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+/*
+    This file is part of libkholidays.
+    Copyright (c) 2004 Allen Winter <winter@kde.org>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+
+#ifndef KHOLIDAYS_LUNARPHASE_H
+#define KHOLIDAYS_LUNARPHASE_H
+
+/**
+  Represents and manages a Lunar Phase
+
+  A Lunar Phase can be one of the following:
+
+   + "new": the moon is not visible; or traditionally: first visible
+            crescent of the Moon.  For religious purposes, the new
+            month begins when the first crescent moon can be seen.
+            Thus, it is impossible to be certain in advance of when
+            months will begin; in particular, the exact date on which
+            Ramadan will begin is not known in advance. In Saudi Arabia,
+            observers are sent up in airplanes if the weather is cloudy
+            when the new moon is expected.
+   + "first quarter": the right 50% of the moon is visible.
+   + "full": the moon is fully visible.
+   + "last quarter": the left 50% of the moon is visible.
+
+   A very good description of the lunar phases can be read at the Wikipedia,
+     http://en.wikipedia.org/wiki/Lunar_phase
+
+   In the southern hemisphere the order of the phases is reversed.
+   So, to be accurate we need to know the hemisphere.
+
+   Note that crescent and gibbous phases are not currently supported.
+*/
+
+#include <qstring.h>
+#include <qdatetime.h>
+
+#include <time.h>
+
+class LunarPhase
+{
+  public:
+    enum Phase { New,  FirstQ, LastQ, Full, None };
+    enum Hemisphere { Northern,  Southern };
+
+    LunarPhase( Hemisphere hemisphere = Northern );
+    ~LunarPhase();
+
+    /**
+       Return the lunar phase for the specified Gregorian date.
+       The enum 'None' is returned if one of the supported phases
+       does not occur on the date.
+
+       @param date compute the lunar phase for the specified Gregorian date.
+    */
+    Phase phase( const QDate &date ) const;
+
+    /**
+       Return the lunar phase as a text string for the specified date.
+       A null string is returned if one of the supported phases does
+       not occur on the date.
+
+       @param date compute the lunar phase for the specified Gregorian date.
+    */
+    QString phaseStr( const QDate &date ) const;
+
+   /**
+      Set the hemisphere.
+
+      @param hemisphere Hemisphere
+   */
+    void setHemisphere( Hemisphere hemisphere = Northern );
+
+    /**
+       Return the hemisphere.
+    */
+    Hemisphere hemisphere() const;
+
+    /**
+       Return hemisphere as a clear text string.
+    */
+    QString hemisphereStr() const;
+
+    /**
+       Return the string representation of hemisphere.
+    */
+    static QString hemisphereName( Hemisphere hemisphere );
+
+    /**
+       Return the string representation of phase.
+
+       @param phase the lunar phase.
+    */
+    static QString phaseName( Phase phase );
+
+private:
+    /**
+       Return the phase of the moon as a percentage of full
+
+       @param t is the time since the Epoch, measured in seconds.
+
+       @return the percent fullness [0,100] of the moon.
+    */
+    double percentFull( uint t ) const;
+    /**
+       Convert degrees to radians.
+
+       @param degree degrees to convert.
+
+       @return degrees in radians.
+    */
+    double degreesToRadians( double degree ) const;
+    /**
+       Adjust value so that 0 <= degree <= 360.
+
+       @param degree a pointer to the degree value.
+    */
+    void adj360( double *degree ) const;
+
+    Hemisphere mHemisphere;
+};
+
+#endif
+
+