qt lightning_tx_dialog: use historical fx rate for fiat amounts

electrum/exchange_rate.py

@@ -614,12 +614,18 @@ class FxThread(ThreadJob):
             return Decimal('NaN')
         return Decimal(rate)
 
-    def format_amount(self, btc_balance):
-        rate = self.exchange_rate()
+    def format_amount(self, btc_balance, *, timestamp: int = None) -> str:
+        if timestamp is None:
+            rate = self.exchange_rate()
+        else:
+            rate = self.timestamp_rate(timestamp)
         return '' if rate.is_nan() else "%s" % self.value_str(btc_balance, rate)
 
-    def format_amount_and_units(self, btc_balance):
-        rate = self.exchange_rate()
+    def format_amount_and_units(self, btc_balance, *, timestamp: int = None) -> str:
+        if timestamp is None:
+            rate = self.exchange_rate()
+        else:
+            rate = self.timestamp_rate(timestamp)
         return '' if rate.is_nan() else "%s %s" % (self.value_str(btc_balance, rate), self.ccy)
 
     def get_fiat_status_text(self, btc_balance, base_unit, decimal_point):
@@ -627,18 +633,18 @@ class FxThread(ThreadJob):
         return _("  (No FX rate available)") if rate.is_nan() else " 1 %s~%s %s" % (base_unit,
             self.value_str(COIN / (10**(8 - decimal_point)), rate), self.ccy)
 
-    def fiat_value(self, satoshis, rate):
+    def fiat_value(self, satoshis, rate) -> Decimal:
         return Decimal('NaN') if satoshis is None else Decimal(satoshis) / COIN * Decimal(rate)
 
-    def value_str(self, satoshis, rate):
+    def value_str(self, satoshis, rate) -> str:
         return self.format_fiat(self.fiat_value(satoshis, rate))
 
-    def format_fiat(self, value):
+    def format_fiat(self, value: Decimal) -> str:
         if value.is_nan():
             return _("No data")
         return "%s" % (self.ccy_amount_str(value, True))
 
-    def history_rate(self, d_t):
+    def history_rate(self, d_t: Optional[datetime]) -> Decimal:
         if d_t is None:
             return Decimal('NaN')
         rate = self.exchange.historical_rate(self.ccy, d_t)
@@ -651,13 +657,13 @@ class FxThread(ThreadJob):
             rate = 'NaN'
         return Decimal(rate)
 
-    def historical_value_str(self, satoshis, d_t):
+    def historical_value_str(self, satoshis, d_t: Optional[datetime]) -> str:
         return self.format_fiat(self.historical_value(satoshis, d_t))
 
-    def historical_value(self, satoshis, d_t):
+    def historical_value(self, satoshis, d_t: Optional[datetime]) -> Decimal:
         return self.fiat_value(satoshis, self.history_rate(d_t))
 
-    def timestamp_rate(self, timestamp):
+    def timestamp_rate(self, timestamp: Optional[int]) -> Decimal:
         from .util import timestamp_to_datetime
         date = timestamp_to_datetime(timestamp)
         return self.history_rate(date)

electrum/gui/qt/lightning_tx_dialog.py

@@ -64,11 +64,12 @@ class LightningTxDialog(WindowModalDialog):
         vbox = QVBoxLayout()
         self.setLayout(vbox)
 
-        # FIXME fiat values here are using today's FX rate instead of historical
-        vbox.addWidget(QLabel(_("Amount") + ": " + self.parent.format_amount_and_units(self.amount)))
+        amount_str = self.parent.format_amount_and_units(self.amount, timestamp=self.timestamp)
+        vbox.addWidget(QLabel(_("Amount") + f": {amount_str}"))
         if self.is_sent:
             fee = Decimal(tx_item['fee_msat']) / 1000
-            vbox.addWidget(QLabel(_("Fee") + ": " + self.parent.format_amount_and_units(fee)))
+            fee_str = self.parent.format_amount_and_units(fee, timestamp=self.timestamp)
+            vbox.addWidget(QLabel(_("Fee") + f": {fee_str}"))
         time_str = datetime.datetime.fromtimestamp(self.timestamp).isoformat(' ')[:-3]
         vbox.addWidget(QLabel(_("Date") + ": " + time_str))
 

electrum/gui/qt/main_window.py

@@ -878,14 +878,14 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger):
         """
         return self.config.format_amount(amount_sat, is_diff=is_diff, whitespaces=whitespaces)
 
-    def format_amount_and_units(self, amount_sat) -> str:
+    def format_amount_and_units(self, amount_sat, *, timestamp: int = None) -> str:
         """Returns string with both bitcoin and fiat amounts, in desired units.
         E.g. 500_000 -> '0.005 BTC (191.42 EUR)'
         """
         text = self.config.format_amount_and_units(amount_sat)
-        x = self.fx.format_amount_and_units(amount_sat) if self.fx else None
-        if text and x:
-            text += ' (%s)'%x
+        fiat = self.fx.format_amount_and_units(amount_sat, timestamp=timestamp) if self.fx else None
+        if text and fiat:
+            text += f' ({fiat})'
         return text
 
     def format_fiat_and_units(self, amount_sat) -> str:

electrum/util.py

@@ -700,7 +700,7 @@ def quantize_feerate(fee) -> Union[None, Decimal, int]:
     return Decimal(fee).quantize(_feerate_quanta, rounding=decimal.ROUND_HALF_DOWN)
 
 
-def timestamp_to_datetime(timestamp):
+def timestamp_to_datetime(timestamp: Optional[int]) -> Optional[datetime]:
     if timestamp is None:
         return None
     return datetime.fromtimestamp(timestamp)