/**
 * 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.storm.task;

import com.codahale.metrics.*;
import org.apache.storm.generated.GlobalStreamId;
import org.apache.storm.generated.Grouping;
import org.apache.storm.generated.StormTopology;
import org.apache.storm.hooks.ITaskHook;
import org.apache.storm.metric.api.IMetric;
import org.apache.storm.metric.api.IReducer;
import org.apache.storm.metric.api.ICombiner;
import org.apache.storm.metric.api.ReducedMetric;
import org.apache.storm.metric.api.CombinedMetric;
import org.apache.storm.metrics2.StormMetricRegistry;
import org.apache.storm.state.ISubscribedState;
import org.apache.storm.tuple.Fields;
import org.apache.storm.utils.Utils;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.commons.lang.NotImplementedException;
import org.json.simple.JSONValue;

/**
 * A `TopologyContext` is given to bolts and spouts in their `prepare()` and `open()`
 * methods, respectively. This object provides information about the component's
 * place within the topology, such as task ids, inputs and outputs, etc.
 *
 * The `TopologyContext` is also used to declare `ISubscribedState` objects to
 * synchronize state with StateSpouts this object is subscribed to.
 */
public class TopologyContext extends WorkerTopologyContext implements IMetricsContext {
    private Integer _taskId;
    private Map<String, Object> _taskData = new HashMap<>();
    private List<ITaskHook> _hooks = new ArrayList<>();
    private Map<String, Object> _executorData;
    private Map<Integer,Map<Integer, Map<String, IMetric>>> _registeredMetrics;
    private clojure.lang.Atom _openOrPrepareWasCalled;


    public TopologyContext(StormTopology topology, Map stormConf,
            Map<Integer, String> taskToComponent, Map<String, List<Integer>> componentToSortedTasks,
            Map<String, Map<String, Fields>> componentToStreamToFields,
            String stormId, String codeDir, String pidDir, Integer taskId,
            Integer workerPort, List<Integer> workerTasks, Map<String, Object> defaultResources,
            Map<String, Object> userResources, Map<String, Object> executorData, Map<Integer, Map<Integer, Map<String, IMetric>>> registeredMetrics,
            clojure.lang.Atom openOrPrepareWasCalled) {
        super(topology, stormConf, taskToComponent, componentToSortedTasks,
                componentToStreamToFields, stormId, codeDir, pidDir,
                workerPort, workerTasks, defaultResources, userResources);
        _taskId = taskId;
        _executorData = executorData;
        _registeredMetrics = registeredMetrics;
        _openOrPrepareWasCalled = openOrPrepareWasCalled;
    }

    /**
     * All state from all subscribed state spouts streams will be synced with
     * the provided object.
     *
     * It is recommended that your ISubscribedState object is kept as an instance
     * variable of this object. The recommended usage of this method is as follows:
     *
     * ```java
     * _myState = context.setAllSubscribedState(new MyState());
     * ```
     *
     * @param obj Provided ISubscribedState implementation
     * @return Returns the ISubscribedState object provided
     */
    public <T extends ISubscribedState> T setAllSubscribedState(T obj) {
        //check that only subscribed to one component/stream for statespout
        //setsubscribedstate appropriately
        throw new NotImplementedException();
    }


    /**
     * Synchronizes the default stream from the specified state spout component
     * id with the provided ISubscribedState object.
     *
     * The recommended usage of this method is as follows:
     *
     * ```java
     * _myState = context.setSubscribedState(componentId, new MyState());
     * ```
     *
     * @param componentId the id of the StateSpout component to subscribe to
     * @param obj Provided ISubscribedState implementation
     * @return Returns the ISubscribedState object provided
     */
    public <T extends ISubscribedState> T setSubscribedState(String componentId, T obj) {
        return setSubscribedState(componentId, Utils.DEFAULT_STREAM_ID, obj);
    }

    /**
     * Synchronizes the specified stream from the specified state spout component
     * id with the provided ISubscribedState object.
     *
     * The recommended usage of this method is as follows:
     *
     * ```java
     * _myState = context.setSubscribedState(componentId, streamId, new MyState());
     * ```
     *
     * @param componentId the id of the StateSpout component to subscribe to
     * @param streamId the stream to subscribe to
     * @param obj Provided ISubscribedState implementation
     * @return Returns the ISubscribedState object provided
     */
    public <T extends ISubscribedState> T setSubscribedState(String componentId, String streamId, T obj) {
        throw new NotImplementedException();
    }

    /**
     * Gets the task id of this task.
     *
     * @return the task id
     */
    public int getThisTaskId() {
        return _taskId;
    }

    /**
     * @return the component id for this task. The component id maps
     * to a component id specified for a Spout or Bolt in the topology definition.
     */
    public String getThisComponentId() {
        return getComponentId(_taskId);
    }

	/**
	 * Gets the declared output fields for the specified stream id for the
	 * component this task is a part of.
	 */
	public Fields getThisOutputFields(String streamId) {
		return getComponentOutputFields(getThisComponentId(), streamId);
	}

	/**
	 * Gets the declared output fields for all streams for the
	 * component this task is a part of.
	 */
	public Map<String, List<String>> getThisOutputFieldsForStreams() {
		Map<String, List<String>> streamToFields = new HashMap<>();
		for (String stream : this.getThisStreams()) {
			streamToFields.put(stream, this.getThisOutputFields(stream).toList());
		}
		return streamToFields;
	}

    /**
     * Gets the set of streams declared for the component of this task.
     */
    public Set<String> getThisStreams() {
        return getComponentStreams(getThisComponentId());
    }

    /**
     * Gets the index of this task id in getComponentTasks(getThisComponentId()).
     * An example use case for this method is determining which task
     * accesses which resource in a distributed resource to ensure an even distribution.
     */
    public int getThisTaskIndex() {
        List<Integer> tasks = new ArrayList<>(getComponentTasks(getThisComponentId()));
        Collections.sort(tasks);
        for(int i=0; i<tasks.size(); i++) {
            if(tasks.get(i) == getThisTaskId()) {
                return i;
            }
        }
        throw new RuntimeException("Fatal: could not find this task id in this component");
    }

    /**
     * Gets the declared input fields for this component.
     *
     * @return A map from sources to streams to fields.
     */
    public Map<String, Map<String, List<String>>> getThisInputFields() {
    	Map<String, Map<String, List<String>>> outputMap = new HashMap<>();
        for (Map.Entry<GlobalStreamId, Grouping> entry : this.getThisSources().entrySet()) {
        	String componentId = entry.getKey().get_componentId();
        	Set<String> streams = getComponentStreams(componentId);
        	for (String stream : streams) {
        		Map<String, List<String>> streamFieldMap = outputMap.get(componentId);
        		if (streamFieldMap == null) {
        			streamFieldMap = new HashMap<>();
        			outputMap.put(componentId, streamFieldMap);
        		}
        		streamFieldMap.put(stream, getComponentOutputFields(componentId, stream).toList());
        	}
        }
        return outputMap;
    }

    /**
     * Gets the declared inputs to this component.
     *
     * @return A map from subscribed component/stream to the grouping subscribed with.
     */
    public Map<GlobalStreamId, Grouping> getThisSources() {
        return getSources(getThisComponentId());
    }

    /**
     * Gets information about who is consuming the outputs of this component, and how.
     *
     * @return Map from stream id to component id to the Grouping used.
     */
    public Map<String, Map<String, Grouping>> getThisTargets() {
        return getTargets(getThisComponentId());
    }

    public void setTaskData(String name, Object data) {
        _taskData.put(name, data);
    }

    public Object getTaskData(String name) {
        return _taskData.get(name);
    }

    public void setExecutorData(String name, Object data) {
        _executorData.put(name, data);
    }

    public Object getExecutorData(String name) {
        return _executorData.get(name);
    }

    public void addTaskHook(ITaskHook hook) {
        hook.prepare(_stormConf, this);
        _hooks.add(hook);
    }

    public Collection<ITaskHook> getHooks() {
        return _hooks;
    }

	private static Map<String, Object> groupingToJSONableMap(Grouping grouping) {
		Map<String, Object> groupingMap = new HashMap<>();
		groupingMap.put("type", grouping.getSetField().toString());
		if (grouping.is_set_fields()) {
			groupingMap.put("fields", grouping.get_fields());
		}
		return groupingMap;
	}
    
    @Override
    public String toJSONString() {
        Map<String, Object> obj = new HashMap<>();
        obj.put("task->component", this.getTaskToComponent());
        obj.put("taskid", this.getThisTaskId());
        obj.put("componentid", this.getThisComponentId());
        List<String> streamList = new ArrayList<>();
        streamList.addAll(this.getThisStreams());
        obj.put("streams", streamList);
        obj.put("stream->outputfields", this.getThisOutputFieldsForStreams());
        // Convert targets to a JSON serializable format
        Map<String, Map<String, Object>> stringTargets = new HashMap<>();
        for (Map.Entry<String, Map<String, Grouping>> entry : this.getThisTargets().entrySet()) {
        	Map<String, Object> stringTargetMap = new HashMap<>();
        	for (Map.Entry<String, Grouping> innerEntry : entry.getValue().entrySet()) {
        		stringTargetMap.put(innerEntry.getKey(), groupingToJSONableMap(innerEntry.getValue()));
        	}
        	stringTargets.put(entry.getKey(), stringTargetMap);
        }
        obj.put("stream->target->grouping", stringTargets);
        // Convert sources to a JSON serializable format
        Map<String, Map<String, Object>> stringSources = new HashMap<>();
        for (Map.Entry<GlobalStreamId, Grouping> entry : this.getThisSources().entrySet()) {
        	GlobalStreamId gid = entry.getKey();
        	Map<String, Object> stringSourceMap = stringSources.get(gid.get_componentId());
        	if (stringSourceMap == null) {
        		stringSourceMap = new HashMap<>();
        		stringSources.put(gid.get_componentId(), stringSourceMap);
        	}
        	stringSourceMap.put(gid.get_streamId(), groupingToJSONableMap(entry.getValue()));        	
        }
        obj.put("source->stream->grouping", stringSources);
        obj.put("source->stream->fields", this.getThisInputFields());
        return JSONValue.toJSONString(obj);
    }

    /*
     * Register a IMetric instance.
     *
     * Storm will then call `getValueAndReset()` on the metric every `timeBucketSizeInSecs`
     * and the returned value is sent to all metrics consumers.
     *
     * You must call this during `IBolt.prepare()` or `ISpout.open()`.
     * @return The IMetric argument unchanged.
     */
    @Deprecated
    public <T extends IMetric> T registerMetric(String name, T metric, int timeBucketSizeInSecs) {
        if((Boolean) _openOrPrepareWasCalled.deref()) {
            throw new RuntimeException("TopologyContext.registerMetric can only be called from within overridden " +
                                       "IBolt::prepare() or ISpout::open() method.");
        }

        if (metric == null) {
            throw new IllegalArgumentException("Cannot register a null metric");
        }

        if (timeBucketSizeInSecs <= 0) {
            throw new IllegalArgumentException("TopologyContext.registerMetric can only be called with timeBucketSizeInSecs " +
                                               "greater than or equal to 1 second.");
        }

        if (getRegisteredMetricByName(name) != null) {
            throw new RuntimeException("The same metric name `" + name + "` was registered twice." );
        }

        Map<Integer, Map<Integer, Map<String, IMetric>>> m1 = _registeredMetrics;
        if(!m1.containsKey(timeBucketSizeInSecs)) {
            m1.put(timeBucketSizeInSecs, new HashMap<Integer, Map<String, IMetric>>());
        }

        Map<Integer, Map<String, IMetric>> m2 = m1.get(timeBucketSizeInSecs);
        if(!m2.containsKey(_taskId)) {
            m2.put(_taskId, new HashMap<String, IMetric>());
        }

        Map<String, IMetric> m3 = m2.get(_taskId);
        if(m3.containsKey(name)) {
            throw new RuntimeException("The same metric name `" + name + "` was registered twice." );
        } else {
            m3.put(name, metric);
        }

        return metric;
    }

    /**
     * Get component's metric from registered metrics by name.
     * Notice: Normally, one component can only register one metric name once.
     *         But now registerMetric has a bug(https://issues.apache.org/jira/browse/STORM-254)
     *         cause the same metric name can register twice.
     *         So we just return the first metric we meet.
     */
    @Deprecated
    public IMetric getRegisteredMetricByName(String name) {
        IMetric metric = null;

        for (Map<Integer, Map<String, IMetric>> taskIdToNameToMetric: _registeredMetrics.values()) {
            Map<String, IMetric> nameToMetric = taskIdToNameToMetric.get(_taskId);
            if (nameToMetric != null) {
                metric = nameToMetric.get(name);
                if (metric != null) {
                    //we just return the first metric we meet
                    break;
                }
            }
        }

        return metric;
    }

    /*
     * Convenience method for registering ReducedMetric.
     */
    @Deprecated
    public ReducedMetric registerMetric(String name, IReducer reducer, int timeBucketSizeInSecs) {
        return registerMetric(name, new ReducedMetric(reducer), timeBucketSizeInSecs);
    }
    /*
     * Convenience method for registering CombinedMetric.
     */
    @Deprecated
    public CombinedMetric registerMetric(String name, ICombiner combiner, int timeBucketSizeInSecs) {
        return registerMetric(name, new CombinedMetric(combiner), timeBucketSizeInSecs);
    }

    public Timer registerTimer(String name){
        return StormMetricRegistry.registry().timer(metricName(name));
    }

    public Histogram registerHistogram(String name){
        return StormMetricRegistry.registry().histogram(metricName(name));
    }

    public Meter registerMeter(String name){
        return StormMetricRegistry.registry().meter(metricName(name));
    }

    public Counter registerCounter(String name){
        return StormMetricRegistry.registry().counter(metricName(name));
    }

    public Gauge registerGauge(String name, Gauge gauge){
        return StormMetricRegistry.registry().register(metricName(name), gauge);
    }

    private String metricName(String name){
        return StormMetricRegistry.metricName(name, this);
    }
}
