feat: add network connectivity observer

app/src/main/AndroidManifest.xml

@@ -3,6 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />

app/src/main/kotlin/dev/meloda/fast/common/di/ApplicationModule.kt

@@ -22,6 +22,7 @@ import dev.meloda.fast.languagepicker.di.languagePickerModule
 import dev.meloda.fast.logger.loggerModule
 import dev.meloda.fast.messageshistory.di.messagesHistoryModule
 import dev.meloda.fast.photoviewer.di.photoViewModule
+import dev.meloda.fast.presentation.NetworkObserver
 import dev.meloda.fast.profile.di.profileModule
 import dev.meloda.fast.provider.ApiLanguageProvider
 import dev.meloda.fast.service.longpolling.di.longPollModule
@@ -72,4 +73,6 @@ val applicationModule = module {
 
     singleOf(::LongPollControllerImpl) bind LongPollController::class
     singleOf(::ResourceProviderImpl) bind ResourceProvider::class
+
+    singleOf(::NetworkObserver)
 }

app/src/main/kotlin/dev/meloda/fast/presentation/MainActivity.kt

@@ -184,6 +184,7 @@ class MainActivity : AppCompatActivity() {
         super.onDestroy()
         stopServices()
         get<LongPollEventsHandler>().onDestroy()
+        get<NetworkObserver>().onDestroy()
     }
 
     companion object {

app/src/main/kotlin/dev/meloda/fast/presentation/NetworkObserver.kt

@@ -0,0 +1,274 @@
+package dev.meloda.fast.presentation
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.LinkProperties
+import android.net.Network
+import android.net.NetworkCapabilities
+import android.net.NetworkRequest
+import dev.meloda.fast.logger.FastLogger
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import java.util.concurrent.ConcurrentHashMap
+
+class NetworkObserver(
+    context: Context,
+    private val logger: FastLogger
+) {
+
+    private val connectivityManager =
+        context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+
+    private val networkStatus = MutableStateFlow(NetworkStatus.UNAVAILABLE)
+    val networkStatusFlow = networkStatus.asStateFlow()
+
+    private val networkState = MutableStateFlow(NetworkState.DISCONNECTED)
+    val networkStateFlow = networkState.asStateFlow()
+
+    private val networks = ConcurrentHashMap<Network, NetworkModel>()
+
+    private var clearCallbacks: (() -> Unit)? = null
+
+    init {
+        startListener()
+    }
+
+    private fun syncNetworkState() {
+        val state = if (networks.values.any { it.isInternetAvailable() }) {
+            NetworkState.CONNECTED
+        } else {
+            NetworkState.DISCONNECTED
+        }
+
+        networkState.value = state
+        networkStatus.value = when (state) {
+            NetworkState.CONNECTED -> NetworkStatus.AVAILABLE
+            NetworkState.DISCONNECTED -> NetworkStatus.UNAVAILABLE
+        }
+
+        log("STATE: $state")
+    }
+
+    private fun startListener() {
+        val callback = object : ConnectivityManager.NetworkCallback() {
+            override fun onAvailable(network: Network) {
+                log("onAvailable(): network: $network")
+
+                networks[network] = mapNetworkModel(
+                    network = network,
+                    capabilities = connectivityManager.getNetworkCapabilities(network),
+                    properties = connectivityManager.getLinkProperties(network),
+                    status = NetworkStatus.AVAILABLE
+                )
+
+                syncNetworkState()
+            }
+
+            override fun onUnavailable() {
+                log("onUnavailable()")
+
+                networks.clear()
+                syncNetworkState()
+            }
+
+            override fun onLost(network: Network) {
+                log("onLost() network: $network")
+
+                networks.remove(network)
+                syncNetworkState()
+            }
+
+            override fun onCapabilitiesChanged(
+                network: Network,
+                networkCapabilities: NetworkCapabilities
+            ) {
+                log("onCapabilitiesChanged(): network: $network; caps: $networkCapabilities")
+
+                val current = networks[network]
+                networks[network] = mapNetworkModel(
+                    network = network,
+                    capabilities = networkCapabilities,
+                    from = current,
+                    status = current?.status ?: NetworkStatus.AVAILABLE
+                )
+
+                syncNetworkState()
+            }
+
+            override fun onBlockedStatusChanged(
+                network: Network,
+                blocked: Boolean
+            ) {
+                log("onBlockedStatusChanged(): network: $network; blocked: $blocked")
+
+                networks[network] = mapNetworkModel(
+                    network = network,
+                    from = networks[network],
+                    status = if (blocked) NetworkStatus.BLOCKED else NetworkStatus.UNBLOCKED
+                )
+
+                syncNetworkState()
+            }
+
+            override fun onLinkPropertiesChanged(
+                network: Network,
+                linkProperties: LinkProperties
+            ) {
+                log("onLinkPropertiesChanged(): network: $network; props: $linkProperties")
+
+                val current = networks[network]
+                networks[network] = mapNetworkModel(
+                    network = network,
+                    properties = linkProperties,
+                    from = current,
+                    status = current?.status ?: NetworkStatus.AVAILABLE
+                )
+
+                syncNetworkState()
+            }
+
+            override fun onLosing(network: Network, maxMsToLive: Int) {
+                log("onLosing(): network: $network; maxMsToLive: $maxMsToLive")
+
+                val current = networks[network]
+                networks[network] = mapNetworkModel(
+                    network = network,
+                    maxMsToLive = maxMsToLive.toLong(),
+                    from = current,
+                    status = current?.status ?: NetworkStatus.AVAILABLE
+                )
+
+                syncNetworkState()
+            }
+
+            override fun onReserved(networkCapabilities: NetworkCapabilities) {
+                log("onReserved(): caps: $networkCapabilities")
+            }
+        }
+
+        val request = NetworkRequest.Builder()
+            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+            .build()
+
+        connectivityManager.registerNetworkCallback(request, callback)
+        clearCallbacks = { connectivityManager.unregisterNetworkCallback(callback) }
+
+        refreshActiveNetwork()
+    }
+
+    private fun refreshActiveNetwork() {
+        val network = connectivityManager.activeNetwork
+        if (network == null) {
+            networks.clear()
+            syncNetworkState()
+            return
+        }
+
+        val capabilities = connectivityManager.getNetworkCapabilities(network)
+        if (capabilities?.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) == true) {
+            networks[network] = mapNetworkModel(
+                network = network,
+                capabilities = capabilities,
+                properties = connectivityManager.getLinkProperties(network),
+                status = NetworkStatus.AVAILABLE
+            )
+        }
+
+        syncNetworkState()
+    }
+
+    private fun log(text: String) {
+        logger.debug(this::class, text)
+    }
+
+    private fun mapNetworkModel(
+        network: Network,
+        capabilities: NetworkCapabilities? = null,
+        properties: LinkProperties? = null,
+        status: NetworkStatus? = null,
+        maxMsToLive: Long? = null,
+        from: NetworkModel? = null
+    ): NetworkModel {
+        val caps = capabilities
+            ?: from?.networkCapabilities
+            ?: connectivityManager.getNetworkCapabilities(network)
+
+        val networkType = when {
+            caps?.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) == true -> NetworkType.CELLULAR
+            caps?.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) == true -> NetworkType.WIFI
+            else -> from?.type ?: NetworkType.UNKNOWN
+        }
+
+        val hasInternet = caps?.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)
+            ?: from?.hasInternet
+            ?: false
+
+        val signalStrength =
+            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.Q) {
+                caps?.signalStrength
+            } else {
+                null
+            } ?: from?.signalStrength ?: Int.MAX_VALUE
+
+        return NetworkModel(
+            id = network.hashCode(),
+            type = networkType,
+            original = network,
+            hasInternet = hasInternet,
+            signalStrength = signalStrength,
+            status = status ?: from?.status ?: NetworkStatus.UNAVAILABLE,
+            maxMsToLive = maxMsToLive ?: from?.maxMsToLive,
+            networkCapabilities = caps,
+            linkProperties = properties
+                ?: from?.linkProperties
+                ?: connectivityManager.getLinkProperties(network)
+        )
+    }
+
+    fun onDestroy() {
+        clearCallbacks?.let { unregisterCallback ->
+            runCatching { unregisterCallback() }
+                .onFailure { throwable ->
+                    logger.error(
+                        this::class.java,
+                        "Failed to unregister network callback",
+                        throwable
+                    )
+                }
+        }
+        clearCallbacks = null
+        networks.clear()
+        syncNetworkState()
+    }
+}
+
+enum class NetworkType {
+    CELLULAR, WIFI, UNKNOWN
+}
+
+data class NetworkModel(
+    val id: Int,
+    val type: NetworkType,
+    val original: Network,
+    val hasInternet: Boolean,
+    val signalStrength: Int,
+    val status: NetworkStatus,
+    val maxMsToLive: Long?,
+    val networkCapabilities: NetworkCapabilities?,
+    val linkProperties: LinkProperties?
+) {
+    fun isStatusOk(): Boolean = status.isOk()
+
+    fun isInternetAvailable(): Boolean = hasInternet && isStatusOk()
+}
+
+enum class NetworkStatus {
+    AVAILABLE, UNAVAILABLE, LOST, BLOCKED, UNBLOCKED;
+
+    fun isOk(): Boolean = when (this) {
+        AVAILABLE, UNBLOCKED -> true
+        UNAVAILABLE, LOST, BLOCKED -> false
+    }
+}
+
+enum class NetworkState { CONNECTED, DISCONNECTED }