codekingpro/portable-devtools

1from __future__ import annotations2 3try:4    import winreg5except ImportError:6    winreg = None7 8import datetime9from typing import Any, Dict, cast10 11from babel.core import get_global12from babel.localtime._helpers import _get_tzinfo_or_raise13 14# When building the cldr data on windows this module gets imported.15# Because at that point there is no global.dat yet this call will16# fail.  We want to catch it down in that case then and just assume17# the mapping was empty.18try:19    tz_names: dict[str, str] = cast(Dict[str, str], get_global('windows_zone_mapping'))20except RuntimeError:21    tz_names = {}22 23 24def valuestodict(key) -> dict[str, Any]:25    """Convert a registry key's values to a dictionary."""26    dict = {}27    size = winreg.QueryInfoKey(key)[1]28    for i in range(size):29        data = winreg.EnumValue(key, i)30        dict[data[0]] = data[1]31    return dict32 33 34def get_localzone_name() -> str:35    # Windows is special. It has unique time zone names (in several36    # meanings of the word) available, but unfortunately, they can be37    # translated to the language of the operating system, so we need to38    # do a backwards lookup, by going through all time zones and see which39    # one matches.40    handle = winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE)41 42    TZLOCALKEYNAME = r'SYSTEM\CurrentControlSet\Control\TimeZoneInformation'43    localtz = winreg.OpenKey(handle, TZLOCALKEYNAME)44    keyvalues = valuestodict(localtz)45    localtz.Close()46    if 'TimeZoneKeyName' in keyvalues:47        # Windows 7 (and Vista?)48 49        # For some reason this returns a string with loads of NUL bytes at50        # least on some systems. I don't know if this is a bug somewhere, I51        # just work around it.52        tzkeyname = keyvalues['TimeZoneKeyName'].split('\x00', 1)[0]53    else:54        # Windows 2000 or XP55 56        # This is the localized name:57        tzwin = keyvalues['StandardName']58 59        # Open the list of timezones to look up the real name:60        TZKEYNAME = r'SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones'61        tzkey = winreg.OpenKey(handle, TZKEYNAME)62 63        # Now, match this value to Time Zone information64        tzkeyname = None65        for i in range(winreg.QueryInfoKey(tzkey)[0]):66            subkey = winreg.EnumKey(tzkey, i)67            sub = winreg.OpenKey(tzkey, subkey)68            data = valuestodict(sub)69            sub.Close()70            if data.get('Std', None) == tzwin:71                tzkeyname = subkey72                break73 74        tzkey.Close()75        handle.Close()76 77    if tzkeyname is None:78        raise LookupError('Can not find Windows timezone configuration')79 80    timezone = tz_names.get(tzkeyname)81    if timezone is None:82        # Nope, that didn't work. Try adding 'Standard Time',83        # it seems to work a lot of times:84        timezone = tz_names.get(f"{tzkeyname} Standard Time")85 86    # Return what we have.87    if timezone is None:88        raise LookupError(f"Can not find timezone {tzkeyname}")89 90    return timezone91 92 93def _get_localzone() -> datetime.tzinfo:94    if winreg is None:95        raise LookupError(96            'Runtime support not available')97 98    return _get_tzinfo_or_raise(get_localzone_name())99