zulip/zerver/views/compatibility.py

72 lines
2.3 KiB
Python

from django.http import HttpResponse, HttpRequest
import re
from typing import Any, List, Dict, Optional, Tuple, Union
from zerver.lib.response import json_error, json_success
from zerver.lib.user_agent import parse_user_agent
def pop_numerals(ver: str) -> Tuple[List[int], str]:
match = re.search(r'^( \d+ (?: \. \d+ )* ) (.*)', ver, re.X)
if match is None:
return [], ver
numerals, rest = match.groups()
numbers = [int(n) for n in numerals.split('.')]
return numbers, rest
def version_lt(ver1: str, ver2: str) -> Optional[bool]:
'''
Compare two Zulip-style version strings.
Versions are dot-separated sequences of decimal integers,
followed by arbitrary trailing decoration. Comparison is
lexicographic on the integer sequences, and refuses to
guess how any trailing decoration compares to any other,
to further numerals, or to nothing.
Returns:
True if ver1 < ver2
False if ver1 >= ver2
None if can't tell.
'''
num1, rest1 = pop_numerals(ver1)
num2, rest2 = pop_numerals(ver2)
if not num1 or not num2:
return None
common_len = min(len(num1), len(num2))
common_num1, rest_num1 = num1[:common_len], num1[common_len:]
common_num2, rest_num2 = num2[:common_len], num2[common_len:]
# Leading numbers win.
if common_num1 != common_num2:
return common_num1 < common_num2
# More numbers beats end-of-string, but ??? vs trailing text.
# (NB at most one of rest_num1, rest_num2 is nonempty.)
if not rest1 and rest_num2:
return True
if rest_num1 and not rest2:
return False
if rest_num1 or rest_num2:
return None
# Trailing text we can only compare for equality.
if rest1 == rest2:
return False
return None
def find_mobile_os(user_agent: str) -> Optional[str]:
if re.search(r'\b Android \b', user_agent, re.I | re.X):
return 'android'
if re.search(r'\b(?: iOS | iPhone\ OS )\b', user_agent, re.I | re.X):
return 'ios'
return None
def check_global_compatibility(request: HttpRequest) -> HttpResponse:
user_agent = parse_user_agent(request.META["HTTP_USER_AGENT"])
if user_agent['name'] == "ZulipInvalid":
return json_error("Client is too old")
return json_success()