err.no Git - scalable-opengroupware.org/blob - SOPE/NGCards/iCalRecurrenceCalculator.m

   1 /*
   2   Copyright (C) 2004-2005 SKYRIX Software AG
   3
   4   This file is part of SOPE.
   5
   6   SOPE is free software; you can redistribute it and/or modify it under
   7   the terms of the GNU Lesser General Public License as published by the
   8   Free Software Foundation; either version 2, or (at your option) any
   9   later version.
  10
  11   SOPE is distributed in the hope that it will be useful, but WITHOUT ANY
  12   WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  14   License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with SOPE; see the file COPYING.  If not, write to the
  18   Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19   02111-1307, USA.
  20 */
  21
  22 #import <NGExtensions/NSCalendarDate+misc.h>
  23 #import <NGExtensions/NGCalendarDateRange.h>
  24 #import <NGExtensions/NSNull+misc.h>
  25 #import <NGExtensions/NSObject+Logs.h>
  26
  27 #import "iCalRecurrenceRule.h"
  28 #import "NSCalendarDate+ICal.h"
  29
  30
  31 #import "iCalRecurrenceCalculator.h"
  32
  33 /* class cluster */
  34
  35
  36 /* Private */
  37
  38 @interface iCalRecurrenceCalculator (PrivateAPI)
  39 - (NSCalendarDate *)lastInstanceStartDate;
  40
  41 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn;
  42 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay;
  43 - (unsigned)offsetFromSundayForCurrentWeekStart;
  44
  45 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn;
  46 @end
  47
  48 @implementation iCalRecurrenceCalculator
  49
  50 static Class NSCalendarDateClass     = Nil;
  51 static Class iCalRecurrenceRuleClass = Nil;
  52 static Class dailyCalcClass   = Nil;
  53 static Class weeklyCalcClass  = Nil;
  54 static Class monthlyCalcClass = Nil;
  55 static Class yearlyCalcClass  = Nil;
  56
  57 + (void)initialize {
  58   static BOOL didInit = NO;
  59
  60   if (didInit) return;
  61   didInit = YES;
  62
  63   NSCalendarDateClass     = [NSCalendarDate class];
  64   iCalRecurrenceRuleClass = [iCalRecurrenceRule class];
  65
  66   dailyCalcClass   = NSClassFromString(@"iCalDailyRecurrenceCalculator");
  67   weeklyCalcClass  = NSClassFromString(@"iCalWeeklyRecurrenceCalculator");
  68   monthlyCalcClass = NSClassFromString(@"iCalMonthlyRecurrenceCalculator");
  69   yearlyCalcClass  = NSClassFromString(@"iCalYearlyRecurrenceCalculator");
  70 }
  71
  72 /* factory */
  73
  74 + (id)recurrenceCalculatorForRecurrenceRule:(iCalRecurrenceRule *)_rrule
  75   withFirstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
  76 {
  77   return [[[self alloc] initWithRecurrenceRule:_rrule
  78                         firstInstanceCalendarDateRange:_range] autorelease];
  79 }
  80
  81 /* complex calculation convenience */
  82
  83 + (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r
  84   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_fir
  85   recurrenceRules:(NSArray *)_rRules
  86   exceptionRules:(NSArray *)_exRules
  87   exceptionDates:(NSArray *)_exDates
  88 {
  89   id                       rule;
  90   iCalRecurrenceCalculator *calc;
  91   NSMutableArray           *ranges;
  92   NSMutableArray           *exDates;
  93   unsigned                 i, count, rCount;
  94
  95   ranges = [NSMutableArray arrayWithCapacity:64];
  96
  97   for (i = 0, count  = [_rRules count]; i < count; i++) {
  98     NSArray *rs;
  99
 100     rule = [_rRules objectAtIndex:i];
 101     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
 102       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
 103
 104     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 105                  withFirstInstanceCalendarDateRange:_fir];
 106
 107     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 108     [ranges addObjectsFromArray:rs];
 109   }
 110
 111   if ([ranges count] == 0)
 112     return nil;
 113
 114   /* test if any exceptions do match */
 115
 116   for (i = 0, count = [_exRules count]; i < count; i++) {
 117     NSArray *rs;
 118
 119     rule = [_exRules objectAtIndex:i];
 120     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
 121       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
 122
 123     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 124                  withFirstInstanceCalendarDateRange:_fir];
 125     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 126     [ranges removeObjectsInArray:rs];
 127   }
 128
 129   if (![ranges isNotEmpty])
 130     return nil;
 131
 132   /* exception dates */
 133
 134   if ((count = [_exDates count]) == 0)
 135     return ranges;
 136
 137   /* sort out exDates not within range */
 138
 139   exDates = [NSMutableArray arrayWithCapacity:count];
 140   for (i = 0; i < count; i++) {
 141     id exDate;
 142
 143     exDate = [_exDates objectAtIndex:i];
 144     if (![exDate isKindOfClass:NSCalendarDateClass])
 145       exDate = [NSCalendarDate calendarDateWithICalRepresentation:exDate];
 146
 147     if ([_r containsDate:exDate])
 148       [exDates addObject:exDate];
 149   }
 150
 151   /* remove matching exDates from ranges */
 152
 153   if ((count = [exDates count]) == 0)
 154     return ranges;
 155
 156   for (i = 0, rCount = [ranges count]; i < count; i++) {
 157     NSCalendarDate      *exDate;
 158     NGCalendarDateRange *r;
 159     unsigned            k;
 160
 161     exDate = [exDates objectAtIndex:i];
 162
 163     for (k = 0; k < rCount; k++) {
 164       unsigned rIdx;
 165
 166       rIdx = (rCount - k) - 1;
 167       r    = [ranges objectAtIndex:rIdx];
 168       if ([r containsDate:exDate]) {
 169         [ranges removeObjectAtIndex:rIdx];
 170         rCount--;
 171         break; /* this is safe because we know that ranges don't overlap */
 172       }
 173     }
 174   }
 175   return ranges;
 176 }
 177
 178
 179 /* init */
 180
 181 - (id)initWithRecurrenceRule:(iCalRecurrenceRule *)_rrule
 182   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
 183 {
 184   iCalRecurrenceFrequency freq;
 185   Class calcClass = Nil;
 186
 187   freq = [_rrule frequency];
 188   if (freq == iCalRecurrenceFrequenceDaily)
 189     calcClass = dailyCalcClass;
 190   else if (freq == iCalRecurrenceFrequenceWeekly)
 191     calcClass = weeklyCalcClass;
 192   else if (freq == iCalRecurrenceFrequenceMonthly)
 193     calcClass = monthlyCalcClass;
 194   else if (freq == iCalRecurrenceFrequenceYearly)
 195     calcClass = yearlyCalcClass;
 196   else {
 197     [self errorWithFormat:@"unsupported rrule frequency: %@", _rrule];
 198     calcClass = Nil;
 199     [self release];
 200     return nil;
 201   }
 202
 203   [self autorelease]; // TODO: why autorelease?
 204   if (calcClass == Nil)
 205     return nil;
 206
 207   if ((self = [[calcClass alloc] init]) != nil) {
 208     self->rrule      = [_rrule retain];
 209     self->firstRange = [_range retain];
 210   }
 211   return self;
 212 }
 213
 214 - (void)dealloc {
 215   [self->firstRange release];
 216   [self->rrule      release];
 217   [super dealloc];
 218 }
 219
 220 /* helpers */
 221
 222 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn {
 223   return (unsigned)((int)(_jn + 1.5)) % 7;
 224 }
 225
 226 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay {
 227   unsigned offset;
 228
 229   switch (_weekDay) {
 230     case iCalWeekDaySunday:    offset = 0; break;
 231     case iCalWeekDayMonday:    offset = 1; break;
 232     case iCalWeekDayTuesday:   offset = 2; break;
 233     case iCalWeekDayWednesday: offset = 3; break;
 234     case iCalWeekDayThursday:  offset = 4; break;
 235     case iCalWeekDayFriday:    offset = 5; break;
 236     case iCalWeekDaySaturday:  offset = 6; break;
 237     default:                   offset = 0; break;
 238   }
 239   return offset;
 240 }
 241
 242 - (unsigned)offsetFromSundayForCurrentWeekStart {
 243   return [self offsetFromSundayForWeekDay:[self->rrule weekStart]];
 244 }
 245
 246 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn {
 247   unsigned    day;
 248   iCalWeekDay weekDay;
 249
 250   day = [self offsetFromSundayForJulianNumber:_jn];
 251   switch (day) {
 252     case 0:  weekDay = iCalWeekDaySunday;    break;
 253     case 1:  weekDay = iCalWeekDayMonday;    break;
 254     case 2:  weekDay = iCalWeekDayTuesday;   break;
 255     case 3:  weekDay = iCalWeekDayWednesday; break;
 256     case 4:  weekDay = iCalWeekDayThursday;  break;
 257     case 5:  weekDay = iCalWeekDayFriday;    break;
 258     case 6:  weekDay = iCalWeekDaySaturday;  break;
 259     default:
 260       [self errorWithFormat:@"got unexpected weekday: %d", day];
 261       weekDay = iCalWeekDaySunday;
 262       break; /* keep compiler happy */
 263   }
 264   return weekDay;
 265 }
 266
 267 /* calculation */
 268
 269 - (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r{
 270   return nil; /* subclass responsibility */
 271 }
 272 - (BOOL)doesRecurrWithinCalendarDateRange:(NGCalendarDateRange *)_range {
 273   NSArray *ranges;
 274
 275   ranges = [self recurrenceRangesWithinCalendarDateRange:_range];
 276   return (ranges == nil || [ranges count] == 0) ? NO : YES;
 277 }
 278
 279 - (NGCalendarDateRange *)firstInstanceCalendarDateRange {
 280   return self->firstRange;
 281 }
 282
 283 - (NGCalendarDateRange *)lastInstanceCalendarDateRange {
 284   NSCalendarDate *start, *end;
 285
 286   if ((start = [self lastInstanceStartDate]) == nil)
 287     return nil;
 288
 289   end   = [start addTimeInterval:[self->firstRange duration]];
 290   return [NGCalendarDateRange calendarDateRangeWithStartDate:start
 291                               endDate:end];
 292 }
 293
 294 - (NSCalendarDate *)lastInstanceStartDate {
 295   NSCalendarDate *until;
 296
 297   /*
 298      NOTE: this is horribly inaccurate and doesn't even consider the use
 299            of repeatCount. It MUST be implemented by subclasses properly!
 300            However, it does the trick for SOGo 1.0 - that's why it's left here.
 301   */
 302   if ((until = [self->rrule untilDate]) != nil)
 303     return until;
 304
 305   return nil;
 306 }
 307
 308 @end /* iCalRecurrenceCalculator */