#include <stdlib.h>

#include <string.h>

#include "calendarspec.h"

#define BITS_WEEKDAYS 127

static void free_chain(CalendarComponent *c) {

CalendarComponent *n;

while (c) {

n = c->next;

free(c);

c = n;

}

}

void calendar_spec_free(CalendarSpec *c) {

if (!c)

return;

free_chain(c->year);

free_chain(c->month);

free_chain(c->day);

free_chain(c->hour);

free_chain(c->minute);

free_chain(c->second);

free(c);

}

static int component_compare(const void *_a, const void *_b) {

CalendarComponent * const *a = _a, * const *b = _b;

if ((*a)->value < (*b)->value)

return -1;

if ((*a)->value > (*b)->value)

return 1;

if ((*a)->repeat < (*b)->repeat)

return -1;

if ((*a)->repeat > (*b)->repeat)

return 1;

return 0;

}

static void sort_chain(CalendarComponent **c) {

unsigned n = 0, k;

CalendarComponent **b, *i, **j, *next;

assert(c);

for (i = *c; i; i = i->next)

n++;

if (n <= 1)

return;

j = b = alloca(sizeof(CalendarComponent*) * n);

for (i = *c; i; i = i->next)

*(j++) = i;

qsort(b, n, sizeof(CalendarComponent*), component_compare);

b[n-1]->next = NULL;

next = b[n-1];

/* Drop non-unique entries */

for (k = n-1; k > 0; k--) {

if (b[k-1]->value == next->value &&

b[k-1]->repeat == next->repeat) {

free(b[k-1]);

continue;

}

b[k-1]->next = next;

next = b[k-1];

}

*c = next;

}

static void fix_year(CalendarComponent *c) {

/* Turns 12 → 2012, 89 → 1989 */

while(c) {

CalendarComponent *n = c->next;

if (c->value >= 0 && c->value < 70)

c->value += 2000;

if (c->value >= 70 && c->value < 100)

c->value += 1900;

c = n;

}

}

int calendar_spec_normalize(CalendarSpec *c) {

assert(c);

if (c->weekdays_bits <= 0 || c->weekdays_bits >= BITS_WEEKDAYS)

c->weekdays_bits = -1;

fix_year(c->year);

sort_chain(&c->year);

sort_chain(&c->month);

sort_chain(&c->day);

sort_chain(&c->hour);

sort_chain(&c->minute);

sort_chain(&c->second);

return 0;

}

_pure_ static bool chain_valid(CalendarComponent *c, int from, int to) {

if (!c)

return true;

if (c->value < from || c->value > to)

return false;

if (c->value + c->repeat > to)

return false;

if (c->next)

return chain_valid(c->next, from, to);

return true;

}

_pure_ bool calendar_spec_valid(CalendarSpec *c) {

assert(c);

if (c->weekdays_bits > BITS_WEEKDAYS)

return false;

if (!chain_valid(c->year, 1970, 2199))

return false;

if (!chain_valid(c->month, 1, 12))

return false;

if (!chain_valid(c->day, 1, 31))

return false;

if (!chain_valid(c->hour, 0, 23))

return false;

if (!chain_valid(c->minute, 0, 59))

return false;

if (!chain_valid(c->second, 0, 59))

return false;

return true;

}

static void format_weekdays(FILE *f, const CalendarSpec *c) {

static const char *const days[] = {

"Mon",

"Tue",

"Wed",

"Thu",

"Fri",

"Sat",

"Sun"

};

int l, x;

bool need_colon = false;

assert(f);

assert(c);

assert(c->weekdays_bits > 0 && c->weekdays_bits <= BITS_WEEKDAYS);

for (x = 0, l = -1; x < (int) ELEMENTSOF(days); x++) {

if (c->weekdays_bits & (1 << x)) {

if (l < 0) {

if (need_colon)

fputc(',', f);

else

need_colon = true;

fputs(days[x], f);

l = x;

}

} else if (l >= 0) {

if (x > l + 1) {

fputc(x > l + 2 ? '-' : ',', f);

fputs(days[x-1], f);

}

l = -1;

}

}

if (l >= 0 && x > l + 1) {

fputc(x > l + 2 ? '-' : ',', f);

fputs(days[x-1], f);

}

}

static void format_chain(FILE *f, int space, const CalendarComponent *c) {

assert(f);

if (!c) {

fputc('*', f);

return;

}

assert(c->value >= 0);

fprintf(f, "%0*i", space, c->value);

if (c->repeat > 0)

fprintf(f, "/%i", c->repeat);

if (c->next) {

fputc(',', f);

format_chain(f, space, c->next);

}

}

int calendar_spec_to_string(const CalendarSpec *c, char **p) {

char *buf = NULL;

size_t sz = 0;

FILE *f;

int r;

assert(c);

assert(p);

f = open_memstream(&buf, &sz);

if (!f)

return -ENOMEM;

if (c->weekdays_bits > 0 && c->weekdays_bits <= BITS_WEEKDAYS) {

format_weekdays(f, c);

fputc(' ', f);

}

format_chain(f, 4, c->year);

fputc('-', f);

format_chain(f, 2, c->month);

fputc('-', f);

format_chain(f, 2, c->day);

fputc(' ', f);

format_chain(f, 2, c->hour);

fputc(':', f);

format_chain(f, 2, c->minute);

fputc(':', f);

format_chain(f, 2, c->second);

r = fflush_and_check(f);

if (r < 0) {

free(buf);

fclose(f);

return r;

}

fclose(f);

*p = buf;

return 0;

}

static int parse_weekdays(const char **p, CalendarSpec *c) {

static const struct {

const char *name;

const int nr;

} day_nr[] = {

{ "Monday", 0 },

{ "Mon", 0 },

{ "Tuesday", 1 },

{ "Tue", 1 },

{ "Wednesday", 2 },

{ "Wed", 2 },

{ "Thursday", 3 },

{ "Thu", 3 },

{ "Friday", 4 },

{ "Fri", 4 },

{ "Saturday", 5 },

{ "Sat", 5 },

{ "Sunday", 6 },

{ "Sun", 6 }

};

int l = -1;

bool first = true;

assert(p);

assert(*p);

assert(c);

for (;;) {

unsigned i;

if (!first && **p == ' ')

return 0;

for (i = 0; i < ELEMENTSOF(day_nr); i++) {

size_t skip;

if (!startswith_no_case(*p, day_nr[i].name))

continue;

skip = strlen(day_nr[i].name);

if ((*p)[skip] != '-' &&

(*p)[skip] != ',' &&

(*p)[skip] != ' ' &&

(*p)[skip] != 0)

return -EINVAL;

c->weekdays_bits |= 1 << day_nr[i].nr;

if (l >= 0) {

int j;

if (l > day_nr[i].nr)

return -EINVAL;

for (j = l + 1; j < day_nr[i].nr; j++)

c->weekdays_bits |= 1 << j;

}

*p += skip;

break;

}

/* Couldn't find this prefix, so let's assume the

if (i >= ELEMENTSOF(day_nr))

return first ? 0 : -EINVAL;

/* We reached the end of the string */

if (**p == 0)

return 0;

/* We reached the end of the weekday spec part */

if (**p == ' ') {

*p += strspn(*p, " ");

return 0;

}

if (**p == '-') {

if (l >= 0)

return -EINVAL;

l = day_nr[i].nr;

} else

l = -1;

*p += 1;

first = false;

}

}

static int prepend_component(const char **p, CalendarComponent **c) {

unsigned long value, repeat = 0;

char *e = NULL, *ee = NULL;

CalendarComponent *cc;

assert(p);

assert(c);

errno = 0;

value = strtoul(*p, &e, 10);

if (errno > 0)

return -errno;

if (e == *p)

return -EINVAL;

if ((unsigned long) (int) value != value)

return -ERANGE;

if (*e == '/') {

repeat = strtoul(e+1, &ee, 10);

if (errno > 0)

return -errno;

if (ee == e+1)

return -EINVAL;

if ((unsigned long) (int) repeat != repeat)

return -ERANGE;

if (repeat <= 0)

return -ERANGE;

e = ee;

}

if (*e != 0 && *e != ' ' && *e != ',' && *e != '-' && *e != ':')

return -EINVAL;

cc = new0(CalendarComponent, 1);

if (!cc)

return -ENOMEM;

cc->value = value;

cc->repeat = repeat;

cc->next = *c;

*p = e;

*c = cc;

if (*e ==',') {

*p += 1;

return prepend_component(p, c);

}

return 0;

}

static int parse_chain(const char **p, CalendarComponent **c) {

const char *t;

CalendarComponent *cc = NULL;

int r;

assert(p);

assert(c);

t = *p;

if (t[0] == '*') {

*p = t + 1;

*c = NULL;

return 0;

}

r = prepend_component(&t, &cc);

if (r < 0) {

free_chain(cc);

return r;

}

*p = t;

*c = cc;

return 0;

}

static int const_chain(int value, CalendarComponent **c) {

CalendarComponent *cc = NULL;

assert(c);

cc = new0(CalendarComponent, 1);

if (!cc)

return -ENOMEM;

cc->value = value;

cc->repeat = 0;

cc->next = *c;

*c = cc;

return 0;

}

static int parse_date(const char **p, CalendarSpec *c) {

const char *t;

int r;

CalendarComponent *first, *second, *third;

assert(p);

assert(*p);

assert(c);

t = *p;

if (*t == 0)

return 0;

r = parse_chain(&t, &first);

if (r < 0)

return r;

/* Already the end? A ':' as separator? In that case this was a time, not a date */

if (*t == 0 || *t == ':') {

free_chain(first);

return 0;

}

if (*t != '-') {

free_chain(first);

return -EINVAL;

}

t++;

r = parse_chain(&t, &second);

if (r < 0) {

free_chain(first);

return r;

}

/* Got two parts, hence it's month and day */

if (*t == ' ' || *t == 0) {

*p = t + strspn(t, " ");

c->month = first;

c->day = second;

return 0;

}

if (*t != '-') {

free_chain(first);

free_chain(second);

return -EINVAL;

}

t++;

r = parse_chain(&t, &third);

if (r < 0) {

free_chain(first);

free_chain(second);

return r;

}

/* Got tree parts, hence it is year, month and day */

if (*t == ' ' || *t == 0) {

*p = t + strspn(t, " ");

c->year = first;

c->month = second;

c->day = third;

return 0;

}

free_chain(first);

free_chain(second);

free_chain(third);

return -EINVAL;

}

static int parse_time(const char **p, CalendarSpec *c) {

CalendarComponent *h = NULL, *m = NULL, *s = NULL;

const char *t;

int r;

assert(p);

assert(*p);

assert(c);

t = *p;

if (*t == 0) {

/* If no time is specified at all, but a date of some

if (c->day || c->weekdays_bits > 0)

goto null_hour;

goto finish;

}

r = parse_chain(&t, &h);

if (r < 0)

goto fail;

if (*t != ':') {

r = -EINVAL;

goto fail;

}

t++;

r = parse_chain(&t, &m);

if (r < 0)

goto fail;

/* Already at the end? Then it's hours and minutes, and seconds are 0 */

if (*t == 0) {

if (m != NULL)

goto null_second;

goto finish;

}

if (*t != ':') {

r = -EINVAL;

goto fail;

}

t++;

r = parse_chain(&t, &s);

if (r < 0)

goto fail;

/* At the end? Then it's hours, minutes and seconds */

if (*t == 0)

goto finish;

r = -EINVAL;

goto fail;

null_hour:

r = const_chain(0, &h);

if (r < 0)

goto fail;

r = const_chain(0, &m);

if (r < 0)

goto fail;

null_second:

r = const_chain(0, &s);

if (r < 0)

goto fail;

finish:

*p = t;

c->hour = h;

c->minute = m;

c->second = s;

return 0;

fail:

free_chain(h);

free_chain(m);

free_chain(s);

return r;

}

int calendar_spec_from_string(const char *p, CalendarSpec **spec) {

CalendarSpec *c;

int r;

assert(p);

assert(spec);

if (isempty(p))

return -EINVAL;

c = new0(CalendarSpec, 1);

if (!c)

return -ENOMEM;

if (strcaseeq(p, "minutely")) {

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else if (strcaseeq(p, "hourly")) {

r = const_chain(0, &c->minute);

if (r < 0)

goto fail;

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else if (strcaseeq(p, "daily")) {

r = const_chain(0, &c->hour);

if (r < 0)

goto fail;

r = const_chain(0, &c->minute);

if (r < 0)

goto fail;

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else if (strcaseeq(p, "monthly")) {

r = const_chain(1, &c->day);

if (r < 0)

goto fail;

r = const_chain(0, &c->hour);

if (r < 0)

goto fail;

r = const_chain(0, &c->minute);

if (r < 0)

goto fail;

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else if (strcaseeq(p, "annually") ||

strcaseeq(p, "yearly") ||

strcaseeq(p, "anually") /* backwards compatibility */ ) {

r = const_chain(1, &c->month);

if (r < 0)

goto fail;

r = const_chain(1, &c->day);

if (r < 0)

goto fail;

r = const_chain(0, &c->hour);

if (r < 0)

goto fail;

r = const_chain(0, &c->minute);

if (r < 0)

goto fail;

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else if (strcaseeq(p, "weekly")) {

c->weekdays_bits = 1;

r = const_chain(0, &c->hour);

if (r < 0)

goto fail;

r = const_chain(0, &c->minute);

if (r < 0)

goto fail;

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else if (strcaseeq(p, "quarterly")) {

r = const_chain(1, &c->month);

if (r < 0)

goto fail;

r = const_chain(4, &c->month);

if (r < 0)

goto fail;

r = const_chain(7, &c->month);

if (r < 0)

goto fail;

r = const_chain(10, &c->month);

if (r < 0)

goto fail;

r = const_chain(1, &c->day);

if (r < 0)

goto fail;

r = const_chain(0, &c->hour);

if (r < 0)

goto fail;

r = const_chain(0, &c->minute);

if (r < 0)

goto fail;

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else if (strcaseeq(p, "biannually") ||

strcaseeq(p, "bi-annually") ||

strcaseeq(p, "semiannually") ||

strcaseeq(p, "semi-annually")) {

r = const_chain(1, &c->month);

if (r < 0)

goto fail;

r = const_chain(7, &c->month);

if (r < 0)

goto fail;

r = const_chain(1, &c->day);

if (r < 0)

goto fail;

r = const_chain(0, &c->hour);

if (r < 0)

goto fail;

r = const_chain(0, &c->minute);

if (r < 0)

goto fail;

r = const_chain(0, &c->second);

if (r < 0)

goto fail;

} else {

r = parse_weekdays(&p, c);

if (r < 0)

goto fail;

r = parse_date(&p, c);

if (r < 0)

goto fail;

r = parse_time(&p, c);

if (r < 0)

goto fail;

if (*p != 0) {

r = -EINVAL;

goto fail;

}

}

r = calendar_spec_normalize(c);

if (r < 0)

goto fail;

if (!calendar_spec_valid(c)) {

r = -EINVAL;

goto fail;

}

*spec = c;

return 0;

fail:

calendar_spec_free(c);

return r;

}

static int find_matching_component(const CalendarComponent *c, int *val) {

const CalendarComponent *n;

int d = -1;

bool d_set = false;

int r;

assert(val);

if (!c)

return 0;

while (c) {

n = c->next;

if (c->value >= *val) {

if (!d_set || c->value < d) {

d = c->value;

d_set = true;

}

} else if (c->repeat > 0) {

int k;

k = c->value + c->repeat * ((*val - c->value + c->repeat -1) / c->repeat);

if (!d_set || k < d) {

d = k;

d_set = true;

}

}

c = n;

}

if (!d_set)

return -ENOENT;

r = *val != d;

*val = d;

return r;

}

static bool tm_out_of_bounds(const struct tm *tm) {

struct tm t;

assert(tm);

t = *tm;

if (mktime(&t) == (time_t) -1)

return true;

/* Did any normalization take place? If so, it was out of bounds before */

return

t.tm_year != tm->tm_year ||

t.tm_mon != tm->tm_mon ||

t.tm_mday != tm->tm_mday ||

t.tm_hour != tm->tm_hour ||

t.tm_min != tm->tm_min ||

t.tm_sec != tm->tm_sec;

}

static bool matches_weekday(int weekdays_bits, const struct tm *tm) {

struct tm t;

int k;

if (weekdays_bits < 0 || weekdays_bits >= BITS_WEEKDAYS)

return true;

t = *tm;

if (mktime(&t) == (time_t) -1)

return false;

k = t.tm_wday == 0 ? 6 : t.tm_wday - 1;

return (weekdays_bits & (1 << k));

}

static int find_next(const CalendarSpec *spec, struct tm *tm) {

struct tm c;

int r;

assert(spec);

assert(tm);

c = *tm;

for (;;) {

/* Normalize the current date */

mktime(&c);

c.tm_isdst = -1;

c.tm_year += 1900;

r = find_matching_component(spec->year, &c.tm_year);

c.tm_year -= 1900;

if (r > 0) {

c.tm_mon = 0;

c.tm_mday = 1;

c.tm_hour = c.tm_min = c.tm_sec = 0;

}

if (r < 0 || tm_out_of_bounds(&c))

return r;

c.tm_mon += 1;

r = find_matching_component(spec->month, &c.tm_mon);

c.tm_mon -= 1;

if (r > 0) {

c.tm_mday = 1;

c.tm_hour = c.tm_min = c.tm_sec = 0;

}

if (r < 0 || tm_out_of_bounds(&c)) {

c.tm_year ++;

c.tm_mon = 0;

c.tm_mday = 1;

c.tm_hour = c.tm_min = c.tm_sec = 0;

continue;

}

r = find_matching_component(spec->day, &c.tm_mday);

if (r > 0)

c.tm_hour = c.tm_min = c.tm_sec = 0;

if (r < 0 || tm_out_of_bounds(&c)) {

c.tm_mon ++;

c.tm_mday = 1;

c.tm_hour = c.tm_min = c.tm_sec = 0;

continue;

}

if (!matches_weekday(spec->weekdays_bits, &c)) {

c.tm_mday++;

c.tm_hour = c.tm_min = c.tm_sec = 0;

continue;

}

r = find_matching_component(spec->hour, &c.tm_hour);

if (r > 0)

c.tm_min = c.tm_sec = 0;

if (r < 0 || tm_out_of_bounds(&c)) {

c.tm_mday ++;

c.tm_hour = c.tm_min = c.tm_sec = 0;

continue;

}

r = find_matching_component(spec->minute, &c.tm_min);

if (r > 0)

c.tm_sec = 0;

if (r < 0 || tm_out_of_bounds(&c)) {

c.tm_hour ++;

c.tm_min = c.tm_sec = 0;

continue;

}

r = find_matching_component(spec->second, &c.tm_sec);

if (r < 0 || tm_out_of_bounds(&c)) {

c.tm_min ++;

c.tm_sec = 0;

continue;

}

*tm = c;

return 0;

}

}

int calendar_spec_next_usec(const CalendarSpec *spec, usec_t usec, usec_t *next) {

struct tm tm;

time_t t;

int r;

assert(spec);

assert(next);

t = (time_t) (usec / USEC_PER_SEC) + 1;

assert_se(localtime_r(&t, &tm));

r = find_next(spec, &tm);

if (r < 0)

return r;

t = mktime(&tm);

if (t == (time_t) -1)

return -EINVAL;

*next = (usec_t) t * USEC_PER_SEC;

return 0;

}