chinwag-android/app/src/main/java/com/keylesspalace/tusky/util/NotificationMaker.java

/* Copyright 2017 Andrew Dawson
 *
 * This file is a part of Tusky.
 *
 * This program 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.
 *
 * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with Tusky; if not,
 * see <http://www.gnu.org/licenses>. */

package com.keylesspalace.tusky.util;

import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Build;
import android.preference.PreferenceManager;
import android.provider.Settings;
import android.support.annotation.Nullable;
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.TaskStackBuilder;
import android.support.v4.content.ContextCompat;
import android.util.Log;

import com.keylesspalace.tusky.MainActivity;
import com.keylesspalace.tusky.R;
import com.keylesspalace.tusky.entity.Notification;
import com.keylesspalace.tusky.receiver.NotificationClearBroadcastReceiver;
import com.keylesspalace.tusky.view.RoundedTransformation;
import com.squareup.picasso.Picasso;

import org.json.JSONArray;
import org.json.JSONException;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class NotificationMaker {
    public static final String TAG = "NotificationMaker";

    /** notification channels used on Android O+ **/
    private static final String CHANNEL_MENTION = "CHANNEL_MENTION";
    private static final String CHANNEL_FOLLOW = "CHANNEL_FOLLOW";
    private static final String CHANNEL_BOOST = "CHANNEL_BOOST";
    private static final String CHANNEL_FAVOURITE =" CHANNEL_FAVOURITE";

    /**
     * Takes a given Mastodon notification and either creates a new Android notification or updates
     * the state of the existing notification to reflect the new interaction.
     *
     * @param context to access application preferences and services
     * @param notifyId an arbitrary number to reference this notification for any future action
     * @param body a new Mastodon notification
     */
    public static void make(final Context context, final int notifyId, Notification body) {
        final SharedPreferences preferences =
                PreferenceManager.getDefaultSharedPreferences(context);
        final SharedPreferences notificationPreferences = context.getSharedPreferences(
                "Notifications", Context.MODE_PRIVATE);

        if (!filterNotification(preferences, body)) {
            return;
        }

        createNotificationChannels(context);

        String rawCurrentNotifications = notificationPreferences.getString("current", "[]");
        JSONArray currentNotifications;

        try {
            currentNotifications = new JSONArray(rawCurrentNotifications);
        } catch (JSONException e) {
            currentNotifications = new JSONArray();
        }

        boolean alreadyContains = false;

        for(int i = 0; i < currentNotifications.length(); i++) {
            try {
                if (currentNotifications.getString(i).equals(body.account.getDisplayName())) {
                    alreadyContains = true;
                }
            } catch (JSONException e) {
                Log.d(TAG, Log.getStackTraceString(e));
            }
        }

        if (!alreadyContains) {
            currentNotifications.put(body.account.getDisplayName());
        }

        notificationPreferences.edit()
                .putString("current", currentNotifications.toString())
                .commit();

        Intent resultIntent = new Intent(context, MainActivity.class);
        resultIntent.putExtra("tab_position", 1);
        TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
        stackBuilder.addParentStack(MainActivity.class);
        stackBuilder.addNextIntent(resultIntent);
        PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0,
                PendingIntent.FLAG_UPDATE_CURRENT);

        Intent deleteIntent = new Intent(context, NotificationClearBroadcastReceiver.class);
        PendingIntent deletePendingIntent = PendingIntent.getBroadcast(context, 0, deleteIntent,
                PendingIntent.FLAG_CANCEL_CURRENT);

        final NotificationCompat.Builder builder = new NotificationCompat.Builder(context, getChannelId(body))
                .setSmallIcon(R.drawable.ic_notify)
                .setContentIntent(resultPendingIntent)
                .setDeleteIntent(deletePendingIntent)
                .setColor(ContextCompat.getColor(context, (R.color.primary)))
                .setDefaults(0); // So it doesn't ring twice, notify only in Target callback

        setupPreferences(preferences, builder);

        if (currentNotifications.length() == 1) {
            builder.setContentTitle(titleForType(context, body))
                    .setContentText(truncateWithEllipses(bodyForType(body), 40));

            //load the avatar synchronously
            Bitmap accountAvatar;
            try {
                accountAvatar = Picasso.with(context)
                        .load(body.account.avatar)
                        .transform(new RoundedTransformation(7, 0))
                        .get();
            } catch (IOException e) {
                Log.d(TAG, "error loading account avatar", e);
                accountAvatar = BitmapFactory.decodeResource(context.getResources(), R.drawable.avatar_default);
            }

            builder.setLargeIcon(accountAvatar);

        } else {
            try {
                String format = context.getString(R.string.notification_title_summary);
                String title = String.format(format, currentNotifications.length());
                String text = truncateWithEllipses(joinNames(context, currentNotifications), 40);
                builder.setContentTitle(title)
                        .setContentText(text);
            } catch (JSONException e) {
                Log.d(TAG, Log.getStackTraceString(e));
            }
        }

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            builder.setVisibility(android.app.Notification.VISIBILITY_PRIVATE);
            builder.setCategory(android.app.Notification.CATEGORY_SOCIAL);
        }

        NotificationManager notificationManager =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(notifyId, builder.build());
    }

    public static void createNotificationChannels(Context context) {
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

        NotificationManager mNotificationManager =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

            String[] channelIds = new String[]{CHANNEL_MENTION, CHANNEL_FOLLOW, CHANNEL_BOOST, CHANNEL_FAVOURITE};
            int[] channelNames = {
                    R.string.notification_channel_mention_name,
                    R.string.notification_channel_follow_name,
                    R.string.notification_channel_boost_name,
                    R.string.notification_channel_favourite_name
            };
            int[] channelDescriptions = {
                    R.string.notification_channel_mention_descriptions,
                    R.string.notification_channel_follow_description,
                    R.string.notification_channel_boost_description,
                    R.string.notification_channel_favourite_description
            };

            List<NotificationChannel> channels = new ArrayList<>(4);

            for(int i=0; i<channelIds.length; i++) {
                String id = channelIds[i];
                String name = context.getString(channelNames[i]);
                String description = context.getString(channelDescriptions[i]);
                int importance = NotificationManager.IMPORTANCE_DEFAULT;
                NotificationChannel channel = new NotificationChannel(id, name, importance);

                channel.setDescription(description);
                channel.enableLights(true);
                channel.enableVibration(true);
                channel.setShowBadge(true);
                channels.add(channel);
            }

            mNotificationManager.createNotificationChannels(channels);

        }
    }

    private static boolean filterNotification(SharedPreferences preferences,
            Notification notification) {

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            return true;  //do not filter on Android O or newer, the system does it for us
        }

            switch (notification.type) {
            default:
            case MENTION:
                return preferences.getBoolean("notificationFilterMentions", true);
            case FOLLOW:
                return preferences.getBoolean("notificationFilterFollows", true);
            case REBLOG:
                return preferences.getBoolean("notificationFilterReblogs", true);
            case FAVOURITE:
                return preferences.getBoolean("notificationFilterFavourites", true);
        }
    }

    private static String getChannelId(Notification notification) {
            switch (notification.type) {
                default:
                case MENTION:
                    return CHANNEL_MENTION;
                case FOLLOW:
                    return CHANNEL_FOLLOW;
                case REBLOG:
                    return CHANNEL_BOOST;
                case FAVOURITE:
                    return CHANNEL_FAVOURITE;
            }

    }

    private static String truncateWithEllipses(String string, int limit) {
        if (string.length() < limit) {
            return string;
        } else {
            return string.substring(0, limit - 3) + "...";
        }
    }

    private static void setupPreferences(SharedPreferences preferences,
            NotificationCompat.Builder builder) {

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            return;  //do nothing on Android O or newer, the system uses the channel settings anyway
        }

        if (preferences.getBoolean("notificationAlertSound", true)) {
            builder.setSound(Settings.System.DEFAULT_NOTIFICATION_URI);
        }

        if (preferences.getBoolean("notificationAlertVibrate", false)) {
            builder.setVibrate(new long[] { 500, 500 });
        }

        if (preferences.getBoolean("notificationAlertLight", false)) {
            builder.setLights(0xFF00FF8F, 300, 1000);
        }
    }

    @Nullable
    private static String joinNames(Context context, JSONArray array) throws JSONException {
        if (array.length() > 3) {
            return String.format(context.getString(R.string.notification_summary_large),
                    array.get(0), array.get(1), array.get(2), array.length() - 3);
        } else if (array.length() == 3) {
            return String.format(context.getString(R.string.notification_summary_medium),
                    array.get(0), array.get(1), array.get(2));
        } else if (array.length() == 2) {
            return String.format(context.getString(R.string.notification_summary_small),
                    array.get(0), array.get(1));
        }

        return null;
    }

    @Nullable
    private static String titleForType(Context context, Notification notification) {
        switch (notification.type) {
            case MENTION:
                return String.format(context.getString(R.string.notification_mention_format),
                        notification.account.getDisplayName());
            case FOLLOW:
                return String.format(context.getString(R.string.notification_follow_format),
                        notification.account.getDisplayName());
            case FAVOURITE:
                return String.format(context.getString(R.string.notification_favourite_format),
                        notification.account.getDisplayName());
            case REBLOG:
                return String.format(context.getString(R.string.notification_reblog_format),
                        notification.account.getDisplayName());
        }
        return null;
    }

    @Nullable
    private static String bodyForType(Notification notification) {
        switch (notification.type) {
            case FOLLOW:
                return notification.account.username;
            case MENTION:
            case FAVOURITE:
            case REBLOG:
                return notification.status.content.toString();
        }
        return null;
    }

}