate output')
+    current_date = datetime.utcnow().isoformat()
+    content = f'# Generated by get_iana_data.py @ {current_date}\n'
+
+    content += '\n'
+
+    content += 'URI_SCHEMES = {\n'
+    for scheme in schemes:
+        content += f"    '{scheme}',\n"
+    content += '}\n'
+
+    outpath.write_text(content)
+    logging.info('Wrote file to %s', outpath)
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description='Generate IANA data')
+    parser.add_argument('out', help='Path to output file')
+    args = parser.parse_args()
+
+    outpath = Path(args.out)
+    if outpath.is_dir():
+        sys.exit('Output path is a directory')
+
+    scheme_content = download_file(SCHEMES_URL)
+    schemes = parse_uri_schemes(scheme_content)
+    output = generate_output(schemes,
+                             outpath)
+    logging.info('Finished !')