Adds method to make order values match the fractional actuality

dexbot/strategies/base.py

@@ -958,6 +958,37 @@ def get_own_spread(self):
         actual_spread = lowest_own_sell_price / highest_own_buy_price - 1
         return actual_spread
 
+    def fix_order_price(price=0, quote_amount=0):
+        """
+        Returns a price and amounts that will match what will actually happen on-chain, and
+        let you continue using float values in the logic.
+        In case the amounts get really small, some returned value might be zero. If so,
+        it is an indication that the funds available aren't sufficient, or they are spread into too many orders.
+        Amounts are rounded to closest possible decimal. Thus the final price might be lower or higher than intended.
+
+        :param float | price: the naively calculated price that is to be corrected
+        :param float | quote_amount: the naively calculated amount
+        :return dict: values that will result in correctly calculated orders
+        """
+        quote_amount_float = quote_amount
+        base_amount_float = quote_amount * price
+        quote_precision = (10 ** self.market['quote']['precision'])
+        base_precision = (10 ** self.market['base']['precision'])
+        quote_amount_internal = round(quote_amount_float * quote_precision)
+        base_amount_internal = round(base_amount_float * (base_precision))
+        target_price_internal = price * (base_precision / quote_precision)
+        if base_amount_internal < quote_amount_internal:
+            quote_amount_internal = round(base_amount_internal / target_price_internal)
+        else:
+            base_amount_internal = round(quote_amount_internal * target_price_internal)
+        quote_amount_float = quote_amount_internal / quote_precision
+        base_amount_float = base_amount_internal / base_precision
+        final_price = float(base_amount_float / quote_amount_float)
+
+        return {'price': final_price,
+                'quote_amount': quote_amount_float,
+                'base_amount': base_amount_float}
+
     def get_updated_order(self, order_id):
         """ Tries to get the updated order from the API. Returns None if the order doesn't exist