#!/usr/bin/env python3.12
# Eryn Wells <eryn@erynwells.me>

import argparse
import datetime
import os.path
import subprocess
from typing import Optional


def content_path() -> str:
    from os.path import abspath, dirname, join
    return abspath(join(dirname(__file__), '..', 'content'))


def next_sunday_noon() -> datetime.datetime:
    today = datetime.date.today()

    current_weekday = today.weekday()
    if current_weekday == 6:
        days_to_next_sunday = 6
    else:
        days_to_next_sunday = 6 - current_weekday

    delta = datetime.timedelta(days=days_to_next_sunday)

    noon = datetime.time(hour=12)

    timezone = datetime.datetime.now().astimezone().tzinfo
    next_sunday_noon = datetime.datetime.combine(
        today + delta,
        noon,
        tzinfo=timezone
    )

    return next_sunday_noon


def weeknotes_path(*, week_number: Optional[int] = None):
    if week_number:
        year = datetime.datetime.now().year
        week_number_str = str(week_number)
    else:
        next_sunday = next_sunday_noon()
        year = next_sunday.year
        week_number_str = next_sunday.strftime('%V')

    weeknotes_filename = f'weeknotes-{year}w{week_number_str}.md'
    return os.path.join(content_path(), 'blog', str(year), weeknotes_filename)


def parse_args(argv, *a, **kw):
    parser = argparse.ArgumentParser(*a, **kw)
    commands = parser.add_subparsers(title='Commands', required=True)

    convert_command = commands.add_parser(
        'convert',
        help='Convert a post from a single file to a page bundle and vice versa'
    )
    convert_command.set_defaults(handler=handle_convert_command)

    edit_command = commands.add_parser(
        'edit',
        help="Edit the current week's weeknotes post"
    )
    edit_command.add_argument(
        '--editor', '-e',
        default=os.environ['EDITOR'] or 'nvim',
    )
    edit_command.add_argument('--week', '-w')
    edit_command.set_defaults(handler=handle_edit_command)

    show_command = commands.add_parser(
        'show',
        aliases=['print'],
        help="Print a path to the current week's weeknotes post",
    )
    show_command.add_argument('--week', '-w')
    show_command.add_argument('--date', action='store_true')
    show_command.set_defaults(handler=handle_show_command)

    args = parser.parse_args(argv)
    return args


def handle_convert_command(args):
    raise NotImplementedError()


def handle_edit_command(args):
    path = weeknotes_path(week_number=args.week)
    subprocess.run(
        f'{args.editor} "{path}"',
        stdin=sys.stdin,
        stdout=sys.stdout,
        stderr=sys.stderr,
        env=os.environ,
        shell=True,
    )


def handle_show_command(args):
    if args.date:
        if args.week:
            raise NotImplementedError('Cannot print date with specified week number')
        print(next_sunday_noon().isoformat())
    else:
        print(weeknotes_path(week_number=args.week))


def main(argv):
    args = parse_args(argv[1:], prog=argv[0])
    args.handler(args)

if __name__ == '__main__':
    import sys
    result = main(sys.argv)
    sys.exit(0 if not result else result)