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  /*
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   * 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
   *
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  package java.time;
  
  import static java.time.temporal.ChronoField.DAY_OF_WEEK;
  import static java.time.temporal.ChronoUnit.DAYS;
  
  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.time.temporal.WeekFields;
  import java.util.Locale;
  
  /**
   * A day-of-week, such as 'Tuesday'.
   * <p>
   * {@code DayOfWeek} is an enum representing the 7 days of the week -
   * Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday.
   * <p>
   * In addition to the textual enum name, each day-of-week has an {@code int} value.
   * The {@code int} value follows the ISO-8601 standard, from 1 (Monday) to 7 (Sunday).
   * It is recommended that applications use the enum rather than the {@code int} value
   * to ensure code clarity.
   * <p>
   * This enum provides access to the localized textual form of the day-of-week.
   * Some locales also assign different numeric values to the days, declaring
   * Sunday to have the value 1, however this class provides no support for this.
   * See {@link WeekFields} for localized week-numbering.
   * <p>
   * <b>Do not use {@code ordinal()} to obtain the numeric representation of {@code DayOfWeek}.
   * 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 day-of-week
   * concept defined exactly equivalent to the ISO calendar system.
   *
   * @implSpec
   * This is an immutable and thread-safe enum.
   *
   * @since 1.8
   */
  public enum DayOfWeek implements TemporalAccessor, TemporalAdjuster {
  
      /**
       * The singleton instance for the day-of-week of Monday.
       * This has the numeric value of {@code 1}.
       */
      MONDAY,
      /**
       * The singleton instance for the day-of-week of Tuesday.
       * This has the numeric value of {@code 2}.
       */
      TUESDAY,
      /**
       * The singleton instance for the day-of-week of Wednesday.
       * This has the numeric value of {@code 3}.
       */
      WEDNESDAY,
      /**
       * The singleton instance for the day-of-week of Thursday.
       * This has the numeric value of {@code 4}.
       */
      THURSDAY,
      /**
       * The singleton instance for the day-of-week of Friday.
       * This has the numeric value of {@code 5}.
       */
      FRIDAY,
      /**
       * The singleton instance for the day-of-week of Saturday.
       * This has the numeric value of {@code 6}.
       */
      SATURDAY,
      /**
       * The singleton instance for the day-of-week of Sunday.
       * This has the numeric value of {@code 7}.
       */
      SUNDAY;
      /**
       * Private cache of all the constants.
       */
      private static final DayOfWeek[] ENUMS = DayOfWeek.values();
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code DayOfWeek} from an {@code int} value.
       * <p>
       * {@code DayOfWeek} is an enum representing the 7 days of the week.
       * This factory allows the enum to be obtained from the {@code int} value.
       * The {@code int} value follows the ISO-8601 standard, from 1 (Monday) to 7 (Sunday).
       *
       * @param dayOfWeek  the day-of-week to represent, from 1 (Monday) to 7 (Sunday)
       * @return the day-of-week singleton, not null
       * @throws DateTimeException if the day-of-week is invalid
       */
      public static DayOfWeek of(int dayOfWeek) {
          if (dayOfWeek < 1 || dayOfWeek > 7) {
              throw new DateTimeException("Invalid value for DayOfWeek: " + dayOfWeek);
          }
          return ENUMS[dayOfWeek - 1];
      }
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code DayOfWeek} from a temporal object.
       * <p>
       * This obtains a day-of-week 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 DayOfWeek}.
       * <p>
       * The conversion extracts the {@link ChronoField#DAY_OF_WEEK DAY_OF_WEEK} field.
       * <p>
       * This method matches the signature of the functional interface {@link TemporalQuery}
       * allowing it to be used as a query via method reference, {@code DayOfWeek::from}.
       *
       * @param temporal  the temporal object to convert, not null
       * @return the day-of-week, not null
       * @throws DateTimeException if unable to convert to a {@code DayOfWeek}
       */
      public static DayOfWeek from(TemporalAccessor temporal) {
          if (temporal instanceof DayOfWeek) {
              return (DayOfWeek) temporal;
          }
          try {
              return of(temporal.get(DAY_OF_WEEK));
          } catch (DateTimeException ex) {
              throw new DateTimeException("Unable to obtain DayOfWeek from TemporalAccessor: " +
                      temporal + " of type " + temporal.getClass().getName(), ex);
          }
      }
  
      //-----------------------------------------------------------------------
      /**
       * Gets the day-of-week {@code int} value.
       * <p>
       * The values are numbered following the ISO-8601 standard, from 1 (Monday) to 7 (Sunday).
       * See {@link WeekFields#dayOfWeek()} for localized week-numbering.
       *
       * @return the day-of-week, from 1 (Monday) to 7 (Sunday)
       */
      public int getValue() {
          return ordinal() + 1;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Gets the textual representation, such as 'Mon' or 'Friday'.
       * <p>
       * This returns the textual name used to identify the day-of-week,
       * 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 day-of-week, not null
       */
      public String getDisplayName(TextStyle style, Locale locale) {
          return new DateTimeFormatterBuilder().appendText(DAY_OF_WEEK, style).toFormatter(locale).format(this);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Checks if the specified field is supported.
       * <p>
       * This checks if this day-of-week 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#DAY_OF_WEEK DAY_OF_WEEK} 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 day-of-week, false if not
       */
      @Override
      public boolean isSupported(TemporalField field) {
          if (field instanceof ChronoField) {
              return field == DAY_OF_WEEK;
          }
          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 day-of-week 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#DAY_OF_WEEK DAY_OF_WEEK} then the
       * range of the day-of-week, from 1 to 7, 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 == DAY_OF_WEEK) {
              return field.range();
          }
          return TemporalAccessor.super.range(field);
      }
  
      /**
       * Gets the value of the specified field from this day-of-week as an {@code int}.
       * <p>
       * This queries this day-of-week 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#DAY_OF_WEEK DAY_OF_WEEK} then the
       * value of the day-of-week, from 1 to 7, 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 == DAY_OF_WEEK) {
              return getValue();
          }
          return TemporalAccessor.super.get(field);
      }
  
      /**
       * Gets the value of the specified field from this day-of-week as a {@code long}.
       * <p>
       * This queries this day-of-week 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#DAY_OF_WEEK DAY_OF_WEEK} then the
       * value of the day-of-week, from 1 to 7, 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 == DAY_OF_WEEK) {
              return getValue();
          } else if (field instanceof ChronoField) {
              throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
          }
          return field.getFrom(this);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Returns the day-of-week that is the specified number of days after this one.
       * <p>
       * The calculation rolls around the end of the week from Sunday to Monday.
       * The specified period may be negative.
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @param days  the days to add, positive or negative
       * @return the resulting day-of-week, not null
       */
      public DayOfWeek plus(long days) {
          int amount = (int) (days % 7);
          return ENUMS[(ordinal() + (amount + 7)) % 7];
      }
  
      /**
       * Returns the day-of-week that is the specified number of days before this one.
       * <p>
       * The calculation rolls around the start of the year from Monday to Sunday.
       * The specified period may be negative.
       * <p>
       * This instance is immutable and unaffected by this method call.
       *
       * @param days  the days to subtract, positive or negative
       * @return the resulting day-of-week, not null
       */
      public DayOfWeek minus(long days) {
          return plus(-(days % 7));
      }
  
      //-----------------------------------------------------------------------
      /**
       * Queries this day-of-week using the specified query.
       * <p>
       * This queries this day-of-week 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.precision()) {
              return (R) DAYS;
          }
          return TemporalAccessor.super.query(query);
      }
  
      /**
       * Adjusts the specified temporal object to have this day-of-week.
       * <p>
       * This returns a temporal object of the same observable type as the input
       * with the day-of-week changed to be the same as this.
       * <p>
       * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
       * passing {@link ChronoField#DAY_OF_WEEK} as the field.
       * Note that this adjusts forwards or backwards within a Monday to Sunday week.
       * See {@link WeekFields#dayOfWeek()} for localized week start days.
       * See {@code TemporalAdjuster} for other adjusters with more control,
       * such as {@code next(MONDAY)}.
       * <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 = thisDayOfWeek.adjustInto(temporal);
       *   temporal = temporal.with(thisDayOfWeek);
       * </pre>
       * <p>
       * For example, given a date that is a Wednesday, the following are output:
       * <pre>
       *   dateOnWed.with(MONDAY);     // two days earlier
       *   dateOnWed.with(TUESDAY);    // one day earlier
       *   dateOnWed.with(WEDNESDAY);  // same date
       *   dateOnWed.with(THURSDAY);   // one day later
       *   dateOnWed.with(FRIDAY);     // two days later
       *   dateOnWed.with(SATURDAY);   // three days later
       *   dateOnWed.with(SUNDAY);     // four days 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) {
          return temporal.with(DAY_OF_WEEK, getValue());
      }
  
  }
  