Custom OkHttpClientFactory to ensure IPv4 preference in order to fix hanging fetch requests.

android/app/build.gradle

@@ -95,7 +95,7 @@ android {
         applicationId "com.minibits_wallet"
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode 58024
+        versionCode 58025
         versionName "0.2.0"
     }
 
@@ -159,7 +159,7 @@ android {
             def abi = output.getFilter(OutputFile.ABI)
             if (abi != null) {  // null for the universal-debug, universal-release variants
                 output.versionCodeOverride =
-                        defaultConfig.versionCode * 1000 + versionCodes.get(abi)
+                    defaultConfig.versionCode * 1000 + versionCodes.get(abi)
             }
 
         }
@@ -177,14 +177,18 @@ dependencies {
         implementation jscFlavor
     }
 
-    // Fetch request hang issue
-    // define a BOM and its version
-    implementation(platform("com.squareup.okhttp3:okhttp-bom:5.0.0-alpha.12"))
-
-    // define any required OkHttp artifacts without version
+    // Minibits: Fetch requests hanging issue - not used for now, does not work with custom DNS selector IPV4_FIRST strategy
+    /* implementation(platform("com.squareup.okhttp3:okhttp-bom:5.0.0-alpha.12"))
+    
     implementation("com.squareup.okhttp3:okhttp")
-    implementation("com.squareup.okhttp3:logging-interceptor")
-    implementation("com.squareup.okhttp3:okhttp-urlconnection")
+    implementation("com.squareup.okhttp3:logging-interceptor")    
+
+    configurations.all {
+        resolutionStrategy {
+            force "com.squareup.okhttp3:okhttp:5.0.0-alpha.12"
+            force "com.squareup.okhttp3:logging-interceptor:5.0.0-alpha.12"
+        }
+    }*/    
 }
 
 // code-push

android/app/src/main/java/com/minibits_wallet/CorePlaneOkHttpClientFactory.kt

@@ -0,0 +1,36 @@
+package com.minibits_wallet
+
+import android.util.Log
+import com.facebook.react.modules.network.OkHttpClientProvider
+import com.facebook.react.modules.network.OkHttpClientFactory
+import okhttp3.OkHttp
+import okhttp3.OkHttpClient
+import okhttp3.EventListener
+import okhttp3.Call
+import java.net.InetSocketAddress
+import java.net.Proxy
+import java.util.concurrent.TimeUnit
+
+class CorePlaneOkHttpClientFactory : OkHttpClientFactory {
+    override fun createNewNetworkModuleClient(): OkHttpClient {
+        val okHttpVersion = OkHttp.VERSION
+        Log.d("OkHttpFactory", "Using OkHttp version: $okHttpVersion")
+
+        return OkHttpClientProvider.createClientBuilder()
+            .dns(CorePlaneOkHttpDNSSelector(CorePlaneOkHttpDNSSelector.IPvMode.IPV4_FIRST))
+            /* .eventListener(object : EventListener() {
+                override fun connectStart(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy) {
+                    Log.d("OkHttpNetwork", "Connecting to ${inetSocketAddress.address}")
+                }
+            })         
+            .addInterceptor { chain ->
+                val request = chain.request()
+                Log.d("OkHttpFactory", "Sending request: ${request.url}")
+                val response = chain.proceed(request)
+                Log.d("OkHttpFactory", "Received response: ${response.code} from ${response.request.url}")
+                response
+            } */            
+            .connectTimeout(10, TimeUnit.SECONDS)
+            .build()
+    }
+}

android/app/src/main/java/com/minibits_wallet/CorePlaneOkHttpDNSSelector.kt

@@ -0,0 +1,52 @@
+package com.minibits_wallet
+
+import okhttp3.Dns
+import java.net.Inet4Address
+import java.net.Inet6Address
+import java.net.InetAddress
+import android.util.Log
+
+class CorePlaneOkHttpDNSSelector(private val mode: IPvMode) : Dns {
+
+    enum class IPvMode(val code: String) {
+        SYSTEM("system"),
+        IPV6_FIRST("ipv6"),
+        IPV4_FIRST("ipv4"),
+        IPV6_ONLY("ipv6only"),
+        IPV4_ONLY("ipv4only");
+
+        companion object {
+            @JvmStatic
+            fun fromString(ipMode: String): IPvMode =
+                values().find { it.code == ipMode } ?: throw IllegalArgumentException("Unknown value: $ipMode")
+        }
+    }
+
+    override fun lookup(hostname: String): List<InetAddress> {
+        var addresses = try {
+            Dns.SYSTEM.lookup(hostname)
+        } catch (e: Exception) {
+            Log.e("OkHttpFactory", "DNS lookup failed for $hostname", e)
+            throw e
+        }
+
+        // Log the raw DNS result before filtering
+        // Log.d("OkHttpFactory", "Raw DNS lookup for $hostname -> ${addresses.joinToString(", ")}")
+
+        val sortedAddresses = when (mode) {
+            IPvMode.IPV6_FIRST -> addresses.sortedByDescending { it is Inet6Address } // IPv6 before IPv4
+            IPvMode.IPV4_FIRST -> addresses.sortedByDescending { it is Inet4Address } // IPv4 before IPv6
+            IPvMode.IPV6_ONLY -> addresses.filter { it is Inet6Address }
+            IPvMode.IPV4_ONLY -> addresses.filter { it is Inet4Address }
+            IPvMode.SYSTEM -> addresses
+        }
+
+        if (sortedAddresses.isEmpty()) {
+            throw RuntimeException("No resolved sortedAddresses for $hostname with mode $mode")
+        }
+
+        // Log.d("OkHttpFactory", "DNS lookup for $hostname -> ${sortedAddresses.joinToString(", ")}")
+
+        return sortedAddresses
+    }
+}

android/app/src/main/java/com/minibits_wallet/MainApplication.kt

@@ -11,6 +11,7 @@ import com.facebook.react.defaults.DefaultReactHost.getDefaultReactHost
 import com.facebook.react.defaults.DefaultReactNativeHost
 import com.facebook.react.soloader.OpenSourceMergedSoMapping
 import com.facebook.soloader.SoLoader
+import com.facebook.react.modules.network.OkHttpClientProvider
 import com.microsoft.codepush.react.CodePush
 
 class MainApplication : Application(), ReactApplication {
@@ -45,6 +46,9 @@ class MainApplication : Application(), ReactApplication {
   override fun onCreate() {
     super.onCreate()
     SoLoader.init(this, OpenSourceMergedSoMapping)
+
+    OkHttpClientProvider.setOkHttpClientFactory(CorePlaneOkHttpClientFactory())
+
     if (BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
       // If you opted-in for the New Architecture, we load the native entry point for this app.
       load()