Create `LocationInfoCache` helper class

1 files changed, 67 insertions, 0 deletions

diff --git a/android/src/main/kotlin/net/mullvad/mullvadvpn/dataproxy/LocationInfoCache.kt b/android/src/main/kotlin/net/mullvad/mullvadvpn/dataproxy/LocationInfoCache.kt
new file mode 100644
index 0000000000..ba3f9cefd4
--- /dev/null
+++ b/android/src/main/kotlin/net/mullvad/mullvadvpn/dataproxy/LocationInfoCache.kt
@@ -0,0 +1,67 @@
+package net.mullvad.mullvadvpn.dataproxy
+
+import kotlinx.coroutines.async
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.Deferred
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.Job
+
+import net.mullvad.mullvadvpn.model.GeoIpLocation
+import net.mullvad.mullvadvpn.model.TunnelStateTransition
+import net.mullvad.mullvadvpn.MullvadDaemon
+
+class LocationInfoCache(val daemon: Deferred<MullvadDaemon>) {
+    private var lastKnownRealLocation: GeoIpLocation? = null
+    private var activeFetch: Job? = null
+
+    var onNewLocation: ((String, String, String) -> Unit)? = null
+
+    var location: GeoIpLocation? = null
+        set(value) {
+            field = value
+            notifyNewLocation(value)
+        }
+
+    fun setState(state: TunnelStateTransition) {
+        activeFetch?.cancel()
+        activeFetch = null
+
+        when (state) {
+            is TunnelStateTransition.Disconnected -> activeFetch = fetchRealLocation()
+            is TunnelStateTransition.Connecting -> activeFetch = fetchRelayLocation()
+            is TunnelStateTransition.Connected -> activeFetch = fetchRelayLocation()
+            is TunnelStateTransition.Disconnecting -> location = lastKnownRealLocation
+            is TunnelStateTransition.Blocked -> location = null
+        }
+    }
+
+    fun notifyNewLocation(location: GeoIpLocation?) {
+        val country = location?.country ?: ""
+        val city = location?.city ?: ""
+        val hostname = location?.hostname ?: ""
+
+        onNewLocation?.invoke(country, city, hostname)
+    }
+
+    private fun fetchRealLocation() = GlobalScope.launch(Dispatchers.Main) {
+        var realLocation: GeoIpLocation? = null
+        var remainingAttempts = 10
+
+        while (realLocation == null && remainingAttempts > 0) {
+            realLocation = fetchLocation().await()
+            remainingAttempts -= 1
+        }
+
+        lastKnownRealLocation = realLocation
+        location = realLocation
+    }
+
+    private fun fetchRelayLocation() = GlobalScope.launch(Dispatchers.Main) {
+        location = fetchLocation().await()
+    }
+
+    private fun fetchLocation() = GlobalScope.async(Dispatchers.Default) {
+        daemon.await().getCurrentLocation()
+    }
+}