Create `RelayListListener` helper type

1 files changed, 113 insertions, 0 deletions

diff --git a/android/src/main/kotlin/net/mullvad/mullvadvpn/relaylist/RelayListListener.kt b/android/src/main/kotlin/net/mullvad/mullvadvpn/relaylist/RelayListListener.kt
new file mode 100644
index 0000000000..87624b116c
--- /dev/null
+++ b/android/src/main/kotlin/net/mullvad/mullvadvpn/relaylist/RelayListListener.kt
@@ -0,0 +1,113 @@
+package net.mullvad.mullvadvpn.relaylist
+
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.GlobalScope
+
+import net.mullvad.mullvadvpn.MainActivity
+import net.mullvad.mullvadvpn.model.Constraint
+import net.mullvad.mullvadvpn.model.LocationConstraint
+import net.mullvad.mullvadvpn.model.RelaySettings
+import net.mullvad.mullvadvpn.MullvadDaemon
+
+class RelayListListener(val parentActivity: MainActivity) {
+    private val daemon = CompletableDeferred<MullvadDaemon>()
+    private val setUpJob = setUp()
+
+    private var relayList: RelayList? = null
+    private var relaySettings: RelaySettings? = null
+
+    var selectedRelayItem: RelayItem? = null
+        set(value) {
+            field = value
+            updateRelaySettings()
+        }
+
+    val selectedRelayLocation: Constraint<LocationConstraint>
+        get() {
+            val location = selectedRelayItem?.location
+
+            if (location == null) {
+                return Constraint.Any()
+            } else {
+                return Constraint.Only(location)
+            }
+        }
+
+    var onRelayListChange: ((RelayList, RelayItem?) -> Unit)? = null
+        set(value) {
+            field = value
+
+            synchronized(this) {
+                val relayList = this.relayList
+
+                if (relayList != null) {
+                    value?.invoke(relayList, selectedRelayItem)
+                }
+            }
+        }
+
+    fun onDestroy() {
+        setUpJob.cancel()
+
+        if (daemon.isActive) {
+            daemon.cancel()
+        } else {
+            daemon.getCompleted().onRelayListChange = null
+        }
+    }
+
+    private fun setUp() = GlobalScope.launch(Dispatchers.Default) {
+        daemon.complete(parentActivity.asyncDaemon.await())
+
+        setUpListener()
+        fetchInitialRelayList()
+    }
+
+    private suspend fun setUpListener() {
+        daemon.await().onRelayListChange = { relayLocations ->
+            relayListChanged(RelayList(relayLocations))
+        }
+    }
+
+    private suspend fun fetchInitialRelayList() {
+        val relayLocations = daemon.await().getRelayLocations()
+
+        relaySettings = parentActivity.asyncSettings.await().relaySettings
+
+        synchronized(this) {
+            if (relayList == null) {
+                relayListChanged(RelayList(relayLocations))
+            }
+        }
+    }
+
+    private fun relayListChanged(newRelayList: RelayList) {
+        synchronized(this) {
+            relayList = newRelayList
+            selectedRelayItem = findSelectedRelayItem()
+
+            onRelayListChange?.invoke(newRelayList, selectedRelayItem)
+        }
+    }
+
+    private fun findSelectedRelayItem(): RelayItem? {
+        val relaySettings = this.relaySettings
+
+        when (relaySettings) {
+            is RelaySettings.CustomTunnelEndpoint -> return null
+            is RelaySettings.RelayConstraints -> {
+                val location = relaySettings.location
+
+                return relayList?.findItemForLocation(location, true)
+            }
+        }
+
+        return null
+    }
+
+    private fun updateRelaySettings() {
+        relaySettings = RelaySettings.RelayConstraints(selectedRelayLocation)
+    }
+}