/**
 * Implements the "search" uri of the Annotator API.
 */
package de.mpiwg.itgroup.annotations.restlet;

/*
 * #%L
 * AnnotationManager
 * %%
 * Copyright (C) 2012 - 2014 MPIWG Berlin
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as 
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 * 
 * This program 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 General Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/lgpl-3.0.html>.
 * #L%
 */

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

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.restlet.data.Form;
import org.restlet.data.Status;
import org.restlet.ext.json.JsonRepresentation;
import org.restlet.representation.Representation;
import org.restlet.resource.Get;

import de.mpiwg.itgroup.annotations.Annotation;
import de.mpiwg.itgroup.annotations.Person;
import de.mpiwg.itgroup.annotations.neo4j.AnnotationStore;
import de.mpiwg.itgroup.annotations.restlet.utils.JSONObjectComparator;

/**
 * Implements the "search" uri of the Annotator API. see
 * <https://github.com/okfn/annotator/wiki/Storage>
 * 
 * @author casties
 * 
 */
public class AnnotatorSearch extends AnnotatorResourceImpl {

    protected String getAllowedMethodsForHeader() {
        return "OPTIONS,GET";
    }

    /**
     * result for JSON content-type. optional search parameters: uri, user, limit,
     * offset, sortBy.
     * 
     * @param entity
     * @return
     */
    @Get("json")
    public Representation doGetJSON(Representation entity) {
        logger.fine("AnnotatorSearch doGetJSON!");
        setCorsHeaders();
        // do authentication
        Person authUser = getUserFromAuthToken(entity);
        logger.fine("request authenticated=" + authUser);

        Form form = getRequest().getResourceRef().getQueryAsForm();
        String uri = form.getFirstValue("uri");
        String user = form.getFirstValue("user");
        int limit = getInt(form.getFirstValue("limit"));
        int offset = getInt(form.getFirstValue("offset"));
        String sortBy = form.getFirstValue("sortBy");

        // do search
        ArrayList<JSONObject> results = new ArrayList<JSONObject>();
        logger.fine(String.format("searching for uri=%s user=%s", uri, user));
        AnnotationStore store = getAnnotationStore();
        List<Annotation> annots = store.searchAnnotationByUriUser(uri, user);
        for (Annotation annot : annots) {
            // check permission
            if (!annot.isActionAllowed("read", authUser, store)) continue;
            JSONObject jo = createAnnotatorJson(annot, (authUser == null));
            if (jo != null) {
                results.add(jo);
            } else {
                setStatus(Status.SERVER_ERROR_INTERNAL, "JSON Error");
                return null;
            }
        }

        // sort if necessary
        if (sortBy != null) {
            JSONObjectComparator.sortAnnotations(results, sortBy);
        }
        
        // put in JSON list
        JSONArray rows = new JSONArray();
        int cnt = 0;
        for (JSONObject result : results) {
            cnt += 1;
            if (offset > 0 && cnt < offset) continue;
            rows.put(result);
            if (limit > 0 && cnt >= limit) break;
        }

        // assemble result object
        JSONObject result = new JSONObject();
        try {
            result.put("rows", rows);
            result.put("total", rows.length());
        } catch (JSONException e) {
            setStatus(Status.SERVER_ERROR_INTERNAL, "JSON Error");
            return null;
        }

        logger.fine("sending response");
        logger.finest(result.toString());
        return new JsonRepresentation(result);
    }

}