Ignore fixing of gross value unit if there is no suitable

Issue: https://forum.portfolio-performance.info/t/fehler-ungueltige-buchungskomponente-gross-value/1396/25

name.abuchen.portfolio.tests/src/name/abuchen/portfolio/model/TransactionTest.java

@@ -0,0 +1,38 @@
+package name.abuchen.portfolio.model;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import java.math.BigDecimal;
+
+import org.junit.Test;
+
+import name.abuchen.portfolio.model.Transaction.Unit;
+import name.abuchen.portfolio.money.CurrencyUnit;
+import name.abuchen.portfolio.money.Money;
+import name.abuchen.portfolio.money.Values;
+
+public class TransactionTest
+{
+
+    @Test
+    public void testUnitValidityCheckWithSmallValues()
+    {
+        Transaction.Unit unit = new Transaction.Unit(Unit.Type.TAX,
+                        Money.of(CurrencyUnit.EUR, Values.Amount.factorize(4.33)),
+                        Money.of("JPY", Values.Amount.factorize(0.03)), //$NON-NLS-1$
+                        BigDecimal.valueOf(131.53));
+
+        assertThat(unit.getAmount().getAmount(), is(Values.Amount.factorize(4.33)));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testUnitRoundingCheck()
+    {
+        new Transaction.Unit(Unit.Type.TAX,
+                        Money.of(CurrencyUnit.EUR, Values.Amount.factorize(4.33)),
+                        Money.of("JPY", Values.Amount.factorize(0.01)), //$NON-NLS-1$
+                        BigDecimal.valueOf(131.53));
+    }
+
+}

name.abuchen.portfolio/src/name/abuchen/portfolio/model/ClientFactory.java

@@ -1396,13 +1396,13 @@ private static void addKeyToTaxonomyClassifications(Client client)
     private static void copyClassificationKeys(Classification from, Classification to)
     {
         to.setKey(from.getKey());
-        
+
         Map<String, Classification> fromChildren = from.getChildren().stream()
-                        .collect(Collectors.toMap(Classification::getName, Function.identity(), (r,l) -> null));
-        
+                        .collect(Collectors.toMap(Classification::getName, Function.identity(), (r, l) -> null));
+
         Map<String, Classification> toChildren = to.getChildren().stream()
-                        .collect(Collectors.toMap(Classification::getName, Function.identity(), (r,l) -> null));
-        
+                        .collect(Collectors.toMap(Classification::getName, Function.identity(), (r, l) -> null));
+
         for (Map.Entry<String, Classification> entry : fromChildren.entrySet())
         {
             String key = entry.getKey();
@@ -1453,14 +1453,24 @@ private static void fixGrossValueUnit(Transaction tx)
             // recalculate the unit to fix the gross value
         }
 
-        Money updatedGrossValue = Money.of(grossValueUnit.getForex().getCurrencyCode(),
-                        BigDecimal.valueOf(calculatedGrossValue.getAmount())
-                                        .divide(grossValueUnit.getExchangeRate(), Values.MC)
-                                        .setScale(0, RoundingMode.HALF_EVEN).longValue());
+        try
+        {
+            Money updatedGrossValue = Money.of(grossValueUnit.getForex().getCurrencyCode(),
+                            BigDecimal.valueOf(calculatedGrossValue.getAmount())
+                                            .divide(grossValueUnit.getExchangeRate(), Values.MC)
+                                            .setScale(0, RoundingMode.HALF_EVEN).longValue());
 
-        tx.removeUnit(grossValueUnit);
-        tx.addUnit(new Unit(Unit.Type.GROSS_VALUE, calculatedGrossValue, updatedGrossValue,
-                        grossValueUnit.getExchangeRate()));
+            tx.removeUnit(grossValueUnit);
+            tx.addUnit(new Unit(Unit.Type.GROSS_VALUE, calculatedGrossValue, updatedGrossValue,
+                            grossValueUnit.getExchangeRate()));
+        }
+        catch (IllegalArgumentException e)
+        {
+            // ignore in case we are still running into rounding differences
+            // (for example: 4,33 EUR / 131,53 = 0,03 JPY but 0,03 JPY * 131,53
+            // = 3,95 EUR) because otherwise the user cannot open the file at
+            // all (and manually fix the issue)
+        }
     }
 
     @SuppressWarnings("nls")

name.abuchen.portfolio/src/name/abuchen/portfolio/model/Transaction.java

@@ -2,6 +2,7 @@
 
 import java.io.Serializable;
 import java.math.BigDecimal;
+import java.math.RoundingMode;
 import java.text.MessageFormat;
 import java.time.Instant;
 import java.time.LocalDateTime;
@@ -91,9 +92,29 @@ private Unit(Type type, Money amount, Money forex, BigDecimal exchangeRate, bool
                 }
 
                 if (amount.getAmount() < lower || amount.getAmount() > upper)
-                    throw new IllegalArgumentException(MessageFormat.format(Messages.MsgErrorIllegalForexUnit,
-                                    type.toString(), Values.Money.format(forex), exchangeRate,
-                                    Values.Money.format(amount)));
+                {
+                    // do the reverse check b/c small currency amounts might not
+                    // allow for a better exchange rate
+
+                    upper = BigDecimal.valueOf(amount.getAmount() + 1).divide(exchangeRate, Values.MC)
+                                    .setScale(0, RoundingMode.HALF_EVEN).longValue();
+                    lower = BigDecimal.valueOf(amount.getAmount() - 1).divide(exchangeRate, Values.MC)
+                                    .setScale(0, RoundingMode.HALF_EVEN).longValue();
+
+                    if (lower > upper)
+                    {
+                        long temp = lower;
+                        lower = upper;
+                        upper = temp;
+                    }
+
+                    if (forex.getAmount() < lower || forex.getAmount() > upper)
+                    {
+                        throw new IllegalArgumentException(MessageFormat.format(Messages.MsgErrorIllegalForexUnit,
+                                        type.toString(), Values.Money.format(forex), exchangeRate,
+                                        Values.Money.format(amount)));
+                    }
+                }
             }
         }