Local/Remote Time Converter

timeconv.py

#!/usr/bin/env python3
# vim: fileencoding=utf-8 ff=unix
from datetime import datetime
from zoneinfo import ZoneInfo
import argparse, os, time


def get_args():
	parser = argparse.ArgumentParser(
		description='Local/Remote Time Converter'
	)
	parser.add_argument(
		'--no-color'
		, action='store_true'
		, default='TERM' not in os.environ
			or 'color' not in os.environ['TERM'].lower()
		, help='disable color display'
	)
	parser.add_argument(
		'-l', '--local-timezone'
		, type=str
		, metavar='TIMEZONE'
		, default=os.environ['TZ'] if 'TZ' in os.environ else 'UTC'
		, help='local timezone name (default: env TZ value or "UTC")'
	)
	parser.add_argument(
		'-r', '--remote-timezone'
		, type=ZoneInfo
		, metavar='TIMEZONE'
		, default=os.environ['TZ'] if 'TZ' in os.environ else 'UTC'
		, help='remote timezone name (default: env TZ value or "UTC")'
	)
	parser.add_argument(
		'datetimes'
		, type=datetime.fromisoformat
		, metavar='DATETIME'
		, nargs='*'
		, help='date/time in ISO format (default: now)'
	)
	return parser.parse_args()


def ansi(s, fg=7, bg=0, fx=0):
	return '\x1b[%d;3%d;4%dm%s\x1b[0m' % (fx, fg, bg, s)


def ansi_output(dt, remotedt):
	print(
		ansi("     Local Time ", bg=1)
		+ ansi(f" {dt} ", fg=1)
	)
	print(
		ansi("    Remote Time ", bg=2)
		+ ansi(f" {remotedt} ", fg=2)
	)
	print(
		ansi("       Timezone ", bg=3)
		+ ansi(f" {remotedt.tzname()} ", fg=3)
	)
	print(
		ansi(" DST Adjustment ", bg=4)
		+ ansi(f" {remotedt.dst()} ", fg=4)
	)


def normal_output(dt, remotedt):
	print(f"    Local Time: {dt}")
	print(f"   Remote Time: {remotedt}")
	print(f"      Timezone: {remotedt.tzname()}")
	print(f"DST Adjustment: {remotedt.dst()}")


def conv_datetime(dt: datetime, tzinfo: ZoneInfo, fn_render):
	'''Convert and display local time to remote time'''
	remotedt = dt.astimezone(tzinfo)
	fn_render(dt, remotedt)


def main():
	args = get_args()
	os.environ['TZ'] = args.local_timezone
	time.tzset()
	fn_output = normal_output if args.no_color else ansi_output
	if args.datetimes:
		for dt in args.datetimes:
			conv_datetime(dt, args.remote_timezone, fn_output)
	else:
		conv_datetime(datetime.now(), args.remote_timezone, fn_output)


if '__main__' == __name__:
	main()