"""
Utilities for XML generation/parsing.
"""

import six

from xml.sax.saxutils import XMLGenerator, quoteattr
from urllib.parse import quote
from rhodecode.lib.str_utils import safe_str


class SimplerXMLGenerator(XMLGenerator):
    def addQuickElement(self, name, contents=None, attrs=None):
        "Convenience method for adding an element with no children"
        if attrs is None:
            attrs = {}
        self.startElement(name, attrs)
        if contents is not None:
            self.characters(contents)
        self.endElement(name)

    def startElement(self, name, attrs):
        self._write('<' + name)
        # sort attributes for consistent output
        for (name, value) in sorted(attrs.items()):
            self._write(' %s=%s' % (name, quoteattr(value)))
        self._write(six.u('>'))


def iri_to_uri(iri):
    """
    Convert an Internationalized Resource Identifier (IRI) portion to a URI
    portion that is suitable for inclusion in a URL.
    This is the algorithm from section 3.1 of RFC 3987.  However, since we are
    assuming input is either UTF-8 or unicode already, we can simplify things a
    little from the full method.
    Returns an ASCII string containing the encoded result.
    """
    # The list of safe characters here is constructed from the "reserved" and
    # "unreserved" characters specified in sections 2.2 and 2.3 of RFC 3986:
    #     reserved    = gen-delims / sub-delims
    #     gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"
    #     sub-delims  = "!" / "$" / "&" / "'" / "(" / ")"
    #                   / "*" / "+" / "," / ";" / "="
    #     unreserved  = ALPHA / DIGIT / "-" / "." / "_" / "~"
    # Of the unreserved characters, urllib.quote already considers all but
    # the ~ safe.
    # The % character is also added to the list of safe characters here, as the
    # end of section 3.1 of RFC 3987 specifically mentions that % must not be
    # converted.
    if iri is None:
        return iri
    return quote(safe_str(iri), safe=b"/#%[]=:;$&()+,!?*@'~")


def force_text(text, strings_only=False):
    return safe_str(text)