text: /*
   * Copyright (C) 2009 Google Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   *
   *     * Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   *     * 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.
   *     * Neither the name of Google Inc. nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS 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 THE COPYRIGHT
   * OWNER OR 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.
   */
  
  #ifndef DateComponents_h
  #define DateComponents_h
  
  #include <limits>
  #include <wtf/Forward.h>
  #include <wtf/unicode/Unicode.h>
  
  namespace WebCore {
  
  // A DateComponents instance represents one of the following date and time combinations:
  // * Month type: year-month
  // * Date type: year-month-day
  // * Week type: year-week
  // * Time type: hour-minute-second-millisecond
  // * DateTime or DateTimeLocal type: year-month-day hour-minute-second-millisecond
  class DateComponents {
  public:
      DateComponents()
          : m_millisecond(0)
          , m_second(0)
          , m_minute(0)
          , m_hour(0)
          , m_monthDay(0)
          , m_month(0)
          , m_year(0)
          , m_week(0)
          , m_type(Invalid)
      {
      }
  
      enum Type {
          Invalid,
          Date,
          DateTime,
          DateTimeLocal,
          Month,
          Time,
          Week,
      };
  
      int millisecond() const { return m_millisecond; }
      int second() const { return m_second; }
      int minute() const { return m_minute; }
      int hour() const { return m_hour; }
      int monthDay() const { return m_monthDay; }
      int month() const { return m_month; }
      int fullYear() const { return m_year; }
      int week() const { return m_week; }
      Type type() const { return m_type; }
  
      enum SecondFormat {
          None, // Suppress the second part and the millisecond part if they are 0.
          Second, // Always show the second part, and suppress the millisecond part if it is 0.
          Millisecond // Always show the second part and the millisecond part.
      };
  
      // Returns an ISO 8601 representation for this instance.
      // The format argument is valid for DateTime, DateTimeLocal, and Time types.
      String toString(SecondFormat format = None) const;
  
      // parse*() and setMillisecondsSince*() functions are initializers for an
      // DateComponents instance. If these functions return false, the instance
      // might be invalid.
  
      // The following six functions parse the input 'src' whose length is
      // 'length', and updates some fields of this instance. The parsing starts at
      // src[start] and examines characters before src[length].
      // 'src' must be non-null. The 'src' string doesn't need to be
      // null-terminated.
      // The functions return true if the parsing succeeds, and set 'end' to the
      // next index after the last consumed. Extra leading characters cause parse
      // failures, and the trailing extra characters don't cause parse failures.
  
      // Sets year and month.
      bool parseMonth(const UChar* src, unsigned length, unsigned start, unsigned& end);
      // Sets year, month and monthDay.
      bool parseDate(const UChar* src, unsigned length, unsigned start, unsigned& end);
      // Sets year and week.
      bool parseWeek(const UChar* src, unsigned length, unsigned start, unsigned& end);
      // Sets hour, minute, second and millisecond.
      bool parseTime(const UChar* src, unsigned length, unsigned start, unsigned& end);
      // Sets year, month, monthDay, hour, minute, second and millisecond.
      bool parseDateTimeLocal(const UChar* src, unsigned length, unsigned start, unsigned& end);
      // Sets year, month, monthDay, hour, minute, second and millisecond, and adjusts timezone.
      bool parseDateTime(const UChar* src, unsigned length, unsigned start, unsigned& end);
  
      // The following setMillisecondsSinceEpochFor*() functions take
      // the number of milliseconds since 1970-01-01 00:00:00.000 UTC as
      // the argument, and update all fields for the corresponding
      // DateComponents type. The functions return true if it succeeds, and
      // false if they fail.
  
      // For Date type. Updates m_year, m_month and m_monthDay.
      bool setMillisecondsSinceEpochForDate(double ms);
      // For DateTime type. Updates m_year, m_month, m_monthDay, m_hour, m_minute, m_second and m_millisecond.
      bool setMillisecondsSinceEpochForDateTime(double ms);
      // For DateTimeLocal type. Updates m_year, m_month, m_monthDay, m_hour, m_minute, m_second and m_millisecond.
      bool setMillisecondsSinceEpochForDateTimeLocal(double ms);
      // For Month type. Updates m_year and m_month.
      bool setMillisecondsSinceEpochForMonth(double ms);
      // For Week type. Updates m_year and m_week.
      bool setMillisecondsSinceEpochForWeek(double ms);
  
      // For Time type. Updates m_hour, m_minute, m_second and m_millisecond.
      bool setMillisecondsSinceMidnight(double ms);
  
      // Another initializer for Month type. Updates m_year and m_month.
      bool setMonthsSinceEpoch(double months);
  
      // Returns the number of milliseconds from 1970-01-01 00:00:00 UTC.
      // For a DateComponents initialized with parseDateTimeLocal(),
      // millisecondsSinceEpoch() returns a value for UTC timezone.
      double millisecondsSinceEpoch() const;
      // Returns the number of months from 1970-01.
      // Do not call this for types other than Month.
      double monthsSinceEpoch() const;
      static inline double invalidMilliseconds() { return std::numeric_limits<double>::quiet_NaN(); }
  
      // Minimum and maxmimum limits for setMillisecondsSince*(),
      // setMonthsSinceEpoch(), millisecondsSinceEpoch(), and monthsSinceEpoch().
      static inline double minimumDate() { return -62135596800000.0; } // 0001-01-01T00:00Z
      static inline double minimumDateTime() { return -62135596800000.0; } // ditto.
      static inline double minimumMonth() { return (1 - 1970) * 12.0 + 1 - 1; } // 0001-01
      static inline double minimumTime() { return 0; } // 00:00:00.000
      static inline double minimumWeek() { return -62135596800000.0; } // 0001-01-01, the first Monday of 0001.
      static inline double maximumDate() { return 8640000000000000.0; } // 275760-09-13T00:00Z
      static inline double maximumDateTime() { return 8640000000000000.0; } // ditto.
      static inline double maximumMonth() { return (275760 - 1970) * 12.0 + 9 - 1; } // 275760-09
      static inline double maximumTime() { return 86399999; } // 23:59:59.999
      static inline double maximumWeek() { return 8639999568000000.0; } // 275760-09-08, the Monday of the week including 275760-09-13.
  
      // HTML5 uses ISO-8601 format with year >= 1. Gregorian calendar started in
      // 1582. However, we need to support 0001-01-01 in Gregorian calendar rule.
      static inline int minimumYear() { return 1; }
      // Date in ECMAScript can't represent dates later than 275760-09-13T00:00Z.
      // So, we have the same upper limit in HTML5 date/time types.
      static inline int maximumYear() { return 275760; }
      static const int minimumWeekNumber;
      static const int maximumWeekNumber;
  
  private:
      // Returns the maximum week number in this DateComponents's year.
      // The result is either of 52 and 53.
      int maxWeekNumberInYear() const;
      bool parseYear(const UChar* src, unsigned length, unsigned start, unsigned& end);
      bool addDay(int);
      bool addMinute(int);
      bool parseTimeZone(const UChar* src, unsigned length, unsigned start, unsigned& end);
      // Helper for millisecondsSinceEpoch().
      double millisecondsSinceEpochForTime() const;
      // Helpers for setMillisecondsSinceEpochFor*().
      bool setMillisecondsSinceEpochForDateInternal(double ms);
      void setMillisecondsSinceMidnightInternal(double ms);
      // Helper for toString().
      String toStringForTime(SecondFormat) const;
  
      // m_weekDay values
      enum {
          Sunday = 0,
          Monday,
          Tuesday,
          Wednesday,
          Thursday,
          Friday,
          Saturday,
      };
  
      int m_millisecond; // 0 - 999
      int m_second;
      int m_minute;
      int m_hour;
      int m_monthDay; // 1 - 31
      int m_month; // 0:January - 11:December
      int m_year; //  1582 -
      int m_week; // 1 - 53
  
      Type m_type;
  };
  
  
  } // namespace WebCore
  
  #endif // DateComponents_h
  