"""

    if isinstance(str_, unicode):

        return str_

    if not from_encoding:

        from kallithea.lib.vcs.conf import settings

        from_encoding = settings.DEFAULT_ENCODINGS

    if not isinstance(from_encoding, (list, tuple)):

        from_encoding = [from_encoding]

    try:

        return unicode(str_)

    except UnicodeDecodeError:

        pass

    for enc in from_encoding:

        try:

            return unicode(str_, enc)

        except UnicodeDecodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(str_)['encoding']

        if encoding is None:

            raise Exception()

        return str_.decode(encoding)

    except (ImportError, UnicodeDecodeError, Exception):

        return unicode(str_, from_encoding[0], 'replace')

def safe_str(unicode_, to_encoding=None):

    """

    safe str function. Does few trick to turn unicode_ into string

    In case of UnicodeEncodeError we try to return it with encoding detected

    by chardet library if it fails fallback to string with errors replaced

    :param unicode_: unicode to encode

    :rtype: str

    :returns: str object

    """

    # if it's not basestr cast to str

    if not isinstance(unicode_, basestring):

        return str(unicode_)

    if isinstance(unicode_, str):

        return unicode_

    if not to_encoding:

        from kallithea.lib.vcs.conf import settings

        to_encoding = settings.DEFAULT_ENCODINGS

    if not isinstance(to_encoding, (list, tuple)):

        to_encoding = [to_encoding]

    for enc in to_encoding:

        try:

            return unicode_.encode(enc)

        except UnicodeEncodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(unicode_)['encoding']

        if encoding is None:

            raise UnicodeEncodeError()

        return unicode_.encode(encoding)

    except (ImportError, UnicodeEncodeError):

        return unicode_.encode(to_encoding[0], 'replace')

def author_email(author):

    """

    returns email address of given author.

    If any of <,> sign are found, it fallbacks to regex findall()

    and returns first found result or empty string

    Regex taken from http://www.regular-expressions.info/email.html

    """

    if not author:

        return ''

    import re

    r = author.find('>')

    l = author.find('<')

    if l == -1 or r == -1:

        # fallback to regex match of email out of a string

        email_re = re.compile(r"""[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!"""

                              r"""#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z"""

                              r"""0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]"""

                              r"""*[a-z0-9])?""", re.IGNORECASE)

        m = re.findall(email_re, author)

def author_name(author):

    """

    get name of author, or else username.

    It'll try to find an email in the author string and just cut it off

    to get the username

    """

    if not author:

        return ''

    if not '@' in author:

        return author

    return author.replace(author_email(author), '').replace('<', '') \

        .replace('>', '').strip()