# -*- coding: utf-8 -*-

# Copyright 2015 Mike Fährmann
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.

"""Collection of functions that work in strings/text"""

import sys
import re
import os.path
import html.parser
import urllib.parse
import platform

def remove_html(text):
    """Remove html-tags from a string"""
    return " ".join(re.sub("<[^>]+?>", " ", text).split())

def filename_from_url(url):
    """Extract the last part of an url to use as a filename"""
    try:
        path = urllib.parse.urlparse(url).path
        pos = path.rindex("/")
        return path[pos+1:]
    except ValueError:
        return url

def clean_path_windows(path):
    """Remove illegal characters from a path-segment (Windows)"""
    try:
        return re.sub(r'[<>:"\\/|?*]', "_", path)
    except TypeError:
        return path

def clean_path_posix(path):
    """Remove illegal characters from a path-segment (Posix)"""
    try:
        return path.replace("/", "_")
    except AttributeError:
        return path

def shorten_path(path, limit=255, encoding=sys.getfilesystemencoding()):
    """Shorten a path segment to at most 'limit' bytes"""
    return (path.encode(encoding)[:limit]).decode(encoding, "ignore")

def shorten_filename(filename, limit=255, encoding=sys.getfilesystemencoding()):
    """Shorten a filename to at most 'limit' bytes while preserving extension"""
    name, extension = os.path.splitext(filename)
    bext = extension.encode(encoding)
    bname = name.encode(encoding)[:limit-len(bext)]
    return bname.decode(encoding, "ignore") + extension

def extract(txt, begin, end, pos=0):
    try:
        first = txt.index(begin, pos) + len(begin)
        last = txt.index(end, first)
        return txt[first:last], last+len(end)
    except ValueError:
        return None, pos

def extract_all(txt, rules, pos=0):
    """Calls extract for each rule and returns the result in a dict"""
    values = {}
    for key, begin, end in rules:
        result, pos = extract(txt, begin, end, pos)
        if key:
            values[key] = result
    return values, pos

if platform.system() == "Windows":
    clean_path = clean_path_windows
else:
    clean_path = clean_path_posix

unquote = urllib.parse.unquote

unescape = html.parser.HTMLParser().unescape