red6/dmn-check

package de.redsix.dmncheck.feel;

import static de.redsix.dmncheck.feel.ExpressionTypes.DOUBLE;
import static de.redsix.dmncheck.feel.ExpressionTypes.INTEGER;
import static de.redsix.dmncheck.feel.ExpressionTypes.LONG;
import static de.redsix.dmncheck.feel.ExpressionTypes.TOP;

import java.util.Arrays;
import org.camunda.bpm.model.dmn.instance.ItemDefinition;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.derive4j.Data;

@Data
public abstract class ExpressionType {

    public interface Cases<R> {
        R TOP();

        R STRING();

        R BOOLEAN();

        R INTEGER();

        R LONG();

        R DOUBLE();

        R DATE();

        R ENUM(String className);

        R ITEMDEFINITION(ItemDefinition itemDefinition);
    }

    public abstract <R> R match(ExpressionType.Cases<R> cases);

    @Override
    public abstract int hashCode();

    @Override
    public abstract boolean equals(@Nullable Object obj);

    @Override
    public abstract String toString();

    public static boolean isNumeric(final ExpressionType givenType) {
        return !TOP().equals(givenType)
                && Arrays.asList(INTEGER(), LONG(), DOUBLE()).contains(givenType);
    }

    public boolean isSubtypeOf(final ExpressionType supertype) {
        return reflexivity(this, supertype)
                || TOPisTopElement(supertype)
                || INTEGERsubtypeOfLONG(this, supertype)
                || INTEGERsubtypeOfDOUBLE(this, supertype);
    }

    private boolean reflexivity(final ExpressionType subtype, final ExpressionType supertype) {
        return subtype.equals(supertype);
    }

    private boolean TOPisTopElement(final ExpressionType supertype) {
        return TOP().equals(supertype);
    }

    private boolean INTEGERsubtypeOfLONG(final ExpressionType subtype, final ExpressionType supertype) {
        return INTEGER().equals(subtype) && LONG().equals(supertype);
    }

    private boolean INTEGERsubtypeOfDOUBLE(final ExpressionType subtype, final ExpressionType supertype) {
        return INTEGER().equals(subtype) && DOUBLE().equals(supertype);
    }
}