tempus/app/src/main/java/com/cappielloantonio/play/util/MusicUtil.java

package com.cappielloantonio.play.util;

import android.content.Context;

import com.cappielloantonio.play.App;
import com.cappielloantonio.play.R;
import com.cappielloantonio.play.glide.CustomGlideRequest;
import com.cappielloantonio.play.model.Song;
import com.google.android.exoplayer2.MediaItem;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Random;

public class MusicUtil {
    private static final String TAG = "MusicUtil";

    public static String getSongFileUri(Song song) {
        String url = App.getSubsonicClientInstance(App.getInstance(), false).getUrl();

        Map<String, String> params = App.getSubsonicClientInstance(App.getInstance(), false).getParams();

        return url + "stream" +
                "?u=" + params.get("u") +
                "&s=" + params.get("s") +
                "&t=" + params.get("t") +
                "&v=" + params.get("v") +
                "&c=" + params.get("c") +
                "&id=" + song.getId();
    }

    public static String getReadableDurationString(long duration, boolean millis) {
        long minutes = 0;
        long seconds = 0;

        if(millis) {
            minutes = (duration / 1000) / 60;
            seconds = (duration / 1000) % 60;
        }
        else {
            minutes = duration / 60;
            seconds = duration % 60;
        }


        if (minutes < 60) {
            return String.format(Locale.getDefault(), "%01d:%02d", minutes, seconds);
        } else {
            long hours = minutes / 60;
            minutes = minutes % 60;
            return String.format(Locale.getDefault(), "%d:%02d:%02d", hours, minutes, seconds);
        }
    }

    public static int getDefaultPicPerCategory(String category) {
        if (category.equals(CustomGlideRequest.SONG_PIC)) {
            return R.drawable.default_album_art;
        } else if (category.equals(CustomGlideRequest.ALBUM_PIC)) {
            return R.drawable.default_album_art;
        } else if (category.equals(CustomGlideRequest.ARTIST_PIC)) {
            return R.drawable.default_album_art;
        } else if (category.equals(CustomGlideRequest.PLAYLIST_PIC)) {
            return R.drawable.default_album_art;
        } else {
            return R.drawable.default_album_art;
        }
    }

    public static List<MediaItem> getMediaItemsFromSongs(List<Song> songs) {
        List<MediaItem> mediaItems = new ArrayList<>();

        for (Song song : songs) {
            mediaItems.add(getMediaItemFromSong(song));
        }

        return mediaItems;
    }

    public static MediaItem getMediaItemFromSong(Song song) {
        String uri = MusicUtil.getSongFileUri(song);
        MediaItem mediaItem = MediaItem.fromUri(uri);
        return mediaItem;
    }

    public static List<Integer> getRandomSongNumber(Context context, int numberOfNumbers, int refreshAfterXHours) {
        List<Integer> list = new ArrayList<>();

        for (int i = 0; i < numberOfNumbers; i++) {
            list.add(getRandomNumber(0, PreferenceUtil.getInstance(context).getSongNumber(), getMidnightTimestamp(System.currentTimeMillis() / 1000, refreshAfterXHours) + i));
        }

        return list;
    }

    private static long getMidnightTimestamp(long timestamp, int hours) {
        return timestamp - timestamp % (hours * 60 * 60); // 24 * 60 * 60 sec in one day
    }

    private static int getRandomNumber(int min, int max, long seed) {
        return new Random(seed).nextInt((max - min) + 1) + min;
    }
}