/**
 * ============LICENSE_START=======================================================
 * org.onap.aai
 * ================================================================================
 * Copyright © 2017-2018 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ============LICENSE_END=========================================================
 */
package org.onap.aai.dbgen;


import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;
import com.google.common.collect.Multimap;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import org.apache.tinkerpop.gremlin.structure.Vertex;
import org.janusgraph.core.Cardinality;
import org.janusgraph.core.Multiplicity;
import org.janusgraph.core.PropertyKey;
import org.janusgraph.core.schema.JanusGraphManagement;
import org.onap.aai.db.props.AAIProperties;
import org.onap.aai.introspection.Introspector;
import org.onap.aai.introspection.Loader;
import org.onap.aai.introspection.LoaderFactory;
import org.onap.aai.introspection.ModelType;
import org.onap.aai.logging.LogFormatTools;
import org.onap.aai.schema.enums.PropertyMetadata;
import org.onap.aai.serialization.db.EdgeRule;
import org.onap.aai.serialization.db.EdgeRules;
import org.onap.aai.util.AAIConfig;


public class SchemaGenerator {

    private static final EELFLogger LOGGER = EELFManager.getInstance().getLogger(SchemaGenerator.class);
    private static boolean addDefaultCR = true;

    private SchemaGenerator() {

    }

    /**
     * Load schema into JanusGraph.
     *  @param graphMgmt the graph mgmt
     * @param addDefaultCloudRegion the add default cloud region
     */
    public static void loadSchemaIntoJanusGraph(final JanusGraphManagement graphMgmt,
        boolean addDefaultCloudRegion) {
        addDefaultCR = addDefaultCloudRegion;
        loadSchemaIntoJanusGraph(graphMgmt);
    }

    /**
     * Load schema into JanusGraph.
     *
     * @param graphMgmt the graph mgmt
     */
    public static void loadSchemaIntoJanusGraph(final JanusGraphManagement graphMgmt) {

        try {
            AAIConfig.init();
        } catch (Exception ex) {
            LOGGER.error(" ERROR - Could not run AAIConfig.init(). " + LogFormatTools.getStackTop(ex));
            System.exit(1);
        }

        // NOTE - JanusGraph 0.5.3 doesn't keep a list of legal node Labels.
        //   They are only used when a vertex is actually being created.  JanusGraph 1.1 will keep track (we think).

        // Use EdgeRules to make sure edgeLabels are defined in the db.  NOTE: the multiplicty used here is
        // always "MULTI".  This is not the same as our internal "Many2Many", "One2One", "One2Many" or "Many2One"
        // We use the same edge-label for edges between many different types of nodes and our internal
        // multiplicty definitions depends on which two types of nodes are being connected.

        Multimap<String, EdgeRule> edges = null;
        Set<String> labels = new HashSet<>();

        edges = EdgeRules.getInstance().getAllRules();
        for (EdgeRule rule : edges.values()) {
            labels.add(rule.getLabel());
        }

        for (String label : labels) {
            addEdgeLabel(graphMgmt, label);
        }

        Loader loader = LoaderFactory.createLoaderForVersion(ModelType.MOXY, AAIProperties.LATEST);
        Map<String, Introspector> objs = loader.getAllObjects();
        Map<String, PropertyKey> seenProps = new HashMap<>();

        for (Introspector obj : objs.values()) {
            for (String propertyName : obj.getProperties()) {
                String dbPropertyName = propertyName;
                Optional<String> alias = obj.getPropertyMetadata(propertyName, PropertyMetadata.DB_ALIAS);
                if (alias.isPresent()) {
                    dbPropertyName = alias.get();
                }
                if (graphMgmt.containsRelationType(propertyName)) {
                    handleExistingProperty(propertyName);
                } else {
                    handleUnknownProperty(graphMgmt, seenProps, obj, propertyName, dbPropertyName);
                }
            }
        }

        String imsg = "-- About to call graphMgmt commit";
        LOGGER.info(imsg);

        graphMgmt.commit();
    }// End of loadSchemaIntoJanusGraph()

    private static void handleUnknownProperty(JanusGraphManagement graphMgmt, Map<String, PropertyKey> seenProps,
        Introspector obj, String propertyName, String dbPropertyName) {

        Class<?> type = obj.getClass(propertyName);
        Cardinality cardinality = Cardinality.SINGLE;
        boolean process = false;
        if (obj.isListType(propertyName) && obj.isSimpleGenericType(propertyName)) {
            cardinality = Cardinality.SET;
            type = obj.getGenericTypeClass(propertyName);
            process = true;
        } else if (obj.isSimpleType(propertyName)) {
            process = true;
        }

        if (process) {
            String imsg =
                "Creating PropertyKey: [" + dbPropertyName + "], [" + type.getSimpleName() + "], [" + cardinality + "]";
            LOGGER.info(imsg);
            PropertyKey propK;
            propK = getPropertyKey(graphMgmt, seenProps, dbPropertyName, type, cardinality);
            buildIndex(graphMgmt, obj, propertyName, dbPropertyName, propK);
        }
    }

    private static void buildIndex(JanusGraphManagement graphMgmt, Introspector obj, String propertyName,
        String dbPropertyName, PropertyKey propK) {
        String imsg;
        if (graphMgmt.containsGraphIndex(dbPropertyName)) {
            String dmsg = " Index  [" + dbPropertyName + "] already existed in the DB. ";
            LOGGER.debug(dmsg);
        } else {
            if (obj.getIndexedProperties().contains(propertyName)) {
                if (obj.getUniqueProperties().contains(propertyName)) {
                    imsg = "Add Unique index for PropertyKey: [" + dbPropertyName + "]";
                    LOGGER.info(imsg);
                    graphMgmt.buildIndex(dbPropertyName, Vertex.class).addKey(propK).unique().buildCompositeIndex();
                } else {
                    imsg = "Add index for PropertyKey: [" + dbPropertyName + "]";
                    LOGGER.info(imsg);
                    graphMgmt.buildIndex(dbPropertyName, Vertex.class).addKey(propK).buildCompositeIndex();
                }
            } else {
                imsg = "No index added for PropertyKey: [" + dbPropertyName + "]";
                LOGGER.info(imsg);
            }
        }
    }

    private static PropertyKey getPropertyKey(JanusGraphManagement graphMgmt, Map<String, PropertyKey> seenProps,
        String dbPropertyName, Class<?> type, Cardinality cardinality) {
        PropertyKey propK;
        if (!seenProps.containsKey(dbPropertyName)) {
            propK = graphMgmt.makePropertyKey(dbPropertyName).dataType(type).cardinality(cardinality).make();
            seenProps.put(dbPropertyName, propK);
        } else {
            propK = seenProps.get(dbPropertyName);
        }
        return propK;
    }

    private static void handleExistingProperty(String propertyName) {
        String dmsg = " PropertyKey  [" + propertyName + "] already existed in the DB. ";
        LOGGER.debug(dmsg);
    }

    private static void addEdgeLabel(JanusGraphManagement graphMgmt, String label) {
        if (graphMgmt.containsRelationType(label)) {
            String dmsg = " EdgeLabel  [" + label + "] already existed. ";
            LOGGER.debug(dmsg);
        } else {
            String dmsg = "Making EdgeLabel: [" + label + "]";
            LOGGER.debug(dmsg);
            graphMgmt.makeEdgeLabel(label).multiplicity(Multiplicity.valueOf("MULTI")).make();
        }
    }

}