//Dstl (c) Crown Copyright 2017
package uk.gov.dstl.baleen.annotators.cleaners;

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

import org.apache.uima.fit.util.JCasUtil;
import org.apache.uima.jcas.JCas;

import com.google.common.base.Strings;
import com.google.common.collect.ImmutableSet;

import uk.gov.dstl.baleen.annotators.cleaners.helpers.AbstractNestedEntities;
import uk.gov.dstl.baleen.core.pipelines.orderers.AnalysisEngineAction;
import uk.gov.dstl.baleen.types.semantic.Location;

/**
 * Remove locations which are contained within other locations, copying across GeoJSON information where applicable
 * 
 * <p>All location entities are looped through, and should a location be found to be entirely contained within another
 *  location it is removed.
 * The comparison is done purely on start and end positions, and ignores other information within the entity.
 * If two entities of the same type have the same start and end position, then the one with the lower confidence is
 * removed; and if both have the same confidence then the first entity in the annotation index is removed.
 * However, if both entities have GeoJSON information, and they aren't the same (string comparison currently - no geo fuzzyness),
 * then both are kept.</p>
 * <p>If the nested entity has GeoJSON information, but the enclosing entity doesn't,
 * then the GeoJSON information is copied across before it is removed.</p>
 * 
 * 
 */
public class RemoveNestedLocations extends AbstractNestedEntities<Location> {

	@Override
	protected Collection<List<Location>> compileEntities(JCas jCas) {
		return Collections.singletonList( new ArrayList<>(JCasUtil.select(jCas, Location.class)) );
	}

	@Override
	protected boolean shouldMerge(Location keep, Location remove) {
		//If they both have GeoJson and the GeoJson differs, then keep both
		if(!Strings.isNullOrEmpty(keep.getGeoJson()) && !Strings.isNullOrEmpty(remove.getGeoJson()) && !keep.getGeoJson().equals(remove.getGeoJson())) {
			return false;
		}
		
		// If keep doesn't have geojson, copy it!
		if(Strings.isNullOrEmpty(keep.getGeoJson()) && !Strings.isNullOrEmpty(remove.getGeoJson())){
			keep.setGeoJson(remove.getGeoJson());
		}
		
		return true;

	}
	
	@Override
	public AnalysisEngineAction getAction() {
		return new AnalysisEngineAction(ImmutableSet.of(Location.class), Collections.emptySet());
	}
}