/* Id: term_tab.c,v 1.6 2020/06/22 19:20:40 schwarze Exp  */
/*
* Copyright (c) 2017 Ingo Schwarze <[email protected]>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.h"

#include <sys/types.h>

#include <stddef.h>

#include "mandoc_aux.h"
#include "out.h"
#include "term.h"

struct tablist {
       size_t  *t;     /* Allocated array of tab positions. */
       size_t   s;     /* Allocated number of positions. */
       size_t   n;     /* Currently used number of positions. */
};

static struct {
       struct tablist   a;     /* All tab positions for lookup. */
       struct tablist   p;     /* Periodic tab positions to add. */
       size_t           d;     /* Default tab width in units of n. */
} tabs;


void
term_tab_set(const struct termp *p, const char *arg)
{
       static int       recording_period;

       struct roffsu    su;
       struct tablist  *tl;
       size_t           pos;
       int              add;

       /* Special arguments: clear all tabs or switch lists. */

       if (arg == NULL) {
               tabs.a.n = tabs.p.n = 0;
               recording_period = 0;
               if (tabs.d == 0) {
                       a2roffsu(".8i", &su, SCALE_IN);
                       tabs.d = term_hen(p, &su);
               }
               return;
       }
       if (arg[0] == 'T' && arg[1] == '\0') {
               recording_period = 1;
               return;
       }

       /* Parse the sign, the number, and the unit. */

       if (*arg == '+') {
               add = 1;
               arg++;
       } else
               add = 0;
       if (a2roffsu(arg, &su, SCALE_EM) == NULL)
               return;

       /* Select the list, and extend it if it is full. */

       tl = recording_period ? &tabs.p : &tabs.a;
       if (tl->n >= tl->s) {
               tl->s += 8;
               tl->t = mandoc_reallocarray(tl->t, tl->s, sizeof(*tl->t));
       }

       /* Append the new position. */

       pos = term_hen(p, &su);
       tl->t[tl->n] = pos;
       if (add && tl->n)
               tl->t[tl->n] += tl->t[tl->n - 1];
       tl->n++;
}

/*
* Simplified version without a parser,
* never incremental, never periodic, for use by tbl(7).
*/
void
term_tab_iset(size_t inc)
{
       if (tabs.a.n >= tabs.a.s) {
               tabs.a.s += 8;
               tabs.a.t = mandoc_reallocarray(tabs.a.t, tabs.a.s,
                   sizeof(*tabs.a.t));
       }
       tabs.a.t[tabs.a.n++] = inc;
}

size_t
term_tab_next(size_t prev)
{
       size_t   i, j;

       for (i = 0;; i++) {
               if (i == tabs.a.n) {
                       if (tabs.p.n == 0)
                               return prev;
                       tabs.a.n += tabs.p.n;
                       if (tabs.a.s < tabs.a.n) {
                               tabs.a.s = tabs.a.n;
                               tabs.a.t = mandoc_reallocarray(tabs.a.t,
                                   tabs.a.s, sizeof(*tabs.a.t));
                       }
                       for (j = 0; j < tabs.p.n; j++)
                               tabs.a.t[i + j] = tabs.p.t[j] +
                                   (i ? tabs.a.t[i - 1] : 0);
               }
               if (prev < tabs.a.t[i])
                       return tabs.a.t[i];
       }
}