1package io.protobase.f7.formulas.math;
 2
 3import io.protobase.f7.errors.NumException;
 4import io.protobase.f7.formulas.AbstractFormula;
 5import io.protobase.f7.formulas.FormulaName;
 6import io.protobase.f7.models.GridColumnRowKey;
 7import io.protobase.f7.utils.Converters;
 8
 9import java.util.function.BiFunction;
10import java.util.function.Function;
11
12public class RANDBETWEEN extends AbstractFormula {
13  public static FormulaName NAME = FormulaName.RANDBETWEEN;
14  public static RANDBETWEEN SELF = new RANDBETWEEN();
15
16  public RANDBETWEEN() {
17    super();
18  }
19
20  public RANDBETWEEN(Function<Object, Object> lookup, BiFunction<GridColumnRowKey, Object, Object> collateralLookup) {
21    super(lookup, collateralLookup);
22  }
23
24  @Override
25  public Object internal(GridColumnRowKey origin, Object... values) {
26    checkLength(values.length, 2, NAME);
27    Double low = Converters.toDouble(Converters.first(collateralLookup.apply(origin, values[0])));
28    Double high = Converters.toDouble(Converters.first(collateralLookup.apply(origin, values[1])));
29    double lowRounded = Math.ceil(low);
30    double highRounded = Math.ceil(high);
31    if (lowRounded > highRounded) {
32      throw new NumException(String.format("Formula RANDBETWEEN parameter 2 value is %f, but it should be greater than or equal to %f.",
33          low, high));
34    }
35    double diff = Math.abs(lowRounded - highRounded);
36    return (double) Math.round(lowRounded + (Math.random() * diff));
37  }
38}