import argparse
import collections
import os
import re
import sys
import typing

import symuid
from symuid._uuid import generate_uuid4_bytes


def _log_path(track_path, msg, stream=None):
    if not stream:  # pytest capsys
        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(tracks: typing.Iterator[symuid.Track], play_count_added_cb=None):
    sync_positions = collections.defaultdict(_SyncPosition)
    for track in tracks:
        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 _walk_tracks(
    paths: typing.List[str],
    path_ignore_regex=None,
    ignored_cb=None,
    unsupported_cb=None,
) -> typing.Iterator[symuid.Track]:
    for path in paths:
        if os.path.isdir(path):
            for track in symuid.Track.walk(
                root_path=path,
                path_ignore_regex=path_ignore_regex,
                ignored_cb=ignored_cb,
                unsupported_cb=unsupported_cb,
            ):
                yield track
        else:
            yield symuid.Track(path)


def _main():
    argparser = argparse.ArgumentParser(description=None)
    argparser.add_argument(
        "paths", metavar="path", nargs="+", help="track or folder containing tracks",
    )
    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",
    )
    args = argparser.parse_args()
    tracks = _walk_tracks(
        paths=args.paths,
        path_ignore_regex=args.path_ignore_regex,
        ignored_cb=lambda p: args.show_ignored and _log_path(p, "ignored"),
        unsupported_cb=lambda p, e: _log_path_error(p, "unsupported type, skipped"),
    )
    sync(
        tracks=tracks,
        play_count_added_cb=lambda track, tag: _log_path(
            track.path, "added play count tag {!r}".format(tag)
        ),
    )