Refactor network detectors to kotlin (#752)

* Rename .java to .kt

* assisted kotlin conversion

* empty to null

* default param

* refactor to simplify

* Rename .java to .kt

* assisted convert to kotlin

* refactor to simplify

* cleanup and format

* Rename .java to .kt

* convert to kotlin

common/src/main/java/io/opentelemetry/android/common/internal/features/networkattributes/data/CurrentNetwork.java

@@ -116,6 +116,9 @@ public Builder carrier(@Nullable Carrier carrier) {
         }
 
         public Builder subType(@Nullable String subType) {
+            if ((subType != null) && subType.isEmpty()) {
+                return subType(null);
+            }
             this.subType = subType;
             return this;
         }

core/src/test/java/io/opentelemetry/android/OpenTelemetryRumBuilderTest.java

@@ -24,6 +24,7 @@
 import static org.mockito.Mockito.when;
 
 import android.app.Application;
+import android.net.ConnectivityManager;
 import android.os.Looper;
 import androidx.annotation.NonNull;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
@@ -98,13 +99,16 @@ public class OpenTelemetryRumBuilderTest {
     @Mock android.content.Context applicationContext;
 
     @Mock InitializationEvents initializationEvents;
+    @Mock ConnectivityManager connectivityManager;
     private AutoCloseable mocks;
 
     @Before
     public void setup() {
         mocks = MockitoAnnotations.openMocks(this);
         when(application.getApplicationContext()).thenReturn(applicationContext);
         when(application.getMainLooper()).thenReturn(looper);
+        when(application.getSystemService(android.content.Context.CONNECTIVITY_SERVICE))
+                .thenReturn(connectivityManager);
         InitializationEvents.set(initializationEvents);
     }
 

services/src/main/java/io/opentelemetry/android/internal/services/network/detector/NetworkDetector.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.android.internal.services.network.detector
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.os.Build
+import android.telephony.TelephonyManager
+import io.opentelemetry.android.common.internal.features.networkattributes.data.CurrentNetwork
+import io.opentelemetry.android.internal.services.network.CarrierFinder
+
+/**
+ * This class is internal and not for public use. Its APIs are unstable and can change at any time.
+ */
+interface NetworkDetector {
+    fun detectCurrentNetwork(): CurrentNetwork
+
+    companion object {
+        @JvmStatic
+        fun create(context: Context): NetworkDetector {
+            // TODO: Use ServiceManager to get the ConnectivityManager or similar (not yet managed/abstracted)
+            val connectivityManager =
+                context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+                // TODO: Use ServiceManager to get the TelephonyManager or similar (not yet managed/abstracted)
+                val telephonyManager =
+                    context.getSystemService(Context.TELEPHONY_SERVICE) as TelephonyManager
+                val carrierFinder = CarrierFinder(telephonyManager)
+                return PostApi28NetworkDetector(
+                    connectivityManager,
+                    telephonyManager,
+                    carrierFinder,
+                    context,
+                )
+            }
+            return SimpleNetworkDetector(connectivityManager)
+        }
+    }
+}

services/src/main/java/io/opentelemetry/android/internal/services/network/detector/PostApi28NetworkDetector.kt

@@ -0,0 +1,125 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.android.internal.services.network.detector
+
+import android.Manifest
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.pm.PackageManager
+import android.net.ConnectivityManager
+import android.net.NetworkCapabilities
+import android.os.Build
+import android.telephony.TelephonyManager
+import android.telephony.TelephonyManager.NETWORK_TYPE_1xRTT
+import android.telephony.TelephonyManager.NETWORK_TYPE_CDMA
+import android.telephony.TelephonyManager.NETWORK_TYPE_EDGE
+import android.telephony.TelephonyManager.NETWORK_TYPE_EHRPD
+import android.telephony.TelephonyManager.NETWORK_TYPE_EVDO_0
+import android.telephony.TelephonyManager.NETWORK_TYPE_EVDO_A
+import android.telephony.TelephonyManager.NETWORK_TYPE_EVDO_B
+import android.telephony.TelephonyManager.NETWORK_TYPE_GPRS
+import android.telephony.TelephonyManager.NETWORK_TYPE_GSM
+import android.telephony.TelephonyManager.NETWORK_TYPE_HSDPA
+import android.telephony.TelephonyManager.NETWORK_TYPE_HSPA
+import android.telephony.TelephonyManager.NETWORK_TYPE_HSPAP
+import android.telephony.TelephonyManager.NETWORK_TYPE_HSUPA
+import android.telephony.TelephonyManager.NETWORK_TYPE_IDEN
+import android.telephony.TelephonyManager.NETWORK_TYPE_IWLAN
+import android.telephony.TelephonyManager.NETWORK_TYPE_LTE
+import android.telephony.TelephonyManager.NETWORK_TYPE_NR
+import android.telephony.TelephonyManager.NETWORK_TYPE_TD_SCDMA
+import android.telephony.TelephonyManager.NETWORK_TYPE_UMTS
+import android.telephony.TelephonyManager.NETWORK_TYPE_UNKNOWN
+import androidx.annotation.RequiresApi
+import androidx.core.app.ActivityCompat
+import io.opentelemetry.android.common.internal.features.networkattributes.data.Carrier
+import io.opentelemetry.android.common.internal.features.networkattributes.data.CurrentNetwork
+import io.opentelemetry.android.common.internal.features.networkattributes.data.NetworkState
+import io.opentelemetry.android.common.internal.features.networkattributes.data.NetworkState.TRANSPORT_CELLULAR
+import io.opentelemetry.android.common.internal.features.networkattributes.data.NetworkState.TRANSPORT_VPN
+import io.opentelemetry.android.common.internal.features.networkattributes.data.NetworkState.TRANSPORT_WIFI
+import io.opentelemetry.android.internal.services.network.CarrierFinder
+import io.opentelemetry.android.internal.services.network.CurrentNetworkProvider
+import io.opentelemetry.android.internal.services.network.CurrentNetworkProvider.UNKNOWN_NETWORK
+
+/**
+ * This class is internal and not for public use. Its APIs are unstable and can change at any time.
+ */
+@RequiresApi(api = Build.VERSION_CODES.P)
+internal class PostApi28NetworkDetector
+    @JvmOverloads
+    constructor(
+        private val connectivityManager: ConnectivityManager,
+        private val telephonyManager: TelephonyManager,
+        private val carrierFinder: CarrierFinder,
+        private val context: Context,
+        private val readPhoneState: () -> Boolean = { canReadPhoneState(context) },
+    ) : NetworkDetector {
+        @SuppressLint("MissingPermission")
+        override fun detectCurrentNetwork(): CurrentNetwork {
+            val capabilities =
+                connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)
+                    ?: return CurrentNetworkProvider.NO_NETWORK
+            val carrier = carrierFinder.get()
+
+            fun hasTransport(transportId: Int): Boolean = capabilities.hasTransport(transportId)
+
+            val network = buildFromCarrier(carrier)
+            return when {
+                hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> withCellDataType(carrier)
+                hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> network(TRANSPORT_WIFI)
+                hasTransport(NetworkCapabilities.TRANSPORT_VPN) -> network(TRANSPORT_VPN)
+                else -> UNKNOWN_NETWORK
+            }
+        }
+
+        private fun buildFromCarrier(carrier: Carrier): (NetworkState) -> CurrentNetwork =
+            { CurrentNetwork.builder(it).carrier(carrier).build() }
+
+        private fun withCellDataType(carrier: Carrier): CurrentNetwork {
+            val builder =
+                CurrentNetwork
+                    .builder(TRANSPORT_CELLULAR)
+                    .carrier(carrier)
+            if (readPhoneState()) {
+                val dataNetworkType = getDataNetworkTypeName(telephonyManager.dataNetworkType)
+                return builder.subType(dataNetworkType).build()
+            }
+            return builder.build()
+        }
+
+        private fun getDataNetworkTypeName(dataNetworkType: Int): String =
+            when (dataNetworkType) {
+                NETWORK_TYPE_1xRTT -> "1xRTT"
+                NETWORK_TYPE_CDMA -> "CDMA"
+                NETWORK_TYPE_EDGE -> "EDGE"
+                NETWORK_TYPE_EHRPD -> "EHRPD"
+                NETWORK_TYPE_EVDO_0 -> "EVDO_0"
+                NETWORK_TYPE_EVDO_A -> "EVDO_A"
+                NETWORK_TYPE_EVDO_B -> "EVDO_B"
+                NETWORK_TYPE_GPRS -> "GPRS"
+                NETWORK_TYPE_GSM -> "GSM"
+                NETWORK_TYPE_HSDPA -> "HSDPA"
+                NETWORK_TYPE_HSPA -> "HSPA"
+                NETWORK_TYPE_HSPAP -> "HSPAP"
+                NETWORK_TYPE_HSUPA -> "HSUPA"
+                NETWORK_TYPE_IDEN -> "IDEN"
+                NETWORK_TYPE_IWLAN -> "IWLAN"
+                NETWORK_TYPE_LTE -> "LTE"
+                NETWORK_TYPE_NR -> "NR"
+                NETWORK_TYPE_TD_SCDMA -> "SCDMA"
+                NETWORK_TYPE_UMTS -> "UMTS"
+                NETWORK_TYPE_UNKNOWN -> "UNKNOWN"
+                else -> "UNKNOWN"
+            }
+    }
+
+// visible for testing
+fun canReadPhoneState(context: Context): Boolean =
+    (
+        ActivityCompat.checkSelfPermission(context, Manifest.permission.READ_PHONE_STATE)
+            == PackageManager.PERMISSION_GRANTED
+    )