--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/tools/common/regex.py	Fri Jun 02 11:49:51 2023 +0200
@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+
+
+# Salut à Toi: an XMPP client
+# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+""" regex tools common to backend and frontends """
+
+import re
+import unicodedata
+
+path_escape = {"%": "%25", "/": "%2F", "\\": "%5c"}
+path_escape_rev = {re.escape(v): k for k, v in path_escape.items()}
+path_escape = {re.escape(k): v for k, v in path_escape.items()}
+#  thanks to Martijn Pieters (https://stackoverflow.com/a/14693789)
+RE_ANSI_REMOVE = re.compile(r'\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])')
+RE_TEXT_URL = re.compile(r'[^a-zA-Z0-9,_]+')
+TEXT_MAX_LEN = 60
+# min lenght is currently deactivated
+TEXT_WORD_MIN_LENGHT = 0
+
+
+def re_join(exps):
+    """Join (OR) various regexes"""
+    return re.compile("|".join(exps))
+
+
+def re_sub_dict(pattern, repl_dict, string):
+    """Replace key, value found in dict according to pattern
+
+    @param pattern(basestr): pattern using keys found in repl_dict
+    @repl_dict(dict): keys found in this dict will be replaced by
+        corresponding values
+    @param string(basestr): string to use for the replacement
+    """
+    return pattern.sub(lambda m: repl_dict[re.escape(m.group(0))], string)
+
+
+path_escape_re = re_join(list(path_escape.keys()))
+path_escape_rev_re = re_join(list(path_escape_rev.keys()))
+
+
+def path_escape(string):
+    """Escape string so it can be use in a file path
+
+    @param string(basestr): string to escape
+    @return (str, unicode): escaped string, usable in a file path
+    """
+    return re_sub_dict(path_escape_re, path_escape, string)
+
+
+def path_unescape(string):
+    """Unescape string from value found in file path
+
+    @param string(basestr): string found in file path
+    @return (str, unicode): unescaped string
+    """
+    return re_sub_dict(path_escape_rev_re, path_escape_rev, string)
+
+
+def ansi_remove(string):
+    """Remove ANSI escape codes from string
+
+    @param string(basestr): string to filter
+    @return (str, unicode): string without ANSI escape codes
+    """
+    return RE_ANSI_REMOVE.sub("", string)
+
+
+def url_friendly_text(text):
+    """Convert text to url-friendly one"""
+    # we change special chars to ascii one,
+    # trick found at https://stackoverflow.com/a/3194567
+    text = unicodedata.normalize('NFD', text).encode('ascii', 'ignore').decode('utf-8')
+    text = RE_TEXT_URL.sub(' ', text).lower()
+    text = '-'.join([t for t in text.split() if t and len(t)>=TEXT_WORD_MIN_LENGHT])
+    while len(text) > TEXT_MAX_LEN:
+        if '-' in text:
+            text = text.rsplit('-', 1)[0]
+        else:
+            text = text[:TEXT_MAX_LEN]
+    return text