import argparse
import collections
import re
import sys
import typing

import symuid
from symuid._uuid import generate_uuid4_bytes


def _log_path(track_path, msg, stream=sys.stdout):
    stream.write("{!r}: {}\n".format(track_path, msg))


def _log_path_error(track_path, msg):
    _log_path(track_path, msg, stream=sys.stderr)


class _SyncPosition:

    def __init__(self):
        self._tracks = set() # type: typing.Set[symuid.Track]
        self._play_counts = set() # type: typing.Set[symuid.PlayCount]

    def add_track(self, track: symuid.Track) -> None:
        self._tracks.add(track)
        self._play_counts.update(track.get_play_counts())

    def sync(self, play_count_added_cb=None) -> None:
        for track in self._tracks:
            track_play_counts = set(track.get_play_counts())
            for play_count in self._play_counts:
                if play_count not in track_play_counts:
                    track.register_play_count(
                        play_count, tag_set_cb=play_count_added_cb)

    def __repr__(self) -> str:
        return repr(vars(self))

def sync(path, path_ignore_regex, show_ignored=False,
         play_count_added_cb=None):
    sync_positions = collections.defaultdict(_SyncPosition)
    for track in symuid.Track.walk(
            root_path=path,
            path_ignore_regex=path_ignore_regex,
            ignored_cb=lambda p: show_ignored and _log_path(p, 'ignored'),
            unsupported_cb=lambda p, e:
                _log_path_error(p, 'unsupported type, skipped'),
    ):
        if track.get_uuid() is None:
            track.assign_uuid(generate_uuid4_bytes())
            _log_path(track.path, 'assigned uuid {!r}'.format(
                track.get_uuid()))
        sync_positions[track.get_uuid()].add_track(track)
    for sync_position in sync_positions.values():
        sync_position.sync(play_count_added_cb=play_count_added_cb)


def _init_argparser():
    argparser = argparse.ArgumentParser(description=None)
    argparser.add_argument('path')
    argparser.add_argument(
        '--path-ignore-regex',
        default=symuid.Track.PATH_DEFAULT_IGNORE_REGEX,
        nargs=1,
        metavar='pattern',
        dest='path_ignore_regex',
        type=re.compile,
        help='(default: %(default)s)',
    )
    argparser.add_argument(
        '--show-ignored',
        action='store_true',
    )
    return argparser


def _main():
    argparser = _init_argparser()
    args = argparser.parse_args()
    sync(**vars(args))