#!/usr/bin/env python3
# Copyright 2024 vgm+dev@devys.org
# SPDX-License-Identifier: MIT

'''
Simple and fancy sleep for console.

Time can be precised as [DDd][HHh][MMm][SS[s]]. Number of digits for days,
hours, minutes or seconds are not restricted. Every type (days, hours,
minutes, seconds) are optional, but at least one must be given. If no suffix
is given, it means seconds. Spaces between group of types can be given but
TIME as a whole must be a single argument.

Time can also be given as HH:MM or HH:MM:SS.

An optional command to run at the end of the time can be given.

Usage: fancy-sleep [options] TIME [--] [COMMAND...]
       fancy-sleep -h|--help

Options:
  -h, --help  Display this help message
  --target   Enable the display of the target time

'''


import contextlib
import datetime
import os
import re
import sys
import termios
import time

import docopt


# to avoid accidental trailing spaces removal, use another character and
# replace.
NUMBERS = [i.replace('.', ' ') for i in (
    """\
 ██████
 ██  ██
 ██  ██
 ██  ██
 ██████
""",
    """\
     ██
     ██
     ██
     ██
     ██
""",
    """\
 ██████
     ██
 ██████
 ██....
 ██████
""",
    """\
 ██████
     ██
 ██████
     ██
 ██████
""",
    """\
 ██  ██
 ██  ██
 ██████
     ██
     ██
""",
    """\
 ██████
 ██....
 ██████
     ██
 ██████
""",
    """\
 ██████
 ██....
 ██████
 ██  ██
 ██████
""",
    """\
 ██████
     ██
     ██
     ██
     ██
""",
    """\
 ██████
 ██  ██
 ██████
 ██  ██
 ██████
""",
    """\
 ██████
 ██  ██
 ██████
     ██
 ██████
""",
    """\
    .
  ██.
    .
  ██.
    .
""",
)]
NUMBERS_LINES = 5


def print_translated(string):
    'print 09:30 style time to big:numbers'
    translated = []
    for character in string:
        index = 0
        if character >= '0' and character <= '9':
            index = ord(character) - ord('0')
        elif character == ':':
            index = 10
        translated.append(NUMBERS[index])
    display_lines = ['', '', '', '', '', '']
    for index in range(5):
        for number in translated:
            display_lines[index] += number.splitlines()[index]
    print('\n'.join(display_lines), end='')


def parse_time(times, time_pattern=re.compile(r'(\d+)([dhms]?)')):
    'return a cumulative datetime.timedelta from time string (times)'
    default = datetime.datetime.strptime('0', '%S')
    timedelta = datetime.timedelta()
    try:
        timedelta += datetime.datetime.strptime(times, '%H:%M:%S') - default
        return timedelta
    except ValueError:
        try:
            timedelta += datetime.datetime.strptime(times, '%H:%M') - default
            return timedelta
        except ValueError:
            pass
    for match in time_pattern.finditer(times):
        if match.group(2) == 'd':
            timedelta += datetime.timedelta(days=float(match.group(1)))
        elif match.group(2) == 'h':
            timedelta += datetime.timedelta(hours=float(match.group(1)))
        elif match.group(2) == 'm':
            timedelta += datetime.timedelta(minutes=float(match.group(1)))
        elif match.group(2) == 's' or match.group(2) == '':
            timedelta += datetime.timedelta(seconds=float(match.group(1)))
    return timedelta


def test_parse_time():
    'test parse_time function (callable with pytest-3)'
    assert parse_time('11') \
            == datetime.timedelta(seconds=11)
    assert parse_time('11s') \
            == datetime.timedelta(seconds=11)
    assert parse_time('11s') == parse_time('11')
    assert parse_time('11h 47m') \
            == datetime.timedelta(hours=11, minutes=47)
    assert parse_time('11h 47m') == parse_time('0d11h47m0s')
    assert parse_time('11h 47') \
            == datetime.timedelta(hours=11, seconds=47)
    assert parse_time('11h 47') == parse_time('11h47s')
    assert parse_time('11h 47m 09') \
            == datetime.timedelta(hours=11, minutes=47, seconds=9)
    assert parse_time('11h 47m 09') == parse_time('11h47m9s')
    assert parse_time('09:53') \
            == datetime.timedelta(hours=9, minutes=53)
    assert parse_time('09:53') == parse_time('09h 53m')
    assert parse_time('8:2') \
            == datetime.timedelta(hours=8, minutes=2)
    assert parse_time('8:2') == parse_time('08:02')
    assert parse_time('8d 6s') \
            == datetime.timedelta(days=8, seconds=6)
    assert parse_time('8d 6s') == parse_time('8d6s')


def get_hms_from_secs(seconds):
    hours = int(seconds / 3600)
    minutes = int(seconds / 60) % 60
    seconds = int(seconds) % 60
    return hours, minutes, seconds


def get_hms_string_from_secs(seconds):
    hours, minutes, seconds = get_hms_from_secs(seconds)
    time_string = '%02d:%02d:%02d' % (hours, minutes, seconds)
    return time_string


def fancy_sleep_display(target_time):
    original_termios_attr = termios.tcgetattr(sys.stdout)
    noecho_termios_attr = original_termios_attr[:]
    noecho_termios_attr[3] &= ~termios.ECHO
    termios.tcsetattr(sys.stdout, termios.TCSANOW, noecho_termios_attr)
    try:
        while True:
            delta = target_time - time.time()
            if delta <= 0:
                break
            #print('\x1b[s', end='') # save cursor
            print_translated(get_hms_string_from_secs(delta))
            print(f'\x1b[{NUMBERS_LINES}A', end='') # go up 5 lines up
            #print('\x1b[u', end='') # restore cursor
            time.sleep(1)
    finally:
        print('\x1b[5B', end='') # go up 5 lines down
        termios.tcsetattr(sys.stdout, termios.TCSANOW, original_termios_attr)


def main():
    'function called only when script invoked directly on command line'
    args = docopt.docopt(__doc__)
    isatty = sys.stdout.isatty()
    curtime = datetime.datetime.now().replace(microsecond=0)
    timedelta = parse_time(args['TIME'])
    target_time = curtime + timedelta

    if timedelta == datetime.timedelta(0):
        print('ERROR: TIME is unparsable or equals to 0', file=sys.stderr)
        sys.exit(1)

    if args['--target']:
        print('Run until:', target_time.strftime('%F %T'))
    sys.stdout.flush()

    interrupted = False
    try:
        if not isatty:
            time.sleep(target_time.timestamp() - time.time())
        else:
            fancy_sleep_display(int(target_time.timestamp()))
    except KeyboardInterrupt:
        interrupted = True
    if isatty:
        print('slept for', get_hms_string_from_secs(
            time.time() - int(curtime.timestamp())))
    if interrupted:
        sys.exit(130)

    if args['COMMAND']:
        os.execvp(args['COMMAND'][0], args['COMMAND'])


if __name__ == '__main__':
    main()