CW-997 coin control enhancements / send ALL fixes (#2114)

* computed sending balance value

* files that didnt get added before

* monero + move unspent calc to view model

* working

* remove old code

* Update lib/view_model/send/send_view_model.dart

---------

Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

lib/view_model/send/send_view_model.dart

@@ -225,6 +225,42 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
     return wallet.balance[selectedCryptoCurrency]!.formattedFullAvailableBalance;
   }
 
+  @action
+  Future<void> updateSendingBalance() async {
+    // force the sendingBalance to recompute since unspent coins aren't observable
+    // or at least mobx can't detect the changes
+
+    final currentType = coinTypeToSpendFrom;
+
+    if (currentType == UnspentCoinType.any) {
+      coinTypeToSpendFrom = UnspentCoinType.nonMweb;
+    } else if (currentType == UnspentCoinType.nonMweb) {
+      coinTypeToSpendFrom = UnspentCoinType.any;
+    } else if (currentType == UnspentCoinType.mweb) {
+      coinTypeToSpendFrom = UnspentCoinType.nonMweb;
+    }
+
+    // set it back to the original value:
+    coinTypeToSpendFrom = currentType;
+  }
+
+  @computed
+  String get sendingBalance {
+    // only for electrum, monero, wownero, decred wallets atm:
+    switch (wallet.type) {
+      case WalletType.bitcoin:
+      case WalletType.litecoin:
+      case WalletType.bitcoinCash:
+      case WalletType.monero:
+      case WalletType.wownero:
+      case WalletType.decred:
+        return wallet.formatCryptoAmount(
+            unspentCoinsListViewModel.getSendingBalance(coinTypeToSpendFrom).toString());
+      default:
+        return balance;
+    }
+  }
+
   @computed
   bool get isFiatDisabled => balanceViewModel.isFiatDisabled;
 
@@ -502,14 +538,14 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
         return bitcoin!.createBitcoinTransactionCredentials(
           outputs,
           priority: priority!,
-          feeRate:feesViewModel. customBitcoinFeeRate,
+          feeRate: feesViewModel.customBitcoinFeeRate,
           coinTypeToSpendFrom: coinTypeToSpendFrom,
         );
       case WalletType.litecoin:
         return bitcoin!.createBitcoinTransactionCredentials(
           outputs,
           priority: priority!,
-          feeRate:feesViewModel. customBitcoinFeeRate,
+          feeRate: feesViewModel.customBitcoinFeeRate,
           // if it's an exchange flow then disable sending from mweb coins
           coinTypeToSpendFrom: provider != null ? UnspentCoinType.nonMweb : coinTypeToSpendFrom,
         );

lib/view_model/unspent_coins/unspent_coins_list_view_model.dart

@@ -131,6 +131,36 @@ abstract class UnspentCoinsListViewModelBase with Store {
     }
   }
 
+    List<Unspent> _getSpecificUnspents(UnspentCoinType overrideCoinTypeToSpendFrom) {
+    switch (wallet.type) {
+      case WalletType.monero:
+        return monero!.getUnspents(wallet);
+      case WalletType.wownero:
+        return wownero!.getUnspents(wallet);
+      case WalletType.bitcoin:
+      case WalletType.litecoin:
+      case WalletType.bitcoinCash:
+        return bitcoin!.getUnspents(wallet, coinTypeToSpendFrom: overrideCoinTypeToSpendFrom);
+      case WalletType.decred:
+        return decred!.getUnspents(wallet);
+      default:
+        return List.empty();
+    }
+  }
+
+  @action
+  int getSendingBalance(UnspentCoinType overrideCoinTypeToSpendFrom) {
+    // return items.where((element) => element.isSending).fold(0, (previousValue, element) => previousValue + element.value);
+    // go through all unspent coins and add up the value minus frozen and non sending:
+    int total = 0;
+
+    for (final item in _getSpecificUnspents(overrideCoinTypeToSpendFrom)) {
+      if (item.isFrozen || !item.isSending) continue;
+      total += item.value;
+    }
+    return total;
+  }
+
   @action
   void _updateUnspentCoinsInfo() {
     items.clear();