1package io.protobase.f7.formulas.lookup;
 2
 3import io.protobase.f7.errors.NumException;
 4import io.protobase.f7.formulas.AbstractFormula;
 5import io.protobase.f7.formulas.FormulaName;
 6import io.protobase.f7.formulas.math.ROUNDDOWN;
 7import io.protobase.f7.models.GridColumnRowKey;
 8import io.protobase.f7.utils.Converters;
 9
10import java.util.function.BiFunction;
11import java.util.function.Function;
12
13public class CHOOSE extends AbstractFormula {
14  public static FormulaName NAME = FormulaName.CHOOSE;
15  public static CHOOSE SELF = new CHOOSE();
16
17  public CHOOSE() {
18    super();
19  }
20
21  public CHOOSE(Function<Object, Object> lookup, BiFunction<GridColumnRowKey, Object, Object> collateralLookup) {
22    super(lookup, collateralLookup);
23  }
24
25  @Override
26  public Object internal(GridColumnRowKey origin, Object... values) {
27    checkAtLeastLength(values.length, 2, NAME);
28    int index = Converters.toDouble(ROUNDDOWN.SELF.apply(null,
29        Converters.toDouble(Converters.first(collateralLookup.apply(origin, values[0]))))).intValue();
30    if (index < 1 || index > values.length - 1) {
31      return new NumException(String.format("CHOOSE parameter 1 value is %d. Valid values are between 1 and %d inclusive.",
32          index, values.length - 1));
33    }
34    return Converters.first(lookup.apply(values[index]));
35  }
36}