#include "CalendarView.h"
#include "GNUstep.h"

@implementation CalendarView

#define isLeapYear(year) (((year % 4) == 0 && ((year % 100) != 0)) || (year % 400) == 0)

static short numberOfDaysInMonth[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

- (void) awakeFromNib
{
  [self setDate: [NSCalendarDate calendarDate]];
}

- (NSCalendarDate *) date
{
  return date;
}

- (void) setDate: (NSCalendarDate *) newDate
{
   int i, currentDay, currentMonth, currentYear;
   int daysInMonth, startDayOfWeek, day;
   NSCalendarDate *firstDayOfMonth, *displayDate;;
   NSButtonCell *tempCell;

   ASSIGN(date, newDate);

   [label setStringValue: [date descriptionWithCalendarFormat: @"%b %Y"]];

   currentMonth = [date monthOfYear];
   currentYear = [date yearOfCommonEra];

   firstDayOfMonth = [NSCalendarDate dateWithYear: currentYear
                                            month: currentMonth
                                              day: 1
                                             hour: 0
                                           minute: 0
                                           second: 0
                                         timeZone: [NSTimeZone localTimeZone]];

   daysInMonth = numberOfDaysInMonth[currentMonth - 1];

   if ((currentMonth == 2) && (isLeapYear(currentYear)))
      daysInMonth++;

   startDayOfWeek = [firstDayOfMonth dayOfWeek];

   day = 1;

   for (i = 0; i < 42; i++)
   {
      tempCell = [dayMatrix cellWithTag: i];
      [tempCell setBordered: NO];

      if (i < startDayOfWeek || i >= (daysInMonth + startDayOfWeek))
      {
         [tempCell setEnabled: NO];
         [tempCell setTitle: @""];
      }
      else
      {
	 displayDate = [firstDayOfMonth dateByAddingYears: 0 months: 0
		                        days: day-1 hours: 0 minutes: 0 
					seconds: 0];
         [tempCell setEnabled: YES];
         [tempCell setTitle: [NSString stringWithFormat: @"%d", day++]];
	 if ([delegate respondsToSelector: @selector(calendarView:willDisplayCell:ofDate:)])
           {
	     [delegate calendarView: self
		       willDisplayCell: tempCell
		       ofDate: displayDate];
	   }
      }
   }

   currentDay = [date dayOfMonth];
   [dayMatrix selectCellWithTag: startDayOfWeek + currentDay - 1];

   // Send notification
   [[NSNotificationCenter defaultCenter]
	   postNotificationName: CalendarViewSelectionDidChangeNotification
	   object: self];
}

- (id) initWithFrame: (NSRect) rect
{
   int i, j, count=0;
   NSImage *rightArrow, *leftArrow;
   NSButtonCell *dayCell, *tempCell;
   NSArray *weekArray;
   NSRect frame;
   NSSize boxMargin, contentSize;

   [super initWithFrame: rect];

   calendarBox = [[NSBox alloc] initWithFrame: NSMakeRect(0, 0, rect.size.width, rect.size.height)];
   [calendarBox setBorderType: NSGrooveBorder];
   [calendarBox setTitlePosition: NSNoTitle];
   [calendarBox setAutoresizingMask: (NSViewWidthSizable | NSViewHeightSizable)];
   boxMargin = [calendarBox contentViewMargins];
   contentSize = [[calendarBox contentView] bounds].size;

   frame = NSMakeRect(18, 
		      contentSize.height-20, contentSize.width-36, 20);
   label = [[NSTextField alloc] initWithFrame: frame];
   [label setStringValue: @"This Year"];
   [label setBezeled: NO];
   [label setBackgroundColor: [NSColor windowBackgroundColor]];
   [label setEditable: NO];
   [label setSelectable: NO];
   [label setAlignment: NSCenterTextAlignment];
   [label setAutoresizingMask: (NSViewWidthSizable | NSViewMinYMargin)];

   leftArrow = [NSImage imageNamed: @"common_ArrowLeft.tif"];
   rightArrow = [NSImage imageNamed: @"common_ArrowRight.tif"];

   frame = NSMakeRect(0, contentSize.height-18,
		      20, 20);
   lastMonthButton = [[NSButton alloc] initWithFrame: frame];
   [lastMonthButton setImage: leftArrow];
   [lastMonthButton setImagePosition: NSImageOnly];
   [lastMonthButton setBordered: NO];
   [lastMonthButton setAutoresizingMask: (NSViewMaxXMargin | NSViewMinYMargin)];

   frame = NSMakeRect(contentSize.width-20, contentSize.height-18,
		      20, 20);
   nextMonthButton = [[NSButton alloc] initWithFrame: frame];
   [nextMonthButton setImage: rightArrow];
   [nextMonthButton setImagePosition: NSImageOnly];
   [nextMonthButton setBordered: NO];
   [nextMonthButton setAutoresizingMask: (NSViewMinXMargin | NSViewMinYMargin)];

   [lastMonthButton setTarget: self];
   [lastMonthButton setAction: @selector(updateDate:)];

   [nextMonthButton setTarget: self];
   [nextMonthButton setAction: @selector(updateDate:)];

   [calendarBox addSubview: label];
   [calendarBox addSubview: lastMonthButton];
   [calendarBox addSubview: nextMonthButton];
   RELEASE(label);
   RELEASE(lastMonthButton);
   RELEASE(nextMonthButton);

   weekArray = [NSArray arrayWithObjects: @"S", @"M", @"T", @"W",
                                          @"T", @"F", @"S", nil];

   dayCell = [[NSButtonCell alloc] initTextCell: @""];
   [dayCell setBordered: NO];
   [dayCell setShowsStateBy: NSOnOffButton];
   [dayCell setAlignment: NSCenterTextAlignment];
   [dayCell setFont: [NSFont userFontOfSize: 10]];

   frame = NSMakeRect(0, 0, contentSize.width, contentSize.height-20);
   dayMatrix = [[NSMatrix alloc] initWithFrame: frame
                                          mode: NSRadioModeMatrix
                                     prototype: dayCell
                                  numberOfRows: 7
                               numberOfColumns: 7];
   [dayMatrix setAutoresizingMask: (NSViewWidthSizable | 
	                            NSViewHeightSizable)];
   [dayMatrix setIntercellSpacing: NSMakeSize(0,0)];
   [dayMatrix setAutosizesCells: YES];

   for (j = 0; j < 7; j++)
   {
      tempCell = [dayMatrix cellAtRow: 0 column: j];
      [tempCell setTitle: [weekArray objectAtIndex: j]];
      [tempCell setAlignment: NSCenterTextAlignment];
      [tempCell setEnabled: NO];
   }

   RELEASE(dayCell);

   count = 0;

   for (i = 1; i < 7; i++)
      for (j = 0; j < 7; j++)
         {
           [[dayMatrix cellAtRow: i column: j] setTag: count++];
         }

   [dayMatrix setTarget: self];
   [dayMatrix setAction: @selector(updateDate:)];

   [calendarBox addSubview: dayMatrix];
   RELEASE(dayMatrix);

   [self addSubview: calendarBox];
   RELEASE(calendarBox);

   return self;
}

- (void) updateDate: (id) sender
{
   int j=0, k=0;
   NSCalendarDate *newDate;

   if (sender == lastMonthButton)
   {
      j = -1;
   }
   else if (sender == nextMonthButton)
   {
      j = 1;
   }
   else if (sender == dayMatrix)
   {
      k = [[[sender selectedCell] title] intValue] - [date dayOfMonth];
   }

   newDate = [date dateByAddingYears: 0
                              months: j
                                days: k
                               hours: 0
                             minutes: 0
                             seconds: 0];
   [self setDate: newDate];
}

- (void) dealloc
{
  [[NSNotificationCenter defaultCenter] removeObserver: delegate];
  RELEASE(date);
  RELEASE(delegate);
  [super dealloc];
}

- (void) setDelegate: (id) d
{
  ASSIGN(delegate, d);
  [[NSNotificationCenter defaultCenter] addObserver: delegate 
                        selector: @selector(calendarViewSelectionDidChange:) 
			name: CalendarViewSelectionDidChangeNotification
                        object: self];
}

- (id) delegate
{
  return delegate;
}

@end