def _parse_narrow_link(cls, link: str) -> ParsedNarrowLink:
"""
Returns either a dict with narrow parameters for supported links or an
empty dict.
"""
# NOTE: The optional stream_id link version is deprecated. The extended
# support is for old messages.
# We expect the fragment to be one of the following types:
# a. narrow/stream/[{stream_id}-]{stream-name}
# b. narrow/stream/[{stream_id}-]{stream-name}/near/{message_id}
# c. narrow/stream/[{stream_id}-]{stream-name}/topic/
# {encoded.20topic.20name}
# d. narrow/stream/[{stream_id}-]{stream-name}/topic/
# {encoded.20topic.20name}/near/{message_id}
fragments = urlparse(link.rstrip("/")).fragment.split("/")
len_fragments = len(fragments)
parsed_link = ParsedNarrowLink()
if len_fragments == 3 and fragments[1] == "stream":
stream_data = cls._decode_stream_data(fragments[2])
parsed_link = dict(narrow="stream", stream=stream_data)
elif (len_fragments == 5 and fragments[1] == "stream"
and fragments[3] == "topic"):
stream_data = cls._decode_stream_data(fragments[2])
topic_name = hash_util_decode(fragments[4])
parsed_link = dict(narrow="stream:topic",
stream=stream_data,
topic_name=topic_name)
elif len_fragments == 5 and fragments[1] == "stream" and fragments[
3] == "near":
stream_data = cls._decode_stream_data(fragments[2])
message_id = cls._decode_message_id(fragments[4])
parsed_link = dict(narrow="stream:near",
stream=stream_data,
message_id=message_id)
elif (len_fragments == 7 and fragments[1] == "stream"
and fragments[3] == "topic" and fragments[5] == "near"):
stream_data = cls._decode_stream_data(fragments[2])
topic_name = hash_util_decode(fragments[4])
message_id = cls._decode_message_id(fragments[6])
parsed_link = dict(
narrow="stream:topic:near",
stream=stream_data,
topic_name=topic_name,
message_id=message_id,
)
return parsed_link
def _decode_stream_data(encoded_stream_data: str) -> DecodedStream:
"""
Returns a dict with optional stream ID and stream name.
"""
# Modern links come patched with the stream ID and '-' as delimiters.
if re.match('^[0-9]+-', encoded_stream_data):
stream_id, *_ = encoded_stream_data.split('-')
# Given how encode_stream() in zerver/lib/url_encoding.py
# replaces ' ' with '-' in the stream name, skip extracting the
# stream name to avoid any ambiguity.
return DecodedStream(stream_id=int(stream_id), stream_name=None)
else:
# Deprecated links did not start with the stream ID.
stream_name = hash_util_decode(encoded_stream_data)
return DecodedStream(stream_id=None, stream_name=stream_name)
def test_hash_util_decode(quoted_string: str, expected_unquoted_string: str) -> None:
return_value = hash_util_decode(quoted_string)
assert return_value == expected_unquoted_string
