PointOfInterestServlet.java

/*
 *  Copyright (C) 2010-2012 Stichting Akvo (Akvo Foundation)
 *
 *  This file is part of Akvo FLOW.
 *
 *  Akvo FLOW is free software: you can redistribute it and modify it under the terms of
 *  the GNU Affero General Public License (AGPL) as published by the Free Software Foundation,
 *  either version 3 of the License or any later version.
 *
 *  Akvo FLOW is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *  See the GNU Affero General Public License included below for more details.
 *
 *  The full license text can also be seen at <http://www.gnu.org/licenses/agpl.html>.
 */

package org.waterforpeople.mapping.app.web;

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

import javax.servlet.http.HttpServletRequest;

import org.json.JSONArray;
import org.json.JSONObject;
import org.waterforpeople.mapping.app.gwt.client.location.PointOfInterestDto;
import org.waterforpeople.mapping.app.web.dto.PointOfInterestRequest;
import org.waterforpeople.mapping.app.web.dto.PointOfInterestResponse;
import org.waterforpeople.mapping.dao.AccessPointDao;
import org.waterforpeople.mapping.domain.AccessPoint;

import com.gallatinsystems.framework.rest.AbstractRestApiServlet;
import com.gallatinsystems.framework.rest.RestRequest;
import com.gallatinsystems.framework.rest.RestResponse;
import com.gallatinsystems.gis.location.GeoLocationService;
import com.gallatinsystems.gis.location.GeoLocationServiceGeonamesImpl;

/**
 * JSON service for returning the list of points near a specific lat/lon point. Points of interest
 * can be access points, tasks or other domains that are locationAware.
 * 
 * @author Christopher Fagiani
 */
public class PointOfInterestServlet extends AbstractRestApiServlet {

    private static final long serialVersionUID = 8748650927754433019L;
    private static final int MAX_DISTANCE_METERS = 10000;
    private AccessPointDao accessPointDao;
    private GeoLocationService geoService;

    public PointOfInterestServlet() {
        setMode(JSON_MODE);
        accessPointDao = new AccessPointDao();
        geoService = new GeoLocationServiceGeonamesImpl();
    }

    @Override
    protected RestRequest convertRequest() throws Exception {
        HttpServletRequest req = getRequest();
        RestRequest restRequest = new PointOfInterestRequest();
        restRequest.populateFromHttpRequest(req);
        return restRequest;
    }

    /**
     * calls the accessPointDao to get the list of access points near the point passed in via the
     * request
     */
    @Override
    protected RestResponse handleRequest(RestRequest req) throws Exception {
        PointOfInterestRequest piReq = (PointOfInterestRequest) req;
        List<AccessPoint> results = accessPointDao.listNearbyAccessPoints(piReq
                .getLat(), piReq.getLon(), piReq.getCountry() != null ? piReq
                .getCountry() : geoService.getCountryCodeForPoint(piReq
                .getLat().toString(), piReq.getLon().toString()),
                MAX_DISTANCE_METERS, piReq.getCursor());

        return convertToResponse(results, AccessPointDao.getCursor(results));
    }

    /**
     * converts the domain objects to dtos and then installs them in an AccessPointResponse object
     */
    protected PointOfInterestResponse convertToResponse(
            List<AccessPoint> apList, String cursor) {
        PointOfInterestResponse resp = new PointOfInterestResponse();
        if (apList != null) {
            List<PointOfInterestDto> dtoList = new ArrayList<PointOfInterestDto>();
            for (AccessPoint ap : apList) {
                PointOfInterestDto dto = new PointOfInterestDto();
                dto.setId(ap.getKey().getId());
                dto.setName(ap.getCommunityCode());
                dto.setType(ap.getPointType() != null ? ap.getPointType()
                        .toString() : "AccessPoint");
                dto.setLatitude(ap.getLatitude());
                dto.setLongitude(ap.getLongitude());
                dto.setCountry(ap.getCountryCode());
                dto.addProperty("status", ap.getPointStatus() != null ? ap
                        .getPointStatus().toString() : "unknown");
                dtoList.add(dto);
            }
            resp.setPointsOfInterest(dtoList);
        }
        resp.setCursor(cursor);
        return resp;
    }

    /**
     * writes response as a JSON string
     */
    @Override
    protected void writeOkResponse(RestResponse resp) throws Exception {
        getResponse().setStatus(200);
        PointOfInterestResponse piResp = (PointOfInterestResponse) resp;
        JSONObject result = new JSONObject(piResp);
        JSONArray arr = result.getJSONArray("pointsOfInterest");
        if (arr != null) {
            for (int i = 0; i < arr.length(); i++) {
                ((JSONObject) arr.get(i)).put("propertyValues", piResp
                        .getPointsOfInterest().get(i).getPropertyValues());

                ((JSONObject) arr.get(i)).put("propertyNames", piResp
                        .getPointsOfInterest().get(i).getPropertyNames());
            }
        }
        getResponse().getWriter().println(result.toString());
    }
}