/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2018 wcm.io
    * %%
    * 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.
   * #L%
   */
  package io.wcm.qa.glnm.configuration;
  
  import java.io.File;
  import java.io.IOException;
  import java.lang.reflect.InvocationTargetException;
  import java.nio.charset.Charset;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Map;
  
  import org.apache.commons.beanutils.BeanUtils;
  import org.apache.commons.csv.CSVFormat;
  import org.apache.commons.csv.CSVParser;
  import org.apache.commons.csv.CSVRecord;
  import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import io.wcm.qa.glnm.exceptions.GaleniumException;
  
  /**
   * Utility methods to parse CSV files.
   *
   * @since 1.0.0
   */
  public final class CsvUtil {
  
    private static final Charset CHARSET_UTF8 = Charset.forName("utf-8");
    private static final CSVFormat FORMAT = CSVFormat.DEFAULT.withQuote(null).withHeader(new String[] {});
  
    private static final Logger LOG = LoggerFactory.getLogger(CsvUtil.class);
  
    private CsvUtil() {
      // do not instantiate
    }
  
    /**
     * Get a parser for CSV file.
     *
     * @param csvFile to get parser for
     * @return parser to access data in CSV file
     * @since 3.0.0
     */
    public static CSVParser parse(File csvFile) {
      return parse(csvFile, false);
    }
  
    /**
     * Get a parser for CSV file.
     *
     * @param csvFile to get parser for
     * @param skipHeaderRecord whether to skip header record while parsing
     * @return parser to access data in CSV file
     * @since 3.0.0
     */
    public static CSVParser parse(File csvFile, boolean skipHeaderRecord) {
      if (csvFile == null) {
        throw new GaleniumException("error when checking CSV input: file is null");
      }
      if (!csvFile.isFile()) {
        throw new GaleniumException("error when reading CSV file: '" + csvFile.getPath() + "'");
      }
      try {
        CSVFormat format = FORMAT.withSkipHeaderRecord(skipHeaderRecord);
        return CSVParser.parse(csvFile, CHARSET_UTF8, format);
      }
      catch (IOException ex) {
        throw new GaleniumException("error when parsing CSV file: '" + csvFile.getPath() + "'", ex);
      }
    }
  
    /**
     * Get a parser for CSV file.
     *
     * @param csvFilePath path to file to get parser for
     * @return parser to access data in CSV file
     * @since 3.0.0
     */
    public static CSVParser parse(String csvFilePath) {
      return parse(new File(csvFilePath));
   }
 
   /**
    * Populate beans with CSV data.
    *
    * @param csvFile to get input data from
    * @param beanClass type of bean to populate
    * @param <T> type of bean as generic to create typed collection
    * @return collection with one bean per row in CSV
    * @since 3.0.0
    */
   public static <T> Collection<T> parseToBeans(File csvFile, Class<T> beanClass) {
     Collection<T> result = new ArrayList<>();
     CSVParser parse = parse(csvFile);
     for (CSVRecord csvRecord : parse) {
       Map<String, String> map = csvRecord.toMap();
       LOG.debug("from csv: " + csvRecord);
       LOG.debug("from csv: " + ReflectionToStringBuilder.toString(csvRecord));
       LOG.debug("map from csv: " + ReflectionToStringBuilder.toString(map));
       try {
         T newInstance = beanClass.newInstance();
         BeanUtils.populate(newInstance, map);
         LOG.debug("populated: " + newInstance);
         result.add(newInstance);
       }
       catch (IllegalAccessException | InvocationTargetException | InstantiationException ex) {
         throw new GaleniumException("error when constructing bean from CSV: '" + csvFile.getPath() + "'", ex);
       }
     }
     return result;
   }
 
 }