# -*- coding: iso-8859-1 -*-
"""Various string utility functions. Note that these functions are not
   necessarily optimised for large strings, so use with care."""
# Copyright (C) 2000-2004  Bastian Kleineidam
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

import re
import textwrap
import sys
import os
import time


def unquote (s):
    """if string s is not empty, strip quotes from s"""
    if not s:
        return s
    if len(s) < 2:
        return s
    if s[0] in ("\"'"):
        s = s[1:]
    if s[-1] in ("\"'"):
        s = s[:-1]
    return s


_para_mac = r"(?:%(sep)s)(?:(?:%(sep)s)\s*)+" % {'sep': '\r'}
_para_posix = r"(?:%(sep)s)(?:(?:%(sep)s)\s*)+" % {'sep': '\n'}
_para_win = r"(?:%(sep)s)(?:(?:%(sep)s)\s*)+" % {'sep': '\r\n'}
_para_ro = re.compile("%s|%s|%s" % (_para_mac, _para_posix, _para_win))

def get_paragraphs (text):
    """A new paragraph is considered to start at a line which follows
       one or more blank lines (lines containing nothing or just spaces).
       The first line of the text also starts a paragraph.
    """
    if not text:
        return []
    return _para_ro.split(text)


def wrap (text, width, **kwargs):
    """Adjust lines of text to be not longer than width. The text will be
       returned unmodified if width <= 0.
       See textwrap.wrap() for a list of supported kwargs.
       Returns text with lines no longer than given width.
    """
    if width <= 0 or not text:
        return text
    ret = []
    for para in get_paragraphs(text):
        ret.extend(textwrap.wrap(para.strip(), width, **kwargs))
    return os.linesep.join(ret)


def get_line_number (s, index):
    """Return the line number of s[index]. Lines are assumed to be separated
       by the ASCII character '\\n'"""
    i = 0
    if index < 0:
        index = 0
    line = 1
    while i < index:
        if s[i] == '\n':
            line += 1
        i += 1
    return line


def paginate (text, lines=22):
    """print text in pages of lines"""
    curline = 1
    for line in text.splitlines():
        print line
        curline += 1
        isatty = hasattr(sys.stdin, "isatty") and sys.stdin.isatty()
        if curline >= lines and isatty:
            curline = 1
            print "press return to continue..."
            sys.stdin.read(1)


_markup_re = re.compile("<.*?>", re.DOTALL)

def remove_markup (s):
    """remove all <*> html markup tags from s"""
    mo = _markup_re.search(s)
    while mo:
        s = s[0:mo.start()] + s[mo.end():]
        mo = _markup_re.search(s)
    return s


def strsize (b):
    """Return human representation of bytes b. A negative number of bytes
       raises a value error.
    """
    if b < 0:
        raise ValueError("Invalid negative byte number")
    if b == 1:
        return u"%d Byte" % b
    if b < 1024:
        return u"%d Bytes" % b
    b /= 1024.0
    if b < 1024:
        return u"%.2f kB" % b
    b /= 1024.0
    if b < 1024:
        return u"%.2f MB" % b
    b /= 1024.0
    return u"%.2f GB"


def strtime (t):
    """return ISO 8601 formatted time"""
    return time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(t)) + \
           strtimezone()


def strduration (duration):
    """return translated and formatted time duration"""
    name = _("seconds")
    if duration > 60:
        duration = duration / 60
        name = _("minutes")
    if duration > 60:
        duration = duration / 60
        name = _("hours")
    return u" %.3f %s" % (duration, name)


def strtimezone ():
    """return timezone info, %z on some platforms, but not supported on all"""
    if time.daylight:
        zone = time.altzone
    else:
        zone = time.timezone
    return "%+04d" % int(-zone/3600)