Improve async error handling

app/src/main/java/com/electricdreams/numo/ModernPOSActivity.kt

@@ -1,5 +1,5 @@
 package com.electricdreams.numo
-import com.electricdreams.numo.R
+import android.widget.Toast
 
 import android.app.Activity
 import android.app.PendingIntent
@@ -166,6 +166,13 @@ class ModernPOSActivity : AppCompatActivity(), SatocashWallet.OperationFeedback,
     // Lifecycle methods
     override fun onResume() {
         super.onResume()
+        CashuWalletManager.setErrorListener(object : CashuWalletManager.WalletErrorListener {
+            override fun onWalletError(message: String) {
+                runOnUiThread {
+                    Toast.makeText(this@ModernPOSActivity, message, Toast.LENGTH_LONG).show()
+                }
+            }
+        })
 
         // Reapply theme when returning from settings
         uiCoordinator.applyTheme()
@@ -184,10 +191,12 @@ class ModernPOSActivity : AppCompatActivity(), SatocashWallet.OperationFeedback,
 
     override fun onPause() {
         super.onPause()
+        CashuWalletManager.setErrorListener(null)
         nfcAdapter?.disableForegroundDispatch(this)
     }
 
     override fun onDestroy() {
+        CashuWalletManager.setErrorListener(null)
         uiCoordinator.stopServices()
         bitcoinPriceWorker?.stop()
         super.onDestroy()

app/src/main/java/com/electricdreams/numo/core/cashu/CashuWalletManager.kt

@@ -51,7 +51,12 @@ object CashuWalletManager : MintManager.MintChangeListener {
         // Build initial wallet
         val initialMints = mintManager.getAllowedMints()
         scope.launch {
-            rebuildWallet(initialMints)
+            try {
+                rebuildWallet(initialMints)
+            } catch (t: Throwable) {
+                Log.e(TAG, "Failed to rebuild wallet during init", t)
+                notifyWalletError("Wallet initialization failed: ${t.localizedMessage ?: "Unknown error"}")
+            }
         }
     }
 
@@ -174,13 +179,23 @@ object CashuWalletManager : MintManager.MintChangeListener {
     override fun onMintsChanged(newMints: List<String>) {
         Log.d(TAG, "Mint list changed, rebuilding wallet with ${'$'}{newMints.size} mints")
         scope.launch {
-            rebuildWallet(newMints)
+            try {
+                rebuildWallet(newMints)
+            } catch (t: Throwable) {
+                Log.e(TAG, "Failed to rebuild wallet after mint change", t)
+                notifyWalletError("Unable to update wallet: ${t.localizedMessage ?: "Unknown error"}")
+            }
         }
     }
 
     /** Current MultiMintWallet instance, or null if initialization failed or not complete. */
     fun getWallet(): MultiMintWallet? = wallet
 
+    /** Set an optional callback that surfaces wallet errors to the UI layer. */
+    fun setErrorListener(listener: WalletErrorListener?) {
+        walletErrorListener = listener
+    }
+
     /** Current database instance, mostly for debugging or future use. */
     fun getDatabase(): WalletSqliteDatabase? = database
 
@@ -416,6 +431,17 @@ object CashuWalletManager : MintManager.MintChangeListener {
             Log.d(TAG, "Initialized MultiMintWallet with ${'$'}{mints.size} mints; DB=${'$'}{dbFile.absolutePath}")
         } catch (t: Throwable) {
             Log.e(TAG, "Failed to initialize MultiMintWallet", t)
+            notifyWalletError("Wallet initialization failed: ${t.localizedMessage ?: "Unknown error"}")
         }
     }
+
+    private fun notifyWalletError(message: String) {
+        walletErrorListener?.onWalletError(message)
+    }
+
+    interface WalletErrorListener {
+        fun onWalletError(message: String)
+    }
+
+    private var walletErrorListener: WalletErrorListener? = null
 }

app/src/main/java/com/electricdreams/numo/feature/settings/MintsSettingsActivity.kt

@@ -17,6 +17,7 @@ import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.cardview.widget.CardView
 import androidx.lifecycle.lifecycleScope
+import android.util.Log
 import com.electricdreams.numo.R
 import com.electricdreams.numo.core.cashu.CashuWalletManager
 import com.electricdreams.numo.core.model.Amount
@@ -208,42 +209,51 @@ class MintsSettingsActivity : AppCompatActivity() {
         }
 
         lifecycleScope.launch {
-            // Load balances
-            val balances = withContext(Dispatchers.IO) {
-                CashuWalletManager.getAllMintBalances()
-            }
-            mintBalances.clear()
-            mintBalances.putAll(balances)
-
-            // Auto-select lightning mint if none selected
-            if (selectedLightningMint == null || !mints.contains(selectedLightningMint)) {
-                val highestBalanceMint = mints.maxByOrNull { mintBalances[it] ?: 0L }
-                highestBalanceMint?.let { setLightningMint(it, animate = false) }
+            try {
+                // Load balances
+                val balances = withContext(Dispatchers.IO) {
+                    CashuWalletManager.getAllMintBalances()
+                }
+                mintBalances.clear()
+                mintBalances.putAll(balances)
+
+                // Auto-select lightning mint if none selected
+                if (selectedLightningMint == null || !mints.contains(selectedLightningMint)) {
+                    val highestBalanceMint = mints.maxByOrNull { mintBalances[it] ?: 0L }
+                    highestBalanceMint?.let { setLightningMint(it, animate = false) }
+                }
+
+                // Build UI
+                buildMintList(mints)
+                updateLightningMintCard()
+                updateTotalBalance()
+
+                // Refresh stale mint info
+                refreshStaleMintInfo()
+            } catch (t: Throwable) {
+                Log.e(TAG, "Failed to load mint balances", t)
+                Toast.makeText(this@MintsSettingsActivity, getString(R.string.error_loading_mints), Toast.LENGTH_LONG).show()
             }
-
-            // Build UI
-            buildMintList(mints)
-            updateLightningMintCard()
-            updateTotalBalance()
-
-            // Refresh stale mint info
-            refreshStaleMintInfo()
         }
     }
 
     private fun refreshBalances() {
         lifecycleScope.launch {
-            val balances = withContext(Dispatchers.IO) {
-                CashuWalletManager.getAllMintBalances()
+            try {
+                val balances = withContext(Dispatchers.IO) {
+                    CashuWalletManager.getAllMintBalances()
+                }
+                mintBalances.clear()
+                mintBalances.putAll(balances)
+
+                // Update UI
+                val mints = mintManager.getAllowedMints()
+                buildMintList(mints)
+                updateLightningMintCard()
+                updateTotalBalance()
+            } catch (t: Throwable) {
+                Log.e(TAG, "Failed to refresh mint balances", t)
             }
-            mintBalances.clear()
-            mintBalances.putAll(balances)
-
-            // Update UI
-            val mints = mintManager.getAllowedMints()
-            buildMintList(mints)
-            updateLightningMintCard()
-            updateTotalBalance()
         }
     }
 
@@ -409,36 +419,41 @@ class MintsSettingsActivity : AppCompatActivity() {
         addMintCard.setLoading(true)
 
         lifecycleScope.launch {
-            val isValid = validateMintUrl(mintUrl)
-
-            if (!isValid) {
-                addMintCard.setLoading(false)
-                Toast.makeText(
-                    this@MintsSettingsActivity,
-                    getString(R.string.mints_invalid_url),
-                    Toast.LENGTH_LONG
-                ).show()
-                return@launch
-            }
-
-            val added = mintManager.addMint(mintUrl)
-            if (added) {
-                fetchAndStoreMintInfo(mintUrl)
-                loadMintsAndBalances()
-                addMintCard.clearInput()
-                addMintCard.collapseIfExpanded()
-
-                // Broadcast that mints changed so other activities can refresh
-                BalanceRefreshBroadcast.send(this@MintsSettingsActivity, BalanceRefreshBroadcast.REASON_MINT_ADDED)
+            try {
+                val isValid = validateMintUrl(mintUrl)
 
-                Toast.makeText(
-                    this@MintsSettingsActivity,
-                    getString(R.string.mints_added_toast),
-                    Toast.LENGTH_SHORT
-                ).show()
+                if (!isValid) {
+                    addMintCard.setLoading(false)
+                    Toast.makeText(
+                        this@MintsSettingsActivity,
+                        getString(R.string.mints_invalid_url),
+                        Toast.LENGTH_LONG
+                    ).show()
+                    return@launch
+                }
+
+                val added = mintManager.addMint(mintUrl)
+                if (added) {
+                    fetchAndStoreMintInfo(mintUrl)
+                    loadMintsAndBalances()
+                    addMintCard.clearInput()
+                    addMintCard.collapseIfExpanded()
+
+                    // Broadcast that mints changed so other activities can refresh
+                    BalanceRefreshBroadcast.send(this@MintsSettingsActivity, BalanceRefreshBroadcast.REASON_MINT_ADDED)
+
+                    Toast.makeText(
+                        this@MintsSettingsActivity,
+                        getString(R.string.mints_added_toast),
+                        Toast.LENGTH_SHORT
+                    ).show()
+                }
+            } catch (t: Throwable) {
+                Log.e(TAG, "Failed to add mint", t)
+                Toast.makeText(this@MintsSettingsActivity, R.string.mints_add_failed, Toast.LENGTH_LONG).show()
+            } finally {
+                addMintCard.setLoading(false)
             }
-
-            addMintCard.setLoading(false)
         }
     }
 
@@ -478,29 +493,37 @@ class MintsSettingsActivity : AppCompatActivity() {
 
     private suspend fun fetchAndStoreMintInfo(mintUrl: String) {
         withContext(Dispatchers.IO) {
-            val info = CashuWalletManager.fetchMintInfo(mintUrl)
-            if (info != null) {
-                val json = CashuWalletManager.mintInfoToJson(info)
-                mintManager.setMintInfo(mintUrl, json)
-                mintManager.setMintRefreshTimestamp(mintUrl)
-
-                info.iconUrl?.let { iconUrl ->
-                    if (iconUrl.isNotEmpty()) {
-                        MintIconCache.downloadAndCacheIcon(mintUrl, iconUrl)
+            try {
+                val info = CashuWalletManager.fetchMintInfo(mintUrl)
+                if (info != null) {
+                    val json = CashuWalletManager.mintInfoToJson(info)
+                    mintManager.setMintInfo(mintUrl, json)
+                    mintManager.setMintRefreshTimestamp(mintUrl)
+
+                    info.iconUrl?.let { iconUrl ->
+                        if (iconUrl.isNotEmpty()) {
+                            MintIconCache.downloadAndCacheIcon(mintUrl, iconUrl)
+                        }
                     }
                 }
+            } catch (t: Throwable) {
+                Log.w(TAG, "Failed to fetch mint info for ${mintUrl}", t)
             }
         }
     }
 
     private fun refreshStaleMintInfo() {
         lifecycleScope.launch {
-            val mintsToRefresh = mintManager.getMintsNeedingRefresh()
-            for (mintUrl in mintsToRefresh) {
-                fetchAndStoreMintInfo(mintUrl)
-            }
-            if (mintsToRefresh.isNotEmpty()) {
-                updateLightningMintCard()
+            try {
+                val mintsToRefresh = mintManager.getMintsNeedingRefresh()
+                for (mintUrl in mintsToRefresh) {
+                    fetchAndStoreMintInfo(mintUrl)
+                }
+                if (mintsToRefresh.isNotEmpty()) {
+                    updateLightningMintCard()
+                }
+            } catch (t: Throwable) {
+                Log.w(TAG, "Failed to refresh mint info", t)
             }
         }
     }