apoc.dv.DataVirtualizationCatalogHandler Maven / Gradle / Ivy

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package apoc.dv;

import apoc.SystemLabels;
import apoc.SystemPropertyKeys;
import apoc.util.JsonUtil;
import apoc.util.Util;
import com.fasterxml.jackson.core.JsonProcessingException;
import org.apache.commons.lang3.tuple.Pair;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Transaction;
import org.neo4j.logging.Log;

import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class DataVirtualizationCatalogHandler {

    private final GraphDatabaseService db;
    private final GraphDatabaseService systemDb;
    private final Log log;

    public DataVirtualizationCatalogHandler(GraphDatabaseService db, GraphDatabaseService systemDb, Log log) {
        this.db = db;
        this.systemDb = systemDb;
        this.log = log;
    }


    private  T withSystemDb(Function action) {
        try (Transaction tx = systemDb.beginTx()) {
            T result = action.apply(tx);
            tx.commit();
            return result;
        }
    }

    public VirtualizedResource add(VirtualizedResource vr) {
        return withSystemDb(tx -> {
            Node node = Util.mergeNode(tx, SystemLabels.DataVirtualizationCatalog, null,
                    Pair.of(SystemPropertyKeys.database.name(), db.databaseName()),
                    Pair.of(SystemPropertyKeys.name.name(), vr.name));
            node.setProperty(SystemPropertyKeys.data.name(), JsonUtil.writeValueAsString(vr));
            return vr;
        });
    }

    public VirtualizedResource get(String name) {
        return withSystemDb(tx -> {
            final List nodes = tx.findNodes(SystemLabels.DataVirtualizationCatalog,
                    SystemPropertyKeys.database.name(), db.databaseName(),
                    SystemPropertyKeys.name.name(), name)
                .stream()
                .collect(Collectors.toList());
            if (nodes.size() > 1) {
                throw new RuntimeException("More than 1 result");
            }
            try {
                Node node = nodes.get(0);
                Map map = JsonUtil.OBJECT_MAPPER.readValue(node.getProperty(SystemPropertyKeys.data.name()).toString(), Map.class);
                return VirtualizedResource.from(name, map);
            } catch (JsonProcessingException e) {
                throw new RuntimeException(e);
            }
        });
    }

    public Stream remove(String name) {
        withSystemDb(tx -> {
            tx.findNodes(SystemLabels.DataVirtualizationCatalog,
                    SystemPropertyKeys.database.name(), db.databaseName(),
                    SystemPropertyKeys.name.name(), name)
                .stream()
                .forEach(Node::delete);
            return null;
        });
        return list();
    }

    public Stream list() {
        return withSystemDb(tx ->
                tx.findNodes(SystemLabels.DataVirtualizationCatalog,
                    SystemPropertyKeys.database.name(), db.databaseName())
                .stream()
                .map(node -> {
                    try {
                        Map map = JsonUtil.OBJECT_MAPPER.readValue(node.getProperty(SystemPropertyKeys.data.name()).toString(), Map.class);
                        String name = node.getProperty(SystemPropertyKeys.name.name()).toString();
                        return VirtualizedResource.from(name, map);
                    } catch (JsonProcessingException e) {
                        throw new RuntimeException(e);
                    }
                })
                .collect(Collectors.toList())
                .stream());
    }
}