Add some error handling to sending crypto

www/assets/js/crypto.js

@@ -46,15 +46,31 @@ function scanPrivateKeyQrCode(callback) {
  * @returns {string} Hex of serialized transaction, suitable for broadcast via Bitcoin Core or an API.
  */
 function createSignedTransaction(bitcoreLib, privateKeyString, sourceAddress, destinationAddress, utxos, outputSatoshis) {
-    var privateKey = new bitcoreLib.PrivateKey(privateKeyString);
+    try {
+        var privateKey = new bitcoreLib.PrivateKey(privateKeyString);
 
-    var transaction = new bitcoreLib.Transaction()
-            .from(utxos)
-            .to(destinationAddress, outputSatoshis)
-            .change(sourceAddress)
-            .sign(privateKey);
+        var transaction = new bitcoreLib.Transaction()
+                .from(utxos)
+                .to(destinationAddress, outputSatoshis)
+                .change(sourceAddress)
+                .sign(privateKey);
 
-    return transaction.serialize();
+        var inputTotal = transaction._getInputAmount();
+
+        var outputTotal = transaction.getFee() + outputSatoshis;
+    } catch (ex) {
+        throw new Error("There was an internal error while creating the transaction. Details: " + ex.message);
+    }
+    console.log(inputTotal, outputTotal);
+    if (outputTotal > inputTotal) {
+        throw new Error("You have insufficient funds to cover the payment and transaction fees.");
+    }
+
+    try {
+        return transaction.serialize();
+    } catch (ex) {
+        throw new Error("Couldn't create the transaction. It's likely you typed something wrong. Check that you have enough funds.");
+    }
 }
 
 /**
@@ -130,7 +146,7 @@ function sendCoins(privatekey, fromaddress, toaddress, amount) {
             utxos.push(createUtxo(fromaddress, success.utxos[i].txHash, success.utxos[i].txOutputIndex, success.utxos[i].script, success.utxos[i].value));
         }
         var bitcore = null;
-        var satoshis = amount * 100000000;
+        var satoshis = parseInt((amount * 100000000).toFixed(0)); // Make sure it's an int and not something like 10.0000000001 or 9.532999999999
         switch (success.currency) {
             case "DOGE":
                 bitcore = require("bitcore-lib-doge");
@@ -143,7 +159,15 @@ function sendCoins(privatekey, fromaddress, toaddress, amount) {
                 app.dialog.alert("This app version doesn't support " + success.currency + ".", "Error");
                 return;
         }
-        var txdata = createSignedTransaction(bitcore, privatekey, fromaddress, toaddress, utxos, satoshis);
+
+        try {
+            var txdata = createSignedTransaction(bitcore, privatekey, fromaddress, toaddress, utxos, satoshis);
+        } catch (ex) {
+            console.error(ex);
+            app.dialog.close();
+            app.dialog.alert(ex.message, "Error");
+            return;
+        }
 
         progressdialog.setProgress(75);
         progressdialog.setText("Sending payment...");
@@ -286,7 +310,7 @@ $("#app").on("input change paste keyup", "#transactionAmountFiat", function () {
     var fiatamount = parseFloat($("#transactionAmountFiat").val());
     var exchangerate = parseFloat($("#transactionAmountFiat").data("exchange-rate"));
     $("#transactionAmount").val((fiatamount / exchangerate).toFixed(8));
-    $("#transactionAmountFiat").val(fiatamount.toFixed(2));
+    //$("#transactionAmountFiat").val(fiatamount.toFixed(2));
 });
 
 $("#app").on("paste blur", "#walletFromAddress", function () {
@@ -304,5 +328,5 @@ $("#app").on("input change paste keyup", "#transactionAmount", function () {
     var amount = parseFloat($("#transactionAmount").val());
     var exchangerate = parseFloat($("#transactionAmountFiat").data("exchange-rate"));
     $("#transactionAmountFiat").val((amount * exchangerate).toFixed(2));
-    $("#transactionAmount").val(amount.toFixed(8));
+    //$("#transactionAmount").val(amount.toFixed(8));
 });