Add findNearestLocation & refactor callbacks management

app/src/main/java/net/pokeranalytics/android/ui/activity/components/PokerAnalyticsActivity.kt

@@ -10,8 +10,8 @@ import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
 import com.google.android.libraries.places.api.model.PlaceLikelihood
 import io.realm.Realm
+import net.pokeranalytics.android.model.realm.Location
 import net.pokeranalytics.android.util.LocationManager
-import java.util.*
 
 
 open class PokerAnalyticsActivity : AppCompatActivity() {
@@ -21,8 +21,7 @@ open class PokerAnalyticsActivity : AppCompatActivity() {
 	}
 
 	private val realm = Realm.getDefaultInstance()
-	private var askFromPlaces = false
-	private var currentCallback: ((success: Boolean, places: ArrayList<PlaceLikelihood>) -> Unit)? = null
+	private var permissionCallback: ((granted: Boolean) -> Unit)? = null
 
 	override fun onCreate(savedInstanceState: Bundle?) {
 		super.onCreate(savedInstanceState)
@@ -36,8 +35,9 @@ open class PokerAnalyticsActivity : AppCompatActivity() {
 				if (permissions.isNotEmpty() && permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION
 					&& grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED
 				) {
-					locationPermissionGranted()
+					permissionCallback?.invoke(true)
 				} else {
+					permissionCallback?.invoke(false)
 					// permission denied, boo! Disable the
 					// functionality that depends on this permission.
 					// showMessage(getString(R.string.error));
@@ -71,35 +71,50 @@ open class PokerAnalyticsActivity : AppCompatActivity() {
 	/**
 	 * Ask for location permission
 	 */
-	private fun askForLocationPermission() {
+	private fun askForLocationPermission(permissionCallback: ((granted: Boolean) -> Unit)) {
+		this.permissionCallback = permissionCallback
 		ActivityCompat.requestPermissions(
-			this, arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
-			PERMISSION_REQUEST_ACCESS_FINE_LOCATION
+			this, arrayOf(Manifest.permission.ACCESS_FINE_LOCATION), PERMISSION_REQUEST_ACCESS_FINE_LOCATION
 		)
 	}
 
-	/**
-	 * Called when the permission location has been granted
-	 */
-	open fun locationPermissionGranted() {
-		if (askFromPlaces) {
-			askFromPlaces = false
-			askForPlacesRequest(currentCallback)
-		}
-	}
 
 	/**
 	 * Ask for places request
 	 */
 	fun askForPlacesRequest(callback: ((success: Boolean, places: ArrayList<PlaceLikelihood>) -> Unit)?) {
-
 		// Call findCurrentPlace and handle the response (first check that the user has granted permission).
 		if (ContextCompat.checkSelfPermission(this, ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
 			LocationManager(this).askForPlacesRequest(callback)
 		} else {
-			askFromPlaces = true
-			currentCallback = callback
-			askForLocationPermission()
+			askForLocationPermission { granted ->
+				if (granted) {
+					LocationManager(this).askForPlacesRequest(callback)
+				} else {
+					callback?.invoke(false, ArrayList())
+				}
+			}
+		}
+	}
+
+	/**
+	 * Find the nearest location from the user
+	 */
+	fun findNearestLocation(callback: ((location: Location?) -> Unit)?) {
+		if (LocationManager(this).databaseContainsLocationsWithCoordinates()) {
+			if (ContextCompat.checkSelfPermission(this, ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
+				LocationManager(this).findNearestLocationFromUser(callback)
+			} else {
+				askForLocationPermission { granted ->
+					if (granted) {
+						LocationManager(this).findNearestLocationFromUser(callback)
+					} else {
+						callback?.invoke(null)
+					}
+				}
+			}
+		} else {
+			callback?.invoke(null)
 		}
 	}
 

app/src/main/java/net/pokeranalytics/android/util/LocationManager.kt

@@ -5,15 +5,25 @@ import android.content.Context
 import android.content.pm.PackageManager
 import androidx.core.content.ContextCompat
 import com.google.android.gms.common.api.ApiException
+import com.google.android.gms.location.FusedLocationProviderClient
+import com.google.android.gms.location.LocationServices
 import com.google.android.libraries.places.api.Places
 import com.google.android.libraries.places.api.model.Place
 import com.google.android.libraries.places.api.model.PlaceLikelihood
 import com.google.android.libraries.places.api.net.FindCurrentPlaceRequest
+import io.realm.Realm
+import io.realm.kotlin.where
+import net.pokeranalytics.android.model.realm.Location
 import timber.log.Timber
 import java.util.*
+import kotlin.collections.ArrayList
 
 class LocationManager(private var context: Context) {
 
+	companion object {
+		const val MAXIMUM_DISTANCE_FROM_USER = 5000 // in meters
+	}
+
 	/**
 	 * Return the [places] around the user
 	 */
@@ -50,8 +60,89 @@ class LocationManager(private var context: Context) {
 
 				callback?.invoke(task.isSuccessful, places)
 			}
+		} else {
+			// If we don't have the permission, return
+			callback?.invoke(false, ArrayList())
 		}
 	}
 
+	/**
+	 * Return if the database contains one or many locations with coordinates
+	 */
+	fun databaseContainsLocationsWithCoordinates(): Boolean {
+		val realm = Realm.getDefaultInstance()
+		val result = realm.where<Location>().isNotNull("latitude")
+			.and().isNotNull("longitude").findAll().isNotEmpty()
+		realm.close()
+		return result
+	}
+
+	/**
+	 * Find the nearest location from user
+	 */
+	fun findNearestLocationFromUser(callback: ((location: Location?) -> Unit)?) {
+
+		val locations = ArrayList<net.pokeranalytics.android.model.realm.Location>()
+		val realm = Realm.getDefaultInstance()
+		val realmResults = realm.where<Location>().isNotNull("latitude")
+			.and().isNotNull("longitude").findAll()
+		locations.addAll(realm.copyFromRealm(realmResults))
+		realm.close()
+
+		// If we have no locations with coordinates, return null
+		if (realmResults.size == 0) {
+			callback?.invoke(null)
+			return
+		}
+
+		val fusedLocationClient: FusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(context)
+
+		if (ContextCompat.checkSelfPermission(context, ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
+			fusedLocationClient.lastLocation.addOnSuccessListener { location: android.location.Location? ->
+				// Got last known location. In some rare situations this can be null.
+
+				location?.let { currentLocation ->
+
+					locations.sortBy {
+						val locationToSort = android.location.Location("")
+						locationToSort.latitude = it.latitude!!
+						locationToSort.longitude = it.longitude!!
+						currentLocation.distanceTo(locationToSort)
+					}
+
+					val nearestLocation = locations.firstOrNull()
+					nearestLocation?.let {
+
+						val locationForDistance = android.location.Location("")
+						locationForDistance.latitude = it.latitude ?: 0.0
+						locationForDistance.longitude = it.longitude ?: 0.0
+
+						// Final check: if the distance between the location and the user is lower than MAXIMUM_DISTANCE_FROM_USER
+						if (currentLocation.distanceTo(locationForDistance) < MAXIMUM_DISTANCE_FROM_USER) {
+							callback?.invoke(nearestLocation)
+						} else {
+							callback?.invoke(null)
+						}
+
+
+					} ?: run {
+						callback?.invoke(null)
+					}
+
+				} ?: run {
+					// If the current location is null, return null
+					callback?.invoke(null)
+				}
+
+			}.addOnCanceledListener {
+				// If there was a problem during the call to last location, return null
+				callback?.invoke(null)
+			}
+		} else {
+			// If we don't have the permission, return null
+			callback?.invoke(null)
+		}
+
+	}
 
 }