package org.activityinfo.server.database.hibernate.dao;

import com.google.common.collect.Lists;
import com.sun.jersey.api.core.InjectParam;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Polygon;
import org.activityinfo.server.database.hibernate.entity.AdminEntity;

import javax.persistence.EntityManager;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import java.util.List;

/**
 * Some how alot of our geometry has been corrupted, and stored
 * as Geometry Collections instead of Polygon / Multipolygon.
 * Fix now.
 */
@Path("/tasks/fixGeometry")
public class FixGeometryTask {

    private GeometryFactory gf = new GeometryFactory();

    @GET @Produces(MediaType.TEXT_PLAIN)
    public String correctGeometry(@InjectParam EntityManager em) {

        while (true) {

            em.getTransaction().begin();

            List<AdminEntity> entities = em.createNativeQuery(
                    "select * from adminentity where GeometryType(Geometry) = 'GEOMETRYCOLLECTION' limit 50",
                    AdminEntity.class).getResultList();

            for (AdminEntity entity : entities) {
                entity.setGeometry(fixGeometry((GeometryCollection) entity.getGeometry()));
            }

            em.getTransaction().commit();

            if (entities.isEmpty()) {
                break;
            }
        }

        return "OK";
    }

    private Geometry fixGeometry(GeometryCollection collection) {

        List<Polygon> polygons = Lists.newArrayList();
        findPolygons(collection, polygons);

        if (polygons.size() == 0) {
            return null;
        } else if (polygons.size() == 1) {
            return polygons.get(0);
        } else {
            return gf.createMultiPolygon(polygons.toArray(new Polygon[polygons.size()]));
        }
    }

    private void findPolygons(GeometryCollection collection, List<Polygon> polygons) {

        for (int i = 0; i != collection.getNumGeometries(); ++i) {
            Geometry geometry = collection.getGeometryN(i);
            if (geometry instanceof Polygon) {
                polygons.add((Polygon) geometry);
            } else if (geometry instanceof GeometryCollection) {
                findPolygons((GeometryCollection) geometry, polygons);
            }
        }
    }

}