Add ability for MPW to run explorer-less

scripts/dashboard/WalletBalance.vue

@@ -1,6 +1,6 @@
 <script setup>
 import { cChainParams, COIN } from '../chain_params.js';
-import { translation } from '../i18n';
+import { translation, tr } from '../i18n';
 import { ref, computed, toRefs } from 'vue';
 import { beautifyNumber } from '../misc';
 import { getEventEmitter } from '../event_bus';
@@ -130,11 +130,13 @@ const emit = defineEmits([
 
 getEventEmitter().on(
     'transparent-sync-status-update',
-    (i, totalPages, finished) => {
-        const str = tr(translation.syncStatusHistoryProgress, [
-            { current: totalPages - i + 1 },
-            { total: totalPages },
-        ]);
+    (i, totalPages, finished, message) => {
+        const str =
+            message ||
+            tr(translation.syncStatusHistoryProgress, [
+                { current: totalPages - i + 1 },
+                { total: totalPages },
+            ]);
         const progress = ((totalPages - i) / totalPages) * 100;
         syncTStr.value = str;
         transparentProgressSyncing.value = progress;

scripts/wallet.js

@@ -701,7 +701,29 @@ export class Wallet {
         // This is just to be sure since blockbook (as we know)
         // usually does not return txs of the actual last block.
         this.#lastProcessedBlock = blockCount - 5;
-        await this.#transparentSync();
+        // Transparent sync is inherently less stable than Shield since it requires heavy
+        // explorer indexing, so we'll attempt once asynchronously, and if it fails, set a
+        // recurring "background" sync interval until it's finally successful.
+        try {
+            await this.#transparentSync();
+        } catch {
+            // We'll set a 5s interval sync until it's finally successful, then nuke the 'thread'.
+            const cThread = new AsyncInterval(async () => {
+                try {
+                    await this.#transparentSync(true);
+                    cThread.clearInterval();
+                } catch {
+                    // Emit a transparent sync warning
+                    getEventEmitter().emit(
+                        'transparent-sync-status-update',
+                        0,
+                        0,
+                        false,
+                        'Explorers are unreachable, your wallet may not be fully synced!'
+                    );
+                }
+            }, 5000);
+        }
         if (this.hasShield()) {
             await this.#syncShield();
         }
@@ -712,8 +734,12 @@ export class Wallet {
         getEventEmitter().emit('new-tx');
     });
 
-    async #transparentSync() {
-        if (!this.isLoaded() || this.#isSynced) return;
+    /**
+     * Synchronise UTXOs via xpub/address from the current explorer.
+     * @param {boolean} [force=false] - Force transparent sync, regardless of state
+     */
+    async #transparentSync(force = false) {
+        if ((!this.isLoaded() || this.#isSynced) && !force) return;
         const cNet = getNetwork();
         const addr = this.getKeyToExport();
         let nStartHeight = Math.max(