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  /*
   * This file is available under and governed by the GNU General Public
   * License version 2 only, as published by the Free Software Foundation.
   * However, the following notice accompanied the original version of this
   * file:
   *
   * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
   *
   * All rights reserved.
   *
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   * modification, are permitted provided that the following conditions are met:
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   *    this list of conditions and the following disclaimer.
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  package java.time;
  
  import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
  import static java.time.temporal.ChronoUnit.MONTHS;
  
  import java.time.chrono.Chronology;
  import java.time.chrono.IsoChronology;
  import java.time.format.DateTimeFormatterBuilder;
  import java.time.format.TextStyle;
  import java.time.temporal.ChronoField;
  import java.time.temporal.Temporal;
  import java.time.temporal.TemporalAccessor;
  import java.time.temporal.TemporalAdjuster;
  import java.time.temporal.TemporalField;
  import java.time.temporal.TemporalQueries;
  import java.time.temporal.TemporalQuery;
  import java.time.temporal.UnsupportedTemporalTypeException;
  import java.time.temporal.ValueRange;
  import java.util.Locale;
  
  /**
   * A month-of-year, such as 'July'.
   * <p>
   * {@code Month} is an enum representing the 12 months of the year -
   * January, February, March, April, May, June, July, August, September, October,
   * November and December.
   * <p>
   * In addition to the textual enum name, each month-of-year has an {@code int} value.
   * The {@code int} value follows normal usage and the ISO-8601 standard,
   * from 1 (January) to 12 (December). It is recommended that applications use the enum
   * rather than the {@code int} value to ensure code clarity.
   * <p>
   * <b>Do not use {@code ordinal()} to obtain the numeric representation of {@code Month}.
   * Use {@code getValue()} instead.</b>
   * <p>
   * This enum represents a common concept that is found in many calendar systems.
   * As such, this enum may be used by any calendar system that has the month-of-year
   * concept defined exactly equivalent to the ISO-8601 calendar system.
   *
   * @implSpec
   * This is an immutable and thread-safe enum.
   *
   * @since 1.8
   */
  public enum Month implements TemporalAccessor, TemporalAdjuster {
  
      /**
       * The singleton instance for the month of January with 31 days.
       * This has the numeric value of {@code 1}.
       */
      JANUARY,
      /**
       * The singleton instance for the month of February with 28 days, or 29 in a leap year.
       * This has the numeric value of {@code 2}.
       */
      FEBRUARY,
      /**
       * The singleton instance for the month of March with 31 days.
       * This has the numeric value of {@code 3}.
       */
      MARCH,
      /**
       * The singleton instance for the month of April with 30 days.
       * This has the numeric value of {@code 4}.
       */
      APRIL,
      /**
       * The singleton instance for the month of May with 31 days.
       * This has the numeric value of {@code 5}.
       */
      MAY,
      /**
       * The singleton instance for the month of June with 30 days.
       * This has the numeric value of {@code 6}.
       */
      JUNE,
      /**
       * The singleton instance for the month of July with 31 days.
       * This has the numeric value of {@code 7}.
       */
      JULY,
      /**
       * The singleton instance for the month of August with 31 days.
       * This has the numeric value of {@code 8}.
       */
      AUGUST,
      /**
       * The singleton instance for the month of September with 30 days.
       * This has the numeric value of {@code 9}.
       */
      SEPTEMBER,
      /**
       * The singleton instance for the month of October with 31 days.
       * This has the numeric value of {@code 10}.
       */
      OCTOBER,
      /**
       * The singleton instance for the month of November with 30 days.
       * This has the numeric value of {@code 11}.
       */
      NOVEMBER,
      /**
       * The singleton instance for the month of December with 31 days.
       * This has the numeric value of {@code 12}.
       */
      DECEMBER;
      /**
       * Private cache of all the constants.
       */
      private static final Month[] ENUMS = Month.values();
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code Month} from an {@code int} value.
       * <p>
       * {@code Month} is an enum representing the 12 months of the year.
       * This factory allows the enum to be obtained from the {@code int} value.
       * The {@code int} value follows the ISO-8601 standard, from 1 (January) to 12 (December).
       *
       * @param month  the month-of-year to represent, from 1 (January) to 12 (December)
       * @return the month-of-year, not null
       * @throws DateTimeException if the month-of-year is invalid
       */
      public static Month of(int month) {
          if (month < 1 || month > 12) {
              throw new DateTimeException("Invalid value for MonthOfYear: " + month);
          }
          return ENUMS[month - 1];
      }
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code Month} from a temporal object.
       * <p>
       * This obtains a month based on the specified temporal.
       * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
       * which this factory converts to an instance of {@code Month}.
       * <p>
       * The conversion extracts the {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} field.
       * The extraction is only permitted if the temporal object has an ISO
       * chronology, or can be converted to a {@code LocalDate}.
       * <p>
       * This method matches the signature of the functional interface {@link TemporalQuery}
       * allowing it to be used as a query via method reference, {@code Month::from}.
       *
       * @param temporal  the temporal object to convert, not null
       * @return the month-of-year, not null
       * @throws DateTimeException if unable to convert to a {@code Month}
       */
      public static Month from(TemporalAccessor temporal) {
          if (temporal instanceof Month) {
              return (Month) temporal;
          }
          try {
              if (IsoChronology.INSTANCE.equals(Chronology.from(temporal)) == false) {
                  temporal = LocalDate.from(temporal);
              }
              return of(temporal.get(MONTH_OF_YEAR));
          } catch (DateTimeException ex) {
              throw new DateTimeException("Unable to obtain Month from TemporalAccessor: " +
                      temporal + " of type " + temporal.getClass().getName(), ex);
          }
      }
  
      //-----------------------------------------------------------------------
      /**
       * Gets the month-of-year {@code int} value.
       * <p>
       * The values are numbered following the ISO-8601 standard,
       * from 1 (January) to 12 (December).
       *
       * @return the month-of-year, from 1 (January) to 12 (December)
       */
      public int getValue() {
          return ordinal() + 1;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Gets the textual representation, such as 'Jan' or 'December'.
       * <p>
       * This returns the textual name used to identify the month-of-year,
       * suitable for presentation to the user.
       * The parameters control the style of the returned text and the locale.
       * <p>
       * If no textual mapping is found then the {@link #getValue() numeric value} is returned.
       *
       * @param style  the length of the text required, not null
       * @param locale  the locale to use, not null
       * @return the text value of the month-of-year, not null
       */
      public String getDisplayName(TextStyle style, Locale locale) {
          return new DateTimeFormatterBuilder().appendText(MONTH_OF_YEAR, style).toFormatter(locale).format(this);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Checks if the specified field is supported.
       * <p>
       * This checks if this month-of-year can be queried for the specified field.
       * If false, then calling the {@link #range(TemporalField) range} and
       * {@link #get(TemporalField) get} methods will throw an exception.
       * <p>
       * If the field is {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} then
       * this method returns true.
       * All other {@code ChronoField} instances will return false.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
       * passing {@code this} as the argument.
       * Whether the field is supported is determined by the field.
       *
       * @param field  the field to check, null returns false
       * @return true if the field is supported on this month-of-year, false if not
       */
      @Override
      public boolean isSupported(TemporalField field) {
          if (field instanceof ChronoField) {
              return field == MONTH_OF_YEAR;
          }
          return field != null && field.isSupportedBy(this);
      }
  
      /**
       * Gets the range of valid values for the specified field.
       * <p>
       * The range object expresses the minimum and maximum valid values for a field.
       * This month is used to enhance the accuracy of the returned range.
       * If it is not possible to return the range, because the field is not supported
       * or for some other reason, an exception is thrown.
       * <p>
       * If the field is {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} then the
       * range of the month-of-year, from 1 to 12, will be returned.
       * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
       * passing {@code this} as the argument.
       * Whether the range can be obtained is determined by the field.
       *
       * @param field  the field to query the range for, not null
       * @return the range of valid values for the field, not null
       * @throws DateTimeException if the range for the field cannot be obtained
       * @throws UnsupportedTemporalTypeException if the field is not supported
       */
      @Override
      public ValueRange range(TemporalField field) {
          if (field == MONTH_OF_YEAR) {
              return field.range();
          }
          return TemporalAccessor.super.range(field);
      }
  
      /**
       * Gets the value of the specified field from this month-of-year as an {@code int}.
       * <p>
       * This queries this month for the value of the specified field.
       * The returned value will always be within the valid range of values for the field.
       * If it is not possible to return the value, because the field is not supported
       * or for some other reason, an exception is thrown.
       * <p>
       * If the field is {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} then the
       * value of the month-of-year, from 1 to 12, will be returned.
       * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
       * passing {@code this} as the argument. Whether the value can be obtained,
       * and what the value represents, is determined by the field.
       *
       * @param field  the field to get, not null
       * @return the value for the field, within the valid range of values
       * @throws DateTimeException if a value for the field cannot be obtained or
       *         the value is outside the range of valid values for the field
       * @throws UnsupportedTemporalTypeException if the field is not supported or
       *         the range of values exceeds an {@code int}
       * @throws ArithmeticException if numeric overflow occurs
       */
      @Override
      public int get(TemporalField field) {
          if (field == MONTH_OF_YEAR) {
              return getValue();
          }
          return TemporalAccessor.super.get(field);
      }
  
      /**
       * Gets the value of the specified field from this month-of-year as a {@code long}.
       * <p>
       * This queries this month for the value of the specified field.
       * If it is not possible to return the value, because the field is not supported
       * or for some other reason, an exception is thrown.
       * <p>
       * If the field is {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} then the
       * value of the month-of-year, from 1 to 12, will be returned.
       * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
       * <p>
       * If the field is not a {@code ChronoField}, then the result of this method
       * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
       * passing {@code this} as the argument. Whether the value can be obtained,
       * and what the value represents, is determined by the field.
       *
       * @param field  the field to get, not null
       * @return the value for the field
       * @throws DateTimeException if a value for the field cannot be obtained
       * @throws UnsupportedTemporalTypeException if the field is not supported
       * @throws ArithmeticException if numeric overflow occurs
       */
      @Override
      public long getLong(TemporalField field) {
          if (field == MONTH_OF_YEAR) {
              return getValue();
          } else if (field instanceof ChronoField) {
              throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
          }
          return field.getFrom(this);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Returns the month-of-year that is the specified number of quarters after this one.
       * <p>
       * The calculation rolls around the end of the year from December to January.
       * The specified period may be negative.
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @param months  the months to add, positive or negative
       * @return the resulting month, not null
       */
      public Month plus(long months) {
          int amount = (int) (months % 12);
          return ENUMS[(ordinal() + (amount + 12)) % 12];
      }
  
      /**
       * Returns the month-of-year that is the specified number of months before this one.
       * <p>
       * The calculation rolls around the start of the year from January to December.
       * The specified period may be negative.
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @param months  the months to subtract, positive or negative
       * @return the resulting month, not null
       */
      public Month minus(long months) {
          return plus(-(months % 12));
      }
  
      //-----------------------------------------------------------------------
      /**
       * Gets the length of this month in days.
       * <p>
       * This takes a flag to determine whether to return the length for a leap year or not.
       * <p>
       * February has 28 days in a standard year and 29 days in a leap year.
       * April, June, September and November have 30 days.
       * All other months have 31 days.
       *
       * @param leapYear  true if the length is required for a leap year
       * @return the length of this month in days, from 28 to 31
       */
      public int length(boolean leapYear) {
          switch (this) {
              case FEBRUARY:
                  return (leapYear ? 29 : 28);
              case APRIL:
              case JUNE:
              case SEPTEMBER:
              case NOVEMBER:
                  return 30;
              default:
                  return 31;
          }
      }
  
      /**
       * Gets the minimum length of this month in days.
       * <p>
       * February has a minimum length of 28 days.
       * April, June, September and November have 30 days.
       * All other months have 31 days.
       *
       * @return the minimum length of this month in days, from 28 to 31
       */
      public int minLength() {
          switch (this) {
              case FEBRUARY:
                  return 28;
              case APRIL:
              case JUNE:
              case SEPTEMBER:
              case NOVEMBER:
                  return 30;
              default:
                  return 31;
          }
      }
  
      /**
       * Gets the maximum length of this month in days.
       * <p>
       * February has a maximum length of 29 days.
       * April, June, September and November have 30 days.
       * All other months have 31 days.
       *
       * @return the maximum length of this month in days, from 29 to 31
       */
      public int maxLength() {
          switch (this) {
              case FEBRUARY:
                  return 29;
              case APRIL:
              case JUNE:
              case SEPTEMBER:
              case NOVEMBER:
                  return 30;
              default:
                  return 31;
          }
      }
  
      //-----------------------------------------------------------------------
      /**
       * Gets the day-of-year corresponding to the first day of this month.
       * <p>
       * This returns the day-of-year that this month begins on, using the leap
       * year flag to determine the length of February.
       *
       * @param leapYear  true if the length is required for a leap year
       * @return the day of year corresponding to the first day of this month, from 1 to 336
       */
      public int firstDayOfYear(boolean leapYear) {
          int leap = leapYear ? 1 : 0;
          switch (this) {
              case JANUARY:
                  return 1;
              case FEBRUARY:
                  return 32;
              case MARCH:
                  return 60 + leap;
              case APRIL:
                  return 91 + leap;
              case MAY:
                  return 121 + leap;
              case JUNE:
                  return 152 + leap;
              case JULY:
                  return 182 + leap;
              case AUGUST:
                  return 213 + leap;
              case SEPTEMBER:
                  return 244 + leap;
              case OCTOBER:
                  return 274 + leap;
              case NOVEMBER:
                  return 305 + leap;
              case DECEMBER:
              default:
                  return 335 + leap;
          }
      }
  
      /**
       * Gets the month corresponding to the first month of this quarter.
       * <p>
       * The year can be divided into four quarters.
       * This method returns the first month of the quarter for the base month.
       * January, February and March return January.
       * April, May and June return April.
       * July, August and September return July.
       * October, November and December return October.
       *
       * @return the first month of the quarter corresponding to this month, not null
       */
      public Month firstMonthOfQuarter() {
          return ENUMS[(ordinal() / 3) * 3];
      }
  
      //-----------------------------------------------------------------------
      /**
       * Queries this month-of-year using the specified query.
       * <p>
       * This queries this month-of-year using the specified query strategy object.
       * The {@code TemporalQuery} object defines the logic to be used to
       * obtain the result. Read the documentation of the query to understand
       * what the result of this method will be.
       * <p>
       * The result of this method is obtained by invoking the
       * {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
       * specified query passing {@code this} as the argument.
       *
       * @param <R> the type of the result
       * @param query  the query to invoke, not null
       * @return the query result, null may be returned (defined by the query)
       * @throws DateTimeException if unable to query (defined by the query)
       * @throws ArithmeticException if numeric overflow occurs (defined by the query)
       */
      @SuppressWarnings("unchecked")
      @Override
      public <R> R query(TemporalQuery<R> query) {
          if (query == TemporalQueries.chronology()) {
              return (R) IsoChronology.INSTANCE;
          } else if (query == TemporalQueries.precision()) {
              return (R) MONTHS;
          }
          return TemporalAccessor.super.query(query);
      }
  
      /**
       * Adjusts the specified temporal object to have this month-of-year.
       * <p>
       * This returns a temporal object of the same observable type as the input
       * with the month-of-year changed to be the same as this.
       * <p>
       * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
       * passing {@link ChronoField#MONTH_OF_YEAR} as the field.
       * If the specified temporal object does not use the ISO calendar system then
       * a {@code DateTimeException} is thrown.
       * <p>
       * In most cases, it is clearer to reverse the calling pattern by using
       * {@link Temporal#with(TemporalAdjuster)}:
       * <pre>
       *   // these two lines are equivalent, but the second approach is recommended
       *   temporal = thisMonth.adjustInto(temporal);
       *   temporal = temporal.with(thisMonth);
       * </pre>
       * <p>
       * For example, given a date in May, the following are output:
       * <pre>
       *   dateInMay.with(JANUARY);    // four months earlier
       *   dateInMay.with(APRIL);      // one months earlier
       *   dateInMay.with(MAY);        // same date
       *   dateInMay.with(JUNE);       // one month later
       *   dateInMay.with(DECEMBER);   // seven months later
       * </pre>
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @param temporal  the target object to be adjusted, not null
       * @return the adjusted object, not null
       * @throws DateTimeException if unable to make the adjustment
       * @throws ArithmeticException if numeric overflow occurs
       */
      @Override
      public Temporal adjustInto(Temporal temporal) {
          if (Chronology.from(temporal).equals(IsoChronology.INSTANCE) == false) {
              throw new DateTimeException("Adjustment only supported on ISO date-time");
          }
          return temporal.with(MONTH_OF_YEAR, getValue());
      }
  
  }
  