# This file is part of beets.
# Copyright 2016, Adrian Sampson.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

"""Helpers around the extraction of album/track ID's from metadata sources."""

import re

# Spotify IDs consist of 22 alphanumeric characters
# (zero-left-padded base62 representation of randomly generated UUID4)
spotify_id_regex = {
    'pattern': r'(^|open\.spotify\.com/{}/)([0-9A-Za-z]{{22}})',
    'match_group': 2,
}

deezer_id_regex = {
    'pattern': r'(^|deezer\.com/)([a-z]*/)?({}/)?(\d+)',
    'match_group': 4,
}

beatport_id_regex = {
    'pattern': r'(^|beatport\.com/release/.+/)(\d+)$',
    'match_group': 2,
}

# A note on Bandcamp: There is no such thing as a Bandcamp album or artist ID,
# the URL can be used as the identifier. The Bandcamp metadata source plugin
# works that way - https://github.com/unrblt/beets-bandcamp. Bandcamp album
# URLs usually look like: https://nameofartist.bandcamp.com/album/nameofalbum


def extract_discogs_id_regex(album_id):
    """Returns the Discogs_id or None."""
    # Discogs-IDs are simple integers. In order to avoid confusion with
    # other metadata plugins, we only look for very specific formats of the
    # input string:
    # - plain integer, optionally wrapped in brackets and prefixed by an
    #   'r', as this is how discogs displays the release ID on its webpage.
    # - legacy url format: discogs.com/<name of release>/release/<id>
    # - current url format: discogs.com/release/<id>-<name of release>
    # See #291, #4080 and #4085 for the discussions leading up to these
    # patterns.
    # Regex has been tested here https://regex101.com/r/wyLdB4/2

    for pattern in [
            r'^\[?r?(?P<id>\d+)\]?$',
            r'discogs\.com/release/(?P<id>\d+)-',
            r'discogs\.com/[^/]+/release/(?P<id>\d+)',
    ]:
        match = re.search(pattern, album_id)
        if match:
            return int(match.group('id'))

    return None