/*
    * Copyright (C) 2013 4th Line GmbH, Switzerland
    *
    * The contents of this file are subject to the terms of either the GNU
    * Lesser General Public License Version 2 or later ("LGPL") or the
    * Common Development and Distribution License Version 1 or later
    * ("CDDL") (collectively, the "License"). You may not use this file
    * except in compliance with the License. See LICENSE.txt for more
    * information.
   *
   * 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.
   */
  
  package org.fourthline.cling.model.types;
  
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.TimeZone;
  
  /**
   * @author Christian Bauer
   */
  public class DateTimeDatatype extends AbstractDatatype<Calendar> {
  
      protected String[] readFormats;
      protected String writeFormat;
  
      public DateTimeDatatype(String[] readFormats, String writeFormat) {
          this.readFormats = readFormats;
          this.writeFormat = writeFormat;
      }
  
      public Calendar valueOf(String s) throws InvalidValueException {
          if (s.equals("")) return null;
  
          Date d = getDateValue(s, readFormats);
          if (d == null) {
              throw new InvalidValueException("Can't parse date/time from: " + s);
          }
  
          Calendar c = Calendar.getInstance(getTimeZone());
          c.setTime(d);
  
          /*
          // TODO: I'm not sure this is necessary and I don't remember why I wrote it
          if (readFormats[0].equals("HH:mm:ssZ") && (getTimeZone().inDaylightTime(d)))
              c.add(Calendar.MILLISECOND, 3600000);
          */
  
          return c;
      }
  
      @Override
      public String getString(Calendar value) throws InvalidValueException {
          if (value == null) return "";
          SimpleDateFormat sdt = new SimpleDateFormat(writeFormat);
          sdt.setTimeZone(getTimeZone());
          return sdt.format(value.getTime());
      }
  
      protected String normalizeTimeZone(String value) {
          if (value.endsWith("Z")) {
              value = value.substring(0, value.length() - 1) + "+0000";
          } else if ((value.length() > 7)
                  && (value.charAt(value.length() - 3) == ':')
                  && ((value.charAt(value.length() - 6) == '-') || (value.charAt(value.length() - 6) == '+'))) {
  
              value = value.substring(0, value.length() - 3) + value.substring(value.length() - 2);
          }
          return value;
      }
  
      protected Date getDateValue(String value, String[] formats) {
  
          value = normalizeTimeZone(value);
  
          Date d = null;
          for (String format : formats) {
              SimpleDateFormat sdt = new SimpleDateFormat(format);
              sdt.setTimeZone(getTimeZone());
              try {
                  d = sdt.parse(value);
                  // Continue, last match is the one we need
              } catch (ParseException ex) {
                  // Just continue
              }
          }
          return d;
      }
  
      protected TimeZone getTimeZone() {
          return TimeZone.getDefault();
      }
  
  }