/*
* Copyright (C) 2003, International Business Machines Corporation and others. All Rights Reserved.
********************************************************************************
*
* File JAPANCAL.H
*
* Modification History:
*
*   Date        Name        Description
*   05/13/2003  srl         copied from gregocal.h
********************************************************************************
*/

#ifndef JAPANCAL_H
#define JAPANCAL_H

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#include "unicode/calendar.h"
#include "unicode/gregocal.h"

U_NAMESPACE_BEGIN

/**
 * Concrete class which provides the Japanese calendar.
 * <P>
 * <code>JapaneseCalendar</code> is a subclass of <code>GregorianCalendar</code>
 * that numbers years and eras based on the reigns of the Japanese emperors.
 * The Japanese calendar is identical to the Gregorian calendar in all respects
 * except for the year and era.  The ascension of each  emperor to the throne
 * begins a new era, and the years of that era are numbered starting with the
 * year of ascension as year 1.
 * <p>
 * Note that in the year of an imperial ascension, there are two possible sets
 * of year and era values: that for the old era and for the new.  For example, a
 * new era began on January 7, 1989 AD.  Strictly speaking, the first six days
 * of that year were in the Showa era, e.g. "January 6, 64 Showa", while the rest
 * of the year was in the Heisei era, e.g. "January 7, 1 Heisei".  This class
 * handles this distinction correctly when computing dates.  However, in lenient
 * mode either form of date is acceptable as input. 
 * <p>
 * In modern times, eras have started on January 8, 1868 AD, Gregorian (Meiji),
 * July 30, 1912 (Taisho), December 25, 1926 (Showa), and January 7, 1989 (Heisei).  Constants
 * for these eras, suitable for use in the <code>UCAL_ERA</code> field, are provided
 * in this class.  Note that the <em>number</em> used for each era is more or
 * less arbitrary.  Currently, the era starting in 1053 AD is era #0; however this
 * may change in the future as we add more historical data.  Use the predefined
 * constants rather than using actual, absolute numbers.
 * <p>
 * @internal
 */
class U_I18N_API JapaneseCalendar : public GregorianCalendar {
public:

    /**
     * Useful constants for JapaneseCalendar.  
     * @internal
     */
    static const uint32_t kCurrentEra; // the current era

    /**
     * Constructs a JapaneseCalendar based on the current time in the default time zone
     * with the given locale.
     *
     * @param aLocale  The given locale.
     * @param success  Indicates the status of JapaneseCalendar object construction.
     *                 Returns U_ZERO_ERROR if constructed successfully.
     * @stable ICU 2.0
     */
    JapaneseCalendar(const Locale& aLocale, UErrorCode& success);


    /**
     * Destructor
     * @internal
     */
    virtual ~JapaneseCalendar();

    /**
     * Copy constructor
     * @param source    the object to be copied.
     * @internal
     */
    JapaneseCalendar(const JapaneseCalendar& source);

    /**
     * Default assignment operator
     * @param right    the object to be copied.
     * @internal
     */
    JapaneseCalendar& operator=(const JapaneseCalendar& right);

    /**
     * Create and return a polymorphic copy of this calendar.
     * @return    return a polymorphic copy of this calendar.
     * @internal
     */
    virtual Calendar* clone(void) const;

    
public:

    /**
     * Override Calendar Returns a unique class ID POLYMORPHICALLY. Pure virtual
     * override. This method is to implement a simple version of RTTI, since not all C++
     * compilers support genuine RTTI. Polymorphic operator==() and clone() methods call
     * this method.
     *
     * @return   The class ID for this object. All objects of a given class have the
     *           same class ID. Objects of other classes have different class IDs.
     * @internal
     */
    virtual UClassID getDynamicClassID(void) const;

    /**
     * Return the class ID for this class. This is useful only for comparing to a return
     * value from getDynamicClassID(). For example:
     *
     *      Base* polymorphic_pointer = createPolymorphicObject();
     *      if (polymorphic_pointer->getDynamicClassID() ==
     *          Derived::getStaticClassID()) ...
     *
     * @return   The class ID for all objects of this class.
     * @internal
     */
    static inline UClassID getStaticClassID(void);

    /**
     * return the calendar type, "japanese".
     *
     * @return calendar type
     * @internal
     */
    virtual const char * getType() const;

    /**
     * @internal 
     * @return TRUE if this calendar has the notion of a default century
     */
    virtual UBool haveDefaultCentury() const;
    virtual UDate defaultCenturyStart() const;
    virtual int32_t defaultCenturyStartYear() const;

    /** 
     * @internal
     * API overrides
     */
    int32_t getMaximum(UCalendarDateFields field) const;
    int32_t getLeastMaximum(UCalendarDateFields field) const;
    inline virtual int32_t getMaximum(EDateFields field) const { return getMaximum((UCalendarDateFields)field); }
    inline virtual int32_t getLeastMaximum(EDateFields field) const { return getLeastMaximum((UCalendarDateFields)field); }

private:
    JapaneseCalendar(); // default constructor not implemented

    static const char fgClassID;

protected:
    virtual int32_t monthLength(int32_t month) const; 
    virtual int32_t monthLength(int32_t month, int32_t year) const; 
    int32_t getGregorianYear(UErrorCode& status) const;
    virtual int32_t internalGetEra() const;
    virtual void timeToFields(UDate theTime, UBool quick, UErrorCode& status);

    /**
     * (Overrides Calendar) Converts Calendar's time field values to GMT as
     * milliseconds. In this case, we have to be concerned with filling in inconsistent
     * information. For example, if the year and era only are set, need to make sure
     * month & date are set correctly.  Ex, 'Heisei 1' starts Jan 8th, not Jan 1st.  
     * Default month and date values will end up giving the wrong Era.
     *
     * @param status  Output param set to success/failure code on exit. If any value
     *                previously set in the time field is invalid, this will be set to
     *                an error status.
     * @stable ICU 2.0
     */

    /***
     * Called by computeJulianDay.  Returns the default month (0-based) for the year,
     * taking year and era into account.  Defaults to 0 for Gregorian, which doesn't care.
     */
    virtual int32_t getDefaultMonthInYear() const;


    /***
     * Called by computeJulianDay.  Returns the default day (1-based) for the month,
     * taking currently-set year and era into account.  Defaults to 1 for Gregorian, which doesn't care. 
     */
    virtual int32_t getDefaultDayInMonth(int32_t month) const;
};

inline UClassID
JapaneseCalendar::getStaticClassID(void)
{ return (UClassID)&fgClassID; }

inline UClassID
JapaneseCalendar::getDynamicClassID(void) const
{ return JapaneseCalendar::getStaticClassID(); }


U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_FORMATTING */

#endif // _GREGOCAL
//eof