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#ifndef DateComponents_h

#define DateComponents_h

#include <limits>

#include <wtf/unicode/Unicode.h>

namespace WebCore {

class String;

// 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)

    {

    }

    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; }

    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 -12219292800000.0; } // This means 1582-10-15T00:00Z.

    static inline double minimumDateTime() { return -12219292800000.0; } // ditto.

    static inline double minimumMonth() { return (1582.0 - 1970) * 12 + 10 - 1; } // 1582-10

    static inline double minimumTime() { return 0; } // 00:00:00.000

    static inline double minimumWeek() { return -12212380800000.0; } // 1583-01-03, the first Monday of 1583.

    static inline double maximumDate() { return std::numeric_limits<double>::max(); }

    static inline double maximumDateTime() { return std::numeric_limits<double>::max(); }

    // DateComponents::m_year can't represent a year greater than INT_MAX.

    static inline double maximumMonth() { return (std::numeric_limits<int>::max() - 1970) * 12.0 + 12 - 1; }

    static inline double maximumTime() { return 86399999; } // 23:59:59.999

    static inline double maximumWeek() { return std::numeric_limits<double>::max(); }

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

    enum Type {

        Invalid,

        Date,

        DateTime,

        DateTimeLocal,

        Month,

        Time,

        Week,

    };

    Type m_type;

};

} // namespace WebCore

#endif // DateComponents_h