jdash.events.producer.ComparingPagesEventProducer Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jdash-events Show documentation

Extension of the client module that allows to emit events when changes are detected between the results of two subsequent requests.

The newest version!

package jdash.events.producer;

import jdash.client.GDClient;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.util.function.Tuples;

import java.util.Set;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static reactor.function.TupleUtils.function;

class ComparingPagesEventProducer implements GDEventProducer {

    private final PagesComparator pagesComparator;
    private Set previous0;
    private Set previous1;

    ComparingPagesEventProducer(PagesComparator pagesComparator) {
        this.pagesComparator = pagesComparator;
    }

    private Set intersection(Set a, Set b) {
        return a.stream()
                .filter(aEl -> b.stream().anyMatch(bEl -> idEquals(aEl, bEl)))
                .collect(Collectors.toUnmodifiableSet());
    }

    private Set union(Set a, Set b) {
        return Set.copyOf(Stream.concat(a.stream(), b.stream())
                .collect(Collectors.toUnmodifiableMap(pagesComparator::idGetter, Function.identity(), (o1, o2) -> o1))
                .values());
    }

    private Set subtract(Set a, Set b) {
        return a.stream()
                .filter(aEl -> b.stream().noneMatch(bEl -> idEquals(aEl, bEl)))
                .collect(Collectors.toUnmodifiableSet());
    }

    private boolean idEquals(T e1, T e2) {
        return pagesComparator.idGetter(e1) == pagesComparator.idGetter(e2);
    }

    @Override
    public Flux