org.obiba.opal.core.identifiers.IdentifiersMaps.java Source code

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Here is the source code for org.obiba.opal.core.identifiers.IdentifiersMaps.java

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/*******************************************************************************
 * Copyright 2008(c) The OBiBa Consortium. All rights reserved.
 *
 * This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package org.obiba.opal.core.identifiers;

import java.util.Iterator;
import java.util.NavigableSet;
import java.util.TreeSet;

import javax.annotation.Nullable;

import org.obiba.magma.Value;
import org.obiba.magma.ValueTable;
import org.obiba.magma.VariableEntity;
import org.obiba.magma.support.VariableEntityBean;
import org.obiba.magma.type.TextType;

import com.google.common.base.Function;
import com.google.common.base.Predicates;
import com.google.common.collect.Iterables;

/**
 * An IdentifiersMap holds the mapping between a system identifier to a private identifier for a given entity type.
 * Both entity type and system/private identifiers are extracted from a given identifiers table
 * and an identifiers mapping name.
 */
public class IdentifiersMaps implements Iterable<IdentifiersMaps.IdentifiersMap> {

    public class IdentifiersMap {

        /**
         * Opal's identifier for the variable entity (the public identifier).
         */
        private final String systemIdentifier;

        /**
         * Private identifier for the variable entity (can be null).
         */
        @Nullable
        private final String privateIdentifier;

        IdentifiersMap(String systemIdentifier, @Nullable String privateIdentifier) {
            this.systemIdentifier = systemIdentifier;
            this.privateIdentifier = privateIdentifier;
        }

        public String getSystemIdentifier() {
            return systemIdentifier;
        }

        public VariableEntity getSystemEntity() {
            return entityFor(getSystemIdentifier());
        }

        @Nullable
        public String getPrivateIdentifier() {
            return privateIdentifier;
        }

        public VariableEntity getPrivateEntity() {
            return entityFor(getPrivateIdentifier());
        }

        private VariableEntity entityFor(@Nullable String identifier) {
            return new VariableEntityBean(identifiersTable.getEntityType(), identifier);
        }

        public boolean hasPrivateIdentifier() {
            return privateIdentifier != null && privateIdentifier.length() > 0;
        }

    }

    private final ValueTable identifiersTable;

    private final String idMapping;

    /**
     * For each entities in the identifiers table, extract the private identifiers corresponding to the named
     * identifiers mapping.
     *
     * @param identifiersTable
     * @param idMapping variable name which values are the private identifiers
     */
    public IdentifiersMaps(ValueTable identifiersTable, String idMapping) {
        this.identifiersTable = identifiersTable;
        this.idMapping = idMapping;
    }

    /**
     * Get all private entities: entities with non-null private identifiers.
     *
     * @return
     */
    public Iterable<VariableEntity> getPrivateEntities() {
        return Iterables.filter(Iterables.transform(this, new Function<IdentifiersMap, VariableEntity>() {

            @Override
            public VariableEntity apply(IdentifiersMap from) {
                return from.hasPrivateIdentifier() ? from.getPrivateEntity() : null;
            }

        }), Predicates.notNull());
    }

    @Override
    public Iterator<IdentifiersMap> iterator() {
        return new Iterator<IdentifiersMap>() {

            private final Iterator<VariableEntity> systemEntities;

            private final Iterator<Value> privateIdentifiers;

            {
                NavigableSet<VariableEntity> entities = new TreeSet<>(identifiersTable.getVariableEntities());

                privateIdentifiers = identifiersTable.hasVariable(idMapping)
                        ? identifiersTable.getVariableValueSource(idMapping).asVectorSource().getValues(entities)
                                .iterator()
                        : Iterables.cycle(TextType.get().nullValue()).iterator();
                systemEntities = entities.iterator();
            }

            @Override
            public boolean hasNext() {
                return systemEntities.hasNext();
            }

            @Override
            public IdentifiersMap next() {
                Value value = privateIdentifiers.next();
                return new IdentifiersMap(systemEntities.next().getIdentifier(),
                        value.isNull() ? null : (String) value.getValue());
            }

            @Override
            public void remove() {
                throw new UnsupportedOperationException();
            }

        };
    }

}