// ::MONO
//
// System.Globalization.JulianCalendar.cs
//
// Copyright (C) Wictor Wilén 2001 (wictor@iBizkit.se)
//
// Contributors: 
//
// Revisions
// 2001-09-14:	First draft
// 2001-09-15:	First release
//
//
// TODO: testing
//
//

using System;

namespace System.Globalization
{

	
	/// <summary>
	/// Summary description for JulianCalendar.
	/// </summary>
	public class JulianCalendar : System.Globalization.Calendar
	{
		
		
		// Public Static (Shared) Fields
		// DONE!
		public static readonly int JulianEra = 1;

		// Public Instance Constructors
		// DONE!
		public JulianCalendar()
		{
		}

		// Public Instance Properties
		// DONE!
		public override int[] Eras 
		{
			get
			{
				return new int[] {1};
			}
		}
		// DONE!
		public override int TwoDigitYearMax 
		{
			get
			{
				return _TwoDigitYearMax;
			} 
			set
			{
				_TwoDigitYearMax = value;
			}
		}

		// Public Instance Methods
		// DONE!
		public override DateTime AddMonths ( DateTime time, int months )
		{
			if(months < -120000 || months > 120000)
				throw new System.ArgumentOutOfRangeException();
			DateTime dt = new DateTime(time.Ticks);			
			dt =  dt.AddMonths(months);
			return dt;
			
		}
		// DONE!
		public override DateTime AddYears ( DateTime time, int years )
		{
			DateTime dt = new DateTime(time.Ticks);
			return dt.AddYears(years);
		}

		// DONE!
		public override int GetDayOfMonth ( DateTime time )
		{
			return time.Day;
		}

		// DONE!
		public override DayOfWeek GetDayOfWeek ( DateTime time )
		{
			return time.DayOfWeek;
		}

		// DONE!
		public override int GetDayOfYear ( DateTime time )
		{
			return time.DayOfYear;
		}
		
		// DONE!
		public override int GetDaysInMonth ( int year, int month, int era )
		{
			if(	year < _MinYear || year > _MaxYear || 
				month < _MinMonth || month > _MaxMonth || 
				era != JulianEra)
				throw new System.ArgumentOutOfRangeException();

			if(this.IsLeapYear(year))
				return _DaysInMonthLeap[month];
			else
				return _DaysInMonth[month];
		}
		

		// DONE!		
		public override int GetDaysInYear ( int year, int era )
		{
			if(year < _MinYear || year > _MaxYear || era != JulianEra)
				throw new System.ArgumentOutOfRangeException();
			return this.GetDaysInYear(year);
		}

		// DONE!
		public override int GetEra ( DateTime time )
		{
			return JulianEra;
		}
		// DONE!
		public override int GetMonth ( DateTime time )
		{
			return time.Month;
		}

		// DONE!		
		public override int GetMonthsInYear ( int year, int era )
		{
			if(year < _MinYear || year > _MaxYear || era != JulianEra)
				throw new System.ArgumentOutOfRangeException();
			return _MaxMonth;
		}
		
		// DONE!
		public override int GetYear ( DateTime time )
		{			
			return time.Year;
		}

		// DONE!
		public override bool IsLeapDay ( int year, int month, int day, int era )
		{			
			int dim;

			if(day < _MinDay || month < _MinMonth || month > _MaxMonth)
				throw new System.ArgumentOutOfRangeException();

			if(this.IsLeapYear(year,era))
				dim = _DaysInMonthLeap[month-1];
			else
				dim = _DaysInMonth[month-1];

			if( day > dim)
				throw new System.ArgumentOutOfRangeException();

			if( month == 2 && day == 29)
				return true;
			
			return false;
		}
		// DONE!
		public override bool IsLeapMonth ( int year, int month )
		{
			if( year < _MinYear || year > _MaxYear || month < _MinMonth || month > _MaxMonth)
				throw new System.ArgumentException();
			return false;	
		}
		// DONE!
		public override bool IsLeapMonth ( int year, int month, int era )
		{
			if( year < _MinYear || year > _MaxYear || month < _MinMonth || month > _MaxMonth || era != JulianEra)
				throw new System.ArgumentException();
			return false;
		}
		
		// DONE!
		public override bool IsLeapYear ( int year, int era )
		{
			if(year < _MinYear || year > _MaxYear || era != JulianEra)
				throw new System.ArgumentOutOfRangeException();
			if(year % 4 == 0)
				return true;
			return false;
		}
		
		// DONE!
		public override DateTime ToDateTime ( int year, int month, int day, int hour, int minute, int second, int millisecond, int era )
		{
			// INFO: year, era and month is checked by GetDaysInMonth()
			int dim;
			dim = GetDaysInMonth(year,month);
			if( day < _MinDay || day > dim || 
				hour < _MinHour || hour > _MaxHour ||
				minute < _MinMinute || minute > _MaxMinute ||
				second < _MinSecond || second > _MaxSecond ||
				millisecond < _MinMillisecond || millisecond > _MaxMillisecond)
				throw new System.ArgumentOutOfRangeException();

			return new DateTime(year,month,day,hour,minute,second,millisecond,this);
		}
		
		// DONE!
		public override int ToFourDigitYear ( int year )
		{
			int y = _TwoDigitYearMax % 100;
			if( year > y )
				y = _TwoDigitYearMax - y - 100 + year;
			else
				y = _TwoDigitYearMax - y + year;

			if( y < _MinYear || y > _MaxYear)
				throw new System.ArgumentException();
			return y;
		}

	}
}