org.onebusaway.nyc.vehicle_tracking.impl.inference.JourneyPhaseSummaryLibrary.java Source code

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Here is the source code for org.onebusaway.nyc.vehicle_tracking.impl.inference.JourneyPhaseSummaryLibrary.java

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/**
 * Copyright (c) 2011 Metropolitan Transportation Authority
 *
 * 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.
 */
package org.onebusaway.nyc.vehicle_tracking.impl.inference;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.commons.lang.ObjectUtils;
import org.onebusaway.nyc.vehicle_tracking.impl.inference.state.BlockState;
import org.onebusaway.nyc.vehicle_tracking.impl.inference.state.JourneyPhaseSummary;
import org.onebusaway.nyc.vehicle_tracking.impl.inference.state.JourneyState;
import org.onebusaway.nyc.vehicle_tracking.impl.inference.state.VehicleState;
import org.onebusaway.nyc.vehicle_tracking.impl.inference.state.JourneyPhaseSummary.Builder;
import org.onebusaway.realtime.api.EVehiclePhase;
import org.onebusaway.transit_data_federation.services.blocks.BlockInstance;
import org.onebusaway.transit_data_federation.services.blocks.ScheduledBlockLocation;
import org.onebusaway.transit_data_federation.services.transit_graph.BlockConfigurationEntry;
import org.springframework.stereotype.Component;

@Component
public class JourneyPhaseSummaryLibrary {

    public List<JourneyPhaseSummary> extendSummaries(VehicleState parentState, BlockState blockState,
            JourneyState journeyState, Observation observation) {

        List<JourneyPhaseSummary> parentSummaries = Collections.emptyList();

        if (parentState != null)
            parentSummaries = parentState.getJourneySummaries();

        List<JourneyPhaseSummary> summaries = new ArrayList<JourneyPhaseSummary>(parentSummaries);

        if (summaries.isEmpty()) {
            JourneyPhaseSummary summary = createJourneySummary(blockState, journeyState, observation);
            summaries.add(summary);
        } else {
            JourneyPhaseSummary previous = summaries.get(summaries.size() - 1);
            JourneyPhaseSummary merged = createMergedJourneySummary(blockState, journeyState, observation,
                    previous);
            if (merged != null) {
                summaries.set(summaries.size() - 1, merged);
            } else {
                JourneyPhaseSummary summary = createJourneySummary(blockState, journeyState, observation);
                summaries.add(summary);
            }
        }

        return summaries;
    }

    public JourneyPhaseSummary getCurrentBlock(List<JourneyPhaseSummary> summaries) {

        if (summaries.isEmpty())
            return null;

        JourneyPhaseSummary summary = summaries.get(summaries.size() - 1);

        if (!EVehiclePhase.isActiveDuringBlock(summary.getPhase()))
            return null;

        return mergeBackwardsSummariesWithSameBlock(summaries, summaries.size() - 1);
    }

    public JourneyPhaseSummary getPreviousBlock(List<JourneyPhaseSummary> summaries,
            JourneyPhaseSummary currentBlock) {

        BlockInstance blockInstance = currentBlock.getBlockInstance();

        for (int i = summaries.size() - 1; i >= 0; i--) {
            JourneyPhaseSummary summary = summaries.get(i);
            if (summary.getBlockInstance() != null && !summary.getBlockInstance().equals(blockInstance))
                return mergeBackwardsSummariesWithSameBlock(summaries, i);
        }

        return null;
    }

    /****
     * Private Methods
     ****/

    private JourneyPhaseSummary createJourneySummary(BlockState blockState, JourneyState journeyState,
            Observation obs) {

        Builder b = JourneyPhaseSummary.builder();
        b.setTimeFrom(obs.getTime());
        b.setTimeTo(obs.getTime());
        b.setPhase(journeyState.getPhase());

        if (blockState != null) {
            BlockInstance blockInstance = blockState.getBlockInstance();
            b.setBlockInstance(blockInstance);

            double blockCompletionRatio = getBlockCompletionRatio(blockState);

            b.setBlockCompletionRatioFrom(blockCompletionRatio);
            b.setBlockCompletionRatioTo(blockCompletionRatio);
        }

        return b.create();
    }

    private JourneyPhaseSummary createMergedJourneySummary(BlockState blockState, JourneyState journeyState,
            Observation obs, JourneyPhaseSummary previous) {

        if (previous.getPhase() != journeyState.getPhase())
            return null;

        BlockInstance blockInstance = null;
        if (blockState != null)
            blockInstance = blockState.getBlockInstance();

        if (!ObjectUtils.equals(previous.getBlockInstance(), blockInstance))
            return null;

        Builder b = JourneyPhaseSummary.builder(previous);
        b.setTimeTo(obs.getTime());

        if (blockState != null) {
            double blockCompletionRatio = getBlockCompletionRatio(blockState);
            b.setBlockCompletionRatioTo(blockCompletionRatio);
        }

        return b.create();
    }

    private double getBlockCompletionRatio(BlockState blockState) {

        BlockInstance blockInstance = blockState.getBlockInstance();
        ScheduledBlockLocation blockLocation = blockState.getBlockLocation();
        BlockConfigurationEntry blockConfig = blockInstance.getBlock();

        return (double) blockLocation.getDistanceAlongBlock() / blockConfig.getTotalBlockDistance();
    }

    private JourneyPhaseSummary mergeBackwardsSummariesWithSameBlock(List<JourneyPhaseSummary> summaries,
            int indexFrom) {

        JourneyPhaseSummary summary = summaries.get(indexFrom);
        Builder b = JourneyPhaseSummary.builder(summary);

        for (int i = indexFrom - 1; i >= 0; i--) {
            JourneyPhaseSummary prev = summaries.get(i);
            if (!ObjectUtils.equals(summary.getBlockInstance(), prev.getBlockInstance()))
                break;
            b.setBlockCompletionRatioFrom(prev.getBlockCompletionRatioFrom());
            b.setTimeFrom(prev.getTimeFrom());
        }

        return b.create();
    }

}