Audinaut-subsonic-app-android/app/src/main/java/net/nullsum/audinaut/util/Util.java

/*
 This file is part of Subsonic.

 Subsonic is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 Subsonic is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with Subsonic.  If not, see <http://www.gnu.org/licenses/>.

 Copyright 2009 (C) Sindre Mehus
 */
package net.nullsum.audinaut.util;

import android.app.Activity;
import android.content.ClipData;
import android.content.ClipboardManager;
import android.content.ComponentName;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.media.AudioManager;
import android.media.AudioManager.OnAudioFocusChangeListener;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.wifi.WifiManager;
import android.os.Build;
import android.os.Environment;
import androidx.annotation.Nullable;
import androidx.annotation.StringRes;
import androidx.appcompat.app.AlertDialog;
import android.text.SpannableString;
import android.text.method.LinkMovementMethod;
import android.text.util.Linkify;
import android.util.Log;
import android.util.SparseArray;
import android.view.Gravity;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import net.nullsum.audinaut.R;
import net.nullsum.audinaut.adapter.DetailsAdapter;
import net.nullsum.audinaut.domain.MusicDirectory;
import net.nullsum.audinaut.domain.PlayerState;
import net.nullsum.audinaut.domain.RepeatMode;
import net.nullsum.audinaut.receiver.MediaButtonIntentReceiver;
import net.nullsum.audinaut.service.DownloadService;

import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.math.BigInteger;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Random;

import okhttp3.HttpUrl;

/**
 * @author Sindre Mehus
 * @version $Id$
 */
public final class Util {
    private static final String EVENT_META_CHANGED = "net.nullsum.audinaut.EVENT_META_CHANGED";
    private static final String EVENT_PLAYSTATE_CHANGED = "net.nullsum.audinaut.EVENT_PLAYSTATE_CHANGED";
    private static final String AVRCP_PLAYSTATE_CHANGED = "com.android.music.playstatechanged";
    private static final String AVRCP_METADATA_CHANGED = "com.android.music.metachanged";
    private static final String TAG = Util.class.getSimpleName();
    private static final DecimalFormat GIGA_BYTE_FORMAT = new DecimalFormat("0.00 GB");
    private static final DecimalFormat MEGA_BYTE_FORMAT = new DecimalFormat("0.00 MB");
    private static final DecimalFormat KILO_BYTE_FORMAT = new DecimalFormat("0 KB");
    // Used by hexEncode()
    private static final char[] HEX_DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
    // private static Map<Integer, Pair<String, String>> tokens = new HashMap<>();
    private static final SparseArray<Pair<String, String>> tokens = new SparseArray<>();
    private static DecimalFormat GIGA_BYTE_LOCALIZED_FORMAT = null;
    private static DecimalFormat MEGA_BYTE_LOCALIZED_FORMAT = null;
    private static DecimalFormat KILO_BYTE_LOCALIZED_FORMAT = null;
    private static DecimalFormat BYTE_LOCALIZED_FORMAT = null;
    private static OnAudioFocusChangeListener focusListener;
    private static boolean pauseFocus = false;
    private static boolean lowerFocus = false;
    private static Toast toast;
    private static Random random;

    private Util() {
    }

    public static boolean isOffline(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getBoolean(Constants.PREFERENCES_KEY_OFFLINE, false);
    }

    public static void setOffline(Context context, boolean offline) {
        SharedPreferences prefs = getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();
        editor.putBoolean(Constants.PREFERENCES_KEY_OFFLINE, offline);
        editor.apply();
    }

    public static boolean isScreenLitOnDownload(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getBoolean(Constants.PREFERENCES_KEY_SCREEN_LIT_ON_DOWNLOAD, false);
    }

    public static RepeatMode getRepeatMode(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return RepeatMode.valueOf(prefs.getString(Constants.PREFERENCES_KEY_REPEAT_MODE, RepeatMode.OFF.name()));
    }

    public static void setRepeatMode(Context context, RepeatMode repeatMode) {
        SharedPreferences prefs = getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();
        editor.putString(Constants.PREFERENCES_KEY_REPEAT_MODE, repeatMode.name());
        editor.apply();
    }

    public static void setActiveServer(Context context, int instance) {
        SharedPreferences prefs = getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();
        editor.putInt(Constants.PREFERENCES_KEY_SERVER_INSTANCE, instance);
        editor.apply();
    }

    public static int getActiveServer(Context context) {
        SharedPreferences prefs = getPreferences(context);
        // Don't allow the SERVER_INSTANCE to ever be 0
        return prefs.getBoolean(Constants.PREFERENCES_KEY_OFFLINE, false) ? 0 : Math.max(1, prefs.getInt(Constants.PREFERENCES_KEY_SERVER_INSTANCE, 1));
    }

    private static int getMostRecentActiveServer(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return Math.max(1, prefs.getInt(Constants.PREFERENCES_KEY_SERVER_INSTANCE, 1));
    }

    public static int getServerCount(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getInt(Constants.PREFERENCES_KEY_SERVER_COUNT, 1);
    }

    public static void removeInstanceName(Context context, int instance, int activeInstance) {
        SharedPreferences prefs = getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();

        int newInstance = instance + 1;

        // Get what the +1 server details are
        String server = prefs.getString(Constants.PREFERENCES_KEY_SERVER_KEY + newInstance, null);
        String serverName = prefs.getString(Constants.PREFERENCES_KEY_SERVER_NAME + newInstance, null);
        String serverUrl = prefs.getString(Constants.PREFERENCES_KEY_SERVER_URL + newInstance, null);
        String userName = prefs.getString(Constants.PREFERENCES_KEY_USERNAME + newInstance, null);
        String password = prefs.getString(Constants.PREFERENCES_KEY_PASSWORD + newInstance, null);
        String musicFolderId = prefs.getString(Constants.PREFERENCES_KEY_MUSIC_FOLDER_ID + newInstance, null);

        // Store the +1 server details in the to be deleted instance
        editor.putString(Constants.PREFERENCES_KEY_SERVER_KEY + instance, server);
        editor.putString(Constants.PREFERENCES_KEY_SERVER_NAME + instance, serverName);
        editor.putString(Constants.PREFERENCES_KEY_SERVER_URL + instance, serverUrl);
        editor.putString(Constants.PREFERENCES_KEY_USERNAME + instance, userName);
        editor.putString(Constants.PREFERENCES_KEY_PASSWORD + instance, password);
        editor.putString(Constants.PREFERENCES_KEY_MUSIC_FOLDER_ID + instance, musicFolderId);

        // Delete the +1 server instance
        // Calling method will loop up to fill this in if +2 server exists
        editor.putString(Constants.PREFERENCES_KEY_SERVER_KEY + newInstance, null);
        editor.putString(Constants.PREFERENCES_KEY_SERVER_NAME + newInstance, null);
        editor.putString(Constants.PREFERENCES_KEY_SERVER_URL + newInstance, null);
        editor.putString(Constants.PREFERENCES_KEY_USERNAME + newInstance, null);
        editor.putString(Constants.PREFERENCES_KEY_PASSWORD + newInstance, null);
        editor.putString(Constants.PREFERENCES_KEY_MUSIC_FOLDER_ID + newInstance, null);
        editor.apply();

        if (instance == activeInstance) {
            if (instance != 1) {
                Util.setActiveServer(context, 1);
            } else {
                Util.setOffline(context, true);
            }
        } else if (newInstance == activeInstance) {
            Util.setActiveServer(context, instance);
        }
    }

    public static String getServerName(Context context) {
        SharedPreferences prefs = getPreferences(context);
        int instance = prefs.getInt(Constants.PREFERENCES_KEY_SERVER_INSTANCE, 1);
        return prefs.getString(Constants.PREFERENCES_KEY_SERVER_NAME + instance, null);
    }

    public static String getServerName(Context context, int instance) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getString(Constants.PREFERENCES_KEY_SERVER_NAME + instance, null);
    }

    public static void setSelectedMusicFolderId(Context context, String musicFolderId) {
        int instance = getActiveServer(context);
        SharedPreferences prefs = getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();
        editor.putString(Constants.PREFERENCES_KEY_MUSIC_FOLDER_ID + instance, musicFolderId);
        editor.apply();
    }

    public static String getSelectedMusicFolderId(Context context) {
        return getSelectedMusicFolderId(context, getActiveServer(context));
    }

    public static String getSelectedMusicFolderId(Context context, int instance) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getString(Constants.PREFERENCES_KEY_MUSIC_FOLDER_ID + instance, null);
    }

    public static boolean getAlbumListsPerFolder(Context context, int instance) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getBoolean(Constants.PREFERENCES_KEY_ALBUMS_PER_FOLDER + instance, false);
    }

    public static boolean getDisplayTrack(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getBoolean(Constants.PREFERENCES_KEY_DISPLAY_TRACK, false);
    }

    public static int getMaxBitrate(Context context) {
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        if (networkInfo == null) {
            return 0;
        }

        boolean wifi = networkInfo.getType() == ConnectivityManager.TYPE_WIFI;
        SharedPreferences prefs = getPreferences(context);
        return Integer.parseInt(prefs.getString(wifi ? Constants.PREFERENCES_KEY_MAX_BITRATE_WIFI : Constants.PREFERENCES_KEY_MAX_BITRATE_MOBILE, "0"));
    }

    public static int getPreloadCount(Context context) {
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        if (networkInfo == null) {
            return 3;
        }

        SharedPreferences prefs = getPreferences(context);
        boolean wifi = networkInfo.getType() == ConnectivityManager.TYPE_WIFI;
        int preloadCount = Integer.parseInt(prefs.getString(wifi ? Constants.PREFERENCES_KEY_PRELOAD_COUNT_WIFI : Constants.PREFERENCES_KEY_PRELOAD_COUNT_MOBILE, "-1"));
        return preloadCount == -1 ? Integer.MAX_VALUE : preloadCount;
    }

    public static int getCacheSizeMB(Context context) {
        SharedPreferences prefs = getPreferences(context);
        int cacheSize = Integer.parseInt(prefs.getString(Constants.PREFERENCES_KEY_CACHE_SIZE, "-1"));
        return cacheSize == -1 ? Integer.MAX_VALUE : cacheSize;
    }

    public static boolean isBatchMode(Context context) {
        return Util.getPreferences(context).getBoolean(Constants.PREFERENCES_KEY_BATCH_MODE, false);
    }

    public static void setBatchMode(Context context, boolean batchMode) {
        Util.getPreferences(context).edit().putBoolean(Constants.PREFERENCES_KEY_BATCH_MODE, batchMode).apply();
    }

    public static String getRestUrl(Context context) {
        return getRestUrl(context, null, true, null);
    }

    // used
    public static String getRestUrl(Context context, String method, boolean allowAltAddress, @Nullable Map<String, String> parameters) {
        SharedPreferences prefs = getPreferences(context);
        int instance = prefs.getInt(Constants.PREFERENCES_KEY_SERVER_INSTANCE, 1);
        return getRestUrl(context, method, prefs, instance, allowAltAddress, parameters);
    }

    public static String getRestUrl(Context context, String method, int instance, boolean allowAltAddress, @Nullable Map<String, String> parameters) {
        SharedPreferences prefs = getPreferences(context);
        return getRestUrl(context, method, prefs, instance, allowAltAddress, parameters);
    }

    private static String getRestUrl(Context context, String method, SharedPreferences prefs, int instance, boolean allowAltAddress, @Nullable Map<String, String> parameters) {
        String serverUrl = prefs.getString(Constants.PREFERENCES_KEY_SERVER_URL + instance, null);

        HttpUrl.Builder builder;
        builder = HttpUrl.parse(serverUrl).newBuilder();

        if (allowAltAddress && Util.isWifiConnected(context)) {
            String SSID = prefs.getString(Constants.PREFERENCES_KEY_SERVER_LOCAL_NETWORK_SSID + instance, "");
            if (!SSID.isEmpty()) {
                String currentSSID = Util.getSSID(context);

                String[] ssidParts = SSID.split(",");
                if (SSID.equals(currentSSID) || Arrays.asList(ssidParts).contains(currentSSID)) {
                    String internalUrl = prefs.getString(Constants.PREFERENCES_KEY_SERVER_INTERNAL_URL + instance, null);
                    if (internalUrl != null && !"".equals(internalUrl) && !"http://".equals(internalUrl)) {
                        serverUrl = internalUrl;
                        builder = HttpUrl.parse(serverUrl).newBuilder();
                    }
                }
            }
        }

        String username = prefs.getString(Constants.PREFERENCES_KEY_USERNAME + instance, null);
        String password = prefs.getString(Constants.PREFERENCES_KEY_PASSWORD + instance, null);

        builder.addPathSegment("rest");
        builder.addPathSegment(method + ".view");

        int hash = (username + password).hashCode();
        Pair<String, String> values = tokens.get(hash);
        if (values == null) {
            String salt = new BigInteger(130, getRandom()).toString(32);
            String token = md5Hex(password + salt);
            values = new Pair<>(salt, token);
            tokens.put(hash, values);
        }

        builder.addQueryParameter("u", username);
        builder.addQueryParameter("s", values.getFirst());
        builder.addQueryParameter("t", values.getSecond());
        builder.addQueryParameter("v", Constants.REST_PROTOCOL_VERSION_SUBSONIC);
        builder.addQueryParameter("c", Constants.REST_CLIENT_ID);

        if (parameters != null) {
            for (Map.Entry<String, String> parameter : parameters.entrySet()) {
                builder.addQueryParameter(parameter.getKey(), parameter.getValue());
            }
        }

        return builder.build().toString();
    }

    public static int getRestUrlHash(Context context) {
        return getRestUrlHash(context, Util.getMostRecentActiveServer(context));
    }

    public static int getRestUrlHash(Context context, int instance) {
        StringBuilder builder = new StringBuilder();

        SharedPreferences prefs = Util.getPreferences(context);
        builder.append(prefs.getString(Constants.PREFERENCES_KEY_SERVER_URL + instance, null));
        builder.append(prefs.getString(Constants.PREFERENCES_KEY_USERNAME + instance, null));

        return builder.toString().hashCode();
    }

    private static String getBlockTokenUsePref(Context context, int instance) {
        return Constants.CACHE_BLOCK_TOKEN_USE + Util.getRestUrl(context, null, instance, false, null);
    }

    public static void setBlockTokenUse(Context context, int instance) {
        SharedPreferences.Editor editor = getPreferences(context).edit();
        editor.putBoolean(getBlockTokenUsePref(context, instance), true);
        editor.apply();
    }

    public static SharedPreferences getPreferences(Context context) {
        return context.getSharedPreferences(Constants.PREFERENCES_FILE_NAME, 0);
    }

    public static String getCacheName(Context context, String name, String id) {
        String s = getRestUrl(context, null, getActiveServer(context), false, null) + id;
        return name + "-" + s.hashCode() + ".ser";
    }

    public static String getCacheName(Context context) {
        return getCacheName(context, "entryLookup", "");
    }

    public static String parseOfflineIDSearch(String id, String cacheLocation) {
        // Try to get this info based off of tags first
        String name = parseOfflineIDSearch(id);
        if (name != null) {
            return name;
        }

        // Otherwise go nuts trying to parse from file structure
        name = id.replace(cacheLocation, "");
        if (name.startsWith("/")) {
            name = name.substring(1);
        }
        name = name.replace(".complete", "").replace(".partial", "");
        int index = name.lastIndexOf(".");
        name = index == -1 ? name : name.substring(0, index);
        String[] details = name.split("/");

        String title = details[details.length - 1];
        if (index == -1) {
            if (details.length > 1) {
                String artist = "artist:\"" + details[details.length - 2] + "\"";
                String simpleArtist = "artist:\"" + title + "\"";
                title = "album:\"" + title + "\"";
                if (details[details.length - 1].equals(details[details.length - 2])) {
                    name = title;
                } else {
                    name = "(" + artist + " AND " + title + ")" + " OR " + simpleArtist;
                }
            } else {
                name = "artist:\"" + title + "\" OR album:\"" + title + "\"";
            }
        } else {
            String artist;
            if (details.length > 2) {
                artist = "artist:\"" + details[details.length - 3] + "\"";
            } else {
                artist = "(artist:\"" + details[0] + "\" OR album:\"" + details[0] + "\")";
            }
            title = "title:\"" + title.substring(title.indexOf('-') + 1) + "\"";
            name = artist + " AND " + title;
        }

        return name;
    }

    private static String parseOfflineIDSearch(String id) {
        MusicDirectory.Entry entry = new MusicDirectory.Entry();
        File file = new File(id);

        if (file.exists()) {
            entry.loadMetadata(file);

            if (entry.getArtist() != null) {
                String title = file.getName();
                title = title.replace(".complete", "").replace(".partial", "");
                int index = title.lastIndexOf(".");
                title = index == -1 ? title : title.substring(0, index);
                title = title.substring(title.indexOf('-') + 1);

                return "artist:\"" + entry.getArtist() + "\"" +
                        " AND title:\"" + title + "\"";
            } else {
                return null;
            }
        } else {
            return null;
        }
    }

    public static boolean isFirstLevelArtist(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getBoolean(Constants.PREFERENCES_KEY_FIRST_LEVEL_ARTIST + getActiveServer(context), true);
    }

    public static void toggleFirstLevelArtist(Context context) {
        SharedPreferences prefs = Util.getPreferences(context);
        SharedPreferences.Editor editor = prefs.edit();

        if (prefs.getBoolean(Constants.PREFERENCES_KEY_FIRST_LEVEL_ARTIST + getActiveServer(context), true)) {
            editor.putBoolean(Constants.PREFERENCES_KEY_FIRST_LEVEL_ARTIST + getActiveServer(context), false);
        } else {
            editor.putBoolean(Constants.PREFERENCES_KEY_FIRST_LEVEL_ARTIST + getActiveServer(context), true);
        }

        editor.apply();
    }

    public static boolean shouldStartOnHeadphones(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getBoolean(Constants.PREFERENCES_KEY_START_ON_HEADPHONES, false);
    }

    public static String getSongPressAction(Context context) {
        return getPreferences(context).getString(Constants.PREFERENCES_KEY_SONG_PRESS_ACTION, "all");
    }

    /**
     * Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
     * <p/>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     *
     * @param input the <code>InputStream</code> to read from
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException          if an I/O error occurs
     */
    public static byte[] toByteArray(InputStream input) throws IOException {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        copy(input, output);
        return output.toByteArray();
    }

    private static void copy(InputStream input, OutputStream output)
            throws IOException {
        byte[] buffer = new byte[1024 * 4];
        long count = 0;
        int n;
        while (-1 != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
    }

    public static void renameFile(File from, File to) {
        if (!from.renameTo(to)) {
            Log.i(TAG, "Failed to rename " + from + " to " + to);
        }
    }

    public static void close(Closeable closeable) {
        try {
            if (closeable != null) {
                closeable.close();
            }
        } catch (Throwable x) {
            // Ignored
        }
    }

    public static boolean delete(File file) {
        if (file != null && file.exists()) {
            if (!file.delete()) {
                Log.w(TAG, "Failed to delete file " + file);
                return false;
            }
            Log.i(TAG, "Deleted file " + file);
        }
        return true;
    }

    public static void toast(Context context, int messageId) {
        toast(context, messageId, true);
    }

    public static void toast(Context context, int messageId, boolean shortDuration) {
        toast(context, context.getString(messageId), shortDuration);
    }

    public static void toast(Context context, String message) {
        toast(context, message, true);
    }

    public static void toast(Context context, String message, boolean shortDuration) {
        if (toast == null) {
            toast = Toast.makeText(context, message, shortDuration ? Toast.LENGTH_SHORT : Toast.LENGTH_LONG);
            toast.setGravity(Gravity.CENTER, 0, 0);
        } else {
            toast.setText(message);
            toast.setDuration(shortDuration ? Toast.LENGTH_SHORT : Toast.LENGTH_LONG);
        }
        toast.show();
    }

    public static void confirmDialog(Context context, DialogInterface.OnClickListener onClick) {
        Util.confirmDialog(context, context.getResources().getString(R.string.common_delete).toLowerCase(), context.getResources().getString(R.string.common_confirm_message_cache), onClick);
    }

    public static void confirmDialog(Context context, int action, String subject, DialogInterface.OnClickListener onClick) {
        Util.confirmDialog(context, context.getResources().getString(action).toLowerCase(), subject, onClick);
    }

    private static void confirmDialog(Context context, String action, String subject, DialogInterface.OnClickListener onClick) {
        new AlertDialog.Builder(context)
                .setIcon(android.R.drawable.ic_dialog_alert)
                .setTitle(R.string.common_confirm)
                .setMessage(context.getResources().getString(R.string.common_confirm_message, action, subject))
                .setPositiveButton(R.string.common_ok, onClick)
                .setNegativeButton(R.string.common_cancel, null)
                .show();
    }

    /**
     * Converts a byte-count to a formatted string suitable for display to the user.
     * For instance:
     * <ul>
     * <li><code>format(918)</code> returns <em>"918 B"</em>.</li>
     * <li><code>format(98765)</code> returns <em>"96 KB"</em>.</li>
     * <li><code>format(1238476)</code> returns <em>"1.2 MB"</em>.</li>
     * </ul>
     * This method assumes that 1 KB is 1024 bytes.
     * To get a localized string, please use formatLocalizedBytes instead.
     *
     * @param byteCount The number of bytes.
     * @return The formatted string.
     */
    public static synchronized String formatBytes(long byteCount) {

        // More than 1 GB?
        if (byteCount >= 1024 * 1024 * 1024) {
            return GIGA_BYTE_FORMAT.format((double) byteCount / (1024 * 1024 * 1024));
        }

        // More than 1 MB?
        if (byteCount >= 1024 * 1024) {
            return MEGA_BYTE_FORMAT.format((double) byteCount / (1024 * 1024));
        }

        // More than 1 KB?
        if (byteCount >= 1024) {
            return KILO_BYTE_FORMAT.format((double) byteCount / 1024);
        }

        return byteCount + " B";
    }

    /**
     * Converts a byte-count to a formatted string suitable for display to the user.
     * For instance:
     * <ul>
     * <li><code>format(918)</code> returns <em>"918 B"</em>.</li>
     * <li><code>format(98765)</code> returns <em>"96 KB"</em>.</li>
     * <li><code>format(1238476)</code> returns <em>"1.2 MB"</em>.</li>
     * </ul>
     * This method assumes that 1 KB is 1024 bytes.
     * This version of the method returns a localized string.
     *
     * @param byteCount The number of bytes.
     * @return The formatted string.
     */
    public static synchronized String formatLocalizedBytes(long byteCount, Context context) {

        // More than 1 GB?
        if (byteCount >= 1024 * 1024 * 1024) {
            if (GIGA_BYTE_LOCALIZED_FORMAT == null) {
                GIGA_BYTE_LOCALIZED_FORMAT = new DecimalFormat(context.getResources().getString(R.string.util_bytes_format_gigabyte));
            }

            return GIGA_BYTE_LOCALIZED_FORMAT.format((double) byteCount / (1024 * 1024 * 1024));
        }

        // More than 1 MB?
        if (byteCount >= 1024 * 1024) {
            if (MEGA_BYTE_LOCALIZED_FORMAT == null) {
                MEGA_BYTE_LOCALIZED_FORMAT = new DecimalFormat(context.getResources().getString(R.string.util_bytes_format_megabyte));
            }

            return MEGA_BYTE_LOCALIZED_FORMAT.format((double) byteCount / (1024 * 1024));
        }

        // More than 1 KB?
        if (byteCount >= 1024) {
            if (KILO_BYTE_LOCALIZED_FORMAT == null) {
                KILO_BYTE_LOCALIZED_FORMAT = new DecimalFormat(context.getResources().getString(R.string.util_bytes_format_kilobyte));
            }

            return KILO_BYTE_LOCALIZED_FORMAT.format((double) byteCount / 1024);
        }

        if (BYTE_LOCALIZED_FORMAT == null) {
            BYTE_LOCALIZED_FORMAT = new DecimalFormat(context.getResources().getString(R.string.util_bytes_format_byte));
        }

        return BYTE_LOCALIZED_FORMAT.format((double) byteCount);
    }

    public static String formatDuration(Integer seconds) {
        if (seconds == null) {
            return null;
        }

        int hours = seconds / 3600;
        int minutes = (seconds / 60) % 60;
        int secs = seconds % 60;

        StringBuilder builder = new StringBuilder(7);
        if (hours > 0) {
            builder.append(hours).append(":");
            if (minutes < 10) {
                builder.append("0");
            }
        }
        builder.append(minutes).append(":");
        if (secs < 10) {
            builder.append("0");
        }
        builder.append(secs);
        return builder.toString();
    }

    public static String formatBoolean(Context context, boolean value) {
        return context.getResources().getString(value ? R.string.common_true : R.string.common_false);
    }

    public static boolean equals(Object object1, Object object2) {
        return object1 == object2 || !(object1 == null || object2 == null) && object1.equals(object2);

    }

    /**
     * Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
     * The returned array will be double the length of the passed array, as it takes two characters to represent any
     * given byte.
     *
     * @param data Bytes to convert to hexadecimal characters.
     * @return A string containing hexadecimal characters.
     */
    private static String hexEncode(byte[] data) {
        int length = data.length;
        char[] out = new char[length << 1];
        // two characters form the hex value.
        for (int i = 0, j = 0; i < length; i++) {
            out[j++] = HEX_DIGITS[(0xF0 & data[i]) >>> 4];
            out[j++] = HEX_DIGITS[0x0F & data[i]];
        }
        return new String(out);
    }

    /**
     * Calculates the MD5 digest and returns the value as a 32 character hex string.
     *
     * @param s Data to digest.
     * @return MD5 digest as a hex string.
     */
    public static String md5Hex(String s) {
        if (s == null) {
            return null;
        }

        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            return hexEncode(md5.digest(s.getBytes(StandardCharsets.UTF_8)));
        } catch (Exception x) {
            throw new RuntimeException(x.getMessage(), x);
        }
    }

    public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {

            // Calculate ratios of height and width to requested height and
            // width
            final int heightRatio = Math.round((float) height / (float) reqHeight);
            final int widthRatio = Math.round((float) width / (float) reqWidth);

            // Choose the smallest ratio as inSampleSize value, this will
            // guarantee
            // a final image with both dimensions larger than or equal to the
            // requested height and width.
            inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
        }

        return inSampleSize;
    }

    public static int getScaledHeight(double height, double width, int newWidth) {
        // Try to keep correct aspect ratio of the original image, do not force a square
        double aspectRatio = height / width;

        // Assume the size given refers to the width of the image, so calculate the new height using
        //  the previously determined aspect ratio
        return (int) Math.round(newWidth * aspectRatio);
    }

    public static int getScaledHeight(Bitmap bitmap, int width) {
        return Util.getScaledHeight((double) bitmap.getHeight(), (double) bitmap.getWidth(), width);
    }

    public static int getStringDistance(CharSequence s, CharSequence t) {
        if (s == null || t == null) {
            throw new IllegalArgumentException("Strings must not be null");
        }

        if (t.toString().toLowerCase().contains(s.toString().toLowerCase())) {
            return 1;
        }

        int n = s.length();
        int m = t.length();

        if (n == 0) {
            return m;
        } else if (m == 0) {
            return n;
        }

        if (n > m) {
            final CharSequence tmp = s;
            s = t;
            t = tmp;
            n = m;
            m = t.length();
        }

        int p[] = new int[n + 1];
        int d[] = new int[n + 1];
        int _d[];

        int i;
        int j;
        char t_j;
        int cost;

        for (i = 0; i <= n; i++) {
            p[i] = i;
        }

        for (j = 1; j <= m; j++) {
            t_j = t.charAt(j - 1);
            d[0] = j;

            for (i = 1; i <= n; i++) {
                cost = s.charAt(i - 1) == t_j ? 0 : 1;
                d[i] = Math.min(Math.min(d[i - 1] + 1, p[i] + 1), p[i - 1] + cost);
            }

            _d = p;
            p = d;
            d = _d;
        }

        return p[n];
    }

    public static boolean isNetworkConnected(Context context) {
        return isNetworkConnected(context, false);
    }

    private static boolean isNetworkConnected(Context context, boolean streaming) {
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        boolean connected = networkInfo != null && networkInfo.isConnected();

        if (streaming) {
            boolean wifiConnected = connected && networkInfo.getType() == ConnectivityManager.TYPE_WIFI;
            boolean wifiRequired = isWifiRequiredForDownload(context);

            return connected && (!wifiRequired || wifiConnected);
        } else {
            return connected;
        }
    }

    private static boolean isWifiConnected(Context context) {
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        boolean connected = networkInfo != null && networkInfo.isConnected();
        return connected && (networkInfo.getType() == ConnectivityManager.TYPE_WIFI);
    }

    public static String getSSID(Context context) {
        if (isWifiConnected(context)) {
            WifiManager wifiManager = (WifiManager) context.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
            if (wifiManager.getConnectionInfo() != null && wifiManager.getConnectionInfo().getSSID() != null) {
                return wifiManager.getConnectionInfo().getSSID().replace("\"", "");
            }
            return null;
        }
        return null;
    }

    public static boolean isExternalStoragePresent() {
        return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
    }

    public static boolean isAllowedToDownload(Context context) {
        return isNetworkConnected(context, true) && !isOffline(context);
    }

    public static boolean isWifiRequiredForDownload(Context context) {
        SharedPreferences prefs = getPreferences(context);
        return prefs.getBoolean(Constants.PREFERENCES_KEY_WIFI_REQUIRED_FOR_DOWNLOAD, false);
    }

    public static void info(Context context, int titleId, int messageId) {
        showDialog(context, titleId, messageId);
    }

    private static void showDialog(Context context, int titleId, int messageId) {
        showDialog(context, context.getResources().getString(titleId), context.getResources().getString(messageId));
    }

    private static void showDialog(Context context, String title, String message) {
        SpannableString ss = new SpannableString(message);
        Linkify.addLinks(ss, Linkify.ALL);

        AlertDialog dialog = new AlertDialog.Builder(context)
                .setIcon(android.R.drawable.ic_dialog_info)
                .setTitle(title)
                .setMessage(ss)
                .setPositiveButton(R.string.common_ok, (dialog1, i) -> dialog1.dismiss())
                .show();

        ((TextView) dialog.findViewById(android.R.id.message)).setMovementMethod(LinkMovementMethod.getInstance());
    }

    public static void showDetailsDialog(Context context, @StringRes int title, List<Integer> headers, List<String> details) {
        List<String> headerStrings = new ArrayList<>();
        for (@StringRes Integer res : headers) {
            headerStrings.add(context.getResources().getString(res));
        }
        showDetailsDialog(context, context.getResources().getString(title), headerStrings, details);
    }

    private static void showDetailsDialog(Context context, String title, List<String> headers, final List<String> details) {
        ListView listView = new ListView(context);
        listView.setAdapter(new DetailsAdapter(context, headers, details));
        listView.setDivider(null);
        listView.setScrollbarFadingEnabled(false);

        // Let the user long-click on a row to copy its value to the clipboard
        final Context contextRef = context;
        listView.setOnItemLongClickListener((parent, view, pos, id) -> {
            TextView nameView = view.findViewById(R.id.detail_name);
            TextView detailsView = view.findViewById(R.id.detail_value);
            if (nameView == null || detailsView == null) {
                return false;
            }

            CharSequence name = nameView.getText();
            CharSequence value = detailsView.getText();

            ClipboardManager clipboard = (ClipboardManager) contextRef.getSystemService(Context.CLIPBOARD_SERVICE);
            ClipData clip = ClipData.newPlainText(name, value);
            clipboard.setPrimaryClip(clip);

            toast(contextRef, "Copied " + name + " to clipboard");

            return true;
        });

        new AlertDialog.Builder(context)
                // .setIcon(android.R.drawable.ic_dialog_info)
                .setTitle(title)
                .setView(listView)
                .setPositiveButton(R.string.common_close, (dialog, i) -> dialog.dismiss())
                .show();
    }

    public static void sleepQuietly(long millis) {
        try {
            Thread.sleep(millis);
        } catch (InterruptedException x) {
            Log.w(TAG, "Interrupted from sleep.", x);
        }
    }

    public static void startActivityWithoutTransition(Activity currentActivity, Intent intent) {
        currentActivity.startActivity(intent);
    }

    public static Drawable createDrawableFromBitmap(Context context, Bitmap bitmap) {
        return new BitmapDrawable(context.getResources(), bitmap);
    }

    public static void registerMediaButtonEventReceiver(Context context) {

        // Only do it if enabled in the settings.
        SharedPreferences prefs = getPreferences(context);
        boolean enabled = prefs.getBoolean(Constants.PREFERENCES_KEY_MEDIA_BUTTONS, true);

        if (enabled) {
            AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
            ComponentName componentName = new ComponentName(context.getPackageName(), MediaButtonIntentReceiver.class.getName());
            audioManager.registerMediaButtonEventReceiver(componentName);
        }
    }

    public static void unregisterMediaButtonEventReceiver(Context context) {
        AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
        ComponentName componentName = new ComponentName(context.getPackageName(), MediaButtonIntentReceiver.class.getName());
        audioManager.unregisterMediaButtonEventReceiver(componentName);
    }

    public static void requestAudioFocus(final Context context) {
        if (focusListener == null) {
            final AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
            audioManager.requestAudioFocus(focusListener = new OnAudioFocusChangeListener() {
                public void onAudioFocusChange(int focusChange) {
                    DownloadService downloadService = (DownloadService) context;
                    switch (focusChange) {
                        case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
                        case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                            if (downloadService.getPlayerState() == PlayerState.STARTED) {
                                Log.i(TAG, "Temporary loss of focus");
                                SharedPreferences prefs = getPreferences(context);
                                int lossPref = Integer.parseInt(prefs.getString(Constants.PREFERENCES_KEY_TEMP_LOSS, "1"));
                                if (lossPref == 2 || (lossPref == 1 && focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK)) {
                                    lowerFocus = true;
                                    downloadService.setVolume(0.1f);
                                } else if (lossPref == 0 || (lossPref == 1 && focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT)) {
                                    pauseFocus = true;
                                    downloadService.pause(true);
                                }
                            }
                            break;
                        case AudioManager.AUDIOFOCUS_GAIN:
                            if (pauseFocus) {
                                pauseFocus = false;
                                downloadService.start();
                            }
                            if (lowerFocus) {
                                lowerFocus = false;
                                downloadService.setVolume(1.0f);
                            }
                            break;
                        case AudioManager.AUDIOFOCUS_LOSS:
                            Log.i(TAG, "Permanently lost focus");
                            focusListener = null;
                            downloadService.pause();
                            audioManager.abandonAudioFocus(this);
                            break;
                    }
                }
            }, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
        }
    }

    /**
     * <p>Broadcasts the given song info as the new song being played.</p>
     */
    public static void broadcastNewTrackInfo(Context context, MusicDirectory.Entry song) {
        try {
            Intent intent = new Intent(EVENT_META_CHANGED);
            Intent avrcpIntent = new Intent(AVRCP_METADATA_CHANGED);

            if (song != null) {
                intent.putExtra("title", song.getTitle());
                intent.putExtra("artist", song.getArtist());
                intent.putExtra("album", song.getAlbum());

                File albumArtFile = FileUtil.getAlbumArtFile(context, song);
                intent.putExtra("coverart", albumArtFile.getAbsolutePath());
                avrcpIntent.putExtra("playing", true);
            } else {
                intent.putExtra("title", "");
                intent.putExtra("artist", "");
                intent.putExtra("album", "");
                intent.putExtra("coverart", "");
                avrcpIntent.putExtra("playing", false);
            }
            addTrackInfo(context, song, avrcpIntent);

            context.sendBroadcast(intent);
            context.sendBroadcast(avrcpIntent);
        } catch (Exception e) {
            Log.e(TAG, "Failed to broadcastNewTrackInfo", e);
        }
    }

    /**
     * <p>Broadcasts the given player state as the one being set.</p>
     */
    public static void broadcastPlaybackStatusChange(Context context, MusicDirectory.Entry song, PlayerState state) {
        try {
            Intent intent = new Intent(EVENT_PLAYSTATE_CHANGED);
            Intent avrcpIntent = new Intent(AVRCP_PLAYSTATE_CHANGED);

            switch (state) {
                case STARTED:
                    intent.putExtra("state", "play");
                    avrcpIntent.putExtra("playing", true);
                    break;
                case STOPPED:
                    intent.putExtra("state", "stop");
                    avrcpIntent.putExtra("playing", false);
                    break;
                case PAUSED:
                    intent.putExtra("state", "pause");
                    avrcpIntent.putExtra("playing", false);
                    break;
                case PREPARED:
                    // Only send quick pause event for samsung devices, causes issues for others
                    if (Build.MANUFACTURER.toLowerCase().contains("samsung")) {
                        avrcpIntent.putExtra("playing", false);
                    } else {
                        return; // Don't broadcast anything
                    }
                    break;
                case COMPLETED:
                    intent.putExtra("state", "complete");
                    avrcpIntent.putExtra("playing", false);
                    break;
                default:
                    return; // No need to broadcast.
            }
            addTrackInfo(context, song, avrcpIntent);

            if (state != PlayerState.PREPARED) {
                context.sendBroadcast(intent);
            }
            context.sendBroadcast(avrcpIntent);
        } catch (Exception e) {
            Log.e(TAG, "Failed to broadcastPlaybackStatusChange", e);
        }
    }

    private static void addTrackInfo(Context context, MusicDirectory.Entry song, Intent intent) {
        if (song != null) {
            DownloadService downloadService = (DownloadService) context;
            File albumArtFile = FileUtil.getAlbumArtFile(context, song);

            intent.putExtra("track", song.getTitle());
            intent.putExtra("artist", song.getArtist());
            intent.putExtra("album", song.getAlbum());
            intent.putExtra("ListSize", (long) downloadService.getSongs().size());
            intent.putExtra("id", (long) downloadService.getCurrentPlayingIndex() + 1);
            intent.putExtra("duration", (long) downloadService.getPlayerDuration());
            intent.putExtra("position", (long) downloadService.getPlayerPosition());
            intent.putExtra("coverart", albumArtFile.getAbsolutePath());
            intent.putExtra("package", "net.nullsum.audinaut");
        } else {
            intent.putExtra("track", "");
            intent.putExtra("artist", "");
            intent.putExtra("album", "");
            intent.putExtra("ListSize", (long) 0);
            intent.putExtra("id", (long) 0);
            intent.putExtra("duration", (long) 0);
            intent.putExtra("position", (long) 0);
            intent.putExtra("coverart", "");
            intent.putExtra("package", "net.nullsum.audinaut");
        }
    }

    public static WifiManager.WifiLock createWifiLock(Context context, String tag) {
        WifiManager wm = (WifiManager) context.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        return wm.createWifiLock(WifiManager.WIFI_MODE_FULL_HIGH_PERF, tag);
    }

    private static Random getRandom() {
        if (random == null) {
            random = new SecureRandom();
        }

        return random;
    }
}