err.no Git - sope/blob - sope-ical/NGiCal/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 #include "iCalRecurrenceCalculator.h"
  23 #include <NGExtensions/NGCalendarDateRange.h>
  24 #include "iCalRecurrenceRule.h"
  25 #include "NSCalendarDate+ICal.h"
  26 #include "common.h"
  27
  28 /* class cluster */
  29
  30
  31 /* Private */
  32
  33 @interface iCalRecurrenceCalculator (PrivateAPI)
  34 - (NSCalendarDate *)lastInstanceStartDate;
  35
  36 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn;
  37 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay;
  38 - (unsigned)offsetFromSundayForCurrentWeekStart;
  39
  40 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn;
  41 @end
  42
  43 @implementation iCalRecurrenceCalculator
  44
  45 static Class NSCalendarDateClass     = Nil;
  46 static Class iCalRecurrenceRuleClass = Nil;
  47 static Class dailyCalcClass   = Nil;
  48 static Class weeklyCalcClass  = Nil;
  49 static Class monthlyCalcClass = Nil;
  50 static Class yearlyCalcClass  = Nil;
  51
  52 + (void)initialize {
  53   static BOOL didInit = NO;
  54
  55   if (didInit) return;
  56   didInit = YES;
  57
  58   NSCalendarDateClass     = [NSCalendarDate class];
  59   iCalRecurrenceRuleClass = [iCalRecurrenceRule class];
  60
  61   dailyCalcClass   = NSClassFromString(@"iCalDailyRecurrenceCalculator");
  62   weeklyCalcClass  = NSClassFromString(@"iCalWeeklyRecurrenceCalculator");
  63   monthlyCalcClass = NSClassFromString(@"iCalMonthlyRecurrenceCalculator");
  64   yearlyCalcClass  = NSClassFromString(@"iCalYearlyRecurrenceCalculator");
  65 }
  66
  67 /* factory */
  68
  69 + (id)recurrenceCalculatorForRecurrenceRule:(iCalRecurrenceRule *)_rrule
  70   withFirstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
  71 {
  72   return [[[self alloc] initWithRecurrenceRule:_rrule
  73                         firstInstanceCalendarDateRange:_range] autorelease];
  74 }
  75
  76 /* complex calculation convenience */
  77
  78 + (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r
  79   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_fir
  80   recurrenceRules:(NSArray *)_rRules
  81   exceptionRules:(NSArray *)_exRules
  82   exceptionDates:(NSArray *)_exDates
  83 {
  84   id                       rule;
  85   iCalRecurrenceCalculator *calc;
  86   NSMutableArray           *ranges;
  87   NSMutableArray           *exDates;
  88   unsigned                 i, count, rCount;
  89
  90   ranges = [NSMutableArray arrayWithCapacity:64];
  91
  92   for (i = 0, count  = [_rRules count]; i < count; i++) {
  93     NSArray *rs;
  94
  95     rule = [_rRules objectAtIndex:i];
  96     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
  97       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
  98
  99     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 100                  withFirstInstanceCalendarDateRange:_fir];
 101     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 102     [ranges addObjectsFromArray:rs];
 103   }
 104
 105   if ([ranges count] == 0)
 106     return nil;
 107
 108   /* test if any exceptions do match */
 109
 110   for (i = 0, count = [_exRules count]; i < count; i++) {
 111     NSArray *rs;
 112
 113     rule = [_exRules objectAtIndex:i];
 114     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
 115       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
 116
 117     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 118                  withFirstInstanceCalendarDateRange:_fir];
 119     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 120     [ranges removeObjectsInArray:rs];
 121   }
 122
 123   if (![ranges isNotEmpty])
 124     return nil;
 125
 126   /* exception dates */
 127
 128   if ((count = [_exDates count]) == 0)
 129     return ranges;
 130
 131   /* sort out exDates not within range */
 132
 133   exDates = [NSMutableArray arrayWithCapacity:count];
 134   for (i = 0; i < count; i++) {
 135     id exDate;
 136
 137     exDate = [_exDates objectAtIndex:i];
 138     if (![exDate isKindOfClass:NSCalendarDateClass])
 139       exDate = [NSCalendarDate calendarDateWithICalRepresentation:exDate];
 140
 141     if ([_r containsDate:exDate])
 142       [exDates addObject:exDate];
 143   }
 144
 145   /* remove matching exDates from ranges */
 146
 147   if ((count = [exDates count]) == 0)
 148     return ranges;
 149
 150   for (i = 0, rCount = [ranges count]; i < count; i++) {
 151     NSCalendarDate      *exDate;
 152     NGCalendarDateRange *r;
 153     unsigned            k;
 154
 155     exDate = [exDates objectAtIndex:i];
 156     for (k = 0; k < rCount; k++) {
 157       unsigned rIdx;
 158
 159       rIdx = (rCount - k) - 1;
 160       r    = [ranges objectAtIndex:rIdx];
 161       if ([r containsDate:exDate]) {
 162         [ranges removeObjectAtIndex:rIdx];
 163         rCount--;
 164         break; /* this is safe because we know that ranges don't overlap */
 165       }
 166     }
 167   }
 168   return ranges;
 169 }
 170
 171
 172 /* init */
 173
 174 - (id)initWithRecurrenceRule:(iCalRecurrenceRule *)_rrule
 175   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
 176 {
 177   iCalRecurrenceFrequency freq;
 178   Class calcClass = Nil;
 179
 180   freq = [_rrule frequency];
 181   if (freq == iCalRecurrenceFrequenceDaily)
 182     calcClass = dailyCalcClass;
 183   else if (freq == iCalRecurrenceFrequenceWeekly)
 184     calcClass = weeklyCalcClass;
 185   else if (freq == iCalRecurrenceFrequenceMonthly)
 186     calcClass = monthlyCalcClass;
 187   else if (freq == iCalRecurrenceFrequenceYearly)
 188     calcClass = yearlyCalcClass;
 189   else {
 190     [self errorWithFormat:@"unsupported rrule frequency: %@", _rrule];
 191     calcClass = Nil;
 192     [self release];
 193     return nil;
 194   }
 195
 196   [self autorelease]; // TODO: why autorelease?
 197   if (calcClass == Nil)
 198     return nil;
 199
 200   if ((self = [[calcClass alloc] init]) != nil) {
 201     self->rrule      = [_rrule retain];
 202     self->firstRange = [_range retain];
 203   }
 204   return self;
 205 }
 206
 207 - (void)dealloc {
 208   [self->firstRange release];
 209   [self->rrule      release];
 210   [super dealloc];
 211 }
 212
 213 /* helpers */
 214
 215 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn {
 216   return (unsigned)((int)(_jn + 1.5)) % 7;
 217 }
 218
 219 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay {
 220   unsigned offset;
 221
 222   switch (_weekDay) {
 223     case iCalWeekDaySunday:    offset = 0; break;
 224     case iCalWeekDayMonday:    offset = 1; break;
 225     case iCalWeekDayTuesday:   offset = 2; break;
 226     case iCalWeekDayWednesday: offset = 3; break;
 227     case iCalWeekDayThursday:  offset = 4; break;
 228     case iCalWeekDayFriday:    offset = 5; break;
 229     case iCalWeekDaySaturday:  offset = 6; break;
 230     default:                   offset = 0; break;
 231   }
 232   return offset;
 233 }
 234
 235 - (unsigned)offsetFromSundayForCurrentWeekStart {
 236   return [self offsetFromSundayForWeekDay:[self->rrule weekStart]];
 237 }
 238
 239 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn {
 240   unsigned    day;
 241   iCalWeekDay weekDay;
 242
 243   day = [self offsetFromSundayForJulianNumber:_jn];
 244   switch (day) {
 245     case 0:  weekDay = iCalWeekDaySunday;    break;
 246     case 1:  weekDay = iCalWeekDayMonday;    break;
 247     case 2:  weekDay = iCalWeekDayTuesday;   break;
 248     case 3:  weekDay = iCalWeekDayWednesday; break;
 249     case 4:  weekDay = iCalWeekDayThursday;  break;
 250     case 5:  weekDay = iCalWeekDayFriday;    break;
 251     case 6:  weekDay = iCalWeekDaySaturday;  break;
 252     default:
 253       [self errorWithFormat:@"got unexpected weekday: %d", day];
 254       weekDay = iCalWeekDaySunday;
 255       break; /* keep compiler happy */
 256   }
 257   return weekDay;
 258 }
 259
 260 /* calculation */
 261
 262 - (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r{
 263   return nil; /* subclass responsibility */
 264 }
 265 - (BOOL)doesRecurrWithinCalendarDateRange:(NGCalendarDateRange *)_range {
 266   NSArray *ranges;
 267
 268   ranges = [self recurrenceRangesWithinCalendarDateRange:_range];
 269   return (ranges == nil || [ranges count] == 0) ? NO : YES;
 270 }
 271
 272 - (NGCalendarDateRange *)firstInstanceCalendarDateRange {
 273   return self->firstRange;
 274 }
 275
 276 - (NGCalendarDateRange *)lastInstanceCalendarDateRange {
 277   NSCalendarDate *start, *end;
 278
 279   if ((start = [self lastInstanceStartDate]) == nil)
 280     return nil;
 281
 282   end   = [start addTimeInterval:[self->firstRange duration]];
 283   return [NGCalendarDateRange calendarDateRangeWithStartDate:start
 284                               endDate:end];
 285 }
 286
 287 - (NSCalendarDate *)lastInstanceStartDate {
 288   NSCalendarDate *until;
 289
 290   /*
 291      NOTE: this is horribly inaccurate and doesn't even consider the use
 292            of repeatCount. It MUST be implemented by subclasses properly!
 293            However, it does the trick for SOGo 1.0 - that's why it's left here.
 294   */
 295   if ((until = [self->rrule untilDate]) != nil)
 296     return until;
 297
 298   return nil;
 299 }
 300
 301 @end /* iCalRecurrenceCalculator */