Datasource bundles

@Singleton
public class DatasourceSupport {

    private final Map<Class, DatasourceBundle> bundles;

    @Inject
    public DatasourceSupport(Set<DatasourceBundle> bundles) {
        this.bundles = bundles
                .stream()
                .collect(toMap(
                        DatasourceBundle::supportedDataSourceType,
                        identity()));
    }

    @SuppressWarnings("unchecked")
    public <DEF> DatasourceBundle<DEF> getDatasourceBundle(DEF def) {
        Objects.requireNonNull(def);
        return Optional.ofNullable(bundles.get(def.getClass())).orElseThrow(() -> new IllegalArgumentException("No such bundle for the type " + def.getClass()));
    }
}



@Multibinding
public abstract class DatasourceBundle<DEF> {

    private final Class<DEF> type;

    public DatasourceBundle(Class<DEF> type) {
        this.type = type;
    }

    public Class<DEF> supportedDataSourceType() {
        return this.type;
    }

    public abstract <T> T lookup(Class<T> type, DEF definition);
}

public class DatasourceComponentParameterResolver implements ParameterResolver {

    private final DatasourceSupport datasourceSupport;
    private final Object datasourceDefinition;

    public DatasourceComponentParameterResolver(DatasourceSupport datasourceSupport, Object datasourceDefinition) {
        this.datasourceSupport = datasourceSupport;
        this.datasourceDefinition = datasourceDefinition;
    }

    @Override
    public Object resolveParameter(ParameterInfo parameter) {
        boolean isDatasourceComponent = Stream.of(parameter.getParameterAnnotations()).anyMatch(DatasourceComponent.class::isInstance);
        if (isDatasourceComponent) {
            return datasourceSupport
                    .getDatasourceBundle(datasourceDefinition)
                    .lookup(parameter.getParameterType(), datasourceDefinition);
        }

        return UNRESOLVED;
    }
}