feat: migrate LightningAddressStore to DataStore

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

@@ -55,13 +55,4 @@ class BalancePrefsStore(context: Context) {
             else remove("fiat_currency")
         }
     }
-
-    // ── Lightning address ─────────────────────────────────────────────────────
-
-    val lightningAddress: String?
-        get() = prefs.getString("lightning_address", null)
-
-    fun setLightningAddress(address: String) {
-        prefs.edit { putString("lightning_address", address) }
-    }
 }

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

@@ -0,0 +1,72 @@
+package com.bitcointxoko.gudariwallet.data
+
+import android.content.Context
+import android.util.Log
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.emptyPreferences
+import androidx.datastore.preferences.core.longPreferencesKey
+import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import com.bitcointxoko.gudariwallet.util.WalletConstants.LNADDRESS_TTL_MS
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
+import java.io.IOException
+
+private val Context.lightningAddressDataStore: DataStore<Preferences>
+        by preferencesDataStore(name = "lightning_address")
+
+class LightningAddressStore(private val context: Context) {
+
+    companion object {
+        private val KEY_ADDRESS    = stringPreferencesKey("lightning_address")
+        private val KEY_FETCHED_AT = longPreferencesKey("lightning_address_fetched_at")
+    }
+
+    // In-memory snapshot — safe for ClipboardViewModel's synchronous lambda
+    @Volatile private var _currentAddress: String? = null
+    val currentAddress: String? get() = _currentAddress
+
+    val lightningAddressFlow: Flow<String?> = context.lightningAddressDataStore.data
+        .catch { e ->
+            if (e is IOException) emit(emptyPreferences())
+            else throw e
+        }
+        .map { prefs ->
+            prefs[KEY_ADDRESS].also { address ->
+                _currentAddress = address
+                Log.d("LightningAddressStore", "LNADDR [CACHE   ] read from cache: " +
+                        if (address != null) "\"$address\"" else "(empty — nothing cached yet)")            }
+        }
+
+    suspend fun isCacheStale(): Boolean {
+        return context.lightningAddressDataStore.data
+            .catch { e ->
+                if (e is IOException) emit(emptyPreferences())
+                else throw e
+            }
+            .map { prefs ->
+                val address   = prefs[KEY_ADDRESS]
+                val fetchedAt = prefs[KEY_FETCHED_AT] ?: 0L
+                val age       = System.currentTimeMillis() - fetchedAt
+                val isStale   = address == null || age > LNADDRESS_TTL_MS
+                Log.d("LightningAddressStore", "LNADDR [TTL     ] cached=${address != null} " +
+                        "age=${age / 1000}s ttl=${LNADDRESS_TTL_MS / 1000}s " +
+                        if (isStale) "→ cache stale, will fetch from API"
+                        else         "→ cache fresh, skipping API call")
+                isStale
+            }
+            .first()
+    }
+
+    suspend fun setLightningAddress(address: String) {
+        context.lightningAddressDataStore.edit { prefs ->
+            prefs[KEY_ADDRESS]    = address
+            prefs[KEY_FETCHED_AT] = System.currentTimeMillis()   // ← add
+        }
+    }
+}
+

app/src/main/java/com/bitcointxoko/gudariwallet/ui/WalletViewModel.kt

@@ -13,11 +13,14 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.launch
 import androidx.fragment.app.FragmentActivity
 import com.bitcointxoko.gudariwallet.data.BalancePrefsStore
+import com.bitcointxoko.gudariwallet.data.LightningAddressStore
 import com.bitcointxoko.gudariwallet.ui.balance.BalanceViewModel
 import com.bitcointxoko.gudariwallet.ui.clipboard.ClipboardViewModel
 import com.bitcointxoko.gudariwallet.ui.fiat.FiatViewModel
 import com.bitcointxoko.gudariwallet.ui.receive.ReceiveViewModel
 import com.bitcointxoko.gudariwallet.ui.send.SendViewModel
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.stateIn
 
 private const val TAG = "WalletViewModel"
 
@@ -26,12 +29,12 @@ class WalletViewModel(
     val         aliasRepo : NodeAliasRepository,
     val         paymentCache: PaymentCacheRepository,
     private val balancePrefs: BalancePrefsStore,
+    private val lnAddressStore     : LightningAddressStore,
     val         balanceVm    : BalanceViewModel,
     val         fiatVm      : FiatViewModel,
     val         receiveVm   : ReceiveViewModel,
     val         sendVm      : SendViewModel,
     val         clipboardVm  : ClipboardViewModel,
-    val         lightningAddress: MutableStateFlow<String?>,
 ) : ViewModel() {
     val balanceState: StateFlow<BalanceState> get() = balanceVm.balanceState
     val balanceHidden: StateFlow<Boolean>   get() = fiatVm.balanceHidden
@@ -63,6 +66,12 @@ class WalletViewModel(
     val clipboardOfferState: StateFlow<ClipboardOfferState> get() = clipboardVm.clipboardOfferState
     fun checkClipboard(text: String?)  = clipboardVm.checkClipboard(text)
     fun dismissClipboardOffer()        = clipboardVm.dismissClipboardOffer()
+    val lightningAddress: StateFlow<String?> = lnAddressStore.lightningAddressFlow
+        .stateIn(
+            scope        = viewModelScope,
+            started      = SharingStarted.Eagerly,
+            initialValue = null
+        )
 
     init {
         observePaymentEvents()
@@ -80,22 +89,26 @@ class WalletViewModel(
     }
 
     private fun fetchLightningAddress() {
-        // If we already have a persisted address, show it immediately and
+        // lightningAddressFlow already emits the cached DataStore value immediately
-        // still refresh in the background (address could have changed).
+        // via SharingStarted.Eagerly — this coroutine only does the network refresh.
         viewModelScope.launch {
+            if (!lnAddressStore.isCacheStale()) {
+                Log.d(TAG, "LNADDR [TTL     ] cache is fresh — skipping network fetch")
+                return@launch
+            }
             runCatching { repo.getLightningAddress() }
                 .onSuccess { address ->
                     if (address != null) {
-                        Log.d(TAG, "LNADDR [FETCH OK ] $address")
+                        Log.d(TAG, "LNADDR [FETCH OK ] fetched from API: \"$address\" — updating cache")
-                        lightningAddress.value = address
+                        lnAddressStore.setLightningAddress(address)
-                        balancePrefs.setLightningAddress(address)
+                        // StateFlow updates automatically via the DataStore flow
                     } else {
-                        Log.d(TAG, "LNADDR [FETCH OK ] no pay link / username found")
+                        Log.d(TAG, "LNADDR [FETCH OK ] fetched from API: no pay link / username configured")
                     }
                 }
                 .onFailure { e ->
-                    Log.w(TAG, "LNADDR [FETCH ERR] ${e.message} — keeping cached value")
+                    Log.w(TAG, "LNADDR [FETCH ERR] API call failed (${e.message}) — falling back to cached value")
-                    // Keep whatever was loaded from prefs; don't clear it on network error
+                    // Nothing to do — DataStore flow already holds the last good value
                 }
         }
     }

app/src/main/java/com/bitcointxoko/gudariwallet/ui/WalletViewModelFactory.kt

@@ -9,6 +9,7 @@ import com.bitcointxoko.gudariwallet.data.BalancePrefsStore
 import com.bitcointxoko.gudariwallet.data.FiatDataStore
 import com.bitcointxoko.gudariwallet.data.NodeAliasServiceRepository
 import com.bitcointxoko.gudariwallet.data.LNbitsWalletRepository
+import com.bitcointxoko.gudariwallet.data.LightningAddressStore
 import com.bitcointxoko.gudariwallet.data.LnurlCacheRepository
 import com.bitcointxoko.gudariwallet.data.PaymentCacheRepository
 import com.bitcointxoko.gudariwallet.security.EncryptedSecretStore
@@ -32,6 +33,7 @@ class WalletViewModelFactory(private val app: Application) : ViewModelProvider.F
         val aliasRepo    = NodeAliasServiceRepository(nodeAliasSvc)
         val repo         = LNbitsWalletRepository(api = api, secrets = secrets)
         val balancePrefs = BalancePrefsStore(app)
+        val lnAddressStore = LightningAddressStore(app)
         val balanceVm    = BalanceViewModel(repo, balancePrefs)
         val fiatVm       = FiatViewModel(repo, balancePrefs, balanceVm, fiatDataStore)
         val receiveVm  = ReceiveViewModel(repo)
@@ -45,11 +47,11 @@ class WalletViewModelFactory(private val app: Application) : ViewModelProvider.F
             }
         )
 
-        val lightningAddress = MutableStateFlow<String?>(balancePrefs.lightningAddress)
+//        val lightningAddress = MutableStateFlow<String?>(balancePrefs.lightningAddress)
 
         val clipboardVm = ClipboardViewModel(
             ownInvoice = { (receiveVm.receiveState.value as? ReceiveState.InvoiceReady)?.bolt11 },
-            ownAddress = { lightningAddress.value }
+            ownAddress = { lnAddressStore.currentAddress }
         )
 
         balanceVm.onBalanceRefreshed = { fiatVm.onBalanceRefreshed() }
@@ -65,7 +67,7 @@ class WalletViewModelFactory(private val app: Application) : ViewModelProvider.F
             receiveVm = receiveVm,
             sendVm = sendVm,
             clipboardVm      = clipboardVm,
-            lightningAddress = lightningAddress
+            lnAddressStore = lnAddressStore,
         ) as T
     }
 }

app/src/main/java/com/bitcointxoko/gudariwallet/util/WalletConstants.kt

@@ -45,4 +45,6 @@ object WalletConstants {
 
     // ── Fiat cache ─────────────────────────────────────────────────────────
     const val RATE_TTL_MS = 5 * 60 * 1_000L   // 5 minutes
+
+    const val LNADDRESS_TTL_MS = 21 * 24 * 60 * 60 * 1_000L // 21 days
 }