/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

package org.apache.falcon.metadata;

import com.tinkerpop.blueprints.Graph;
import com.tinkerpop.blueprints.Vertex;
import org.apache.falcon.FalconException;
import org.apache.falcon.entity.CatalogStorage;
import org.apache.falcon.entity.FeedHelper;
import org.apache.falcon.entity.Storage;
import org.apache.falcon.entity.common.FeedDataPath;
import org.apache.falcon.entity.store.ConfigurationStore;
import org.apache.falcon.entity.v0.EntityType;
import org.apache.falcon.entity.v0.SchemaHelper;
import org.apache.falcon.entity.v0.cluster.Cluster;
import org.apache.falcon.entity.v0.feed.Feed;
import org.apache.falcon.entity.v0.feed.LocationType;
import org.apache.falcon.entity.v0.process.Process;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.falcon.workflow.WorkflowExecutionArgs;
import org.apache.falcon.workflow.WorkflowExecutionContext;

import java.net.URISyntaxException;

/**
 * Instance Metadata relationship mapping helper.
 */
public class InstanceRelationshipGraphBuilder extends RelationshipGraphBuilder {

    private static final Logger LOG = LoggerFactory.getLogger(InstanceRelationshipGraphBuilder.class);

    private static final String FEED_INSTANCE_FORMAT = "yyyyMMddHHmm"; // computed

    // process workflow properties from message
    private static final WorkflowExecutionArgs[] INSTANCE_WORKFLOW_PROPERTIES = {
        WorkflowExecutionArgs.USER_WORKFLOW_NAME,
        WorkflowExecutionArgs.USER_WORKFLOW_ENGINE,
        WorkflowExecutionArgs.WORKFLOW_ID,
        WorkflowExecutionArgs.RUN_ID,
        WorkflowExecutionArgs.STATUS,
        WorkflowExecutionArgs.WF_ENGINE_URL,
        WorkflowExecutionArgs.USER_SUBFLOW_ID,
    };


    public InstanceRelationshipGraphBuilder(Graph graph, boolean preserveHistory) {
        super(graph, preserveHistory);
    }

    public Vertex addProcessInstance(WorkflowExecutionContext context) throws FalconException {
        String processInstanceName = getProcessInstanceName(context);
        LOG.info("Adding process instance: " + processInstanceName);

        Vertex processInstance = addVertex(processInstanceName,
                RelationshipType.PROCESS_INSTANCE, context.getTimeStampAsISO8601());
        addWorkflowInstanceProperties(processInstance, context);

        addInstanceToEntity(processInstance, context.getEntityName(),
                RelationshipType.PROCESS_ENTITY, RelationshipLabel.INSTANCE_ENTITY_EDGE);
        addInstanceToEntity(processInstance, context.getClusterName(),
                RelationshipType.CLUSTER_ENTITY, RelationshipLabel.PROCESS_CLUSTER_EDGE);
        addInstanceToEntity(processInstance, context.getWorkflowUser(),
                RelationshipType.USER, RelationshipLabel.USER);

        if (isPreserveHistory()) {
            Process process = ConfigurationStore.get().get(EntityType.PROCESS, context.getEntityName());
            addDataClassification(process.getTags(), processInstance);
            addPipelines(process.getPipelines(), processInstance);
        }

        return processInstance;
    }

    public String getProcessInstanceName(WorkflowExecutionContext context) {
        return context.getEntityName() + "/" + context.getNominalTimeAsISO8601();
    }

    public void addWorkflowInstanceProperties(Vertex processInstance,
                                              WorkflowExecutionContext context) {
        for (WorkflowExecutionArgs instanceWorkflowProperty : INSTANCE_WORKFLOW_PROPERTIES) {
            addProperty(processInstance, context, instanceWorkflowProperty);
        }

        processInstance.setProperty(RelationshipProperty.VERSION.getName(),
                context.getUserWorkflowVersion());
    }

    private void addProperty(Vertex vertex, WorkflowExecutionContext context,
                             WorkflowExecutionArgs optionName) {
        String value = context.getValue(optionName);
        if (value == null || value.length() == 0) {
            return;
        }

        vertex.setProperty(optionName.getName(), value);
    }

    public void addInstanceToEntity(Vertex instanceVertex, String entityName,
                                    RelationshipType entityType, RelationshipLabel edgeLabel) {
        Vertex entityVertex = findVertex(entityName, entityType);
        LOG.info("Vertex exists? name={}, type={}, v={}", entityName, entityType, entityVertex);
        if (entityVertex == null) {
            // todo - throw new IllegalStateException(entityType + " entity vertex must exist " + entityName);
            LOG.error("Illegal State: {} vertex must exist for {}", entityType, entityName);
            return;
        }

        addEdge(instanceVertex, entityVertex, edgeLabel.getName());
    }

    public void addOutputFeedInstances(WorkflowExecutionContext context,
                                       Vertex processInstance) throws FalconException {
        String outputFeedNamesArg = context.getOutputFeedNames();
        if ("NONE".equals(outputFeedNamesArg)) {
            return; // there are no output feeds for this process
        }

        String[] outputFeedNames = context.getOutputFeedNamesList();
        String[] outputFeedInstancePaths = context.getOutputFeedInstancePathsList();

        for (int index = 0; index < outputFeedNames.length; index++) {
            String feedName = outputFeedNames[index];
            String feedInstanceDataPath = outputFeedInstancePaths[index];
            addFeedInstance(processInstance, RelationshipLabel.PROCESS_FEED_EDGE,
                    context, feedName, feedInstanceDataPath);
        }
    }

    public void addInputFeedInstances(WorkflowExecutionContext context,
                                      Vertex processInstance) throws FalconException {
        String inputFeedNamesArg = context.getInputFeedNames();
        if ("NONE".equals(inputFeedNamesArg)) {
            return; // there are no input feeds for this process
        }

        String[] inputFeedNames = context.getInputFeedNamesList();
        String[] inputFeedInstancePaths = context.getInputFeedInstancePathsList();

        for (int index = 0; index < inputFeedNames.length; index++) {
            String inputFeedName = inputFeedNames[index];
            String inputFeedInstancePath = inputFeedInstancePaths[index];
            // Multiple instance paths for a given feed is separated by ","
            String[] feedInstancePaths = inputFeedInstancePath.split(",");

            for (String feedInstanceDataPath : feedInstancePaths) {
                addFeedInstance(processInstance, RelationshipLabel.FEED_PROCESS_EDGE,
                        context, inputFeedName, feedInstanceDataPath);
            }
        }
    }

    private void addFeedInstance(Vertex processInstance, RelationshipLabel edgeLabel,
                                 WorkflowExecutionContext context, String feedName,
                                 String feedInstanceDataPath) throws FalconException {
        String clusterName = context.getClusterName();
        LOG.info("Computing feed instance for : name=" + feedName + ", path= "
                + feedInstanceDataPath + ", in cluster: " + clusterName);
        String feedInstanceName = getFeedInstanceName(feedName, clusterName, feedInstanceDataPath);
        LOG.info("Adding feed instance: " + feedInstanceName);
        Vertex feedInstance = addVertex(feedInstanceName, RelationshipType.FEED_INSTANCE,
                context.getTimeStampAsISO8601());

        addProcessFeedEdge(processInstance, feedInstance, edgeLabel);

        addInstanceToEntity(feedInstance, feedName,
                RelationshipType.FEED_ENTITY, RelationshipLabel.INSTANCE_ENTITY_EDGE);
        addInstanceToEntity(feedInstance, clusterName,
                RelationshipType.CLUSTER_ENTITY, RelationshipLabel.FEED_CLUSTER_EDGE);
        addInstanceToEntity(feedInstance, context.getWorkflowUser(),
                RelationshipType.USER, RelationshipLabel.USER);

        if (isPreserveHistory()) {
            Feed feed = ConfigurationStore.get().get(EntityType.FEED, feedName);
            addDataClassification(feed.getTags(), feedInstance);
            addGroups(feed.getGroups(), feedInstance);
        }
    }

    public String getFeedInstanceName(String feedName, String clusterName,
                                      String feedInstancePath) throws FalconException {
        try {
            Feed feed = ConfigurationStore.get().get(EntityType.FEED, feedName);
            Cluster cluster = ConfigurationStore.get().get(EntityType.CLUSTER, clusterName);

            Storage.TYPE storageType = FeedHelper.getStorageType(feed, cluster);
            return storageType == Storage.TYPE.TABLE
                    ? getTableFeedInstanceName(feed, feedInstancePath, storageType)
                    : getFileSystemFeedInstanceName(feedInstancePath, feed, cluster);

        } catch (URISyntaxException e) {
            throw new FalconException(e);
        }
    }

    private String getTableFeedInstanceName(Feed feed, String feedInstancePath,
                                            Storage.TYPE storageType) throws URISyntaxException {
        CatalogStorage instanceStorage = (CatalogStorage) FeedHelper.createStorage(
                storageType.name(), feedInstancePath);
        return feed.getName() + "/" + instanceStorage.toPartitionAsPath();
    }

    private String getFileSystemFeedInstanceName(String feedInstancePath, Feed feed,
                                                 Cluster cluster) throws FalconException {
        Storage rawStorage = FeedHelper.createStorage(cluster, feed);
        String feedPathTemplate = rawStorage.getUriTemplate(LocationType.DATA);
        String instance = feedInstancePath;

        String[] elements = FeedDataPath.PATTERN.split(feedPathTemplate);
        for (String element : elements) {
            instance = instance.replaceFirst(element, "");
        }

        return feed.getName() + "/"
                + SchemaHelper.formatDateUTCToISO8601(instance, FEED_INSTANCE_FORMAT);
    }
}