/*
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 * without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
 * must also contain a copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
 * without prior written permission of Intalio, Inc. For written permission, please contact
 * info@exolab.org.
 *
 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
 * Intalio, Inc.
 *
 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 2001 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$ Date Author Changes 04/18/2002 Arnaud constructor with string 05/24/2001 Arnaud Blandin
 * Created
 */
package org.exolab.castor.types;

import java.text.SimpleDateFormat;
import java.text.ParseException;

/**
 * Describe an XML schema gYearMonth type.
 * <p>
 * The format is defined by W3C XML Schema Recommendation and ISO8601 i.e
 * <tt>(-)CCYY-MM(Z|(+|-)hh:mm)</tt>
 * 
 * @author <a href="mailto:blandin@intalio.com">Arnaud Blandin</a>
 * @author <a href="mailto:edward.kuns@aspect.com">Edward Kuns</a>
 * @version $Revision$
 */
public class GYearMonth extends DateTimeBase {

  /** SerialVersionUID */
  private static final long serialVersionUID = -8864050276805766473L;

  /** The gYearMonth SimpleDateFormat string. */
  private static final String YEARMONTH_FORMAT = "yyyy-MM";
  /** Prefix of any complaint we make. */
  private static final String BAD_GYEARMONTH = "Bad gYearMonth format: ";

  /**
   * public only for the generated source code
   */
  public GYearMonth() {
    // Nothing to do
  }

  /**
   * Instantiates a new gYearMonth given the value of the month and the value of the day.
   * 
   * @param century the month value
   * @param year the year value
   * @param month the month value
   */
  public GYearMonth(short century, short year, short month) {
    this.setCentury(century);
    this.setYear(year);
    this.setMonth(month);
  }

  /**
   * Instantiates a new gYearMonth given the value of the month and the value of the day.
   * 
   * @param year the year value
   * @param month the month value
   */
  public GYearMonth(int year, int month) {
    short century = (short) (year / 100);
    year = year % 100;
    setCentury(century);
    setYear((short) year);
    setMonth((short) month);
  }

  /**
   * Constructs a XML Schema GYearMonth instance given all the values of the different fields. By
   * default a GYearMonth is not UTC and is local.
   * 
   * @param values an array of shorts that represent the different fields of Time.
   */
  public GYearMonth(short[] values) {
    setValues(values);
  }

  /**
   * Constructs a GYearMonth given a string representation
   * 
   * @param gyearMonth the string representation of the GYearMonth to instantiate
   * @throws ParseException a parse exception is thrown if the string to parse does not follow the
   *         rigth format (see the description of this class)
   */
  public GYearMonth(String gyearMonth) throws ParseException {
    parseGYearMonthInternal(gyearMonth, this);
  }

  /**
   * Sets all the fields by reading the values in an array
   * <p>
   * if a Time Zone is specificied it has to be set by using
   * {@link DateTimeBase#setZone(short, short) setZone}.
   *
   * @param values an array of shorts with the values the array is supposed to be of length 3 and
   *        ordered like the following:
   *        <ul>
   *        <li>century</li>
   *        <li>year</li>
   *        <li>month</li>
   *        </ul>
   */
  public void setValues(short[] values) {
    if (values.length != 3) {
      throw new IllegalArgumentException("GYearMonth#setValues: not the right number of values");
    }
    this.setCentury(values[0]);
    this.setYear(values[1]);
    this.setMonth(values[2]);
  }

  /**
   * Returns an array of short with all the fields that describe this gYearMonth type.
   * <p>
   * Note:the time zone is not included.
   * 
   * @return an array of short with all the fields that describe this Date type.
   */
  public short[] getValues() {
    short[] result = new short[3];
    result[0] = this.getCentury();
    result[1] = this.getYear();
    result[2] = this.getMonth();
    return result;
  } // getValues

  /**
   * converts this gYearMonth into a local java Date.
   * 
   * @return a local date representing this Date.
   */
  public java.util.Date toDate() {
    SimpleDateFormat df = new SimpleDateFormat(YEARMONTH_FORMAT);
    setDateFormatTimeZone(df);

    java.util.Date date = null;
    try {
      date = df.parse(this.toString());
    } catch (ParseException e) {
      // this can't happen since toString() should return the proper string format
      e.printStackTrace();
      return null;
    }

    return date;
  } // toDate()

  /**
   * convert this gYearMonth to a string The format is defined by W3C XML Schema recommendation and
   * ISO8601 i.e (+|-)CCYY-MM(Z|(+|-)hh:mm)
   * 
   * @return a string representing this Date
   */
  public String toString() {
    StringBuffer result = new StringBuffer();

    if (isNegative()) {
      result.append('-');
    }

    if ((this.getCentury() / 10) == 0) {
      result.append(0);
    }
    result.append(this.getCentury());
    if ((this.getYear() / 10) == 0) {
      result.append(0);
    }
    result.append(this.getYear());

    result.append('-');

    if ((this.getMonth() / 10) == 0) {
      result.append(0);
    }
    result.append(this.getMonth());

    appendTimeZoneString(result);

    return result.toString();
  } // toString

  /**
   * parse a String and convert it into an java.lang.Object
   * 
   * @param str the string to parse
   * @return an Object represented by the string
   * @throws ParseException a parse exception is thrown if the string to parse does not follow the
   *         rigth format (see the description of this class)
   */
  public static Object parse(String str) throws ParseException {
    return parseGYearMonth(str);
  }

  /**
   * parse a String and convert it into a gYearMonth.
   * 
   * @param str the string to parse
   * @return the Date represented by the string
   * @throws ParseException a parse exception is thrown if the string to parse does not follow the
   *         rigth format (see the description of this class)
   */
  public static GYearMonth parseGYearMonth(String str) throws ParseException {
    GYearMonth result = new GYearMonth();
    return parseGYearMonthInternal(str, result);
  }

  private static GYearMonth parseGYearMonthInternal(String str, GYearMonth result)
      throws ParseException {
    if (str == null) {
      throw new IllegalArgumentException("The string to be parsed must not be null.");
    }

    if (result == null) {
      result = new GYearMonth();
    }

    char[] chars = str.toCharArray();
    int idx = 0;

    if (chars[idx] == '-') {
      result.setNegative();
      idx++;
    }

    // Century
    if (!Character.isDigit(chars[idx]) || !Character.isDigit(chars[idx + 1])
        || !Character.isDigit(chars[idx + 2]) || !Character.isDigit(chars[idx + 3])) {
      throw new ParseException(
          BAD_GYEARMONTH + str + "\nA gYearMonth must follow the pattern CCYY(Z|((+|-)hh:mm)).",
          idx);
    }

    short value1 = (short) ((chars[idx] - '0') * 10 + (chars[idx + 1] - '0'));
    short value2 = (short) ((chars[idx + 2] - '0') * 10 + (chars[idx + 3] - '0'));
    if (value1 == 0 && value2 == 0) {
      throw new ParseException(BAD_GYEARMONTH + str + "\n'0000' is not allowed as a year.", idx);
    }

    result.setCentury(value1);
    result.setYear(value2);

    idx += 4;

    if (chars[idx] != '-') {
      throw new ParseException(
          BAD_GYEARMONTH + str + "\nA gYearMonth must follow the pattern CCYY(Z|((+|-)hh:mm)).",
          idx);
    }

    idx++;

    // Month
    if (!Character.isDigit(chars[idx]) || !Character.isDigit(chars[idx + 1])) {
      throw new ParseException(BAD_GYEARMONTH + str + "\nThe Month must be 2 digits long", idx);
    }

    value1 = (short) ((chars[idx] - '0') * 10 + (chars[idx + 1] - '0'));
    result.setMonth(value1);

    idx += 2;

    parseTimeZone(str, result, chars, idx, BAD_GYEARMONTH);

    return result;
  } // parse

  /////////////////////////// DISALLOWED METHODS ///////////////////////////

  public boolean hasDay() {
    return false;
  }

  public short getDay() {
    String err = "org.exolab.castor.types.GYearMonth does not have a Day field.";
    throw new UnsupportedOperationException(err);
  }

  public void setDay(short day) {
    String err = "org.exolab.castor.types.GYearMonth does not have a Day field.";
    throw new UnsupportedOperationException(err);
  }

  public boolean hasHour() {
    return false;
  }

  public short getHour() {
    String err = "org.exolab.castor.types.GYearMonth does not have an Hour field.";
    throw new UnsupportedOperationException(err);
  }

  public void setHour(short hour) {
    String err = "org.exolab.castor.types.GYearMonth does not have an Hour field.";
    throw new UnsupportedOperationException(err);
  }

  public boolean hasMinute() {
    return false;
  }

  public short getMinute() {
    String err = "org.exolab.castor.types.GYearMonth does not have a Minute field.";
    throw new UnsupportedOperationException(err);
  }

  public void setMinute(short minute) {
    String err = "org.exolab.castor.types.GYearMonth does not have a Minute field.";
    throw new UnsupportedOperationException(err);
  }

  public boolean hasSeconds() {
    return false;
  }

  public short getSeconds() {
    String err = "org.exolab.castor.types.GYearMonth does not have a Seconds field.";
    throw new UnsupportedOperationException(err);
  }

  public void setSecond(short second) {
    String err = "org.exolab.castor.types.GYearMonth does not have a Seconds field.";
    throw new UnsupportedOperationException(err);
  }

  public boolean hasMilli() {
    return false;
  }

  public short getMilli() {
    String err = "org.exolab.castor.types.GYearMonth does not have a Milliseconds field.";
    throw new UnsupportedOperationException(err);
  }

  public void setMilliSecond(short millisecond) {
    String err = "org.exolab.castor.types.GYearMonth does not have a Milliseconds field.";
    throw new UnsupportedOperationException(err);
  }

}
