/*
    * Copyright 2010 James Pether Sörling
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *   http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   *	$Id$
   *  $HeadURL$
  */
  package com.hack23.cia.service.external.vdem.impl;
  
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.commons.csv.CSVFormat;
  import org.apache.commons.csv.CSVParser;
  import org.apache.commons.csv.CSVRecord;
  import org.apache.poi.ss.usermodel.Row;
  import org.apache.poi.xssf.usermodel.XSSFSheet;
  import org.apache.poi.xssf.usermodel.XSSFWorkbook;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.stereotype.Service;
  import org.springframework.util.StringUtils;
  
  import com.hack23.cia.model.external.vdem.indicators.impl.CountryQuestionData;
  import com.hack23.cia.model.external.vdem.indicators.impl.CountryQuestionDataEmbeddedId;
  import com.hack23.cia.model.external.vdem.indicators.impl.Question;
  import com.hack23.cia.service.external.vdem.api.VdemService;
  
  /**
   * The Class VdemServiceImpl.
   */
  @Service
  public final class VdemServiceImpl implements VdemService {
  
  	/** The Constant VDEM_DATA_DOWNLOAD_URL. */
  	private static final String VDEM_DATA_DOWNLOAD_URL = "https://s3-eu-west-1.amazonaws.com/vdemdata/V-Dem-DS-CY-v5.csv";
  
  	/** The Constant LOGGER. */
  	private static final Logger LOGGER = LoggerFactory.getLogger(VdemServiceImpl.class);
  
  	@Override
  	public List<Question> getQuestions() {
  
  		final List<Question> list = new ArrayList<>();
  		try {
  			final XSSFWorkbook myWorkBook = new XSSFWorkbook(VdemServiceImpl.class.getResourceAsStream("/V-DemQuestionIDsv5(2016).xlsx"));
  			final XSSFSheet mySheet = myWorkBook.getSheetAt(0);
  			final Iterator<Row> rowIterator = mySheet.iterator();
  
  			rowIterator.next();
  
  			while (rowIterator.hasNext()) {
  				final Row row = rowIterator.next();
  
  				final Question question = new Question();
  
  				if (row.getCell(0) == null) {
  					question.setTag(row.getCell(1).toString());
  					question.setName(row.getCell(2).toString());
  				} else {
  					question.setQuestionId(row.getCell(0).toString());
  					question.setTag(row.getCell(1).toString());
  					question.setName(row.getCell(2).toString());
  				}
  				list.add(question);
  			}
  
  			myWorkBook.close();
  		} catch (final IOException e) {
  			LOGGER.warn("Problem loading", e);
  		}
  
  		return list;
  
  	}
  
  	/**
  	 * Gets the country question data.
  	 *
  	 * @return the country question data
  	 */
  	@Override
  	public List<CountryQuestionData> getCountryQuestionData() {
 		final List<CountryQuestionData> list = new ArrayList<>();
 
 		final List<Question> questions = getQuestions();
 
 		try {
 			final Reader in = new InputStreamReader(new URL(VDEM_DATA_DOWNLOAD_URL).openStream());
 
 			final CSVParser parser = new CSVParser(in, CSVFormat.EXCEL.withHeader().withDelimiter(','));
 
 			for (final CSVRecord record : parser) {
 				final String countryName = record.get("country_name");
 				final String countryId = record.get("country_id");
 				final String countryTextId = record.get("country_text_id");
 				final String year = record.get("year");
 				final String gapStart = record.get("gapstart");
 				final String gapEnd = record.get("gapend");
 				final String codingEnd = record.get("codingend");
 				final String cowCode = record.get("COWcode");
 
 				final int currentSize = list.size();
 				LOGGER.info("Loading vdem data for country:{} year {} ",countryName,year);
 
 				for (final Question question : questions) {
 					addQuestionDataToList(list, record, countryName, countryId, countryTextId, year, gapStart, gapEnd,
 							codingEnd, cowCode, question);
 				}
 
 				final int afterSize = list.size();
 				LOGGER.info("Found vdem data for country:{} year:{} data points:{}",countryName,year,afterSize -currentSize);
 
 			}
 			parser.close();
 
 		} catch (final IOException e) {
 
 			LOGGER.warn("Problem loading vdem data", e);
 		}
 
 		return list;
 	}
 
 	/**
 	 * Adds the question data to list.
 	 *
 	 * @param list
 	 *            the list
 	 * @param record
 	 *            the record
 	 * @param countryName
 	 *            the country name
 	 * @param countryId
 	 *            the country id
 	 * @param countryTextId
 	 *            the country text id
 	 * @param year
 	 *            the year
 	 * @param gapStart
 	 *            the gap start
 	 * @param gapEnd
 	 *            the gap end
 	 * @param codingEnd
 	 *            the coding end
 	 * @param cowCode
 	 *            the cow code
 	 * @param question
 	 *            the question
 	 */
 	private static void addQuestionDataToList(final List<CountryQuestionData> list, final CSVRecord record,
 			final String countryName, final String countryId, final String countryTextId, final String year,
 			final String gapStart, final String gapEnd, final String codingEnd, final String cowCode,
 			final Question question) {
 		if (question.getQuestionId() != null) {
 
 			if (record.isMapped(question.getTag())) {
 
 				try {
 					final String questionValue = record.get(question.getTag());
 
 					if (questionValue != null && StringUtils.hasText(questionValue)) {
 						final CountryQuestionData countryQuestionData = new CountryQuestionData();
 						final CountryQuestionDataEmbeddedId embeddedId = new CountryQuestionDataEmbeddedId();
 
 						embeddedId.setCountryName(countryName);
 						embeddedId.setCountryId(countryId);
 						embeddedId.setIndicatorId(question.getTag());
 						embeddedId.setYear(Integer.parseInt(year));
 						embeddedId.setCountryId(countryId);
 
 						countryQuestionData.setEmbeddedId(embeddedId);
 
 						countryQuestionData.setCountryTextId(countryTextId);
 						countryQuestionData.setGapstart(gapStart);
 						countryQuestionData.setGapend(gapEnd);
 						countryQuestionData.setCodingend(codingEnd);
 						countryQuestionData.setCowCode(cowCode);
 						countryQuestionData.setQuestionValue(questionValue.trim());
 
 						list.add(countryQuestionData);
 					}
 				} catch (final RuntimeException e) {
 					LOGGER.warn("Missing value for:"+ question.getTag(), e);
 				}
 			}
 		}
 	}
 
 }