/**
* Return a dt object that forgot about DT's zone and uses ZONE instead. */
DEFUN struct dt_dt_s
dtz_forgetz(struct dt_dt_s d, zif_t zone)
{
struct dt_dt_s res;
dt_ssexy_t d_unix;
if (dt_sandwich_only_d_p(d) || dt_sandwich_only_t_p(d)) {
return d;
}
/* convert date/time part to unix stamp */
d_unix = ____to_unix_epoch(d);
d_unix = zif_utc_time(zone, d_unix);
/* convert the date part back */
if (d.typ > (dt_dttyp_t)DT_DUNK && d.typ < (dt_dttyp_t)DT_NDTYP) {
int32_t sexy = __pos_mod(d_unix, 86400);
/* temporarily go daisy */
res.d.typ = DT_DAISY;
res.d.daisy = d_unix / 86400 + DAISY_UNIX_BASE;
res.d = dt_dconv(d.d.typ, res.d);
/* set the other flags too */
res.sandwich = d.sandwich;
res.dur = 0;
res.neg = 0;
/* convert the time part back */
res.t.hms.s = sexy % 60;
res.t.hms.m = (sexy % 3600) / 60;
res.t.hms.h = sexy / 3600;
res.t.hms.ns = d.t.hms.ns;
res.t.typ = DT_HMS;
res.t.dur = 0;
res.t.neg = 0;
res.t.carry = 0;
} else if (d.typ == DT_SEXY) {
res.typ = DT_SEXY;
res.sandwich = 0;
res.dur = 0;
res.neg = 0;
res.sxepoch = d_unix;
} else {
res = dt_dt_initialiser();
}
return res;
}
static inline dt_ssexy_t
____to_unix_epoch(struct dt_dt_s dt)
{
/* daisy is competing with the prevalent unix epoch, this is the offset */
#define DAISY_UNIX_BASE (19359)
if (dt.typ == DT_SEXY) {
/* no way to find out, is there */
return dt.sexy;
} else if (dt_sandwich_p(dt) || dt_sandwich_only_d_p(dt)) {
struct dt_d_s d = dt_dconv(DT_DAISY, dt.d);
dt_daisy_t dd = d.daisy;
dt_ssexy_t res = (dd - DAISY_UNIX_BASE) * SECS_PER_DAY;
if (dt_sandwich_p(dt)) {
res += (dt.t.hms.h * 60 + dt.t.hms.m) * 60 + dt.t.hms.s;
}
return res;
}
return 0;
}
static struct dt_d_s
dround_ddur(struct dt_d_s d, struct dt_ddur_s dur, bool nextp)
{
switch (dur.durtyp) {
unsigned int tgt;
bool forw;
case DT_DURD:
if (dur.dv > 0) {
tgt = dur.dv;
forw = true;
} else if (dur.dv < 0) {
tgt = -dur.dv;
forw = false;
} else {
/* user is an idiot */
break;
}
switch (d.typ) {
unsigned int mdays;
case DT_YMD:
if ((forw && d.ymd.d < tgt) ||
(!forw && d.ymd.d > tgt)) {
/* no month or year adjustment */
;
} else if (d.ymd.d == tgt && !nextp) {
/* we're ON the date already and no
* next/prev date is requested */
;
} else if (forw) {
if (LIKELY(d.ymd.m < GREG_MONTHS_P_YEAR)) {
d.ymd.m++;
} else {
d.ymd.m = 1;
d.ymd.y++;
}
} else {
if (UNLIKELY(--d.ymd.m < 1)) {
d.ymd.m = GREG_MONTHS_P_YEAR;
d.ymd.y--;
}
}
/* get ultimo */
mdays = __get_mdays(d.ymd.y, d.ymd.m);
if (UNLIKELY(tgt > mdays)) {
tgt = mdays;
}
/* final assignment */
d.ymd.d = tgt;
break;
default:
break;
}
break;
case DT_DURBD:
/* bizsis only work on bizsidurs atm */
if (dur.dv > 0) {
tgt = dur.dv;
forw = true;
} else if (dur.dv < 0) {
tgt = -dur.dv;
forw = false;
} else {
/* user is an idiot */
break;
}
switch (d.typ) {
unsigned int bdays;
case DT_BIZDA:
if ((forw && d.bizda.bd < tgt) ||
(!forw && d.bizda.bd > tgt)) {
/* no month or year adjustment */
;
} else if (d.bizda.bd == tgt && !nextp) {
/* we're ON the date already and no
* next/prev date is requested */
;
} else if (forw) {
if (LIKELY(d.bizda.m < GREG_MONTHS_P_YEAR)) {
d.bizda.m++;
} else {
d.bizda.m = 1;
d.bizda.y++;
}
} else {
if (UNLIKELY(--d.bizda.m < 1)) {
d.bizda.m = GREG_MONTHS_P_YEAR;
d.bizda.y--;
}
}
/* get ultimo */
bdays = __get_bdays(d.bizda.y, d.bizda.m);
if (UNLIKELY(tgt > bdays)) {
tgt = bdays;
}
/* final assignment */
d.bizda.bd = tgt;
break;
default:
break;
}
break;
case DT_DURYMD:
switch (d.typ) {
unsigned int mdays;
case DT_YMD:
tgt = dur.ymd.m;
forw = !dt_dur_neg_p(dur);
if ((forw && d.ymd.m < tgt) ||
(!forw && d.ymd.m > tgt)) {
/* no year adjustment */
;
} else if (d.ymd.m == tgt && !nextp) {
/* we're IN the month already and no
* next/prev date is requested */
;
} else if (forw) {
/* years don't wrap around */
d.ymd.y++;
} else {
/* years don't wrap around */
d.ymd.y--;
}
/* final assignment */
d.ymd.m = tgt;
/* fixup ultimo mismatches */
mdays = __get_mdays(d.ymd.y, d.ymd.m);
if (UNLIKELY(d.ymd.d > mdays)) {
d.ymd.d = mdays;
}
break;
default:
break;
}
break;
case DT_DURYMCW: {
struct dt_d_s tmp;
unsigned int wday;
signed int diff;
forw = !dt_dur_neg_p(dur);
tgt = dur.ymcw.w;
tmp = dt_dconv(DT_DAISY, d);
wday = dt_get_wday(tmp);
diff = (signed)tgt - (signed)wday;
if ((forw && wday < tgt) ||
(!forw && wday > tgt)) {
/* nothing to do */
;
} else if (wday == tgt && !nextp) {
/* we're on WDAY already, do fuckall */
;
} else if (forw) {
/* week wrap */
diff += 7;
} else {
/* week wrap */
diff -= 7;
}
/* final assignment */
tmp.daisy += diff;
d = dt_dconv(d.typ, tmp);
break;
}
case DT_DURWK:
if (dur.dv > 0) {
tgt = dur.dv;
forw = true;
} else if (dur.dv < 0) {
tgt = -dur.dv;
forw = false;
} else {
/* user is an idiot */
break;
}
switch (d.typ) {
unsigned int nw;
case DT_YWD:
if ((forw && d.ywd.c < tgt) ||
(!forw && d.ywd.c > tgt)) {
/* no year adjustment */
;
} else if (d.ywd.c == tgt && !nextp) {
/* we're IN the week already and no
* next/prev date is requested */
;
} else if (forw) {
/* years don't wrap around */
d.ywd.y++;
} else {
/* years don't wrap around */
d.ywd.y--;
}
/* final assignment */
d.ywd.c = tgt;
/* fixup ultimo mismatches */
nw = __get_isowk(d.ywd.y);
if (UNLIKELY(d.ywd.c > nw)) {
d.ywd.c = nw;
}
break;
default:
break;
}
break;
default:
break;
}
return d;
}
