package cgeo.geocaching.sorting;

import cgeo.geocaching.cgCache;
import cgeo.geocaching.geopoint.Geopoint;

import java.util.List;

/**
 * sorts caches by distance to given position
 *
 */
public class DistanceComparator extends AbstractCacheComparator {

    public DistanceComparator(final Geopoint coords, List<cgCache> list) {
        // calculate all distances to avoid duplicate calculations during sorting
        for (cgCache cache : list) {
            if (cache.getCoords() != null) {
                cache.setDistance(coords.distanceTo(cache.getCoords()));
            }
            else {
                cache.setDistance(null);
            }
        }
    }

    @Override
    protected boolean canCompare(cgCache cache1, cgCache cache2) {
        return true;
    }

    @Override
    protected int compareCaches(final cgCache cache1, final cgCache cache2) {
        if (cache1.getCoords() == null && cache2.getCoords() == null) {
            return 0;
        }
        if (cache1.getCoords() == null) {
            return 1;
        }
        if (cache2.getCoords() == null) {
            return -1;
        }
        return Float.compare(cache1.getDistance(), cache2.getDistance());
    }

}