termux-app/termux-shared/src/main/java/com/termux/shared/notification/NotificationUtils.java

package com.termux.shared.notification;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.os.Build;

import androidx.annotation.Nullable;

import com.termux.shared.logger.Logger;
import com.termux.shared.settings.preferences.TermuxAppSharedPreferences;
import com.termux.shared.settings.preferences.TermuxPreferenceConstants;
import com.termux.shared.termux.TermuxConstants;

public class NotificationUtils {

    /** Do not show notification */
    public static final int NOTIFICATION_MODE_NONE = 0;
    /** Show notification without sound, vibration or lights */
    public static final int NOTIFICATION_MODE_SILENT = 1;
    /** Show notification with sound */
    public static final int NOTIFICATION_MODE_SOUND = 2;
    /** Show notification with vibration */
    public static final int NOTIFICATION_MODE_VIBRATE = 3;
    /** Show notification with lights */
    public static final int NOTIFICATION_MODE_LIGHTS = 4;
    /** Show notification with sound and vibration */
    public static final int NOTIFICATION_MODE_SOUND_AND_VIBRATE = 5;
    /** Show notification with sound and lights */
    public static final int NOTIFICATION_MODE_SOUND_AND_LIGHTS = 6;
    /** Show notification with vibration and lights */
    public static final int NOTIFICATION_MODE_VIBRATE_AND_LIGHTS = 7;
    /** Show notification with sound, vibration and lights */
    public static final int NOTIFICATION_MODE_ALL = 8;

    private static final String LOG_TAG = "NotificationUtils";

    /**
     * Get the {@link NotificationManager}.
     *
     * @param context The {@link Context} for operations.
     * @return Returns the {@link NotificationManager}.
     */
    @Nullable
    public static NotificationManager getNotificationManager(final Context context) {
        if (context == null) return null;
        return (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    }

    /**
     * Try to get the next unique notification id that isn't already being used by the app.
     *
     * Termux app and its plugin must use unique notification ids from the same pool due to usage of android:sharedUserId.
     * https://commonsware.com/blog/2017/06/07/jobscheduler-job-ids-libraries.html
     *
     * @param context The {@link Context} for operations.
     * @return Returns the notification id that should be safe to use.
     */
    public synchronized static int getNextNotificationId(final Context context) {
        if (context == null) return TermuxPreferenceConstants.TERMUX_APP.DEFAULT_VALUE_KEY_LAST_NOTIFICATION_ID;

        TermuxAppSharedPreferences preferences = TermuxAppSharedPreferences.build(context);
        if (preferences == null) return TermuxPreferenceConstants.TERMUX_APP.DEFAULT_VALUE_KEY_LAST_NOTIFICATION_ID;

        int lastNotificationId = preferences.getLastNotificationId();

        int nextNotificationId = lastNotificationId + 1;
        while(nextNotificationId == TermuxConstants.TERMUX_APP_NOTIFICATION_ID || nextNotificationId == TermuxConstants.TERMUX_RUN_COMMAND_NOTIFICATION_ID) {
            nextNotificationId++;
        }

        if (nextNotificationId == Integer.MAX_VALUE || nextNotificationId < 0)
            nextNotificationId = TermuxPreferenceConstants.TERMUX_APP.DEFAULT_VALUE_KEY_LAST_NOTIFICATION_ID;

        preferences.setLastNotificationId(nextNotificationId);
        return nextNotificationId;
    }

    /**
     * Get {@link Notification.Builder}.
     *
     * @param context The {@link Context} for operations.
     * @param title The title for the notification.
     * @param notifiationText The second line text of the notification.
     * @param notificationBigText The full text of the notification that may optionally be styled.
     * @param pendingIntent The {@link PendingIntent} which should be sent when notification is clicked.
     * @param notificationMode The notification mode. It must be one of {@code NotificationUtils.NOTIFICATION_MODE_*}.
     *                         The builder returned will be {@code null} if {@link #NOTIFICATION_MODE_NONE}
     *                         is passed. That case should ideally be handled before calling this function.
     * @return Returns the {@link Notification.Builder}.
     */
    @Nullable
    public static Notification.Builder geNotificationBuilder(final Context context, final String channelId, final int priority, final CharSequence title, final CharSequence notifiationText, final CharSequence notificationBigText, final PendingIntent pendingIntent, final int notificationMode) {
        if (context == null) return null;
        Notification.Builder builder = new Notification.Builder(context);
        builder.setContentTitle(title);
        builder.setContentText(notifiationText);
        builder.setStyle(new Notification.BigTextStyle().bigText(notificationBigText));
        builder.setContentIntent(pendingIntent);

        builder.setPriority(priority);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
            builder.setChannelId(channelId);

        builder = setNotificationDefaults(builder, notificationMode);

        return builder;
    }

    /**
     * Setup the notification channel if Android version is greater than or equal to
     * {@link Build.VERSION_CODES#O}.
     *
     * @param context The {@link Context} for operations.
     * @param channelId The id of the channel. Must be unique per package.
     * @param channelName The user visible name of the channel.
     * @param importance The importance of the channel. This controls how interruptive notifications
     *                   posted to this channel are.
     */
    public static void setupNotificationChannel(final Context context, final String channelId, final CharSequence channelName, final int importance) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return;

        NotificationChannel channel = new NotificationChannel(channelId, channelName, importance);

        NotificationManager notificationManager = getNotificationManager(context);
        if (notificationManager != null)
            notificationManager.createNotificationChannel(channel);
    }

    public static Notification.Builder setNotificationDefaults(Notification.Builder builder, final int notificationMode) {

        // TODO: setDefaults() is deprecated and should also implement setting notification mode via notification channel
        switch (notificationMode) {
            case NOTIFICATION_MODE_NONE:
                Logger.logWarn(LOG_TAG, "The NOTIFICATION_MODE_NONE passed to setNotificationDefaults(), force setting builder to null.");
                return null; // return null since notification is not supposed to be shown
            case NOTIFICATION_MODE_SILENT:
                break;
            case NOTIFICATION_MODE_SOUND:
                builder.setDefaults(Notification.DEFAULT_SOUND);
                break;
            case NOTIFICATION_MODE_VIBRATE:
                builder.setDefaults(Notification.DEFAULT_VIBRATE);
                break;
            case NOTIFICATION_MODE_LIGHTS:
                builder.setDefaults(Notification.DEFAULT_LIGHTS);
                break;
            case NOTIFICATION_MODE_SOUND_AND_VIBRATE:
                builder.setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE);
                break;
            case NOTIFICATION_MODE_SOUND_AND_LIGHTS:
                builder.setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_LIGHTS);
                break;
            case NOTIFICATION_MODE_VIBRATE_AND_LIGHTS:
                builder.setDefaults(Notification.DEFAULT_VIBRATE | Notification.DEFAULT_LIGHTS);
                break;
            case NOTIFICATION_MODE_ALL:
                builder.setDefaults(Notification.DEFAULT_ALL);
                break;
            default:
                Logger.logError(LOG_TAG, "Invalid notificationMode: \"" + notificationMode + "\" passed to setNotificationDefaults()");
                break;
        }

        return builder;
    }

}