1package io.protobase.f7.formulas;
 2
 3import io.protobase.f7.errors.F7Exception;
 4import io.protobase.f7.errors.NAException;
 5import io.protobase.f7.models.GridColumnRowKey;
 6
 7import java.util.function.BiFunction;
 8import java.util.function.Function;
 9
10/**
11 * Abstract formula that has some defaults to ensure the safe execution of formulas.
12 */
13public abstract class AbstractFormula implements Formula {
14  private static final Function<Object, Object> DEFAULT_LOOKUP = (value) -> value;
15  private static final BiFunction<GridColumnRowKey, Object, Object> DEFAULT_COLLATERAL_LOOKUP = (origin, value) -> value;
16
17  protected Function<Object, Object> lookup;
18  protected BiFunction<GridColumnRowKey, Object, Object> collateralLookup;
19
20  public AbstractFormula() {
21    lookup = DEFAULT_LOOKUP;
22    collateralLookup = DEFAULT_COLLATERAL_LOOKUP;
23  }
24
25  public AbstractFormula(Function<Object, Object> lookup, BiFunction<GridColumnRowKey, Object, Object> collateralLookup) {
26    this.lookup = lookup;
27    this.collateralLookup = collateralLookup;
28  }
29
30  /**
31   * Ensure that argument lengths are equal. If not, throw {@link NAException}.
32   *
33   * @param actualLength   - actual length of arguments.
34   * @param expectedLength - expected length of arguments.
35   * @param caller         - name of formula calling this.
36   */
37  public static void checkLength(int actualLength, int expectedLength, FormulaName caller) {
38    if (actualLength != expectedLength) {
39      throw new NAException(String.format("Wrong number of arguments to %s. Expected %d arguments, but got %d arguments",
40          caller, expectedLength, actualLength));
41    }
42  }
43
44  /**
45   * Ensure that arguments are at least a certain length. If not, throw {@link NAException}.
46   *
47   * @param actualLength      - actual length of arguments.
48   * @param minExpectedLength - minimum expected length of arguments.
49   * @param caller            - name of formula calling this.
50   */
51  public static void checkAtLeastLength(int actualLength, int minExpectedLength, FormulaName caller) {
52    if (actualLength < minExpectedLength) {
53      throw new NAException(String.format("Wrong number of arguments to %s. Expected at least %d arguments, but got %d arguments",
54          caller, minExpectedLength, actualLength));
55    }
56  }
57
58  /**
59   * Ensure that arguments are between a minimum and maximum length. If not, throw {@link NAException}.
60   *
61   * @param actualLength - actual length of arguments.
62   * @param min          - minimum expected length of arguments, inclusively
63   * @param max          - maximum expected length of arguments, inclusively
64   * @param caller       - name of formula being called.
65   */
66  public static void checkLengthBetween(int actualLength, int min, int max, FormulaName caller) {
67    if (actualLength < min || actualLength > max) {
68      throw new NAException(String.format("Wrong number of arguments to %s. Expected between %d and %d arguments, but got %d arguments",
69          caller, min, max, actualLength));
70    }
71  }
72
73  /**
74   * By default, when we execute a formula, we want to catch the errors and return them as the resulting value.
75   *
76   * @param origin - origin cell that is running this formula.
77   * @param values - to use when calling the formula.
78   * @return the result of the formula implemented by the sub-class, or the error thrown by the formula implemented by
79   * the sub-class.
80   */
81  public Object apply(GridColumnRowKey origin, Object... values) {
82    try {
83      return this.internal(origin, values);
84    } catch (F7Exception error) {
85      return error;
86    }
87  }
88}