/*
 *  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.analytics;

import java.util.List;

import org.waterforpeople.mapping.dao.SurveyInstanceDAO;
import org.waterforpeople.mapping.domain.QuestionAnswerStore;

import com.gallatinsystems.common.util.StringUtil;
import com.gallatinsystems.framework.analytics.summarization.DataSummarizationRequest;
import com.gallatinsystems.framework.analytics.summarization.DataSummarizer;
import com.gallatinsystems.framework.domain.DataChangeRecord;
import com.google.appengine.api.taskqueue.Queue;
import com.google.appengine.api.taskqueue.QueueFactory;
import com.google.appengine.api.taskqueue.TaskOptions;

/**
 * cleans data by fixing capitalization of Name field values. Though not really a summarization, it
 * is declared to implement DataSummarizer to piggyback on the summarization task infrastructure.
 * 
 * @author Christopher Fagiani
 */
public class NameQuestionDataCleanser implements DataSummarizer {

    private String currentCursor;
    private SurveyInstanceDAO dao;

    public NameQuestionDataCleanser() {
        dao = new SurveyInstanceDAO();
    }

    /**
     * rather than summarizing, this will iterate over all "Name" questions and clean the data by
     * changing the case of the response to have capital letters for the initial character in each
     * word. If the value changed, it will fire a LCR message to the change listener queue.
     */
    @Override
    public boolean performSummarization(String key, String type, String value,
            Integer offset, String cursor) {
        List<QuestionAnswerStore> answers = dao
                .listQuestionAnswerStoreForQuestion(key, cursor);
        if (answers != null && answers.size() > 0) {
            currentCursor = SurveyInstanceDAO.getCursor(answers);
        } else {
            currentCursor = null;
        }
        if (answers != null && answers.size() > 0) {
            for (QuestionAnswerStore answer : answers) {
                if (answer.getValue() != null) {
                    String newValue = StringUtil.capitalizeString(answer
                            .getValue());
                    if (!answer.getValue().equals(newValue)) {
                        sendChangeMessage(new DataChangeRecord(
                                QuestionAnswerStore.class.getName(), key,
                                answer.getValue(), newValue));
                        answer.setValue(newValue);
                    }
                }
            }
            // now persist the changes
            dao.save(answers);
        }
        if (currentCursor != null) {
            return false;
        } else {
            return true;
        }
    }

    @Override
    public String getCursor() {
        return currentCursor;
    }

    /**
     * sends a logical change record over the change task queue for the question given
     * 
     * @param value
     */
    private void sendChangeMessage(DataChangeRecord value) {
        Queue queue = QueueFactory.getQueue("dataUpdate");
        queue.add(TaskOptions.Builder.withUrl("/app_worker/dataupdate")
                .param(DataSummarizationRequest.OBJECT_KEY, value.getId())
                .param(DataSummarizationRequest.OBJECT_TYPE,
                        "QuestionDataChange")
                .param(DataSummarizationRequest.VALUE_KEY, value.packString()));
    }

}