summaryrefslogblamecommitdiffstats
path: root/src/ical.c
blob: 4360a766d97225858587c59e2eabb3509284e15e (plain) (tree)
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256






































                                                                        



































































































































































































































































































































































































                                                                                





                                               



















































































































































































































































































































































































































































                                                                               
                           


















                                                                 
                                         
                             
                      











































































































































































































































































































































































                                                                               
/*
 * Calcurse - text-based organizer
 *
 * Copyright (c) 2004-2011 calcurse Development Team <misc@calcurse.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer in the documentation and/or other
 *        materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Send your feedback or comments to : misc@calcurse.org
 * Calcurse home page : http://calcurse.org
 *
 */

#include <sys/types.h>

#include "calcurse.h"

#define ICALDATEFMT      "%Y%m%d"
#define ICALDATETIMEFMT  "%Y%m%dT%H%M%S"

typedef enum {
  ICAL_VEVENT,
  ICAL_VTODO,
  ICAL_TYPES
} ical_types_e;

typedef enum {
  UNDEFINED,
  APPOINTMENT,
  EVENT
} ical_vevent_e;

typedef struct {
  enum recur_type type;
  int             freq;
  long            until;
  unsigned        count;
} ical_rpt_t;

static void ical_export_header (FILE *);
static void ical_export_recur_events (FILE *);
static void ical_export_events (FILE *);
static void ical_export_recur_apoints (FILE *);
static void ical_export_apoints (FILE *);
static void ical_export_todo (FILE *);
static void ical_export_footer (FILE *);

static char *ical_recur_type[RECUR_TYPES] =
  { "", "DAILY", "WEEKLY", "MONTHLY", "YEARLY" };

/* iCal alarm notification. */
static void
ical_export_valarm (FILE *stream)
{
  fputs ("BEGIN:VALARM\n", stream);
  pthread_mutex_lock (&nbar.mutex);
  fprintf (stream, "TRIGGER:-P%dS\n", nbar.cntdwn);
  pthread_mutex_unlock (&nbar.mutex);
  fputs ("ACTION:DISPLAY\n", stream);
  fputs ("END:VALARM\n", stream);
}

/* Export header. */
static void
ical_export_header (FILE *stream)
{
  fputs ("BEGIN:VCALENDAR\n", stream);
  fprintf (stream, "PRODID:-//calcurse//NONSGML v%s//EN\n", VERSION);
  fputs ("VERSION:2.0\n", stream);
}

/* Export footer. */
static void
ical_export_footer (FILE *stream)
{
  fputs ("END:VCALENDAR\n", stream);
}

/* Export recurrent events. */
static void
ical_export_recur_events (FILE *stream)
{
  llist_item_t *i, *j;
  char ical_date[BUFSIZ];

  LLIST_FOREACH (&recur_elist, i)
    {
      struct recur_event *rev = LLIST_GET_DATA (i);
      date_sec2date_fmt (rev->day, ICALDATEFMT, ical_date);
      fputs ("BEGIN:VEVENT\n", stream);
      fprintf (stream, "DTSTART:%s\n", ical_date);
      fprintf (stream, "RRULE:FREQ=%s;INTERVAL=%d",
               ical_recur_type[rev->rpt->type], rev->rpt->freq);

      if (rev->rpt->until != 0)
        {
          date_sec2date_fmt (rev->rpt->until, ICALDATEFMT, ical_date);
          fprintf (stream, ";UNTIL=%s\n", ical_date);
        }
      else
        fputc ('\n', stream);

      if (LLIST_FIRST (&rev->exc))
        {
          fputs ("EXDATE:", stream);
          LLIST_FOREACH (&rev->exc, j)
            {
              struct excp *exc = LLIST_GET_DATA (j);
              date_sec2date_fmt (exc->st, ICALDATEFMT, ical_date);
              fprintf (stream, "%s", ical_date);
              if (LLIST_NEXT (j))
                fputc (',', stream);
              else
                fputc ('\n', stream);
            }
        }

      fprintf (stream, "SUMMARY:%s\n", rev->mesg);
      fputs ("END:VEVENT\n", stream);
    }
}

/* Export events. */
static void
ical_export_events (FILE *stream)
{
  llist_item_t *i;
  char ical_date[BUFSIZ];

  LLIST_FOREACH (&eventlist, i)
    {
      struct event *ev = LLIST_TS_GET_DATA (i);
      date_sec2date_fmt (ev->day, ICALDATEFMT, ical_date);
      fputs ("BEGIN:VEVENT\n", stream);
      fprintf (stream, "DTSTART:%s\n", ical_date);
      fprintf (stream, "SUMMARY:%s\n", ev->mesg);
      fputs ("END:VEVENT\n", stream);
    }
}

/* Export recurrent appointments. */
static void
ical_export_recur_apoints (FILE *stream)
{
  llist_item_t *i, *j;
  char ical_datetime[BUFSIZ];
  char ical_date[BUFSIZ];

  LLIST_TS_LOCK (&recur_alist_p);
  LLIST_TS_FOREACH (&recur_alist_p, i)
    {
      struct recur_apoint *rapt = LLIST_TS_GET_DATA (i);

      date_sec2date_fmt (rapt->start, ICALDATETIMEFMT, ical_datetime);
      fputs ("BEGIN:VEVENT\n", stream);
      fprintf (stream, "DTSTART:%s\n", ical_datetime);
      fprintf (stream, "DURATION:PT0H0M%ldS\n", rapt->dur);
      fprintf (stream, "RRULE:FREQ=%s;INTERVAL=%d",
               ical_recur_type[rapt->rpt->type], rapt->rpt->freq);

      if (rapt->rpt->until != 0)
        {
          date_sec2date_fmt (rapt->rpt->until + HOURINSEC, ICALDATEFMT,
                             ical_date);
          fprintf (stream, ";UNTIL=%s\n", ical_date);
        }
      else
        fputc ('\n', stream);

      if (LLIST_FIRST (&rapt->exc))
        {
          fputs ("EXDATE:", stream);
          LLIST_FOREACH (&rapt->exc, j)
            {
              struct excp *exc = LLIST_GET_DATA (j);
              date_sec2date_fmt (exc->st, ICALDATEFMT, ical_date);
              fprintf (stream, "%s", ical_date);
              if (LLIST_NEXT (j))
                fputc (',', stream);
              else
                fputc ('\n', stream);
            }
        }

      fprintf (stream, "SUMMARY:%s\n", rapt->mesg);
      if (rapt->state & APOINT_NOTIFY)
        ical_export_valarm (stream);
      fputs ("END:VEVENT\n", stream);
    }
  LLIST_TS_UNLOCK (&recur_alist_p);
}

/* Export appointments. */
static void
ical_export_apoints (FILE *stream)
{
  llist_item_t *i;
  char ical_datetime[BUFSIZ];

  LLIST_TS_LOCK (&alist_p);
  LLIST_TS_FOREACH (&alist_p, i)
    {
      struct apoint *apt = LLIST_TS_GET_DATA (i);
      date_sec2date_fmt (apt->start, ICALDATETIMEFMT, ical_datetime);
      fputs ("BEGIN:VEVENT\n", stream);
      fprintf (stream, "DTSTART:%s\n", ical_datetime);
      fprintf (stream, "DURATION:P%ldDT%ldH%ldM%ldS\n",
               apt->dur / DAYINSEC,
               (apt->dur / HOURINSEC) % DAYINHOURS,
               (apt->dur / MININSEC) % HOURINMIN,
               apt->dur % MININSEC);
      fprintf (stream, "SUMMARY:%s\n", apt->mesg);
      if (apt->state & APOINT_NOTIFY)
        ical_export_valarm (stream);
      fputs ("END:VEVENT\n", stream);
    }
  LLIST_TS_UNLOCK (&alist_p);
}

/* Export todo items. */
static void
ical_export_todo (FILE *stream)
{
  llist_item_t *i;

  LLIST_FOREACH (&todolist, i)
    {
      struct todo *todo = LLIST_TS_GET_DATA (i);
      if (todo->id < 0)  /* completed items */
        continue;

      fputs ("BEGIN:VTODO\n", stream);
      fprintf (stream, "PRIORITY:%d\n", todo->id);
      fprintf (stream, "SUMMARY:%s\n", todo->mesg);
      fputs ("END:VTODO\n", stream);
    }
}

/* Print a header to describe import log report format. */
static void
ical_log_init (FILE *log, float version)
{
  const char *header =
    "+-------------------------------------------------------------------+\n"
    "| Calcurse icalendar import log.                                    |\n"
    "|                                                                   |\n"
    "| Items imported from icalendar file, version %1.1f                   |\n"
    "| Some items could not be imported, they are described hereafter.   |\n"
    "| The log line format is as follows:                                |\n"
    "|                                                                   |\n"
    "|       TYPE [LINE]: DESCRIPTION                                    |\n"
    "|                                                                   |\n"
    "| where:                                                            |\n"
    "|  * TYPE represents the item type ('VEVENT' or 'VTODO')            |\n"
    "|  * LINE is the line in the input stream at which this item begins |\n"
    "|  * DESCRIPTION indicates why the item could not be imported       |\n"
    "+-------------------------------------------------------------------+\n\n";

  if (log)
    fprintf (log, header, version);
}

/*
 * Used to build a report of the import process.
 * The icalendar item for which a problem occurs is mentioned (by giving its
 * first line inside the icalendar file), together with a message describing the
 * problem.
 */
static void
ical_log (FILE *log, ical_types_e type, unsigned lineno, char *msg)
{
  const char *typestr[ICAL_TYPES] = {"VEVENT", "VTODO"};

  RETURN_IF (type < 0 || type >= ICAL_TYPES, _("unknown ical type"));
  if (log)
    fprintf (log, "%s [%d]: %s\n", typestr[type], lineno, msg);
}

static void
ical_store_todo (int priority, char *mesg, char *note)
{
  todo_add (mesg, priority, note);
  mem_free (mesg);
  erase_note (&note);
}

static void
ical_store_event (char *mesg, char *note, long day, long end, ical_rpt_t *rpt,
                  llist_t *exc)
{
  const int EVENTID = 1;

  if (rpt)
    {
      recur_event_new (mesg, note, day, EVENTID, rpt->type, rpt->freq,
                       rpt->until, exc);
      mem_free (rpt);
    }
  else if (end && end != day)
    {
      /* Here we have an event that spans over several days. */
      rpt = mem_malloc (sizeof (ical_rpt_t));
      rpt->type = RECUR_DAILY;
      rpt->freq = 1;
      rpt->count = 0;
      rpt->until = end;
      recur_event_new (mesg, note, day, EVENTID, rpt->type, rpt->freq,
                       rpt->until, exc);
      mem_free (rpt);
    }
  else
    {
      event_new (mesg, note, day, EVENTID);
    }
  mem_free (mesg);
  erase_note (&note);
}

static void
ical_store_apoint (char *mesg, char *note, long start, long dur,
                   ical_rpt_t *rpt, llist_t *exc, int has_alarm)
{
  char state = 0L;

  if (has_alarm)
    state |= APOINT_NOTIFY;
  if (rpt)
    {
      recur_apoint_new (mesg, note, start, dur, state, rpt->type, rpt->freq,
                        rpt->until, exc);
      mem_free (rpt);
    }
  else
    {
      apoint_new (mesg, note, start, dur, state);
    }
  mem_free (mesg);
  erase_note (&note);
}

/*
 * Returns an allocated string representing the string given in argument once
 * unformatted.
 *
 * Note:
 * Even if the RFC2445 recommends not to have more than 75 octets on one line of
 * text, I prefer not to restrict the parsing to this size, thus I use a buffer
 * of size BUFSIZ.
 *
 * Extract from RFC2445:
 * Lines of text SHOULD NOT be longer than 75 octets, excluding the line
 * break.
 */
static char *
ical_unformat_line (char *line)
{
  char *p, uline[BUFSIZ];
  int len;

  if (strlen (line) >= BUFSIZ)
    return NULL;

  bzero (uline, BUFSIZ);
  for (len = 0, p = line; *p; p++)
    {
      switch (*p)
        {
        case '\\':
          switch (*(p + 1))
            {
            case 'n':
              uline[len++] = '\n';
              p++;
              break;
            case 't':
              uline[len++] = '\t';
              p++;
              break;
            case ';':
            case ':':
            case ',':
              uline[len++] = *(p + 1);
              p++;
              break;
            default:
              uline[len++] = *p;
              break;
            }
          break;
        default:
          uline[len++] = *p;
          break;
        }
    }

  return mem_strdup (uline);
}

static void
ical_readline_init (FILE *fdi, char *buf, char *lstore, unsigned *ln)
{
  char *eol;

  *buf = *lstore = '\0';
  if (fgets (lstore, BUFSIZ, fdi))
    {
      if ((eol = strchr(lstore, '\n')) != NULL)
        *eol = '\0';
      (*ln)++;
    }
}

static int
ical_readline (FILE *fdi, char *buf, char *lstore, unsigned *ln)
{
  char *eol;

  strncpy (buf, lstore, BUFSIZ);
  (*ln)++;

  while (fgets (lstore, BUFSIZ, fdi) != NULL)
    {
      if ((eol = strchr(lstore, '\n')) != NULL)
        *eol = '\0';
      if (*lstore != SPACE && *lstore != TAB)
        break;
      strncat (buf, lstore + 1, BUFSIZ);
      buf[BUFSIZ - 1] = '\0';
      (*ln)++;
    }

  if (feof (fdi))
    {
      *lstore = '\0';
      if (*buf == '\0')
        return 0;
    }

  return 1;
}

static float
ical_chk_header (FILE *fd, char *buf, char *lstore, unsigned *lineno)
{
  const int HEADER_MALFORMED = -1;
  const struct string icalheader = STRING_BUILD ("BEGIN:VCALENDAR");
  float version;

  if (!ical_readline (fd, buf, lstore, lineno))
    return HEADER_MALFORMED;

  str_toupper (buf);
  if (strncmp (buf, icalheader.str, icalheader.len) != 0)
    return HEADER_MALFORMED;

  while (!sscanf (buf, "VERSION:%f", &version))
    {
      if (!ical_readline (fd, buf, lstore, lineno))
        return HEADER_MALFORMED;
    }
  return version;
}

/*
 * iCalendar date-time format is based on the ISO 8601 complete
 * representation. It should be something like : DATE 'T' TIME
 * where DATE is 'YYYYMMDD' and TIME is 'HHMMSS'.
 * The time and 'T' separator are optional (in the case of an day-long event).
 *
 * Optionnaly, if the type pointer is given, specify if it is an event
 * (no time is given, meaning it is an all-day event), or an appointment
 * (time is given).
 *
 * The timezone is not yet handled by calcurse.
 */
static long
ical_datetime2long (char *datestr, ical_vevent_e *type)
{
  const int NOTFOUND = 0, FORMAT_DATE = 3, FORMAT_DATETIME = 5;
  struct date date;
  unsigned hour, min;
  long datelong;
  int format;

  format = sscanf (datestr, "%04u%02u%02uT%02u%02u",
                   &date.yyyy, &date.mm, &date.dd, &hour, &min);
  if (format == FORMAT_DATE)
    {
      if (type)
        *type = EVENT;
      datelong = date2sec (date, 0, 0);
    }
  else if (format == FORMAT_DATETIME)
    {
      if (type)
        *type = APPOINTMENT;
      datelong = date2sec (date, hour, min);
    }
  else
    {
      datelong = NOTFOUND;
    }
  return datelong;
}

static long
ical_durtime2long (char *timestr)
{
  long timelong;
  char *p;

  if ((p = strchr (timestr, 'T')) == NULL)
    timelong = 0;
  else
    {
      int nbmatch;
      struct {
        unsigned hour, min, sec;
      } time;

      p++;
      bzero (&time, sizeof time);
      nbmatch = sscanf (p, "%uH%uM%uS", &time.hour, &time.min, &time.sec);
      if (nbmatch < 1 || nbmatch > 3)
        timelong = 0;
      else
        timelong = time.hour * HOURINSEC + time.min * MININSEC + time.sec;
    }
  return timelong;
}

/*
 * Extract from RFC2445:
 *
 * Value Name: DURATION
 *
 * Purpose: This value type is used to identify properties that contain
 * duration of time.
 *
 * Formal Definition: The value type is defined by the following
 * notation:
 *
 * dur-value  = (["+"] / "-") "P" (dur-date / dur-time / dur-week)
 * dur-date   = dur-day [dur-time]
 * dur-time   = "T" (dur-hour / dur-minute / dur-second)
 * dur-week   = 1*DIGIT "W"
 * dur-hour   = 1*DIGIT "H" [dur-minute]
 * dur-minute = 1*DIGIT "M" [dur-second]
 * dur-second = 1*DIGIT "S"
 * dur-day    = 1*DIGIT "D"
 *
 * Example: A duration of 15 days, 5 hours and 20 seconds would be:
 * P15DT5H0M20S
 * A duration of 7 weeks would be:
 * P7W
 */
static long
ical_dur2long (char *durstr)
{
  const int NOTFOUND = -1;
  long durlong;
  char *p;
  struct {
    unsigned week, day;
  } date;

  bzero (&date, sizeof date);
  if ((p = strchr (durstr, 'P')) == NULL)
    durlong = NOTFOUND;
  else
    {
      p++;
      if (*p == '-')
        return NOTFOUND;
      else if (*p == '+')
        p++;

      if (*p == 'T')                                      /* dur-time */
        durlong = ical_durtime2long (p);
      else if (strchr (p, 'W'))                           /* dur-week */
        {
          if (sscanf (p, "%u", &date.week) == 1)
            durlong = date.week * WEEKINDAYS * DAYINSEC;
          else
            durlong = NOTFOUND;
        }
      else
        {
          if (strchr (p, 'D'))                            /* dur-date */
            {
              if (sscanf (p, "%uD", &date.day) == 1)
                {
                  durlong = date.day * DAYINSEC;
                  durlong += ical_durtime2long (p);
                }
              else
                durlong = NOTFOUND;
            }
          else
            durlong = NOTFOUND;
        }
    }
  return durlong;
}

/*
 * Compute the vevent repetition end date from the repetition count.
 *
 * Extract from RFC2445:
 * The COUNT rule part defines the number of occurrences at which to
 * range-bound the recurrence. The "DTSTART" property value, if specified,
 * counts as the first occurrence.
 */
static long
ical_compute_rpt_until (long start, ical_rpt_t *rpt)
{
  long until;

  switch (rpt->type)
    {
    case RECUR_DAILY:
      until = date_sec_change (start, 0,  rpt->freq * (rpt->count - 1));
      break;
    case RECUR_WEEKLY:
      until = date_sec_change (start, 0,
                               rpt->freq * WEEKINDAYS * (rpt->count - 1));
      break;
    case RECUR_MONTHLY:
      until = date_sec_change (start, rpt->freq * (rpt->count - 1), 0);
      break;
    case RECUR_YEARLY:
      until = date_sec_change (start, rpt->freq * 12 * (rpt->count - 1), 0);
      break;
    default:
      until = 0;
      break;
      /* NOTREACHED */
    }
  return until;
}

/*
 * Read a recurrence rule from an iCalendar RRULE string.
 *
 * Value Name: RECUR
 *
 * Purpose: This value type is used to identify properties that contain
 * a recurrence rule specification.
 *
 * Formal Definition: The value type is defined by the following
 * notation:
 *
 * recur      = "FREQ"=freq *(
 *
 * ; either UNTIL or COUNT may appear in a 'recur',
 * ; but UNTIL and COUNT MUST NOT occur in the same 'recur'
 *
 * ( ";" "UNTIL" "=" enddate ) /
 * ( ";" "COUNT" "=" 1*DIGIT ) /
 *
 * ; the rest of these keywords are optional,
 * ; but MUST NOT occur more than
 * ; once
 *
 * ( ";" "INTERVAL" "=" 1*DIGIT )          /
 * ( ";" "BYSECOND" "=" byseclist )        /
 * ( ";" "BYMINUTE" "=" byminlist )        /
 * ( ";" "BYHOUR" "=" byhrlist )           /
 * ( ";" "BYDAY" "=" bywdaylist )          /
 * ( ";" "BYMONTHDAY" "=" bymodaylist )    /
 * ( ";" "BYYEARDAY" "=" byyrdaylist )     /
 * ( ";" "BYWEEKNO" "=" bywknolist )       /
 * ( ";" "BYMONTH" "=" bymolist )          /
 * ( ";" "BYSETPOS" "=" bysplist )         /
 * ( ";" "WKST" "=" weekday )              /
 * ( ";" x-name "=" text )
 * )
*/
static ical_rpt_t *
ical_read_rrule (FILE *log, char *rrulestr, unsigned *noskipped,
                 const int itemline)
{
  const struct string daily = STRING_BUILD ("DAILY");
  const struct string weekly = STRING_BUILD ("WEEKLY");
  const struct string monthly = STRING_BUILD ("MONTHLY");
  const struct string yearly = STRING_BUILD ("YEARLY");
  const struct string count = STRING_BUILD ("COUNT=");
  const struct string interv = STRING_BUILD ("INTERVAL=");
  unsigned interval;
  ical_rpt_t *rpt;
  char *p;

  rpt = NULL;
  if ((p = strchr (rrulestr, ':')) != NULL)
    {
      char freqstr[BUFSIZ];

      p++;
      rpt = mem_malloc (sizeof (ical_rpt_t));
      bzero (rpt, sizeof (ical_rpt_t));
      if (sscanf (p, "FREQ=%s", freqstr) != 1)
        {
          ical_log (log, ICAL_VEVENT, itemline,
                    _("recurrence frequence not found."));
          (*noskipped)++;
          mem_free (rpt);
          return NULL;
        }
      else
        {
          if (strncmp (freqstr, daily.str, daily.len) == 0)
            rpt->type = RECUR_DAILY;
          else if (strncmp (freqstr, weekly.str, weekly.len) == 0)
            rpt->type = RECUR_WEEKLY;
          else if (strncmp (freqstr, monthly.str, monthly.len) == 0)
            rpt->type = RECUR_MONTHLY;
          else if (strncmp (freqstr, yearly.str, yearly.len) == 0)
            rpt->type = RECUR_YEARLY;
          else
            {
              ical_log (log, ICAL_VEVENT, itemline,
                        _("recurrence frequence not recognized."));
              (*noskipped)++;
              mem_free (rpt);
              return NULL;
            }
        }
      /*
        The UNTIL rule part defines a date-time value which bounds the
        recurrence rule in an inclusive manner.  If not present, and the
        COUNT rule part is also not present, the RRULE is considered to
        repeat forever.

        The COUNT rule part defines the number of occurrences at which to
        range-bound the recurrence.  The "DTSTART" property value, if
        specified, counts as the first occurrence.
      */
      if ((p = strstr (rrulestr, "UNTIL")) != NULL)
        {
          char *untilstr;

          untilstr = strchr (p, '=');
          rpt->until = ical_datetime2long (++untilstr, NULL);
        }
      else
        {
          unsigned cnt;
          char *countstr;

          if ((countstr = strstr (rrulestr, count.str)) != NULL)
            {
              countstr += count.len;
              if (sscanf (countstr, "%u", &cnt) != 1)
                {
                  rpt->until = 0;
                  /* endless repetition */
                }
              else
                {
                  rpt->count = cnt;
                }
            }
          else
            rpt->until = 0;
        }

      if ((p = strstr (rrulestr, interv.str)) != NULL)
        {
          p += interv.len;
          if (sscanf (p, "%u", &interval) != 1)
            {
              rpt->freq = 1;
              /* default frequence if none specified */
            }
          else
            {
              rpt->freq = interval;
            }
        }
      else
        {
          rpt->freq = 1;
        }
    }
  else
    {
      ical_log (log, ICAL_VEVENT, itemline, _("recurrence rule malformed."));
      (*noskipped)++;
    }
  return rpt;
}

static void
ical_add_exc (llist_t *exc_head, long date)
{
  if (date != 0)
    {
      struct excp *exc = mem_malloc (sizeof (struct excp));
      exc->st = date;

      LLIST_ADD (exc_head, exc);
    }
}

/*
 * This property defines the list of date/time exceptions for a
 * recurring calendar component.
 */
void
ical_read_exdate (llist_t *exc, FILE *log, char *exstr, unsigned *noskipped,
                  const int itemline)
{
  char *p, *q;
  long date;

  LLIST_INIT (exc);
  if ((p = strchr (exstr, ':')) != NULL)
    {
      p++;
      while ((q = strchr (p, ',')) != NULL)
        {
          char buf[BUFSIZ];
          const int buflen = q - p;

          strncpy (buf, p, buflen);
          buf[buflen] = '\0';
          date = ical_datetime2long (buf, NULL);
          ical_add_exc (exc, date);
          p = ++q;
        }
      date = ical_datetime2long (p, NULL);
      ical_add_exc (exc, date);
    }
  else
    {
      ical_log (log, ICAL_VEVENT, itemline,
                _("recurrence exception dates malformed."));
      (*noskipped)++;
    }
}

/* Return an allocated string containing the name of the newly created note. */
static char *
ical_read_note (char *line, unsigned *noskipped, ical_vevent_e item_type,
                const int itemline, FILE *log)
{
  char *p, *notestr, *note;

  if ((p = strchr (line, ':')) != NULL)
    {
      p++;
      notestr = ical_unformat_line (p);
      if (notestr == NULL)
        {
          ical_log (log, item_type, itemline,
                    _("could not get entire item description."));
          (*noskipped)++;
          return NULL;
        }
      else if (strlen (notestr) == 0)
        {
          mem_free (notestr);
          return NULL;
        }
      else
        {
          note = generate_note (notestr);
          mem_free (notestr);
          return note;
        }
    }
  else
    {
      ical_log (log, item_type, itemline, _("description malformed."));
      (*noskipped)++;
      return NULL;
    }
}

/* Returns an allocated string containing the ical item summary. */
static char *
ical_read_summary (char *line)
{
  char *p, *summary;

  if ((p = strchr (line, ':')) != NULL)
    {
      p++;
      summary = ical_unformat_line (p);
      return summary;
    }
  else
    return NULL;
}

static void
ical_read_event (FILE *fdi, FILE *log, unsigned *noevents, unsigned *noapoints,
                 unsigned *noskipped, char *buf, char *lstore,
                 unsigned *lineno)
{
  const int ITEMLINE = *lineno;
  const struct string endevent = STRING_BUILD ("END:VEVENT");
  const struct string summary  = STRING_BUILD ("SUMMARY");
  const struct string dtstart  = STRING_BUILD ("DTSTART");
  const struct string dtend    = STRING_BUILD ("DTEND");
  const struct string duration = STRING_BUILD ("DURATION");
  const struct string rrule    = STRING_BUILD ("RRULE");
  const struct string exdate   = STRING_BUILD ("EXDATE");
  const struct string alarm    = STRING_BUILD ("BEGIN:VALARM");
  const struct string endalarm = STRING_BUILD ("END:VALARM");
  const struct string desc     = STRING_BUILD ("DESCRIPTION");
  ical_vevent_e vevent_type;
  char *p, buf_upper[BUFSIZ];
  struct {
    llist_t       exc;
    ical_rpt_t   *rpt;
    char         *mesg, *note;
    long          start, end, dur;
    int           has_alarm;
  } vevent;
  int skip_alarm;

  vevent_type = UNDEFINED;
  bzero (&vevent, sizeof vevent);
  skip_alarm = 0;
  while (ical_readline (fdi, buf, lstore, lineno))
    {
      strncpy (buf_upper, buf, BUFSIZ);
      buf_upper[BUFSIZ - 1] = '\0';
      str_toupper (buf_upper);

      if (skip_alarm)
        {
          /* Need to skip VALARM properties because some keywords could
             interfere, such as DURATION, SUMMARY,.. */
          if (strncmp (buf_upper, endalarm.str, endalarm.len) == 0)
            skip_alarm = 0;
          continue;
        }
      if (strncmp (buf_upper, endevent.str, endevent.len) == 0)
        {
          if (vevent.mesg)
            {
              if (vevent.rpt && vevent.rpt->count)
                vevent.rpt->until = ical_compute_rpt_until (vevent.start,
                                                            vevent.rpt);

              switch (vevent_type)
                {
                case APPOINTMENT:
                  if (vevent.start == 0)
                    {
                      ical_log (log, ICAL_VEVENT, ITEMLINE,
                                _("appointment has no start time."));
                      goto cleanup;
                    }
                  if (vevent.dur == 0)
                    {
                      if (vevent.end == 0)
                        {
                          ical_log (log, ICAL_VEVENT, ITEMLINE,
                                    _("could not compute duration "
                                    "(no end time)."));
                          goto cleanup;
                        }
                      else if (vevent.start == vevent.end)
                        {
                          vevent_type = EVENT;
                          vevent.end = 0L;
                          ical_store_event (vevent.mesg, vevent.note,
                                            vevent.start, vevent.end,
                                            vevent.rpt, &vevent.exc);
                          (*noevents)++;
                          return;
                        }
                      else
                        {
                          vevent.dur = vevent.end - vevent.start;
                          if (vevent.dur < 0)
                            {
                              ical_log (log, ICAL_VEVENT, ITEMLINE,
                                        _("item has a negative duration."));
                              goto cleanup;
                            }
                        }
                    }
                  ical_store_apoint (vevent.mesg, vevent.note, vevent.start,
                                     vevent.dur, vevent.rpt, &vevent.exc,
                                     vevent.has_alarm);
                  (*noapoints)++;
                  break;
                case EVENT:
                  if (vevent.start == 0)
                    {
                      ical_log (log, ICAL_VEVENT, ITEMLINE,
                                _("event date is not defined."));
                      goto cleanup;
                    }
                  ical_store_event (vevent.mesg, vevent.note, vevent.start,
                                    vevent.end, vevent.rpt, &vevent.exc);
                  (*noevents)++;
                  break;
                case UNDEFINED:
                  ical_log (log, ICAL_VEVENT, ITEMLINE,
                            _("item could not be identified."));
                  goto cleanup;
                  break;
                }
            }
          else
            {
              ical_log (log, ICAL_VEVENT, ITEMLINE,
                        _("could not retrieve item summary."));
              goto cleanup;
            }
          return;
        }
      else
        {
          if (strncmp (buf_upper, dtstart.str, dtstart.len) == 0)
            {
              if ((p = strchr (buf, ':')) != NULL)
                vevent.start = ical_datetime2long (++p, &vevent_type);
              if (!vevent.start)
                {
                  ical_log (log, ICAL_VEVENT, ITEMLINE,
                            _("could not retrieve event start time."));
                  goto cleanup;
                }
            }
          else if (strncmp (buf_upper, dtend.str, dtend.len) == 0)
            {
              if ((p = strchr (buf, ':')) != NULL)
                vevent.end = ical_datetime2long (++p, &vevent_type);
              if (!vevent.end)
                {
                  ical_log (log, ICAL_VEVENT, ITEMLINE,
                            _("could not retrieve event end time."));
                  goto cleanup;
                }
            }
          else if (strncmp (buf_upper, duration.str, duration.len) == 0)
            {
              if ((vevent.dur = ical_dur2long (buf)) <= 0)
                {
                  ical_log (log, ICAL_VEVENT, ITEMLINE,
                           _("item duration malformed."));
                  goto cleanup;
                }
            }
          else if (strncmp (buf_upper, rrule.str, rrule.len) == 0)
            {
              vevent.rpt = ical_read_rrule (log, buf, noskipped, ITEMLINE);
            }
          else if (strncmp (buf_upper, exdate.str, exdate.len) == 0)
            {
              ical_read_exdate (&vevent.exc, log, buf, noskipped, ITEMLINE);
            }
          else if (strncmp (buf_upper, summary.str, summary.len) == 0)
            {
              vevent.mesg = ical_read_summary (buf);
            }
          else if (strncmp (buf_upper, alarm.str, alarm.len) == 0)
            {
              skip_alarm = 1;
              vevent.has_alarm = 1;
            }
          else if (strncmp (buf_upper, desc.str, desc.len) == 0)
            {
              vevent.note = ical_read_note (buf, noskipped, ICAL_VEVENT,
                                            ITEMLINE, log);
            }
        }
    }
  ical_log (log, ICAL_VEVENT, ITEMLINE,
            _("The ical file seems to be malformed. "
            "The end of item was not found."));

cleanup:

  if (vevent.note)
    mem_free (vevent.note);
  if (vevent.mesg)
    mem_free (vevent.mesg);
  if (vevent.rpt)
    mem_free (vevent.rpt);
  LLIST_FREE (&vevent.exc);
  (*noskipped)++;
}

static void
ical_read_todo (FILE *fdi, FILE *log, unsigned *notodos, unsigned *noskipped,
                char *buf, char *lstore, unsigned *lineno)
{
  const struct string endtodo  = STRING_BUILD ("END:VTODO");
  const struct string summary  = STRING_BUILD ("SUMMARY");
  const struct string alarm    = STRING_BUILD ("BEGIN:VALARM");
  const struct string endalarm = STRING_BUILD ("END:VALARM");
  const struct string desc     = STRING_BUILD ("DESCRIPTION");
  const int LOWEST = 9;
  const int ITEMLINE = *lineno;
  char buf_upper[BUFSIZ];
  struct {
    char *mesg, *note;
    int has_priority, priority;
  } vtodo;
  int skip_alarm;

  bzero (&vtodo, sizeof vtodo);
  skip_alarm = 0;
  while (ical_readline (fdi, buf, lstore, lineno))
    {
      strncpy (buf_upper, buf, BUFSIZ);
      buf_upper[BUFSIZ - 1] = '\0';
      str_toupper (buf_upper);
      if (skip_alarm)
        {
          /* Need to skip VALARM properties because some keywords could
             interfere, such as DURATION, SUMMARY,.. */
          if (strncmp (buf_upper, endalarm.str, endalarm.len) == 0)
            skip_alarm = 0;
          continue;
        }
      if (strncmp (buf_upper, endtodo.str, endtodo.len) == 0)
        {
          if (!vtodo.has_priority)
            vtodo.priority = LOWEST;
          if (vtodo.mesg)
            {
              ical_store_todo (vtodo.priority, vtodo.mesg, vtodo.note);
              (*notodos)++;
            }
          else
            {
              ical_log (log, ICAL_VTODO, ITEMLINE,
                        _("could not retrieve item summary."));
              goto cleanup;
            }
          return;
        }
      else
        {
          int tmpint;

          if (sscanf (buf_upper, "PRIORITY:%d", &tmpint) == 1)
            {
              if (tmpint <= 9 && tmpint >= 1)
                {
                  vtodo.priority = tmpint;
                  vtodo.has_priority = 1;
                }
              else
                {
                  ical_log (log, ICAL_VTODO, ITEMLINE,
                           _("item priority is not acceptable "
                           "(must be between 1 and 9)."));
                  vtodo.priority = LOWEST;
                }
            }
          else if (strncmp (buf_upper, summary.str, summary.len) == 0)
            {
              vtodo.mesg = ical_read_summary (buf);
            }
          else if (strncmp (buf_upper, alarm.str, alarm.len) == 0)
            {
              skip_alarm = 1;
            }
          else if (strncmp (buf_upper, desc.str, desc.len) == 0)
            {
              vtodo.note = ical_read_note (buf, noskipped, ICAL_VTODO,
                                           ITEMLINE, log);
            }
        }
    }
  ical_log (log, ICAL_VTODO, ITEMLINE,
            _("The ical file seems to be malformed. "
            "The end of item was not found."));

cleanup:

  if (vtodo.note)
    mem_free (vtodo.note);
  if (vtodo.mesg)
    mem_free (vtodo.mesg);
  (*noskipped)++;
}

/* Import calcurse data. */
void
ical_import_data (FILE *stream, FILE *log, unsigned *events, unsigned *apoints,
                  unsigned *todos, unsigned *lines, unsigned *skipped)
{
  const struct string vevent = STRING_BUILD ("BEGIN:VEVENT");
  const struct string vtodo = STRING_BUILD ("BEGIN:VTODO");
  char buf[BUFSIZ], lstore[BUFSIZ];
  float ical_version;

  ical_readline_init (stream, buf, lstore, lines);
  ical_version = ical_chk_header (stream, buf, lstore, lines);
  RETURN_IF (ical_version < 0,
             _("Warning: ical header malformed or wrong version number. "
               "Aborting..."));

  ical_log_init (log, ical_version);

  while (ical_readline (stream, buf, lstore, lines))
    {
      (*lines)++;
      str_toupper (buf);
      if (strncmp (buf, vevent.str, vevent.len) == 0)
        {
          ical_read_event (stream, log, events, apoints, skipped, buf, lstore,
                           lines);
        }
      else if (strncmp (buf, vtodo.str, vtodo.len) == 0)
        {
          ical_read_todo (stream, log, todos, skipped, buf, lstore, lines);
        }
    }
}

/* Export calcurse data. */
void
ical_export_data (FILE *stream)
{
  ical_export_header (stream);
  ical_export_recur_events (stream);
  ical_export_events (stream);
  ical_export_recur_apoints (stream);
  ical_export_apoints (stream);
  ical_export_todo (stream);
  ical_export_footer (stream);
}