# -*- coding: utf-8 -*-
#
# Copyright (C) 2003-2006 Edgewall Software
# Copyright (C) 2003-2004 Jonas Borgström <jonas@edgewall.com>
# Copyright (C) 2006 Matthew Good <trac@matt-good.net>
# Copyright (C) 2005-2006 Christian Boos <cboos@neuf.fr>
# All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at http://trac.edgewall.com/license.html.
#
# This software consists of voluntary contributions made by many
# individuals. For exact contribution history, see the revision
# history and logs, available at http://projects.edgewall.com/trac/.
#
# Author: Jonas Borgström <jonas@edgewall.com>
#         Matthew Good <trac@matt-good.net>

import locale
import md5
import os
import re
import sys
import time
import tempfile
from urllib import quote, unquote, urlencode

# Imports for backward compatibility
from trac.core import TracError
from trac.util.markup import escape, unescape, Markup, Deuglifier
from trac.util.text import CRLF, to_utf8, to_unicode, shorten_line, \
                           wrap, pretty_size
from trac.util.datefmt import pretty_timedelta, format_datetime, \
                              format_date, format_time, \
                              get_date_format_hint, \
                              get_datetime_format_hint, http_date, \
                              parse_date

# -- req/session utils

def get_reporter_id(req, arg_name=None):
    if req.authname != 'anonymous':
        return req.authname
    if arg_name:
        r = req.args.get(arg_name)
        if r:
            return r
    name = req.session.get('name', None)
    email = req.session.get('email', None)
    if name and email:
        return '%s <%s>' % (name, email)
    return name or email or req.authname # == 'anonymous'


# -- algorithmic utilities

try:
    reversed = reversed
except NameError:
    def reversed(x):
        if hasattr(x, 'keys'):
            raise ValueError('mappings do not support reverse iteration')
        i = len(x)
        while i > 0:
            i -= 1
            yield x[i]

try:
    sorted = sorted
except NameError:
    def sorted(iterable, cmp=None, key=None, reverse=False):
        """Partial implementation of the "sorted" function from Python 2.4"""
        if key is None:
            lst = list(iterable)
        else:
            lst = [(key(val), idx, val) for idx, val in enumerate(iterable)]
        lst.sort()
        if key is None:
            if reverse:
                return lst[::-1]
            return lst
        if reverse:
            lst = reversed(lst)
        return [i[-1] for i in lst]

DIGITS = re.compile(r'(\d+)')
def embedded_numbers(s):
    """Comparison function for natural order sorting based on
    http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/214202."""
    pieces = DIGITS.split(s)
    pieces[1::2] = map(int, pieces[1::2])
    return pieces


# -- os utilities

def create_unique_file(path):
    """Create a new file. An index is added if the path exists"""
    parts = os.path.splitext(path)
    idx = 1
    while 1:
        try:
            flags = os.O_CREAT + os.O_WRONLY + os.O_EXCL
            if hasattr(os, 'O_BINARY'):
                flags += os.O_BINARY
            return path, os.fdopen(os.open(path, flags), 'w')
        except OSError:
            idx += 1
            # A sanity check
            if idx > 100:
                raise Exception('Failed to create unique name: ' + path)
            path = '%s.%d%s' % (parts[0], idx, parts[1])


class NaivePopen:
    """This is a deadlock-safe version of popen that returns an object with
    errorlevel, out (a string) and err (a string).

    The optional `input`, which must be a `str` object, is first written
    to a temporary file from which the process will read.
    
    (`capturestderr` may not work under Windows 9x.)

    Example: print Popen3('grep spam','\n\nhere spam\n\n').out
    """
    def __init__(self, command, input=None, capturestderr=None):
        outfile = tempfile.mktemp()
        command = '( %s ) > %s' % (command, outfile)
        if input:
            infile = tempfile.mktemp()
            tmp = open(infile, 'w')
            tmp.write(input)
            tmp.close()
            command = command + ' <' + infile
        if capturestderr:
            errfile = tempfile.mktemp()
            command = command + ' 2>' + errfile
        try:
            self.err = None
            self.errorlevel = os.system(command) >> 8
            outfd = file(outfile, 'r')
            self.out = outfd.read()
            outfd.close()
            if capturestderr:
                errfd = file(errfile,'r')
                self.err = errfd.read()
                errfd.close()
        finally:
            if os.path.isfile(outfile):
                os.remove(outfile)
            if input and os.path.isfile(infile):
                os.remove(infile)
            if capturestderr and os.path.isfile(errfile):
                os.remove(errfile)

# -- sys utils

def get_last_traceback():
    import traceback
    from StringIO import StringIO
    tb = StringIO()
    traceback.print_exc(file=tb)
    return tb.getvalue()

def safe__import__(module_name):
    """
    Safe imports: rollback after a failed import.
    
    Initially inspired from the RollbackImporter in PyUnit,
    but it's now much simpler and works better for our needs.
    
    See http://pyunit.sourceforge.net/notes/reloading.html
    """
    already_imported = sys.modules.copy()
    try:
        return __import__(module_name, globals(), locals(), [])
    except Exception, e:
        for modname in sys.modules.copy():
            if not already_imported.has_key(modname):
                del(sys.modules[modname])
        raise e


# -- crypto utils

def hex_entropy(bytes=32):
    import md5
    import random
    return md5.md5(str(random.random())).hexdigest()[:bytes]


# Original license for md5crypt:
# Based on FreeBSD src/lib/libcrypt/crypt.c 1.2
#
# "THE BEER-WARE LICENSE" (Revision 42):
# <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
# can do whatever you want with this stuff. If we meet some day, and you think
# this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
def md5crypt(password, salt, magic='$1$'):
    # /* The password first, since that is what is most unknown */
    # /* Then our magic string */
    # /* Then the raw salt */
    m = md5.new()
    m.update(password + magic + salt)

    # /* Then just as many characters of the MD5(pw,salt,pw) */
    mixin = md5.md5(password + salt + password).digest()
    for i in range(0, len(password)):
        m.update(mixin[i % 16])

    # /* Then something really weird... */
    # Also really broken, as far as I can tell.  -m
    i = len(password)
    while i:
        if i & 1:
            m.update('\x00')
        else:
            m.update(password[0])
        i >>= 1

    final = m.digest()

    # /* and now, just to make sure things don't run too fast */
    for i in range(1000):
        m2 = md5.md5()
        if i & 1:
            m2.update(password)
        else:
            m2.update(final)

        if i % 3:
            m2.update(salt)

        if i % 7:
            m2.update(password)

        if i & 1:
            m2.update(final)
        else:
            m2.update(password)

        final = m2.digest()

    # This is the bit that uses to64() in the original code.

    itoa64 = './0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'

    rearranged = ''
    for a, b, c in ((0, 6, 12), (1, 7, 13), (2, 8, 14), (3, 9, 15), (4, 10, 5)):
        v = ord(final[a]) << 16 | ord(final[b]) << 8 | ord(final[c])
        for i in range(4):
            rearranged += itoa64[v & 0x3f]; v >>= 6

    v = ord(final[11])
    for i in range(2):
        rearranged += itoa64[v & 0x3f]; v >>= 6

    return magic + salt + '$' + rearranged