#!/usr/bin/python3

from datetime import datetime, timedelta
import argparse
import os
import random
import shutil
import string

DEL_TIME = '.delete_in'

def parse_opts():
    class _HelpAction(argparse._HelpAction):
        def __call__(self, parser, namespace, values, option_string=None):
            parser.print_help()
            print("")
            # retrieve subparsers from parser
            subparsers_actions = [
                action for action in parser._actions
                if isinstance(action, argparse._SubParsersAction)
            ]
            for subparsers_action in subparsers_actions:
                # get all subparsers and print help
                for choice, subparser in subparsers_action.choices.items():
                    print("Command: {}".format(choice))
                    print(subparser.format_help())

            parser.exit()

    parser = argparse.ArgumentParser(add_help=False)
    parser.add_argument(
        '--help', '-h',
        action = _HelpAction,
        help = 'Show this help message and exit'
    )

    subparsers = parser.add_subparsers(
        dest="command",
        help = "Command defaults to add"
    )
    add_parser = subparsers.add_parser('add', add_help=False)
    add_parser.add_argument(
        "days",
        action = "store",
        type = int,
        help = "Days to keep files",
        default = 30,
        nargs = '?'
    )
    add_parser = subparsers.add_parser('list', add_help=False)
    add_parser = subparsers.add_parser('del', add_help=False)
    return parser.parse_args()

def random_char():
    return random.choice(string.ascii_uppercase + string.digits)


def random_name():
    chars = [random_char() for x in range(6)]
    chars.insert(3, '-')
    return ''.join(chars)


def create_new(p, days):
    os.mkdir(p)
    with open(os.path.join(p, DEL_TIME), 'wt') as fp:
        fp.write(str(days))


def get_stats(p):
    try:
        with open(os.path.join(p, DEL_TIME), 'rt') as fp:
            do_del = int(fp.read(64))
        now = datetime.now()
        mtime = datetime.fromtimestamp( os.path.getmtime(os.path.join(p, DEL_TIME)) )
        del_delta = timedelta(days = do_del)
        del_time = mtime + del_delta
        to_del_time = del_time - now
        is_due = now > del_time
        return mtime, del_time, to_del_time, is_due
    except Exception as e:
        print(e)
        return (None, None, False)


def get_sub_files(p):
    file_list = sorted([x for x in os.listdir(p) if not x.startswith(".")])
    dir_list = [x + "/" for x in file_list if os.path.isdir(os.path.join(p, x))]
    file_list = [x for x in file_list if os.path.isfile(os.path.join(p, x))]
    return dir_list + file_list


def get_folder_names():
    dir_list = [(p,os.path.getmtime(os.path.join(p, DEL_TIME))) for p in os.listdir(".") if os.path.exists(os.path.join(p, DEL_TIME))]
    dir_list.sort(key = lambda t: -t[1])
    return [p[0] for p in dir_list]


def list_folders():
    names = get_folder_names()
    print("Folder   Created    ToDelete    InDays")
    for p in names:
        stats = get_stats(p)
        sub_files = get_sub_files(p)
        due = "*" if stats[3] else ""
        print("{}/ {} {} {: 3d}d{}".format(
            p,
            stats[0].isoformat()[0:10],
            stats[1].isoformat()[0:10],
            stats[2].days,
            due
        ))
        for sp in sub_files:
            print("  {}".format(sp))
        #print(p, stats, sub_files)


def del_due_folders():
    names = get_folder_names()
    for p in names:
        stats = get_stats(p)
        due = stats[3]
        if due:
            print("Deleting {}".format(p))
            shutil.rmtree(p)


if __name__ == '__main__':
    opts = parse_opts()

    if opts.command == 'add':
        new_name = random_name()
        while os.path.exists(new_name):
            new_name = random_name()
        create_new(new_name, opts.days)
        print(os.path.abspath(new_name))

    if opts.command == "list" or opts.command == None:
        list_folders()

    if opts.command == "del":
        del_due_folders()