package org.pihole.dnsproxy;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;

import android.location.LocationManager;

import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;

import android.os.IBinder;

import android.preference.PreferenceManager;

import android.util.Log;

public class WifiListenerService extends Service
{

    public static String NOTIFICATION_CHANNEL_ID = "org.pihole.dnsproxy.service.wifiListener.NOTIFICATION";
    public static String ACTION_START = "org.pihole.dnsproxy.service.wifiListener.START";
    public static String ACTION_STOP = "org.pihole.dnsproxy.service.wifiListener.STOP";
    public static String ACTION_STOP_SET_PREFERENCE = "org.pihole.dnsproxy.service.wifiListener.STOP_SET_PREFERENCE";

    private BroadcastReceiver receiver = new WifiListenerReceiver();

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // start the service
        if (intent.getAction().equals(WifiListenerService.ACTION_START)) {
            this.listen();

            return Service.START_STICKY;
        }

        // stop the service
        else if (intent.getAction().equals(WifiListenerService.ACTION_STOP)) {
            try {
                this.deafen();
            } catch (Exception exception) {}

            return Service.START_NOT_STICKY;
        }

        // stop and disable
        else if (intent.getAction().equals(WifiListenerService.ACTION_STOP_SET_PREFERENCE)) {
            WifiListenerService.disable(this);

            return Service.START_NOT_STICKY;
        }

        return Service.START_NOT_STICKY;
    }

    @Override
    public void onDestroy() {
        this.deafen();

        super.onDestroy();
    }

    @Override
    public IBinder onBind(Intent intent) { return null; }

    /**
     * Start the service
     */
    public static void start(Context context) {
        context.startService((new Intent(context, WifiListenerService.class)).setAction(WifiListenerService.ACTION_START));
    }

    /**
     * Stop the service
     */
    public static void stop(Context context) {
        context.startService((new Intent(context, WifiListenerService.class)).setAction(WifiListenerService.ACTION_STOP));
    }

    /**
     * Start/Stop based on setting
     */
    public static void toggle(Context context) {
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);

        if (sharedPreferences.getBoolean("use_wifi_listener", false)) {
            WifiListenerService.start(context);
        } else {
            WifiListenerService.stop(context);
        }
    }

    /**
     * Stop Wifi Listener and disable completely
     */
    public static void disable(Context context) {
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
        SharedPreferences.Editor sharedPreferencesEditor = sharedPreferences.edit();

        WifiListenerService.stop(context);
        sharedPreferencesEditor.putBoolean("use_wifi_listener", false);
        sharedPreferencesEditor.commit();

        WifiListenerService.OnActivationListener.disable(context);
    }

    /**
     * Get current Wifi SSID
     */
    public static String getWifiSSID(Context context) {
        WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
        WifiInfo wifiInfo = wifiManager.getConnectionInfo();
        String ssid = wifiInfo.getSSID();

        // remove quotes around ssid
        ssid = ssid.substring(1, ssid.length() - 1);

        return ssid;
    }

    /**
     * Setup listener
     */
    private void listen() {
        registerReceiver(this.receiver, new IntentFilter(WifiManager.NETWORK_STATE_CHANGED_ACTION));

        this.startForeground();
    }

    /**
     * Stop listening
     */
    private void deafen() {
        unregisterReceiver(this.receiver);

        stopForeground(true);
    }

    /**
     * Start the Foreground notification process
     */
    private void startForeground() {
        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

        NotificationChannel channel = new NotificationChannel(
            WifiListenerService.NOTIFICATION_CHANNEL_ID,
            WifiListenerService.NOTIFICATION_CHANNEL_ID,
            NotificationManager.IMPORTANCE_DEFAULT
        );
        manager.createNotificationChannel(channel);

        Notification notification = new Notification.Builder(this, WifiListenerService.NOTIFICATION_CHANNEL_ID)
            .setSmallIcon(R.drawable.logo)
            .setContentTitle("Pihole DNS Proxy - WiFi Listener")
            .setContentText("Listening for WiFi connection change")
            .setContentIntent(PendingIntent.getActivity(this, 0, new Intent(this, SettingsActivity.class), Intent.FLAG_ACTIVITY_NEW_TASK))
            .addAction(
                R.drawable.logo,
                "Stop Listener",
                PendingIntent.getService(this, 0,
                    (new Intent(this, WifiListenerService.class)).setAction(WifiListenerService.ACTION_STOP_SET_PREFERENCE),
                    PendingIntent.FLAG_IMMUTABLE
                )
            )
            .addAction(
                R.drawable.logo,
                "Start Proxy",
                PendingIntent.getService(this, 0,
                    (new Intent(this, DNSProxyService.class)).setAction(DNSProxyService.ACTION_START),
                    PendingIntent.FLAG_IMMUTABLE
                )
            )
            .build();

        startForeground(2, notification);
    }

    /**
     * SubClass to enable auto-activation
     */
    public static class OnActivationListener {

        /**
         * Disable auto-activation
         */
        public static void disable(Context context) {
            SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
            SharedPreferences.Editor sharedPreferencesEditor = sharedPreferences.edit();
            LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

            sharedPreferencesEditor.putBoolean("use_wifi_listener_for_activation", false);
            sharedPreferencesEditor.commit();

            if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
                context.startActivity((new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS)).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK));
            }
        }

        /**
         * Check if location services are needed
         */
        public static boolean checkLocationNeeded(Context context) {
            SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);

            if (!sharedPreferences.getBoolean("use_wifi_listener_for_activation", false)) {
                return false;
            }

            LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

            return !locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
        }

        /**
         * Ask User to enable location services if they are needed
         */
        public static void askLocationIfNeeded(Activity context) {
            if (checkLocationNeeded(context)) {
                context.requestPermissions(new String[]{
                    android.Manifest.permission.ACCESS_FINE_LOCATION,
                }, 3765);

                context.startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));
            }
        }
    }
}