Add reorg detection, server failover, and live server switching

- Add reorg detection with user-facing repair dialog (clear app data) - Add server picker dialog with connectivity indicators for all 6 lite servers - Probe server reachability via TCP before connecting; auto-skip dead servers - Support live server switching without app restart (resetSynchronizer) - Update server list and default server URL to dragonx.is endpoints - Update build config for DragonX mainnet
2026-03-21 03:50:04 -05:00
parent 2d676f27ee
commit d501255c6b
7 changed files with 197 additions and 18 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -71,3 +71,4 @@ fastlane/readme.md
 # misc.
 backup/
 .editorconfig
+external/
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -47,13 +47,13 @@ android {
        zcashtestnet {
            dimension 'network'
            applicationId 'cash.z.ecc.android.testnet'
-            buildConfigField "String", "DEFAULT_SERVER_URL", '"dragonlite.printogre.com"'
+            buildConfigField "String", "DEFAULT_SERVER_URL", '"lite.dragonx.is"'
            matchingFallbacks = ['zcashtestnet', 'debug']
        }

        zcashmainnet {
            dimension 'network'
-            buildConfigField "String", "DEFAULT_SERVER_URL", '"dragonlite.printogre.com"'
+            buildConfigField "String", "DEFAULT_SERVER_URL", '"lite.dragonx.is"'
            matchingFallbacks = ['zcashmainnet', 'release']
        }
    }
--- a/app/src/main/java/cash/z/ecc/android/di/DependenciesHolder.kt
+++ b/app/src/main/java/cash/z/ecc/android/di/DependenciesHolder.kt
@@ -6,7 +6,10 @@ import cash.z.ecc.android.ZcashWalletApp
 import cash.z.ecc.android.ext.Const
 import cash.z.ecc.android.feedback.*
 import cash.z.ecc.android.lockbox.LockBox
+import cash.z.ecc.android.sdk.Initializer
 import cash.z.ecc.android.sdk.Synchronizer
+import cash.z.ecc.android.sdk.model.LightWalletEndpoint
+import cash.z.ecc.android.sdk.type.UnifiedViewingKey
 import cash.z.ecc.android.ui.util.DebugFileTwig
 import cash.z.ecc.android.util.SilentTwig
 import cash.z.ecc.android.util.Twig
@@ -18,7 +21,38 @@ object DependenciesHolder {

    val initializerComponent by lazy { InitializerComponent() }

-    val synchronizer by lazy { Synchronizer.newBlocking(initializerComponent.initializer) }
+    private var _synchronizer: Synchronizer? = null
+    val synchronizer: Synchronizer
+        get() {
+            if (_synchronizer == null) {
+                _synchronizer = Synchronizer.newBlocking(initializerComponent.initializer)
+            }
+            return _synchronizer!!
+        }
+
+    /**
+     * Stop the current synchronizer and reinitialize with the server
+     * currently saved in preferences, so a new synchronizer will be
+     * created on next access pointing to the new server.
+     */
+    fun resetSynchronizer() {
+        _synchronizer?.let {
+            it.stop()
+            _synchronizer = null
+        }
+        // Rebuild the initializer with the new server from prefs
+        val host = prefs[Const.Pref.SERVER_HOST] ?: Const.Default.Server.HOST
+        val port = prefs[Const.Pref.SERVER_PORT] ?: Const.Default.Server.PORT
+        val network = ZcashWalletApp.instance.defaultNetwork
+        val extfvk = lockBox.getCharsUtf8(Const.Backup.VIEWING_KEY)
+        val extpub = lockBox.getCharsUtf8(Const.Backup.PUBLIC_KEY)
+        if (extfvk != null && extpub != null) {
+            val vk = UnifiedViewingKey(extfvk = String(extfvk), extpub = String(extpub))
+            initializerComponent.createInitializer(Initializer.Config {
+                it.importWallet(vk, null, network, LightWalletEndpoint(host, port, true))
+            })
+        }
+    }

    val clipboardManager by lazy { provideAppContext().getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager }

--- a/app/src/main/java/cash/z/ecc/android/ext/Const.kt
+++ b/app/src/main/java/cash/z/ecc/android/ext/Const.kt
@@ -48,9 +48,13 @@ object Const {
    object Default {
        object Server {
            // Select a random server from list
-            private val serverList = listOf(
-                "dragonlite.printogre.com",
-                "lite.dragonx.is"
+            val serverList = listOf(
+                "lite.dragonx.is",
+                "lite1.dragonx.is",
+                "lite2.dragonx.is",
+                "lite3.dragonx.is",
+                "lite4.dragonx.is",
+                "lite5.dragonx.is"
            )
            private val randomIndex = Random.nextInt(serverList.size);
            private val randomServer = serverList[randomIndex]
--- a/app/src/main/java/cash/z/ecc/android/ext/Dialogs.kt
+++ b/app/src/main/java/cash/z/ecc/android/ext/Dialogs.kt
@@ -5,12 +5,20 @@ import android.app.Dialog
 import android.content.Context
 import android.text.Html
 import android.util.Log
+import android.widget.ArrayAdapter
+import android.widget.ListView
+import android.widget.TextView
 import androidx.annotation.StringRes
+import androidx.appcompat.app.AlertDialog
 import androidx.core.content.getSystemService
 import cash.z.ecc.android.R
 import cash.z.ecc.android.feedback.Report
+import cash.z.ecc.android.ui.MainActivity
 import cash.z.ecc.android.ui.scan.ScanFragment
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import kotlinx.coroutines.*
+import java.net.InetSocketAddress
+import java.net.Socket
 import kotlin.system.exitProcess

 fun Context.showClearDataConfirmation(onDismiss: () -> Unit = {}, onCancel: () -> Unit = {}): Dialog {
@@ -99,15 +107,9 @@ fun Context.showCriticalMessage(title: String, message: String, onDismiss: () ->
    var pluckedError = splitError[0]

    if(pluckedError == "UNAVAILABLE"){
-        return MaterialAlertDialogBuilder(this)
-            .setTitle("Server Unavailable")
-            .setMessage("Please close and restart the app to try another random server.")
-            .setCancelable(false)
-            .setNegativeButton("Exit") { dialog, _ ->
-                dialog.dismiss()
-                exitProcess(0)
-            }
-            .show()
+        return showServerPickerDialog(onServerSelected = { host ->
+            onDismiss()
+        })
    }

    return MaterialAlertDialogBuilder(this)
@@ -212,3 +214,87 @@ fun Context.showSharedLibraryCriticalError(e: Throwable): Dialog = showCriticalM
    messageResId = R.string.dialog_error_critical_link_message,
    onDismiss = { throw e }
 )
+
+fun Context.showReorgRepairDialog(onDismiss: () -> Unit = {}): Dialog {
+    return MaterialAlertDialogBuilder(this)
+        .setTitle("Incompatible Block Data")
+        .setMessage(
+            "The wallet contains block data from an old or incompatible chain. " +
+            "This prevents syncing.\n\n" +
+            "Would you like to clear the old data and sync fresh from the network?\n" +
+            "(Your wallet keys and addresses will be preserved)"
+        )
+        .setCancelable(false)
+        .setPositiveButton("Clear & Resync") { dialog, _ ->
+            dialog.dismiss()
+            onDismiss()
+            getSystemService<ActivityManager>()?.clearApplicationUserData()
+        }
+        .setNegativeButton("Cancel") { dialog, _ ->
+            dialog.dismiss()
+            onDismiss()
+        }
+        .show()
+}
+
+fun Context.showServerPickerDialog(onServerSelected: (String) -> Unit = {}): Dialog {
+    val servers = Const.Default.Server.serverList
+    val port = Const.Default.Server.PORT
+    // Display names start as "Checking..." and get updated
+    val displayItems = servers.map { "$it — checking..." }.toMutableList()
+
+    val adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, displayItems)
+
+    val listView = ListView(this).apply {
+        this.adapter = adapter
+        setPadding(32, 16, 32, 16)
+    }
+
+    val dialog = MaterialAlertDialogBuilder(this)
+        .setTitle("Select a Server")
+        .setMessage("The current server is unavailable. Choose a server to connect to:")
+        .setView(listView)
+        .setCancelable(false)
+        .setNegativeButton("Exit") { d, _ ->
+            d.dismiss()
+            exitProcess(0)
+        }
+        .show()
+
+    // Check each server's connectivity in the background
+    val scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
+    servers.forEachIndexed { index, host ->
+        scope.launch {
+            val online = try {
+                Socket().use { socket ->
+                    socket.connect(InetSocketAddress(host, port), 5000)
+                    true
+                }
+            } catch (e: Exception) {
+                false
+            }
+            withContext(Dispatchers.Main) {
+                displayItems[index] = if (online) "✓  $host" else "✗  $host  (offline)"
+                adapter.notifyDataSetChanged()
+            }
+        }
+    }
+
+    listView.setOnItemClickListener { _, _, position, _ ->
+        val host = servers[position]
+        // Save selected server to preferences
+        val prefs = cash.z.ecc.android.di.DependenciesHolder.prefs
+        prefs[Const.Pref.SERVER_HOST] = host
+        prefs[Const.Pref.SERVER_PORT] = port
+        dialog.dismiss()
+        scope.cancel()
+        onServerSelected(host)
+        // Reconnect with the new server without restarting
+        (this as? MainActivity)?.let { activity ->
+            cash.z.ecc.android.di.DependenciesHolder.resetSynchronizer()
+            activity.startSync(isRestart = true)
+        }
+    }
+
+    return dialog
+}
--- a/app/src/main/java/cash/z/ecc/android/ui/MainActivity.kt
+++ b/app/src/main/java/cash/z/ecc/android/ui/MainActivity.kt
@@ -528,6 +528,7 @@ class MainActivity : AppCompatActivity(R.layout.main_activity) {

    // TODO: clean up this error handling
    private var ignoredErrors = 0
+    private var reorgCount = 0
    private fun onProcessorError(error: Throwable?): Boolean {
        var notified = false
        when (error) {
@@ -553,6 +554,17 @@ class MainActivity : AppCompatActivity(R.layout.main_activity) {
                    }
                }
            }
+            is CompactBlockProcessorException.FailedReorgRepair -> {
+                if (dialog == null) {
+                    notified = true
+                    runOnUiThread {
+                        dialog = showReorgRepairDialog {
+                            dialog = null
+                        }
+                    }
+                }
+                return false // stop retrying
+            }
        }
        if (!notified) {
            ignoredErrors++
@@ -573,6 +585,8 @@ class MainActivity : AppCompatActivity(R.layout.main_activity) {
    }

    private fun onChainError(errorHeight: BlockHeight, rewindHeight: BlockHeight) {
+        reorgCount++
+        twig("Chain reorg detected (#$reorgCount): error at $errorHeight, rewinding to $rewindHeight")
        feedback.report(Reorg(errorHeight, rewindHeight))
    }

--- a/app/src/main/java/cash/z/ecc/android/ui/setup/WalletSetupViewModel.kt
+++ b/app/src/main/java/cash/z/ecc/android/ui/setup/WalletSetupViewModel.kt
@@ -20,6 +20,8 @@ import cash.z.ecc.android.sdk.type.UnifiedViewingKey
 import cash.z.ecc.android.ui.setup.WalletSetupViewModel.WalletSetupState.*
 import cash.z.ecc.android.util.twig
 import cash.z.ecc.kotlin.mnemonic.Mnemonics
+import java.net.InetSocketAddress
+import java.net.Socket
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
@@ -99,12 +101,13 @@ class WalletSetupViewModel : ViewModel() {
        val vk =
            loadUnifiedViewingKey() ?: onMissingViewingKey(network).also { overwriteVks = true }
        val birthdayHeight = loadBirthdayHeight() ?: onMissingBirthday(network)
-        val host = prefs[Const.Pref.SERVER_HOST] ?: Const.Default.Server.HOST
+        val savedHost = prefs[Const.Pref.SERVER_HOST] ?: Const.Default.Server.HOST
        val port = prefs[Const.Pref.SERVER_PORT] ?: Const.Default.Server.PORT

-        Log.d("SilentDragon", "host: $host")
+        // Check if the preferred server is reachable; if not, try others
+        val host = findReachableServer(savedHost, port)

-        // TODO: Maybe check server availability here
+        Log.d("SilentDragon", "host: $host")

        twig("Done loading config variables")
        return Initializer.Config {
@@ -113,6 +116,43 @@ class WalletSetupViewModel : ViewModel() {
        }
    }

+    /**
+     * Check if the preferred server is reachable via TCP. If not, try each server
+     * in the list until one responds. Returns the first reachable server, or falls
+     * back to the preferred server if none respond.
+     */
+    private fun findReachableServer(preferredHost: String, port: Int): String {
+        // Try preferred server first
+        if (isServerReachable(preferredHost, port)) {
+            return preferredHost
+        }
+        twig("Preferred server $preferredHost is unreachable, trying alternatives...")
+
+        // Try each server in the list
+        for (server in Const.Default.Server.serverList) {
+            if (server != preferredHost && isServerReachable(server, port)) {
+                twig("Found reachable server: $server")
+                // Save working server to preferences for next time
+                prefs[Const.Pref.SERVER_HOST] = server
+                return server
+            }
+        }
+
+        twig("WARNING: No servers responded, using preferred: $preferredHost")
+        return preferredHost
+    }
+
+    private fun isServerReachable(host: String, port: Int): Boolean {
+        return try {
+            Socket().use { socket ->
+                socket.connect(InetSocketAddress(host, port), 5000)
+                true
+            }
+        } catch (e: Exception) {
+            false
+        }
+    }
+
    private fun loadUnifiedViewingKey(): UnifiedViewingKey? {
        val extfvk = lockBox.getCharsUtf8(Const.Backup.VIEWING_KEY)
        val extpub = lockBox.getCharsUtf8(Const.Backup.PUBLIC_KEY)