err.no Git - sope/blob - sope-ical/NGiCal/iCalRecurrenceCalculator.m

   1 /*
   2   Copyright (C) 2004-2007 SKYRIX Software AG
   3   Copyright (C) 2007      Helge Hess
   4
   5   This file is part of SOPE.
   6
   7   SOPE is free software; you can redistribute it and/or modify it under
   8   the terms of the GNU Lesser General Public License as published by the
   9   Free Software Foundation; either version 2, or (at your option) any
  10   later version.
  11
  12   SOPE is distributed in the hope that it will be useful, but WITHOUT ANY
  13   WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15   License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public
  18   License along with SOPE; see the file COPYING.  If not, write to the
  19   Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20   02111-1307, USA.
  21 */
  22
  23 #include "iCalRecurrenceCalculator.h"
  24 #include <NGExtensions/NGCalendarDateRange.h>
  25 #include "iCalRecurrenceRule.h"
  26 #include "NSCalendarDate+ICal.h"
  27 #include "common.h"
  28
  29 /* class cluster */
  30
  31
  32 /* Private */
  33
  34 @interface iCalRecurrenceCalculator (PrivateAPI)
  35 - (NSCalendarDate *)lastInstanceStartDate;
  36
  37 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn;
  38 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay;
  39 - (unsigned)offsetFromSundayForCurrentWeekStart;
  40
  41 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn;
  42 @end
  43
  44 @implementation iCalRecurrenceCalculator
  45
  46 static Class NSCalendarDateClass     = Nil;
  47 static Class iCalRecurrenceRuleClass = Nil;
  48 static Class dailyCalcClass   = Nil;
  49 static Class weeklyCalcClass  = Nil;
  50 static Class monthlyCalcClass = Nil;
  51 static Class yearlyCalcClass  = Nil;
  52
  53 + (void)initialize {
  54   static BOOL didInit = NO;
  55
  56   if (didInit) return;
  57   didInit = YES;
  58
  59   NSCalendarDateClass     = [NSCalendarDate class];
  60   iCalRecurrenceRuleClass = [iCalRecurrenceRule class];
  61
  62   dailyCalcClass   = NSClassFromString(@"iCalDailyRecurrenceCalculator");
  63   weeklyCalcClass  = NSClassFromString(@"iCalWeeklyRecurrenceCalculator");
  64   monthlyCalcClass = NSClassFromString(@"iCalMonthlyRecurrenceCalculator");
  65   yearlyCalcClass  = NSClassFromString(@"iCalYearlyRecurrenceCalculator");
  66 }
  67
  68 /* factory */
  69
  70 + (id)recurrenceCalculatorForRecurrenceRule:(iCalRecurrenceRule *)_rrule
  71   withFirstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
  72 {
  73   return [[[self alloc] initWithRecurrenceRule:_rrule
  74                         firstInstanceCalendarDateRange:_range] autorelease];
  75 }
  76
  77 /* complex calculation convenience */
  78
  79 + (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r
  80   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_fir
  81   recurrenceRules:(NSArray *)_rRules
  82   exceptionRules:(NSArray *)_exRules
  83   exceptionDates:(NSArray *)_exDates
  84 {
  85   id                       rule;
  86   iCalRecurrenceCalculator *calc;
  87   NSMutableArray           *ranges;
  88   NSMutableArray           *exDates;
  89   unsigned                 i, count, rCount;
  90
  91   ranges = [NSMutableArray arrayWithCapacity:64];
  92
  93   for (i = 0, count  = [_rRules count]; i < count; i++) {
  94     NSArray *rs;
  95
  96     rule = [_rRules objectAtIndex:i];
  97     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
  98       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
  99
 100     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 101                  withFirstInstanceCalendarDateRange:_fir];
 102     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 103     [ranges addObjectsFromArray:rs];
 104   }
 105
 106   if ([ranges count] == 0)
 107     return nil;
 108
 109   /* test if any exceptions do match */
 110
 111   for (i = 0, count = [_exRules count]; i < count; i++) {
 112     NSArray *rs;
 113
 114     rule = [_exRules objectAtIndex:i];
 115     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
 116       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
 117
 118     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 119                  withFirstInstanceCalendarDateRange:_fir];
 120     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 121     [ranges removeObjectsInArray:rs];
 122   }
 123
 124   if (![ranges isNotEmpty])
 125     return nil;
 126
 127   /* exception dates */
 128
 129   if ((count = [_exDates count]) == 0)
 130     return ranges;
 131
 132   /* sort out exDates not within range */
 133
 134   exDates = [NSMutableArray arrayWithCapacity:count];
 135   for (i = 0; i < count; i++) {
 136     id exDate;
 137
 138     exDate = [_exDates objectAtIndex:i];
 139     if (![exDate isKindOfClass:NSCalendarDateClass])
 140       exDate = [NSCalendarDate calendarDateWithICalRepresentation:exDate];
 141
 142     if ([_r containsDate:exDate])
 143       [exDates addObject:exDate];
 144   }
 145
 146   /* remove matching exDates from ranges */
 147
 148   if ((count = [exDates count]) == 0)
 149     return ranges;
 150
 151   for (i = 0, rCount = [ranges count]; i < count; i++) {
 152     NSCalendarDate      *exDate;
 153     NGCalendarDateRange *r;
 154     unsigned            k;
 155
 156     exDate = [exDates objectAtIndex:i];
 157     for (k = 0; k < rCount; k++) {
 158       unsigned rIdx;
 159
 160       rIdx = (rCount - k) - 1;
 161       r    = [ranges objectAtIndex:rIdx];
 162       if ([r containsDate:exDate]) {
 163         [ranges removeObjectAtIndex:rIdx];
 164         rCount--;
 165         break; /* this is safe because we know that ranges don't overlap */
 166       }
 167     }
 168   }
 169   return ranges;
 170 }
 171
 172
 173 /* init */
 174
 175 - (id)initWithRecurrenceRule:(iCalRecurrenceRule *)_rrule
 176   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
 177 {
 178   iCalRecurrenceFrequency freq;
 179   Class calcClass = Nil;
 180
 181   freq = [_rrule frequency];
 182   if (freq == iCalRecurrenceFrequenceDaily)
 183     calcClass = dailyCalcClass;
 184   else if (freq == iCalRecurrenceFrequenceWeekly)
 185     calcClass = weeklyCalcClass;
 186   else if (freq == iCalRecurrenceFrequenceMonthly)
 187     calcClass = monthlyCalcClass;
 188   else if (freq == iCalRecurrenceFrequenceYearly)
 189     calcClass = yearlyCalcClass;
 190   else {
 191     [self errorWithFormat:@"unsupported rrule frequency: %@", _rrule];
 192     calcClass = Nil;
 193     [self release];
 194     return nil;
 195   }
 196
 197   [self autorelease]; // TODO: why autorelease?
 198   if (calcClass == Nil)
 199     return nil;
 200
 201   if ((self = [[calcClass alloc] init]) != nil) {
 202     self->rrule      = [_rrule retain];
 203     self->firstRange = [_range retain];
 204   }
 205   return self;
 206 }
 207
 208 - (void)dealloc {
 209   [self->firstRange release];
 210   [self->rrule      release];
 211   [super dealloc];
 212 }
 213
 214 /* helpers */
 215
 216 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn {
 217   return (unsigned)((int)(_jn + 1.5)) % 7;
 218 }
 219
 220 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay {
 221   unsigned offset;
 222
 223   switch (_weekDay) {
 224     case iCalWeekDaySunday:    offset = 0; break;
 225     case iCalWeekDayMonday:    offset = 1; break;
 226     case iCalWeekDayTuesday:   offset = 2; break;
 227     case iCalWeekDayWednesday: offset = 3; break;
 228     case iCalWeekDayThursday:  offset = 4; break;
 229     case iCalWeekDayFriday:    offset = 5; break;
 230     case iCalWeekDaySaturday:  offset = 6; break;
 231     default:                   offset = 0; break;
 232   }
 233   return offset;
 234 }
 235
 236 - (unsigned)offsetFromSundayForCurrentWeekStart {
 237   return [self offsetFromSundayForWeekDay:[self->rrule weekStart]];
 238 }
 239
 240 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn {
 241   unsigned    day;
 242   iCalWeekDay weekDay;
 243
 244   day = [self offsetFromSundayForJulianNumber:_jn];
 245   switch (day) {
 246     case 0:  weekDay = iCalWeekDaySunday;    break;
 247     case 1:  weekDay = iCalWeekDayMonday;    break;
 248     case 2:  weekDay = iCalWeekDayTuesday;   break;
 249     case 3:  weekDay = iCalWeekDayWednesday; break;
 250     case 4:  weekDay = iCalWeekDayThursday;  break;
 251     case 5:  weekDay = iCalWeekDayFriday;    break;
 252     case 6:  weekDay = iCalWeekDaySaturday;  break;
 253     default:
 254       [self errorWithFormat:@"got unexpected weekday: %d", day];
 255       weekDay = iCalWeekDaySunday;
 256       break; /* keep compiler happy */
 257   }
 258   return weekDay;
 259 }
 260
 261 /* calculation */
 262
 263 - (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r{
 264   return nil; /* subclass responsibility */
 265 }
 266 - (BOOL)doesRecurrWithinCalendarDateRange:(NGCalendarDateRange *)_range {
 267   NSArray *ranges;
 268
 269   ranges = [self recurrenceRangesWithinCalendarDateRange:_range];
 270   return (ranges == nil || [ranges count] == 0) ? NO : YES;
 271 }
 272
 273 - (NGCalendarDateRange *)firstInstanceCalendarDateRange {
 274   return self->firstRange;
 275 }
 276
 277 - (NGCalendarDateRange *)lastInstanceCalendarDateRange {
 278   NSCalendarDate *start, *end;
 279
 280   if ((start = [self lastInstanceStartDate]) == nil)
 281     return nil;
 282
 283   end   = [start addTimeInterval:[self->firstRange duration]];
 284   return [NGCalendarDateRange calendarDateRangeWithStartDate:start
 285                               endDate:end];
 286 }
 287
 288 - (NSCalendarDate *)lastInstanceStartDate {
 289   NSCalendarDate *until;
 290
 291   /*
 292      NOTE: this is horribly inaccurate and doesn't even consider the use
 293            of repeatCount. It MUST be implemented by subclasses properly!
 294            However, it does the trick for SOGo 1.0 - that's why it's left here.
 295   */
 296   if ((until = [self->rrule untilDate]) != nil)
 297     return until;
 298
 299   return nil;
 300 }
 301
 302
 303 /* descriptions */
 304
 305 - (NSString *)description {
 306   NSMutableString *ms;
 307
 308   ms = [NSMutableString stringWithCapacity:128];
 309   [ms appendFormat:@"<0x%p[%@]:", self, NSStringFromClass([self class])];
 310
 311   if (self->rrule != nil)
 312     [ms appendFormat:@" rrule=%@", self->rrule];
 313
 314   if (self->firstRange != nil)
 315     [ms appendFormat:@" range1=%@", self->firstRange];
 316
 317   [ms appendString:@">"];
 318   return ms;
 319 }
 320
 321 @end /* iCalRecurrenceCalculator */