using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.Locations;
using Android.Util;
using System.Timers;

namespace CommonLib
{
    public class LocationInfo : Activity, ILocationListener
    {
        protected Location currentLocation = null;
        protected LocationManager locationManager = null;
        string locationProvider = string.Empty;
        DateTime locationReceiveTime = DateTime.Now;

        public void InitLocationInfo()
        {
            try
            {
                CheckGpsService();
                this.locationManager = (LocationManager)GetSystemService(LocationService);
                RequestLocationUpdates();
            }
            catch
            {
            }
        }

        public void OnLocationChanged(Location location)
        {
            try
            {
                currentLocation = location;
                OnLocationChanged();
            }
            catch
            {
            }
        }

        protected virtual void OnLocationChanged()
        {
            this.locationReceiveTime = DateTime.Now;
        }

        public Boolean GetGeoLocation(ref double dLatPoint, ref double dLongitude)
        {
            if (currentLocation == null)
                return false;
            dLatPoint = currentLocation.Latitude;
            dLongitude = currentLocation.Longitude;
            return true;
        }

        public void RequestLocationUpdates()
        {
            try
            {
                if (this.locationManager.IsProviderEnabled(LocationManager.GpsProvider) == true)
                {
                    // GPS·Î ºÎÅÍ À§Ä¡ Á¤º¸¸¦ ¾÷µ¥ÀÌÆ® ¿äû
                    this.locationManager.RequestLocationUpdates(LocationManager.GpsProvider, 0, 0, this);
                }
                else
                {
                }
                // ±âÁö±¹À¸·ÎºÎÅÍ À§Ä¡ Á¤º¸¸¦ ¾÷µ¥ÀÌÆ® ¿äû
                this.locationManager.RequestLocationUpdates(LocationManager.NetworkProvider, 1000, 0, this);
            }
            catch(Exception)
            {

            }
        }

        public double GetDistance(double lat1, double lon1, double lat2, double lon2)
        {

            double theta, dist;
            theta = lon1 - lon2;
            dist = Math.Sin(deg2rad(lat1)) * Math.Sin(deg2rad(lat2)) + Math.Cos(deg2rad(lat1))
                  * Math.Cos(deg2rad(lat2)) * Math.Cos(deg2rad(theta));
            dist = Math.Acos(dist);
            dist = rad2deg(dist);

            dist = dist * 60 * 1.1515;
            dist = dist * 1.609344;    // ´ÜÀ§ mile ¿¡¼­ km º¯È¯.  
            dist = dist * 1000.0;      // ´ÜÀ§  km ¿¡¼­ m ·Î º¯È¯  

            return dist;
        }

        // ÁÖ¾îÁø µµ(degree) °ªÀ» ¶óµð¾ðÀ¸·Î º¯È¯  
        private double deg2rad(double deg)
        {
            return (double)(deg * Math.PI / (double)180d);
        }

        // ÁÖ¾îÁø ¶óµð¾ð(radian) °ªÀ» µµ(degree) °ªÀ¸·Î º¯È¯  
        private double rad2deg(double rad)
        {
            return (double)(rad * (double)180d / Math.PI);
        }

        protected override void OnResume()
        {
            base.OnResume();
        }

        protected override void OnPause()
        {
            base.OnPause();
        }

        public void OnStatusChanged(string provider, Availability status, Bundle extras)
        {
        }

        public void OnProviderDisabled(string provider)
        {
        }

        public void OnProviderEnabled(string provider)
        {
        }


        private bool CheckGpsService()
        {
            String strGPS = Android.Provider.Settings.Secure.GetString(ContentResolver, Android.Provider.Settings.Secure.LocationProvidersAllowed);
            int nPos = strGPS.IndexOf("gps");
            if (nPos < 0)
            {
                MessageBox messageBox = MessageBox.Execute(this, "À§Ä¡¼­ºñ½º ¼³Á¤", "¹«¼± ³×Æ®¿öÅ© »ç¿ë, GPS À§¼º »ç¿ëÀ» ¸ðµÎ üũÇÏ¼Å¾ß Á¤È®ÇÑ À§Ä¡ ¼­ºñ½º°¡ °¡´ÉÇÕ´Ï´Ù.\nÀ§Ä¡ ¼­ºñ½º ±â´ÉÀ» ¼³Á¤ÇϽðڽÀ´Ï±î?", "È®ÀÎ");
                messageBox.okEvent += OnMessageBoxOK;
                return false;
            }
            return true;
        }

        void OnMessageBoxOK()
        {
            Intent intent = new Intent(Android.Provider.Settings.ActionLocationSourceSettings);
            intent.AddCategory(Intent.CategoryDefault);
            StartActivity(intent);
        }
    }
}