refactor: WalletViewModel extract BalanceViewModel

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

@@ -8,7 +8,6 @@ import com.bitcointxoko.gudariwallet.data.LnurlCacheRepository
 import com.bitcointxoko.gudariwallet.data.NodeAliasRepository
 import com.bitcointxoko.gudariwallet.data.PaymentCacheRepository
 import com.bitcointxoko.gudariwallet.data.WalletRepository
-import com.bitcointxoko.gudariwallet.service.WalletNotificationService
 import com.bitcointxoko.gudariwallet.util.LnurlMetadataParser
 import com.bitcointxoko.gudariwallet.util.RouteHintAnalyzer
 import com.bitcointxoko.gudariwallet.util.SendInputDetector
@@ -29,6 +28,7 @@ import androidx.fragment.app.FragmentActivity
 import com.bitcointxoko.gudariwallet.api.RouteHintHop
 import com.bitcointxoko.gudariwallet.data.BalancePrefsStore
 import com.bitcointxoko.gudariwallet.data.FiatRateCache
+import com.bitcointxoko.gudariwallet.ui.balance.BalanceViewModel
 import com.bitcointxoko.gudariwallet.util.BiometricHelper
 
 private const val TAG = "WalletViewModel"
@@ -39,12 +39,11 @@ class WalletViewModel(
     val         lnurlCache: LnurlCacheRepository,
     val         paymentCache: PaymentCacheRepository,
     private val balancePrefs: BalancePrefsStore,
+    val         balanceVm    : BalanceViewModel,
 ) : ViewModel() {
 
     // ── Balance state ─────────────────────────────────────────────────────────
-    private val _balanceState = MutableStateFlow<BalanceState>(BalanceState.Loading)
+    val balanceState: StateFlow<BalanceState> get() = balanceVm.balanceState
-    val balanceState: StateFlow<BalanceState> = _balanceState
-
     // ── Balance visible state ─────────────────────────────────────────────────
     private val _balanceHidden = MutableStateFlow(balancePrefs.isBalanceHidden)
     val balanceHidden: StateFlow<Boolean> = _balanceHidden
@@ -59,7 +58,7 @@ class WalletViewModel(
     val fiatRate: Double?
         get() = fiatCache.currentRate
     val fiatCurrency: String? get() = _selectedCurrency.value
-    val fiatSatsPerUnit: StateFlow<Double?> = balanceState
+    val fiatSatsPerUnit: StateFlow<Double?> = balanceVm.balanceState
         .mapNotNull { state ->
             (state as? BalanceState.Success)?.let { s ->
                 if (s.fiatAmount != null && s.sats > 0)
@@ -79,13 +78,12 @@ class WalletViewModel(
         if (currency == _selectedCurrency.value) return
         _selectedCurrency.value = currency
         balancePrefs.setSelectedCurrency(currency)
-        fiatCache.invalidateRate()   // ← replaces the three raw-var resets
+        fiatCache.invalidateRate()
         Log.d(TAG, "FIAT [CURRENCY  ] changed to ${currency ?: "none"} — cache invalidated")
         if (currency != null) {
             viewModelScope.launch { fetchAndApplyFiatRate() }
         } else {
-            val current = _balanceState.value as? BalanceState.Success ?: return
+            balanceVm.applyFiat(null, null)   // ← fix
-            _balanceState.value = current.copy(fiatAmount = null, fiatCurrency = null)
         }
     }
 
@@ -108,106 +106,34 @@ class WalletViewModel(
     // ── Init ──────────────────────────────────────────────────────────────────
 
     init {
-        loadBalanceWithCache()
         observePaymentEvents()
         fetchLightningAddress()
     }
 
-    // ── Balance loading ───────────────────────────────────────────────────────
-
-    private fun loadBalanceWithCache() {
-        val savedSats = balancePrefs.savedBalanceSats
-        val savedAt   = balancePrefs.balanceSavedAt
-        val ageMs     = System.currentTimeMillis() - savedAt
-
-        if (savedSats >= 0 && ageMs < WalletConstants.BALANCE_CACHE_TTL_MS) {
-            Log.d(TAG, "BALANCE [CACHE HIT ] $savedSats sats (age ${ageMs / 1000}s) — showing immediately")
-            _balanceState.value = BalanceState.Success(
-                sats         = savedSats,
-                isRefreshing = true,
-                lastUpdated  = savedAt
-            )
-        } else {
-            if (savedSats >= 0) {
-                Log.d(TAG, "BALANCE [CACHE STALE] $savedSats sats, age ${ageMs / 1000}s > TTL ${WalletConstants.BALANCE_CACHE_TTL_MS / 1000}s — cold load")
-            } else {
-                Log.d(TAG, "BALANCE [CACHE MISS ] No persisted balance — cold load")
-            }
-            _balanceState.value = BalanceState.Loading
-        }
-
-        refreshBalance()
-    }
-
-    fun refreshBalance() {
-        val current = _balanceState.value
-        if (current is BalanceState.Success && !current.isRefreshing) {
-            Log.d(TAG, "BALANCE [REFRESH   ] Manual refresh triggered (current: ${current.sats} sats)")
-            _balanceState.value = current.copy(isRefreshing = true)
-        }
-
-        viewModelScope.launch {
-            runCatching { repo.getBalance() }
-                .onSuccess { balance ->
-                    val sats = balance.sats
-                    val prev = (_balanceState.value as? BalanceState.Success)?.sats
-                    when {
-                        prev == null -> Log.d(TAG, "BALANCE [NETWORK   ] $sats sats — cold load complete")
-                        prev == sats -> Log.d(TAG, "BALANCE [NETWORK   ] $sats sats — matches cache, no change")
-                        else         -> Log.d(TAG, "BALANCE [NETWORK   ] $sats sats — was $prev sats (diff ${sats - prev})")
-                    }
-                    _balanceState.value = BalanceState.Success(
-                        sats         = sats,
-                        isRefreshing = false,
-                        lastUpdated  = System.currentTimeMillis()
-                    )
-                    persistBalance(sats)
-                    fetchAndApplyFiatRate()
-                }
-                .onFailure { e ->
-                    Log.w(TAG, "BALANCE [NET ERROR ] ${e.message}")
-                    val staleSats = (_balanceState.value as? BalanceState.Success)?.sats
-                        ?: balancePrefs.savedBalanceSats.takeIf { it >= 0 }
-                    if (staleSats != null) {
-                        Log.w(TAG, "BALANCE [NET ERROR ] Falling back to stale value: $staleSats sats")
-                    } else {
-                        Log.w(TAG, "BALANCE [NET ERROR ] No stale value available — showing error state")
-                    }
-                    _balanceState.value = BalanceState.Error(
-                        message   = e.message ?: "Failed to load balance",
-                        staleSats = staleSats
-                    )
-                }
-        }
-    }
-    private fun persistBalance(sats: Long) {
-        balancePrefs.persistBalance(sats)
-        Log.d(TAG, "BALANCE [PERSIST  ] $sats sats written to SharedPreferences")
-    }
-
     // ── Fiat rate fetch + apply ───────────────────────────────────────────────
     private suspend fun fetchAndApplyFiatRate() {
         val currency = _selectedCurrency.value ?: return
 
         val rate: Double = fiatCache.getRate(currency, RATE_TTL_MS)
             ?: run {
-                // Cache miss — fetch from network
                 runCatching { repo.getFiatRate(currency) }
                     .getOrElse { e ->
                         Log.w(TAG, "FIAT [RATE ERROR ] $currency — ${e.message}")
                         Log.w(TAG, "FIAT [RATE MISS  ] $currency — no fallback available, suppressing fiat display")
-                        return   // nothing to show; leave fiatAmount = null
+                        return
                     }
                     .also { fresh -> fiatCache.putRate(currency, fresh) }
             }
 
-        val current = _balanceState.value as? BalanceState.Success ?: return
+        // ← fix: delegate to balanceVm instead of writing to _balanceState
-        val fiat    = satsToFiat(current.sats, rate)
+        val currentSats = (balanceVm.balanceState.value as? BalanceState.Success)?.sats ?: return
-        Log.d(TAG, "FIAT [APPLY     ] ${current.sats} sats ÷ $rate sats/$currency = $fiat $currency")
+        val fiat = satsToFiat(currentSats, rate)
-        _balanceState.value = current.copy(fiatAmount = fiat, fiatCurrency = currency)
+        Log.d(TAG, "FIAT [APPLY     ] $currentSats sats ÷ $rate sats/$currency = $fiat $currency")
+        balanceVm.applyFiat(fiat, currency)
     }
 
 
+
     // ── Currency list ────────────────────────────────────────────────────────
     suspend fun getSupportedCurrencies(): List<String> {
         fiatCache.getCurrencies()?.let { return it }
@@ -228,24 +154,7 @@ class WalletViewModel(
 
     private fun observePaymentEvents() {
         viewModelScope.launch {
-            WalletNotificationService.paymentEvents.collect { event ->
+            balanceVm.incomingPayment.collect { event ->
-                Log.d(TAG, "BALANCE [WS EVENT  ] ${if (event.isOutgoing) "SENT" else "RECEIVED"} ${event.amountSats} sats")
-
-                val current = _balanceState.value
-                if (current is BalanceState.Success) {
-                    val delta   = if (event.isOutgoing) -event.amountSats else event.amountSats
-                    val newSats = (current.sats + delta).coerceAtLeast(0L)
-                    Log.d(TAG, "BALANCE [WS DELTA  ] ${current.sats} ${if (delta >= 0) "+" else ""}$delta = $newSats sats (optimistic)")
-                    _balanceState.value = current.copy(sats = newSats, isRefreshing = true)
-                    persistBalance(newSats)
-                } else {
-                    Log.w(TAG, "BALANCE [WS EVENT  ] Received event but balance state is ${current::class.simpleName} — skipping delta")
-                }
-
-                refreshBalance()
-                fetchAndApplyFiatRate()
-
-                if (!event.isOutgoing) {
                 val rs = _receiveState.value
                 if (rs is ReceiveState.InvoiceReady) {
                     Log.d(TAG, "BALANCE [WS RECEIVE] Marking invoice ${rs.paymentHash.take(8)}… as received")
@@ -258,9 +167,6 @@ class WalletViewModel(
             }
         }
     }
-    }
-
-
     private fun fetchLightningAddress() {
         // If we already have a persisted address, show it immediately and
         // still refresh in the background (address could have changed).
@@ -672,7 +578,10 @@ class WalletViewModel(
         _clipboardOfferState.value = ClipboardOfferState.None
     }
 
+    fun refreshBalance() = balanceVm.refreshBalance()
+
     // ── Private helpers ───────────────────────────────────────────────────────
+
     private fun buildLnurlReadyState(raw: LnurlScanResponse, lnurl: String): SendState.LnurlReady {
         return SendState.LnurlReady(
             callback       = raw.callback ?: "",

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

@@ -11,6 +11,7 @@ import com.bitcointxoko.gudariwallet.data.LnurlCacheRepository
 import com.bitcointxoko.gudariwallet.data.PaymentCacheRepository
 import com.bitcointxoko.gudariwallet.security.EncryptedSecretStore
 import com.bitcointxoko.gudariwallet.service.NodeAliasService
+import com.bitcointxoko.gudariwallet.ui.balance.BalanceViewModel
 
 class WalletViewModelFactory(private val app: Application) : ViewModelProvider.Factory {
     override fun <T : ViewModel> create(modelClass: Class<T>): T {
@@ -21,15 +22,17 @@ class WalletViewModelFactory(private val app: Application) : ViewModelProvider.F
         val aliasRepo    = LNbitsNodeAliasRepository(nodeAliasSvc)
         val repo         = LNbitsWalletRepository(api = api, secrets = secrets, context = app)
         val balancePrefs = BalancePrefsStore(app)
+        val balanceVm    = BalanceViewModel(repo, balancePrefs)
         val lnurlCache   = LnurlCacheRepository(app)
         val paymentCache = PaymentCacheRepository(app)
         @Suppress("UNCHECKED_CAST")
         return WalletViewModel(
-            balancePrefs = balancePrefs,
+            repo,
-            repo         = repo,
+            aliasRepo,
-            aliasRepo    = aliasRepo,
+            lnurlCache,
-            lnurlCache   = lnurlCache,
+            paymentCache,
-            paymentCache = paymentCache
+            balancePrefs,
+            balanceVm
         ) as T
     }
 }

app/src/main/java/com/bitcointxoko/gudariwallet/ui/balance/BalanceViewModel.kt

@@ -0,0 +1,153 @@
+package com.bitcointxoko.gudariwallet.ui.balance
+
+import android.util.Log
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.bitcointxoko.gudariwallet.data.BalancePrefsStore
+import com.bitcointxoko.gudariwallet.data.WalletRepository
+import com.bitcointxoko.gudariwallet.service.WalletNotificationService
+import com.bitcointxoko.gudariwallet.ui.BalanceState
+import com.bitcointxoko.gudariwallet.util.WalletConstants
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.launch
+
+private const val TAG = "BalanceViewModel"
+
+class BalanceViewModel(
+    private val repo         : WalletRepository,
+    private val balancePrefs : BalancePrefsStore,
+) : ViewModel() {
+
+    private val _balanceState = MutableStateFlow<BalanceState>(BalanceState.Loading)
+    val balanceState: StateFlow<BalanceState> = _balanceState
+
+    // Emits after every successful balance refresh so other ViewModels
+    // (e.g. FiatViewModel) can react without polling.
+    private val _balanceRefreshed = MutableSharedFlow<Long>(extraBufferCapacity = 1)
+    val balanceRefreshed: SharedFlow<Long> = _balanceRefreshed
+
+    // Emits incoming payment events so ReceiveViewModel can update its state.
+    private val _incomingPayment = MutableSharedFlow<IncomingPaymentEvent>(extraBufferCapacity = 1)
+    val incomingPayment: SharedFlow<IncomingPaymentEvent> = _incomingPayment
+
+    init {
+        loadBalanceWithCache()
+        observePaymentEvents()
+    }
+
+    private fun loadBalanceWithCache() {
+        val savedSats = balancePrefs.savedBalanceSats
+        val savedAt   = balancePrefs.balanceSavedAt
+        val ageMs     = System.currentTimeMillis() - savedAt
+
+        if (savedSats >= 0 && ageMs < WalletConstants.BALANCE_CACHE_TTL_MS) {
+            Log.d(TAG, "BALANCE [CACHE HIT ] $savedSats sats (age ${ageMs / 1000}s) — showing immediately")
+            _balanceState.value = BalanceState.Success(
+                sats         = savedSats,
+                isRefreshing = true,
+                lastUpdated  = savedAt
+            )
+        } else {
+            if (savedSats >= 0) {
+                Log.d(TAG, "BALANCE [CACHE STALE] $savedSats sats, age ${ageMs / 1000}s > TTL ${WalletConstants.BALANCE_CACHE_TTL_MS / 1000}s — cold load")
+            } else {
+                Log.d(TAG, "BALANCE [CACHE MISS ] No persisted balance — cold load")
+            }
+            _balanceState.value = BalanceState.Loading
+        }
+
+        refreshBalance()
+    }
+
+    fun refreshBalance() {
+        val current = _balanceState.value
+        if (current is BalanceState.Success && !current.isRefreshing) {
+            Log.d(TAG, "BALANCE [REFRESH   ] Manual refresh triggered (current: ${current.sats} sats)")
+            _balanceState.value = current.copy(isRefreshing = true)
+        }
+
+        viewModelScope.launch {
+            runCatching { repo.getBalance() }
+                .onSuccess { balance ->
+                    val sats = balance.sats
+                    val prev = (_balanceState.value as? BalanceState.Success)?.sats
+                    when {
+                        prev == null -> Log.d(TAG, "BALANCE [NETWORK   ] $sats sats — cold load complete")
+                        prev == sats -> Log.d(TAG, "BALANCE [NETWORK   ] $sats sats — matches cache, no change")
+                        else         -> Log.d(TAG, "BALANCE [NETWORK   ] $sats sats — was $prev sats (diff ${sats - prev})")
+                    }
+                    _balanceState.value = BalanceState.Success(
+                        sats         = sats,
+                        isRefreshing = false,
+                        lastUpdated  = System.currentTimeMillis()
+                    )
+                    persistBalance(sats)
+                    _balanceRefreshed.tryEmit(sats)  // notify FiatViewModel
+                }
+                .onFailure { e ->
+                    Log.w(TAG, "BALANCE [NET ERROR ] ${e.message}")
+                    val staleSats = (_balanceState.value as? BalanceState.Success)?.sats
+                        ?: balancePrefs.savedBalanceSats.takeIf { it >= 0 }
+                    if (staleSats != null) {
+                        Log.w(TAG, "BALANCE [NET ERROR ] Falling back to stale value: $staleSats sats")
+                    } else {
+                        Log.w(TAG, "BALANCE [NET ERROR ] No stale value available — showing error state")
+                    }
+                    _balanceState.value = BalanceState.Error(
+                        message   = e.message ?: "Failed to load balance",
+                        staleSats = staleSats
+                    )
+                }
+        }
+    }
+
+    private fun persistBalance(sats: Long) {
+        balancePrefs.persistBalance(sats)
+        Log.d(TAG, "BALANCE [PERSIST  ] $sats sats written to SharedPreferences")
+    }
+
+    private fun observePaymentEvents() {
+        viewModelScope.launch {
+            WalletNotificationService.paymentEvents.collect { event ->
+                Log.d(TAG, "BALANCE [WS EVENT  ] ${if (event.isOutgoing) "SENT" else "RECEIVED"} ${event.amountSats} sats")
+
+                val current = _balanceState.value
+                if (current is BalanceState.Success) {
+                    val delta   = if (event.isOutgoing) -event.amountSats else event.amountSats
+                    val newSats = (current.sats + delta).coerceAtLeast(0L)
+                    Log.d(TAG, "BALANCE [WS DELTA  ] ${current.sats} ${if (delta >= 0) "+" else ""}$delta = $newSats sats (optimistic)")
+                    _balanceState.value = current.copy(sats = newSats, isRefreshing = true)
+                    persistBalance(newSats)
+                } else {
+                    Log.w(TAG, "BALANCE [WS EVENT  ] Received event but balance state is ${current::class.simpleName} — skipping delta")
+                }
+
+                refreshBalance()
+
+                if (!event.isOutgoing) {
+                    _incomingPayment.tryEmit(
+                        IncomingPaymentEvent(
+                            amountSats = event.amountSats,
+                            memo       = event.memo
+                        )
+                    )
+                }
+            }
+        }
+    }
+
+    fun applyFiat(fiatAmount: Double?, fiatCurrency: String?) {
+        val current = _balanceState.value as? BalanceState.Success ?: return
+        _balanceState.value = current.copy(fiatAmount = fiatAmount, fiatCurrency = fiatCurrency)
+    }
+
+}
+
+/** Thin event type so ReceiveViewModel doesn't depend on the WS model directly. */
+data class IncomingPaymentEvent(
+    val amountSats: Long,
+    val memo      : String?
+)