team-1/backend/src/room.py

from dataclasses import dataclass

from .song import Song

USER_SCORE_WEIGHT = 0.7
ARTIST_WEIGHT = 0.1
TAG_WEIGHT = 0.1
RANDOM_WEIGHT = 0.1
RECENT_PENALTY = 0.5
RECENT_COUNT = 10


type UserScoredSong = tuple[Song, int]


@dataclass
class Room:
    id: int
    coord: tuple[float, float]
    name: str
    pin: int | None
    tags: set[str]

    songs: dict[str, UserScoredSong]  # canzoni + voto
    history: list[Song]  # canzoni riprodotte (in ordine)
    playing: list[Song]  # canzoni che sono i riproduzione

    def rank_song(self, song: Song, user_score: int) -> float:
        rank = 0.0
        song_items = self.songs.items()

        lowest_score = min(song_items, key=lambda item: item[1][1])[1][1]
        highest_score = min(song_items, key=lambda item: item[1][1])[1][1]

        rank += translate(user_score, lowest_score, highest_score, 0.0, USER_SCORE_WEIGHT)

        recent_songs = self.history[-RECENT_COUNT:]

        tag_counts = {}
        artist_counts = {}
        for song in recent_songs:
            for tag in song.tags:
                if tag not in tag_counts:
                    tag_counts[tag] = 0
                tag_counts[tag] += 1
            if song.artist not in artist_counts:
                artist_counts[song.artist] = 0
            artist_counts[song.artist] += 1

        tag_total = 0
        for tag in song.tags:
            if tag in tag_counts:
                tag_total += tag_counts[tag]

        rank += translate(tag_total, 0, RECENT_COUNT, 0, TAG_WEIGHT)
        rank += translate(artist_counts[song.artist], 0, RECENT_COUNT, 0, ARTIST_WEIGHT)

        if song in recent_songs:
            rank -= RECENT_PENALTY

        return rank


def translate(value: float, in_min: float, in_max: float, out_min: float, out_max: float):
    return (value - in_min) / (in_max - in_min) * (out_max - out_min) + out_min