feat: parse bolt11 locally with network fallback

app/src/main/java/com/bitcointxoko/gudariwallet/data/DomainModels.kt

@@ -2,6 +2,7 @@ package com.bitcointxoko.gudariwallet.data
 
 import com.bitcointxoko.gudariwallet.api.LnurlScanResponse
 import com.bitcointxoko.gudariwallet.api.RouteHintHop
+import java.time.Instant
 
 /**
  * Domain model classes for the wallet layer.
@@ -24,7 +25,11 @@ data class DecodedBolt11(
     val amountSats : Long,
     val memo       : String,
     val payee      : String?,
-    val routeHints : List<RouteHintHop> = emptyList()
+    val routeHints : List<RouteHintHop> = emptyList(),
+    val paymentHash     : String,           // hex; unique receipt ID (required field)
+    val createdAt       : Instant,          // invoice creation timestamp
+    val expiresAt       : Instant,          // createdAt + expiry (default +1h); show countdown
+    val fallbackAddress : String? = null    // on-chain fallback address, if present
 )
 
 data class ScannedLnurl(

app/src/main/java/com/bitcointxoko/gudariwallet/data/LNbitsWalletRepository.kt

@@ -4,9 +4,11 @@ import android.net.Uri
 import android.util.Log
 import com.bitcointxoko.gudariwallet.api.*
 import com.bitcointxoko.gudariwallet.security.SecretStore
+import com.bitcointxoko.gudariwallet.util.Bolt11Decoder
 import com.bitcointxoko.gudariwallet.util.LnurlBech32
 import com.bitcointxoko.gudariwallet.util.LnurlMetadataParser
 import com.bitcointxoko.gudariwallet.util.WalletConstants
+import java.time.Instant
 
 private const val TAG = "LNbitsWalletRepo"
 
@@ -47,22 +49,51 @@ class LNbitsWalletRepository(
     // ── Send ──────────────────────────────────────────────────────────────────
 
     override suspend fun decodeBolt11(bolt11: String): DecodedBolt11 {
+        // ── 1. Try local decode first (no network, no latency) ───────────────
+        val local = runCatching { Bolt11Decoder.decode(bolt11) }.getOrNull()
+        if (local != null) {
+            Log.i("WalletRepository", "decodeBolt11: decoded locally ✓")
+            return local
+        }
+
+        // ── 2. Fall back to network API ───────────────────────────────────────
+        Log.w("WalletRepository", "decodeBolt11: local decode failed, falling back to network")
         val response = api.decodeInvoice(secrets.invoiceKey(), DecodeInvoiceRequest(data = bolt11))
+        Log.i("WalletRepository", "decodeBolt11: decoded via network ✓")
+
         val amountSats = response.amountMsat
             ?.takeIf { it > 0L }
             ?.div(WalletConstants.MSAT_PER_SAT)
             ?: throw UnsupportedOperationException(
                 "Zero-amount invoices are not supported. Please ask the sender to specify an amount."
             )
+
+        val paymentHash = response.paymentHash
+            ?: throw UnsupportedOperationException(
+                "Invoice is missing a payment hash and cannot be paid."
+            )
+
+        // createdAt / expiresAt / fallbackAddress are not returned by the API —
+        // use safe defaults and warn so we know if this path is hit in practice.
+        Log.w("WalletRepository", "decodeBolt11: network response has no timestamp/expiry — " +
+                "using Instant.now() + 1h as fallback")
+        val createdAt = Instant.now()
+        val expiresAt = createdAt.plusSeconds(3600L)
+
         return DecodedBolt11(
-            amountSats = amountSats,
-            memo       = response.description ?: "",
-            payee      = response.payee?.takeIf { it.isNotBlank() },
-            routeHints = response.routeHints?.flatten() ?: emptyList()
+            amountSats      = amountSats,
+            memo            = response.description ?: "",
+            payee           = response.payee?.takeIf { it.isNotBlank() },
+            routeHints      = response.routeHints?.flatten() ?: emptyList(),
+            paymentHash     = paymentHash,
+            createdAt       = createdAt,
+            expiresAt       = expiresAt,
+            fallbackAddress = null
         )
     }
 
 
+
     override suspend fun scanLnurl(code: String): ScannedLnurl {
         val r = api.lnurlScan(secrets.invoiceKey(), code)
         return ScannedLnurl(