refactor: WalletViewModel extract FiatViewModel

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

@@ -13,22 +13,18 @@ import com.bitcointxoko.gudariwallet.util.RouteHintAnalyzer
 import com.bitcointxoko.gudariwallet.util.SendInputDetector
 import com.bitcointxoko.gudariwallet.util.SendInputType
 import com.bitcointxoko.gudariwallet.util.WalletConstants
-import com.bitcointxoko.gudariwallet.util.satsToFiat
 import com.bitcointxoko.gudariwallet.util.parseApiError
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.flow.mapNotNull
-import kotlinx.coroutines.flow.stateIn
-import kotlinx.coroutines.flow.SharingStarted
 import com.bitcointxoko.gudariwallet.util.lnurlProtocolError
 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.ui.fiat.FiatViewModel
 import com.bitcointxoko.gudariwallet.util.BiometricHelper
 
 private const val TAG = "WalletViewModel"
@@ -40,60 +36,22 @@ class WalletViewModel(
     val         paymentCache: PaymentCacheRepository,
     private val balancePrefs: BalancePrefsStore,
     val         balanceVm    : BalanceViewModel,
+    val         fiatVm      : FiatViewModel
 ) : ViewModel() {
 
     // ── Balance state ─────────────────────────────────────────────────────────
     val balanceState: StateFlow<BalanceState> get() = balanceVm.balanceState
-    // ── Balance visible state ─────────────────────────────────────────────────
+    val balanceHidden: StateFlow<Boolean>   get() = fiatVm.balanceHidden
-    private val _balanceHidden = MutableStateFlow(balancePrefs.isBalanceHidden)
+    val selectedCurrency: StateFlow<String?> get() = fiatVm.selectedCurrency
-    val balanceHidden: StateFlow<Boolean> = _balanceHidden
+    val fiatSatsPerUnit: StateFlow<Double?>  get() = fiatVm.fiatSatsPerUnit
-    fun toggleBalanceVisibility() {
+    fun toggleBalanceVisibility()            = fiatVm.toggleBalanceVisibility()
-        val next = !_balanceHidden.value
+    fun setSelectedCurrency(c: String?)      = fiatVm.setSelectedCurrency(c)
-        _balanceHidden.value = next
+    suspend fun getSupportedCurrencies()     = fiatVm.getSupportedCurrencies()
-        balancePrefs.setBalanceHidden(next)
+    val fiatRate: Double?  get() = fiatVm.fiatRate
-    }
+    val fiatCurrency: String? get() = fiatVm.fiatCurrency
-
-    // ── Fiat cache ────────────────────────────────────────────────────────────
-    private val fiatCache = FiatRateCache(balancePrefs)
-    val fiatRate: Double?
-        get() = fiatCache.currentRate
-    val fiatCurrency: String? get() = _selectedCurrency.value
-    val fiatSatsPerUnit: StateFlow<Double?> = balanceVm.balanceState
-        .mapNotNull { state ->
-            (state as? BalanceState.Success)?.let { s ->
-                if (s.fiatAmount != null && s.sats > 0)
-                    s.sats.toDouble() / s.fiatAmount
-                else null
-            }
-        }
-        .stateIn(
-            scope        = viewModelScope,
-            started      = SharingStarted.Eagerly,
-            initialValue = null
-        )
-    private val _selectedCurrency = MutableStateFlow(balancePrefs.selectedCurrency)
-    val selectedCurrency: StateFlow<String?> = _selectedCurrency
-
-    fun setSelectedCurrency(currency: String?) {
-        if (currency == _selectedCurrency.value) return
-        _selectedCurrency.value = currency
-        balancePrefs.setSelectedCurrency(currency)
-        fiatCache.invalidateRate()
-        Log.d(TAG, "FIAT [CURRENCY  ] changed to ${currency ?: "none"} — cache invalidated")
-        if (currency != null) {
-            viewModelScope.launch { fetchAndApplyFiatRate() }
-        } else {
-            balanceVm.applyFiat(null, null)   // ← fix
-        }
-    }
-
-    companion object {
-        private const val RATE_TTL_MS = 5 * 60 * 1_000L   // 5 minutes
-    }
 
 
     // ── Other states ──────────────────────────────────────────────────────────
-
     private val _receiveState = MutableStateFlow<ReceiveState>(ReceiveState.Idle)
     val receiveState: StateFlow<ReceiveState> = _receiveState
     private val _sendState = MutableStateFlow<SendState>(SendState.Idle)
@@ -110,48 +68,7 @@ class WalletViewModel(
         fetchLightningAddress()
     }
 
-    // ── Fiat rate fetch + apply ───────────────────────────────────────────────
-    private suspend fun fetchAndApplyFiatRate() {
-        val currency = _selectedCurrency.value ?: return
-
-        val rate: Double = fiatCache.getRate(currency, RATE_TTL_MS)
-            ?: run {
-                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
-                    }
-                    .also { fresh -> fiatCache.putRate(currency, fresh) }
-            }
-
-        // ← fix: delegate to balanceVm instead of writing to _balanceState
-        val currentSats = (balanceVm.balanceState.value as? BalanceState.Success)?.sats ?: return
-        val fiat = satsToFiat(currentSats, rate)
-        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 }
-        // Cache miss (memory + disk) — fetch from network
-        return fetchAndCacheCurrencies()
-    }
-
-    private suspend fun fetchAndCacheCurrencies(): List<String> {
-        return runCatching { repo.getSupportedCurrencies() }
-            .getOrElse { e ->
-                Log.w(TAG, "FIAT [CURRENCIES] network fetch failed — ${e.message}")
-                emptyList()
-            }
-            .also { list -> fiatCache.putCurrencies(list) }
-    }
-
     // ── WebSocket event collection ────────────────────────────────────────────
-
     private fun observePaymentEvents() {
         viewModelScope.launch {
             balanceVm.incomingPayment.collect { event ->

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

@@ -12,6 +12,7 @@ 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
+import com.bitcointxoko.gudariwallet.ui.fiat.FiatViewModel
 
 class WalletViewModelFactory(private val app: Application) : ViewModelProvider.Factory {
     override fun <T : ViewModel> create(modelClass: Class<T>): T {
@@ -23,6 +24,8 @@ class WalletViewModelFactory(private val app: Application) : ViewModelProvider.F
         val repo         = LNbitsWalletRepository(api = api, secrets = secrets, context = app)
         val balancePrefs = BalancePrefsStore(app)
         val balanceVm    = BalanceViewModel(repo, balancePrefs)
+        val fiatVm       = FiatViewModel(repo, balancePrefs, balanceVm)
+        balanceVm.onBalanceRefreshed = { fiatVm.onBalanceRefreshed() }
         val lnurlCache   = LnurlCacheRepository(app)
         val paymentCache = PaymentCacheRepository(app)
         @Suppress("UNCHECKED_CAST")
@@ -32,7 +35,8 @@ class WalletViewModelFactory(private val app: Application) : ViewModelProvider.F
             lnurlCache,
             paymentCache,
             balancePrefs,
-            balanceVm
+            balanceVm,
+            fiatVm
         ) as T
     }
 }

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

@@ -27,12 +27,13 @@ class BalanceViewModel(
     // 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
 
+    var onBalanceRefreshed: (() -> Unit)? = null
+
     init {
         loadBalanceWithCache()
         observePaymentEvents()
@@ -85,7 +86,8 @@ class BalanceViewModel(
                         lastUpdated  = System.currentTimeMillis()
                     )
                     persistBalance(sats)
-                    _balanceRefreshed.tryEmit(sats)  // notify FiatViewModel
+                    _balanceRefreshed.tryEmit(sats)
+                    onBalanceRefreshed?.invoke()
                 }
                 .onFailure { e ->
                     Log.w(TAG, "BALANCE [NET ERROR ] ${e.message}")

app/src/main/java/com/bitcointxoko/gudariwallet/ui/fiat/FiatViewModel.kt

@@ -0,0 +1,120 @@
+package com.bitcointxoko.gudariwallet.ui.fiat
+
+import android.util.Log
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.bitcointxoko.gudariwallet.data.BalancePrefsStore
+import com.bitcointxoko.gudariwallet.data.FiatRateCache
+import com.bitcointxoko.gudariwallet.data.WalletRepository
+import com.bitcointxoko.gudariwallet.ui.BalanceState
+import com.bitcointxoko.gudariwallet.ui.balance.BalanceViewModel
+import com.bitcointxoko.gudariwallet.util.satsToFiat
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.mapNotNull
+import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
+
+private const val TAG = "FiatViewModel"
+private const val RATE_TTL_MS = 5 * 60 * 1_000L   // 5 minutes
+
+class FiatViewModel(
+    private val repo        : WalletRepository,
+    private val balancePrefs: BalancePrefsStore,
+    private val balanceVm   : BalanceViewModel,
+) : ViewModel() {
+
+    private val fiatCache = FiatRateCache(balancePrefs)
+
+    val fiatRate: Double?
+        get() = fiatCache.currentRate
+
+    val fiatCurrency: String?
+        get() = _selectedCurrency.value
+
+    // ── Balance hidden ───────────────────────────────────────────────────────
+    private val _balanceHidden = MutableStateFlow(balancePrefs.isBalanceHidden)
+    val balanceHidden: StateFlow<Boolean> = _balanceHidden
+
+    fun toggleBalanceVisibility() {
+        val next = !_balanceHidden.value
+        _balanceHidden.value = next
+        balancePrefs.setBalanceHidden(next)
+    }
+
+    // ── Selected currency ────────────────────────────────────────────────────
+    private val _selectedCurrency = MutableStateFlow(balancePrefs.selectedCurrency)
+    val selectedCurrency: StateFlow<String?> = _selectedCurrency
+
+    fun setSelectedCurrency(currency: String?) {
+        if (currency == _selectedCurrency.value) return
+        _selectedCurrency.value = currency
+        balancePrefs.setSelectedCurrency(currency)
+        fiatCache.invalidateRate()
+        Log.d(TAG, "FIAT [CURRENCY  ] changed to ${currency ?: "none"} — cache invalidated")
+        if (currency != null) {
+            viewModelScope.launch { fetchAndApplyFiatRate() }
+        } else {
+            balanceVm.applyFiat(null, null)
+        }
+    }
+
+    // ── Sats-per-fiat-unit derived flow ──────────────────────────────────────
+    // Used by UnitWheelPicker to convert between sats and fiat amounts.
+    val fiatSatsPerUnit: StateFlow<Double?> = balanceVm.balanceState
+        .mapNotNull { state ->
+            (state as? BalanceState.Success)?.let { s ->
+                if (s.fiatAmount != null && s.sats > 0)
+                    s.sats.toDouble() / s.fiatAmount
+                else null
+            }
+        }
+        .stateIn(
+            scope        = viewModelScope,
+            started      = SharingStarted.Eagerly,
+            initialValue = null
+        )
+
+    // ── Called by BalanceViewModel after every successful balance refresh ────
+    // Keeps fiat display in sync whenever the balance changes.
+    fun onBalanceRefreshed() {
+        viewModelScope.launch { fetchAndApplyFiatRate() }
+    }
+
+    // ── Rate fetch + apply ───────────────────────────────────────────────────
+    private suspend fun fetchAndApplyFiatRate() {
+        val currency = _selectedCurrency.value ?: return
+
+        val rate: Double = fiatCache.getRate(currency, RATE_TTL_MS)
+            ?: run {
+                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
+                    }
+                    .also { fresh -> fiatCache.putRate(currency, fresh) }
+            }
+
+        val currentSats = (balanceVm.balanceState.value as? BalanceState.Success)?.sats ?: return
+        val fiat = satsToFiat(currentSats, rate)
+        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 }
+        return fetchAndCacheCurrencies()
+    }
+
+    private suspend fun fetchAndCacheCurrencies(): List<String> {
+        return runCatching { repo.getSupportedCurrencies() }
+            .getOrElse { e ->
+                Log.w(TAG, "FIAT [CURRENCIES] network fetch failed — ${e.message}")
+                emptyList()
+            }
+            .also { list -> fiatCache.putCurrencies(list) }
+    }
+}