/***************************************************************************
    File                 : String2DayOfWeekFilter.h
    Project              : SciDAVis
    --------------------------------------------------------------------
    Copyright            : (C) 2007 by Knut Franke, Tilman Benkert
    Email (use @ for *)  : knut.franke*gmx.de, thzs*gmx.net
    Description          : Conversion filter String -> QDateTime, interpreting
                           the input as days of the week (either numeric or "Mon" etc).
                           
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *  This program 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 program 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                                           *
 *                                                                         *
 ***************************************************************************/
#ifndef STRING2DAYOFWEEK_FILTER_H
#define STRING2DAYOFWEEK_FILTER_H

#include "../AbstractSimpleFilter.h"
#include <QDateTime>
#include <math.h>
#include "lib/XmlStreamReader.h"
#include <QXmlStreamWriter>

//! Conversion filter String -> QDateTime, interpreting the input as days of the week (either numeric or "Mon" etc).
class String2DayOfWeekFilter : public AbstractSimpleFilter
{
	Q_OBJECT

	public:
		virtual QDate dateAt(int row) const 
		{
			return dateTimeAt(row).date();
		}

		virtual QTime timeAt(int row) const 
		{
			return dateTimeAt(row).time();
		}

		virtual QDateTime dateTimeAt(int row) const
		{
			if (!d_inputs.value(0)) return QDateTime();

			QString input_value = d_inputs.value(0)->textAt(row);
			if (input_value.isEmpty()) return QDateTime();
			bool ok;
			int day_value = input_value.toInt(&ok);
			if(!ok)
			{
#if QT_VERSION <= 0x040300  
				// workaround for Qt bug #171920
				QDate temp = QDate(1900,1,1);
				for(int i=1; i<=7; i++)
					if( (input_value.toLower() == QDate::longDayName(i).toLower())
							|| (input_value.toLower() == QDate::shortDayName(i).toLower()) )
					{
						temp = QDate(1900,1,i);
						break;
					}

#else 
				QDate temp = QDate::fromString(input_value, "ddd");
				if(!temp.isValid())
					temp = QDate::fromString(input_value, "dddd");
#endif
				if(!temp.isValid())
					return QDateTime();
				else
					day_value = temp.dayOfWeek();
			}

			// Don't use Julian days here since support for years < 1 is bad
			// Use 1900-01-01 instead (a Monday)
			QDate result_date = QDate(1900,1,1).addDays(day_value - 1);
			QTime result_time = QTime(0,0,0,0);
			return QDateTime(result_date, result_time);
		}
		virtual bool isInvalid(int row) const { 
			const AbstractColumn *col = d_inputs.value(0);
			if (!col) return false;
			return !(dateTimeAt(row).isValid()) || col->isInvalid(row);
		}
		virtual bool isInvalid(Interval<int> i) const {
			if (!d_inputs.value(0)) return false;
			for (int row = i.start(); row <= i.end(); row++) {
				if (!isInvalid(row))
					return false;
			}
			return true;
		}
		virtual QList< Interval<int> > invalidIntervals() const 
		{
			IntervalAttribute<bool> validity;
			if (d_inputs.value(0)) {
				int rows = d_inputs.value(0)->rowCount();
				for (int i=0; i<rows; i++) 
					validity.setValue(i, isInvalid(i));
			}
			return validity.intervals();
		}

		//! Return the data type of the column
		virtual SciDAVis::ColumnDataType dataType() const { return SciDAVis::TypeQDateTime; }

	protected:
		virtual bool inputAcceptable(int, const AbstractColumn *source) {
			return source->dataType() == SciDAVis::TypeQString;
		}
};

#endif // ifndef STRING2DAYOFWEEK_FILTER_H

