/**
 * Namespace: System.Web.UI.WebControls
 * Class:     Calendar
 * 
 * Author:  Gaurav Vaish
 * Maintainer: gvaish@iitk.ac.in
 * Contact: <my_scripts2001@yahoo.com>, <gvaish@iitk.ac.in>
 * Status:  60%
 * 
 * (C) Gaurav Vaish (2001)
 */

using System;
using System.Collections;
using System.Globalization;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Drawing;

namespace System.Web.UI.WebControls
{
	public class Calendar : WebControl, IPostBackEventHandler
	{
		//
		
		private TableItemStyle          dayHeaderStyle;
		private TableItemStyle          dayStyle;
		private TableItemStyle          nextPrevStyle;
		private TableItemStyle          otherMonthDayStyle;
		private SelectedDatesCollection selectedDates;
		private ArrayList               selectedDatesList;
		private TableItemStyle          selectedDayStyle;
		private TableItemStyle          selectorStyle;
		private TableItemStyle          titleStyle;
		private TableItemStyle          todayDayStyle;
		private TableItemStyle          weekendDayStyle;

		private static readonly object DayRenderEvent           = new object();
		private static readonly object SelectionChangedEvent    = new object();
		private static readonly object VisibleMonthChangedEvent = new object();
		
		private Color defaultTextColor;
		private System.Globalization.Calendar globCal;

		public Calendar(): base()
		{
			//TODO: Initialization
		}
		
		public int CellPadding
		{
			get
			{
				object o = ViewState["CellPadding"];
				if(o!=null)
					return (int)o;
				return 2;
			}
			set
			{
				ViewState["CellPadding"] = value;
			}
		}

		public int CellSpacing
		{
			get
			{
				object o = ViewState["CellSpacing"];
				if(o!=null)
					return (int)o;
				return 0;
			}
			set
			{
				if(value<-1)
					throw new ArgumentOutOfRangeException();
				ViewState["CellSpacing"] = value;
			}
		}
		
		public TableItemStyle DayHeaderStyle
		{
			get
			{
				if(dayHeaderStyle==null)
					dayHeaderStyle = new TableItemStyle();
				return dayHeaderStyle;
			}
		}

		public DayNameFormat DayNameFormat
		{
			get
			{
				object o = ViewState["DayNameFormat"];
				if(o!=null)
					return (DayNameFormat)o;
				return DayNameFormat.Short;
			}
			set
			{
				if(!System.Enum.IsDefined(typeof(DayNameFormat),value))
					throw new ArgumentException();
				ViewState["DayNameFormat"] = value;
			}
		}

		public TableItemStyle DayStyle
		{
			get
			{
				if(dayStyle==null)
					dayStyle = new TableItemStyle();
				return dayStyle;
			}
		}
		
		public FirstDayOfWeek FirstDayOfWeek
		{
			get
			{
				object o = ViewState["FirstDayOfWeek"];
				if(o!=null)
					return (FirstDayOfWeek)o;
				return FirstDayOfWeek.Default;
			}
			set
			{
				if(!System.Enum.IsDefined(typeof(FirstDayOfWeek), value))
					throw new ArgumentException();
				ViewState["FirstDayOfWeek"] = value;
			}
		}
		
		public string NextMonthText
		{
			get
			{
				object o = ViewState["NextMonthText"];
				if(o!=null)
					return (string)o;
				return "&gt;";
			}
			set
			{
				ViewState["NextMonthText"] = value;
			}
		}
		
		public NextPrevFormat NextPrevFormat
		{
			get
			{
				object o = ViewState["NextPrevFormat"];
				if(o!=null)
					return (NextPrevFormat)o;
				return NextPrevFormat.CustomText;
			}
			set
			{
				if(!System.Enum.IsDefined(typeof(NextPrevFormat), value))
					throw new ArgumentException();
				ViewState["NextPrevFormat"] = value;
			}
		}
		
		public TableItemStyle NextPrevStyle
		{
			get
			{
				if(nextPrevStyle == null)
					nextPrevStyle = new TableItemStyle();
				return nextPrevStyle;
			}
		}
		
		public TableItemStyle OtherMonthDayStyle
		{
			get
			{
				if(otherMonthDayStyle == null)
					otherMonthDayStyle = new TableItemStyle();
				return otherMonthDayStyle;
			}
		}
		
		public string PrevMonthText
		{
			get
			{
				object o = ViewState["PrevMonthText"];
				if(o!=null)
					return (string)o;
				return "&lt;";
			}
			set
			{
				ViewState["PrevMonthText"] = value;
			}
		}
		
		public DateTime SelectedDate
		{
			// TODO: Am I right here? I got confused with the "Remarks" written in the documentation
			/*
			 * Looks like I have to first do something with SelectionMode,
			 * then with SelectedDates,
			 * Update when SelectionChanged is called => Link to the function.
			 * Pretty confused at this point
			*/
			get
			{
				object o = ViewState["SelectedDate"];
				if(o!=null)
					return (DateTime)o;
				return DateTime.MinValue;
			}
			set
			{
				ViewState["SelectedDate"] = value;
			}
		}
		
		public SelectedDatesCollection SelectedDates
		{
			get
			{
				if(selectedDates==null)
				{
					if(selectedDatesList == null)
						selectedDatesList = new ArrayList();
					selectedDates = new SelectedDatesCollection(selectedDatesList);
				}
				return selectedDates;
			}
		}
		
		public TableItemStyle SelectedDayStyle
		{
			get
			{
				if(selectedDayStyle==null)
					selectedDayStyle = new TableItemStyle();
				return selectedDayStyle;
			}
		}

		public CalendarSelectionMode SelectionMode
		{
			get
			{
				object o = ViewState["SelectionMode"];
				if(o!=null)
					return (CalendarSelectionMode)o;
				return CalendarSelectionMode.Day;
			}
			set
			{
				if(!System.Enum.IsDefined(typeof(CalendarSelectionMode), value))
					throw new ArgumentException();
				ViewState["SelectionMode"] = value;
			}
		}
		
		public string SelectedMonthText
		{
			get
			{
				object o = ViewState["SelectedMonthText"];
				if(o!=null)
					return (string)o;
				return "&gt;&gt;";
			}
			set
			{
				ViewState["SelectedMonthText"] = value;
			}
		}

		public TableItemStyle SelectorStyle
		{
			get
			{
				if(selectorStyle==null)
					selectorStyle = new TableItemStyle();
				return selectorStyle;
			}
		}
		
		public string SelectedWeekText
		{
			get
			{
				object o = ViewState["SelectedWeekText"];
				if(o!=null)
					return (string)o;
				return "&gt;";
			}
			set
			{
				ViewState["SelectedWeekText"] = value;
			}
		}
		
		public bool ShowDayHeader
		{
			get
			{
				object o = ViewState["ShowDayHeader"];
				if(o!=null)
					return (bool)o;
				return true;
			}
			set
			{
				ViewState["ShowDayHeader"] = value;
			}
		}
		
		public bool ShowGridLines
		{
			get
			{
				object o = ViewState["ShowGridLines"];
				if(o!=null)
					return (bool)o;
				return false;
			}
			set
			{
				ViewState["ShowGridLines"] = value;
			}
		}
		
		public bool ShowNextPrevMonth
		{
			get
			{
				object o = ViewState["ShowNextPrevMonth"];
				if(o!=null)
					return (bool)o;
				return true;
			}
			set
			{
				ViewState["ShowNextPrevMonth"] = value;
			}
		}
		
		public bool ShowTitle
		{
			get
			{
				object o = ViewState["ShowTitle"];
				if(o!=null)
					return (bool)o;
				return true;
			}
			set
			{
				ViewState["ShowTitle"] = value;
			}
		}

		public TitleFormat TitleFormat
		{
			get
			{
				object o = ViewState["TitleFormat"];
				if(o!=null)
					return (TitleFormat)o;
				return TitleFormat.MonthYear;
			}
			set
			{
				if(!System.Enum.IsDefined(typeof(TitleFormat), value))
					throw new ArgumentException();
				ViewState["TitleFormat"] = value;
			}
		}
		
		public TableItemStyle TitleStyle
		{
			get
			{
				if(titleStyle==null)
					titleStyle = new TableItemStyle();
				return titleStyle;
			}
		}
		
		public TableItemStyle TodayDayStyle
		{
			get
			{
				if(todayDayStyle==null)
					todayDayStyle = new TableItemStyle();
				return todayDayStyle;
			}
		}
		
		public DateTime TodaysDate
		{
			get
			{
				object o = ViewState["TodaysDate"];
				if(o!=null)
					return (DateTime)o;
				return DateTime.Today;
			}
			set
			{
				ViewState["TodaysDate"] = value;
			}
		}
		
		public DateTime VisibleDate
		{
			get
			{
				object o = ViewState["VisibleDate"];
				if(o!=null)
					return (DateTime)o;
				return DateTime.MinValue;
			}
			set
			{
				ViewState["VisibleDate"] = value;
			}
		}
		
		public TableItemStyle WeekendDayStyle
		{
			get
			{
				if(weekendDayStyle == null)
					weekendDayStyle = new TableItemStyle();
				return weekendDayStyle;
			}
		}
		
		public event DayRenderEventHandler DayRender
		{
			add
			{
				Events.AddHandler(DayRenderEvent, value);
			}
			remove
			{
				Events.RemoveHandler(DayRenderEvent, value);
			}
		}
		
		public event EventHandler SelectionChanged
		{
			add
			{
				Events.AddHandler(SelectionChangedEvent, value);
			}
			remove
			{
				Events.RemoveHandler(SelectionChangedEvent, value);
			}
		}

		public event MonthChangedEventHandler VisibleMonthChanged
		{
			add
			{
				Events.AddHandler(VisibleMonthChangedEvent, value);
			}
			remove
			{
				Events.RemoveHandler(VisibleMonthChangedEvent, value);
			}
		}
		
		protected virtual void OnDayRender(TableCell cell, CalendarDay day)
		{
			if(Events!=null)
			{
				DayRenderEventHandler dreh = (DayRenderEventHandler)(Events[DayRenderEvent]);
				if(dreh!=null)
					dreh(this, new DayRenderEventArgs(cell, day));
			}
		}
		
		protected virtual void OnSelectionChanged()
		{
			if(Events!=null)
			{
				EventHandler eh = (EventHandler)(Events[SelectionChangedEvent]);
				if(eh!=null)
					eh(this, new EventArgs());
			}
		}
		
		protected virtual void OnVisibleMonthChanged(DateTime newDate, DateTime prevDate)
		{
			if(Events!=null)
			{
				MonthChangedEventHandler mceh = (MonthChangedEventHandler)(Events[VisibleMonthChangedEvent]);
				if(mceh!=null)
					mceh(this, new MonthChangedEventArgs(newDate, prevDate));
			}
		}
		
		public void RaisePostBackEvent(string eventArgument)
		{
			//TODO: Implement Me
			// Written to keep compile get going
			throw new NotImplementedException();
		}
		
		protected override void Render(HtmlTextWriter writer)
		{
			//TODO: Implement me
			throw new NotImplementedException();
			globCal = DateTimeFormatInfo.CurrentInfo.Calendar;
			SetFirstCalendarDay(GetEffectiveVisibleDate());
			/*
			 * ForeColor else defaultTextColor
			 * Draw a table
			 * if(ControlStyleCreated())
			 * 	then
			 * {
			 *	 ApplyStyle(ControlStyle)
			 * }
			 * GridLines?
			 * RenderBeginTag(writer)
			 * RenderTitle(writer, visibleDate from GetEffectiveVisibleDate, this.SelectionMode, IsEnabled)
			 * if(ShowHeader)
			 *  RenderHeader(writer, visibleDate, SelectionMode, IsEnabled, 
			 * RenderAllDays
			 * RenderEndTag(writer)
			 */
		}
		
		protected override ControlCollection CreateControlCollection()
		{
			return new EmptyControlCollection(this);
		}
		
		protected override void LoadViewState(object savedState)
		{
			if(savedState!=null)
			{
				//TODO: Implement me
				//object[] states = (object[]) savedState;
				//loadViewState of all the states/styles
			}
			throw new NotImplementedException();
		}
		
		protected override object SaveViewState()
		{
			//TODO: Implement me
			// SaveViewState of all the styles
			throw new NotImplementedException();
		}
		
		protected override void TrackViewState()
		{
			base.TrackViewState();
			if(titleStyle!=null)
			{
				titleStyle.TrackViewState();
			}
			if(nextPrevStyle!=null)
			{
				nextPrevStyle.TrackViewState();
			}
			if(dayStyle!=null)
			{
				dayStyle.TrackViewState();
			}
			if(dayHeaderStyle!=null)
			{
				dayHeaderStyle.TrackViewState();
			}
			if(todayDayStyle!=null)
			{
				todayDayStyle.TrackViewState();
			}
			if(weekendDayStyle!=null)
			{
				weekendDayStyle.TrackViewState();
			}
			if(otherMonthStyle!=null)
			{
				otherMonthStyle.TrackViewState();
			}
			if(selectedDayStyle!=null)
			{
				selectedDayStyle.TrackViewState();
			}
			if(selectorStyle!=null)
			{
				selectorStyle.TrackViewState();
			}
		}
		
		//TODO: Recheck, I am through with all the functions?
		
		private void RenderAllDays(HtmlTextWriter writer, DateTime firstDay, DateTime activeDate, CalendarSelectionMode mode, bool isActive, bool isDownLevel)
		{
			throw new NotImplementedException();
			//TODO: Implement me
			/*
			 * "<tr>"
			 * "</tr>"
			 */
		}
		
		private void RenderHeader(HtmlTextWriter writer, DateTime firstDay, CalendarSelectionMode mode, bool isActive, bool isDownLevel)
		{
			throw new NotImplementedException();
			//TODO: Implement Me
			/*
			 * "<tr>"
			 * "</tr>"
			 */
		}
		
		private void RenderTitle(HtmlTextWriter writer, DateTime visibleDate, CalendarSelectionMode mode, bool isActive)
		{
			throw new NotImplementedException();
			//TODO: Implement me
			/*
			 * Make a row with the following contents: "<tr>"
			 * Draw a table, with cell having the following properties
			 * if(mode==CalendarSelectionMode.DayWeek || mode==CalendarSelectionMode.DayWeekMonth)
			 *	then draw a column with colspan=8
			 * else
			 *	draw with colspan=7
			 * set gridlines?
			 * set width
			 * set cellspacing
			 * ApplyStyleToTitle(table, cell, style)
			 * RenderBeginTag(writer)
			 * RenderBeginTag(writer)
			 * "<tr>"
			 * -> The next/previous months things
			 * GetCalendarText("previousMonth", PrevMonthText, NextPrevStyle.ForeColor, isActive)
			 * RenderCalendarCell(writer, cell, ^^^)
			 * ..
			 * ..
			 * Then for NextMonthText
			 * "</tr>"
			 * "</tr>"
			 */
		}
		
		private void ApplyStyleToTitle(Table table, TableCell cell, TableItemStyle style)
		{
			throw new NotImplementedException();
			//TODO: Implement me
			/*
			 * Font
			 * Background color
			 * Foreground color
			 * Border color
			 * Border width
			 * Border style
			 * Vertical alignment
			 */
		}
		
		private void RenderCalendarCell(HtmlTextWriter writer, TableCell cell, string text)
		{
			cell.RenderBeginTag(writer);
			writer.Write(text);
			cell.RenderEndTag(writer);
		}
		
		private DateTime SetFirstCalendarDay(DateTime visibleDate)
		{
			globCal = visibleDate;
			throw new NotImplementedException();
			//TODO: Implement me
		}
		
		private DateTime GetEffectiveVisibleDate()
		{
			DateTime dt = VisibleDate;
			if(dt.Equals(DateTime.MinValue))
			{
				dt = TodaysDate;
			}
			return new DateTime(globCal.GetYear(dt), globCal.GetMonth(dt), globCal.GetDayOfMonth(dt), globCal);
		}
		
		/*
		 * Creates text to be displayed, with all attributes if to be
		 * shown as a hyperlink
		 */
		private string GetCalendarText(string eventArg, string text, Color foreground, bool isLink)
		{
			if(isLink)
			{
				StringBuilder dispVal = new StringBuilder();
				dispVal.Append("<a href=\"");
				dispVal.Append(Page.GetPostBackClientHyperlink(this, eventArg));
				dispVal.Append("\" style=\"color: ");
				if(foreground.IsEmpty)
				{
					dispVal.Append(ColorTranslater.ToHtml(defaultTextColor);
				} else
				{
					dispVal.Append(ColorTranslater.ToHtml(foreground);
				}
				dispVal.Append("\">");
				dispVal.Append(text);
				dispVal.Append("</a>");
				return dispVal.ToString();
			}
			return text;
		}

		private string GetHtmlForCell(TableCell cell, bool showLinks)
		{
			StringWriter sw = new StringWriter();
			HtmlTextWriter htw = new HtmlTextWriter(sw);
			RenderBeginTag(htw);
			if(showLinks)
			{
				//sw.Write(GetCalendarText(,,true, ForeColor));
				//TODO: Implement me
			}
			throw new NotImplementedException();
		}
	}
}