allow to use exchange rates while offline

lib/commands.py

@@ -449,6 +449,10 @@ class Commands:
             end_date = datetime.datetime(year+1, 1, 1)
             kwargs['from_timestamp'] = time.mktime(start_date.timetuple())
             kwargs['to_timestamp'] = time.mktime(end_date.timetuple())
+        if show_fiat:
+            from .exchange_rate import FxThread
+            fx = FxThread(self.config, None)
+            kwargs['fx'] = fx
         return self.wallet.export_history(**kwargs)
 
     @command('w')

lib/daemon.py

@@ -121,13 +121,12 @@ class Daemon(DaemonThread):
         self.config = config
         if config.get('offline'):
             self.network = None
-            self.fx = None
         else:
             self.network = Network(config)
             self.network.start()
-            self.fx = FxThread(config, self.network)
+        self.fx = FxThread(config, self.network)
+        if self.network:
             self.network.add_jobs([self.fx])
-
         self.gui = None
         self.wallets = {}
         # Setup JSONRPC server

lib/exchange_rate.py

@@ -61,9 +61,10 @@ class ExchangeBase(PrintError):
         t.setDaemon(True)
         t.start()
 
-    def get_historical_rates_safe(self, ccy, cache_dir):
+    def read_historical_rates(self, ccy, cache_dir):
         filename = os.path.join(cache_dir, self.name() + '_'+ ccy)
-        if os.path.exists(filename) and (time.time() - os.stat(filename).st_mtime) < 24*3600:
+        if os.path.exists(filename):
+            timestamp = os.stat(filename).st_mtime
             try:
                 with open(filename, 'r') as f:
                     h = json.loads(f.read())
@@ -71,7 +72,15 @@ class ExchangeBase(PrintError):
                 h = None
         else:
             h = None
-        if h is None:
+            timestamp = False
+        if h:
+            self.history[ccy] = h
+            self.on_history()
+        return h, timestamp
+
+    def get_historical_rates_safe(self, ccy, cache_dir):
+        h, timestamp = self.read_historical_rates()
+        if h is None or time.time() - timestamp < 24*3600:
             try:
                 self.print_error("requesting fx history for", ccy)
                 h = self.request_history(ccy)
@@ -397,8 +406,8 @@ class FxThread(ThreadJob):
         self.history_used_spot = False
         self.ccy_combo = None
         self.hist_checkbox = None
-        self.set_exchange(self.config_exchange())
         self.cache_dir = os.path.join(config.path, 'cache')
+        self.set_exchange(self.config_exchange())
         if not os.path.exists(self.cache_dir):
             os.mkdir(self.cache_dir)
 
@@ -471,12 +480,15 @@ class FxThread(ThreadJob):
         # A new exchange means new fx quotes, initially empty.  Force
         # a quote refresh
         self.timeout = 0
+        self.exchange.read_historical_rates(self.ccy, self.cache_dir)
 
     def on_quotes(self):
-        self.network.trigger_callback('on_quotes')
+        if self.network:
+            self.network.trigger_callback('on_quotes')
 
     def on_history(self):
-        self.network.trigger_callback('on_history')
+        if self.network:
+            self.network.trigger_callback('on_history')
 
     def exchange_rate(self):
         '''Returns None, or the exchange rate as a Decimal'''
@@ -514,6 +526,11 @@ class FxThread(ThreadJob):
         rate = self.history_rate(d_t)
         return self.value_str(satoshis, rate)
 
+    def historical_value(self, satoshis, d_t):
+        rate = self.history_rate(d_t)
+        if rate:
+            return Decimal(satoshis) / COIN * Decimal(rate)
+
     def timestamp_rate(self, timestamp):
         from electrum.util import timestamp_to_datetime
         date = timestamp_to_datetime(timestamp)