From 13274964a94a38975e66b8963c1c5622a7cec022 Mon Sep 17 00:00:00 2001
From: Matthias <xmatthias@outlook.com>
Date: Sat, 11 Jan 2020 11:53:44 +0100
Subject: [PATCH] Implement validation for valid stake currency

---
 freqtrade/constants.py         |  2 +-
 freqtrade/exchange/exchange.py | 25 +++++++++++++++++++++++--
 tests/conftest.py              |  1 +
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/freqtrade/constants.py b/freqtrade/constants.py
index 598a64337..53bc4af53 100644
--- a/freqtrade/constants.py
+++ b/freqtrade/constants.py
@@ -61,7 +61,7 @@ CONF_SCHEMA = {
     'properties': {
         'max_open_trades': {'type': ['integer', 'number'], 'minimum': -1},
         'ticker_interval': {'type': 'string'},
-        'stake_currency': {'type': 'string', 'enum': ['BTC', 'XBT', 'ETH', 'USDT', 'EUR', 'USD']},
+        'stake_currency': {'type': 'string'},
         'stake_amount': {
             'type': ['number', 'string'],
             'minimum': 0.0001,
diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 1ee6c2f1c..e15f6885c 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -116,6 +116,7 @@ class Exchange:
             self._load_markets()
 
             # Check if all pairs are available
+            self.validate_stakecurrency(config['stake_currency'])
             self.validate_pairs(config['exchange']['pair_whitelist'])
             self.validate_ordertypes(config.get('order_types', {}))
             self.validate_order_time_in_force(config.get('order_time_in_force', {}))
@@ -210,6 +211,14 @@ class Exchange:
             markets = {k: v for k, v in markets.items() if market_is_active(v)}
         return markets
 
+    def get_quote_currencies(self) -> List[str]:
+        """
+        Return a list of supported quote currencies
+        """
+        markets = self.markets
+        currencies = set([x['quote'] for _, x in markets.items()])
+        return list(currencies)
+
     def klines(self, pair_interval: Tuple[str, str], copy=True) -> DataFrame:
         if pair_interval in self._klines:
             return self._klines[pair_interval].copy() if copy else self._klines[pair_interval]
@@ -259,11 +268,23 @@ class Exchange:
         except ccxt.BaseError:
             logger.exception("Could not reload markets.")
 
+    def validate_stakecurrency(self, stake_currency) -> None:
+        """
+        Checks stake-currency against available currencies on the exchange.
+        :param stake_currency: Stake-currency to validate
+        :raise: OperationalException if stake-currency is not available.
+        """
+        quote_currencies = self.get_quote_currencies()
+        if stake_currency not in quote_currencies:
+            raise OperationalException(
+                    f"{stake_currency} is not available as stake on {self.name}."
+                    f"Available currencies are: {','.join(quote_currencies)}")
+
     def validate_pairs(self, pairs: List[str]) -> None:
         """
         Checks if all given pairs are tradable on the current exchange.
-        Raises OperationalException if one pair is not available.
         :param pairs: list of pairs
+        :raise: OperationalException if one pair is not available
         :return: None
         """
 
@@ -319,7 +340,7 @@ class Exchange:
             raise OperationalException(
                 f"Invalid ticker interval '{timeframe}'. This exchange supports: {self.timeframes}")
 
-        if timeframe_to_minutes(timeframe) < 1:
+        if timeframe and timeframe_to_minutes(timeframe) < 1:
             raise OperationalException(
                 f"Timeframes < 1m are currently not supported by Freqtrade.")
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 7bb4cf4c9..ac1b10284 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -60,6 +60,7 @@ def patch_exchange(mocker, api_mock=None, id='bittrex', mock_markets=True) -> No
     mocker.patch('freqtrade.exchange.Exchange.validate_pairs', MagicMock())
     mocker.patch('freqtrade.exchange.Exchange.validate_timeframes', MagicMock())
     mocker.patch('freqtrade.exchange.Exchange.validate_ordertypes', MagicMock())
+    mocker.patch('freqtrade.exchange.Exchange.validate_stakecurrency', MagicMock())
     mocker.patch('freqtrade.exchange.Exchange.id', PropertyMock(return_value=id))
     mocker.patch('freqtrade.exchange.Exchange.name', PropertyMock(return_value=id.title()))
     if mock_markets: