# OneToManyCycleConfigurer.java

    package org.codefilarete.stalactite.engine.configurer.onetomany;

    import java.util.Collection;
    import java.util.LinkedHashSet;
    import java.util.Set;

    import org.codefilarete.stalactite.engine.configurer.CascadeConfigurationResult;
    import org.codefilarete.stalactite.engine.configurer.builder.PostInitializer;
    import org.codefilarete.stalactite.engine.runtime.ConfiguredRelationalPersister;
    import org.codefilarete.stalactite.engine.runtime.cycle.OneToManyCycleLoader;

    /**
     * Container of {@link OneToManyRelationConfigurer}s of same entity type and their relation name (through {@link RelationConfigurer}).
     * Expected to exist as a one-per-entity-type.
     *
     * As a {@link PostInitializer}, will invoke every registered {@link OneToManyRelationConfigurer}
     * {@link OneToManyConfigurerTemplate#configureWithSelectIn2Phases(String, ConfiguredRelationalPersister, FirstPhaseCycleLoadListener)} configureWithSelectIn2Phases method}
     * with a {@link OneToManyCycleLoader}.
     *
     * @param <TRGT> type of all registered {@link OneToManyRelationConfigurer}
     */
    class OneToManyCycleConfigurer<TRGT> extends PostInitializer<TRGT> {

    	// instantiated as a LinkedHashSet only for steady debugging purpose, could be replaced by a HashSet
    	private final Set<RelationConfigurer<?, ?, ?>> relations = new LinkedHashSet<>();

    	public OneToManyCycleConfigurer(Class<TRGT> entityType) {
    		super(entityType);
    	}

    	public <SRC> void addCycleSolver(String relationIdentifier,
    									 OneToManyConfigurerTemplate<SRC, TRGT, ?, ?, ? extends Collection<TRGT>, ?> oneToManyRelationConfigurer) {
    		this.relations.add(new RelationConfigurer<>(relationIdentifier, oneToManyRelationConfigurer));
    	}

    	@Override
    	public void consume(ConfiguredRelationalPersister<TRGT, ?> targetPersister) {
    		registerRelationLoader(targetPersister);
    	}

    	private <SRC, TRGTID> void registerRelationLoader(ConfiguredRelationalPersister<TRGT, TRGTID> targetPersister) {
    		OneToManyCycleLoader<SRC, TRGT, TRGTID> oneToManyCycleLoader = new OneToManyCycleLoader<>(targetPersister);
    		targetPersister.addSelectListener(oneToManyCycleLoader);
    		((Set<RelationConfigurer<SRC, ?, TRGTID>>) (Set) relations).forEach(c -> {
    			String tableAlias = c.relationName.replaceAll("\\W", "_");
    			CascadeConfigurationResult<SRC, TRGT> configurationResult = c.oneToManyRelationConfigurer.configureWithSelectIn2Phases(
    					tableAlias, targetPersister, oneToManyCycleLoader.buildRowReader(c.relationName));
    			oneToManyCycleLoader.addRelation(c.relationName, configurationResult);
    		});
    	}

    	private class RelationConfigurer<SRC, SRCID, TRGTID> {

    		private final String relationName;
    		private final OneToManyConfigurerTemplate<SRC, TRGT, SRCID, TRGTID, Collection<TRGT>, ?> oneToManyRelationConfigurer;

    		public RelationConfigurer(String relationName,
    								  OneToManyConfigurerTemplate<SRC, TRGT, SRCID, TRGTID, ? extends Collection<TRGT>, ?> oneToManyRelationConfigurer) {
    			this.relationName = relationName;
    			this.oneToManyRelationConfigurer = (OneToManyConfigurerTemplate<SRC, TRGT, SRCID, TRGTID, Collection<TRGT>, ?>) oneToManyRelationConfigurer;
    		}
    	}
    }