/* $OpenBSD: roff_term.c,v 1.25 2025/08/21 15:36:20 schwarze Exp $ */
/*
 * Copyright (c) 2010, 2014, 2015, 2017-2021, 2025
 *               Ingo Schwarze <schwarze@openbsd.org>
 *
 * 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 <sys/types.h>

#include <assert.h>
#include <stdio.h>
#include <string.h>

#include "mandoc.h"
#include "roff.h"
#include "out.h"
#include "term.h"

#define ROFF_TERM_ARGS struct termp *p, const struct roff_node *n

typedef void    (*roff_term_pre_fp)(ROFF_TERM_ARGS);

static  void      roff_term_pre_br(ROFF_TERM_ARGS);
static  void      roff_term_pre_ce(ROFF_TERM_ARGS);
static  void      roff_term_pre_ft(ROFF_TERM_ARGS);
static  void      roff_term_pre_ll(ROFF_TERM_ARGS);
static  void      roff_term_pre_mc(ROFF_TERM_ARGS);
static  void      roff_term_pre_po(ROFF_TERM_ARGS);
static  void      roff_term_pre_sp(ROFF_TERM_ARGS);
static  void      roff_term_pre_ta(ROFF_TERM_ARGS);
static  void      roff_term_pre_ti(ROFF_TERM_ARGS);

static  const roff_term_pre_fp roff_term_pre_acts[ROFF_MAX] = {
        roff_term_pre_br,  /* br */
        roff_term_pre_ce,  /* ce */
        roff_term_pre_br,  /* fi */
        roff_term_pre_ft,  /* ft */
        roff_term_pre_ll,  /* ll */
        roff_term_pre_mc,  /* mc */
        roff_term_pre_br,  /* nf */
        roff_term_pre_po,  /* po */
        roff_term_pre_ce,  /* rj */
        roff_term_pre_sp,  /* sp */
        roff_term_pre_ta,  /* ta */
        roff_term_pre_ti,  /* ti */
};


void
roff_term_pre(struct termp *p, const struct roff_node *n)
{
        assert(n->tok < ROFF_MAX);
        (*roff_term_pre_acts[n->tok])(p, n);
}

static void
roff_term_pre_br(ROFF_TERM_ARGS)
{
        term_newln(p);
        if (p->flags & TERMP_BRIND) {
                p->tcol->offset = p->tcol->rmargin;
                p->tcol->rmargin = p->maxrmargin;
                p->trailspace = 0;
                p->flags &= ~(TERMP_NOBREAK | TERMP_BRIND);
                p->flags |= TERMP_NOSPACE;
        }
}

static void
roff_term_pre_ce(ROFF_TERM_ARGS)
{
        const struct roff_node  *nc1, *nc2;

        roff_term_pre_br(p, n);
        p->flags |= n->tok == ROFF_ce ? TERMP_CENTER : TERMP_RIGHT;
        nc1 = n->child->next;
        while (nc1 != NULL) {
                nc2 = nc1;
                do {
                        nc2 = nc2->next;
                } while (nc2 != NULL && (nc2->type != ROFFT_TEXT ||
                    (nc2->flags & NODE_LINE) == 0));
                while (nc1 != nc2) {
                        if (nc1->type == ROFFT_TEXT)
                                term_word(p, nc1->string);
                        else
                                roff_term_pre(p, nc1);
                        nc1 = nc1->next;
                }
                p->flags |= TERMP_NOSPACE;
                term_flushln(p);
        }
        p->flags &= ~(TERMP_CENTER | TERMP_RIGHT);
}

static void
roff_term_pre_ft(ROFF_TERM_ARGS)
{
        const char      *cp;

        cp = n->child->string;
        switch (mandoc_font(cp, (int)strlen(cp))) {
        case ESCAPE_FONTBOLD:
        case ESCAPE_FONTCB:
                term_fontrepl(p, TERMFONT_BOLD);
                break;
        case ESCAPE_FONTITALIC:
        case ESCAPE_FONTCI:
                term_fontrepl(p, TERMFONT_UNDER);
                break;
        case ESCAPE_FONTBI:
                term_fontrepl(p, TERMFONT_BI);
                break;
        case ESCAPE_FONTPREV:
                term_fontlast(p);
                break;
        case ESCAPE_FONTROMAN:
        case ESCAPE_FONTCR:
                term_fontrepl(p, TERMFONT_NONE);
                break;
        default:
                break;
        }
}

static void
roff_term_pre_ll(ROFF_TERM_ARGS)
{
        term_setwidth(p, n->child != NULL ? n->child->string : NULL);
}

static void
roff_term_pre_mc(ROFF_TERM_ARGS)
{
        if (p->col) {
                p->flags |= TERMP_NOBREAK;
                term_flushln(p);
                p->flags &= ~(TERMP_NOBREAK | TERMP_NOSPACE);
        }
        if (n->child != NULL) {
                p->mc = n->child->string;
                p->flags |= TERMP_NEWMC;
        } else
                p->flags |= TERMP_ENDMC;
}

static void
roff_term_pre_po(ROFF_TERM_ARGS)
{
        struct roffsu    su;

        /* Page offsets in basic units. */
        static int       polast;  /* Previously requested. */
        static int       po;      /* Currently requested. */
        static int       pouse;   /* Currently used. */
        int              pomin;   /* Minimum to be used. */
        int              pomax;   /* Maximum to be used. */
        int              ponew;   /* Newly requested. */

        /* Revert the currently active page offset. */
        p->tcol->offset -= pouse;

        /* Determine the requested page offset. */
        if (n->child != NULL &&
            a2roffsu(n->child->string, &su, SCALE_EM) != NULL) {
                ponew = term_hspan(p, &su);
                if (*n->child->string == '+' ||
                    *n->child->string == '-')
                        ponew += po;
        } else
                ponew = polast;

        /* Remember both the previous and the newly requested offset. */
        polast = po;
        po = ponew;

        /* Truncate to the range [-offset, 60], remember, and apply it. */
        pomin = -p->tcol->offset;
        pomax = term_len(p, 60);
        pouse = po > pomax ? pomax : po < pomin ? pomin : po;
        p->tcol->offset += pouse;
}

static void
roff_term_pre_sp(ROFF_TERM_ARGS)
{
        struct roffsu    su;
        int              len;

        if (n->child != NULL) {
                if (a2roffsu(n->child->string, &su, SCALE_VS) == NULL)
                        su.scale = 1.0;
                len = term_vspan(p, &su);
        } else
                len = 1;

        if (len < 0)
                p->skipvsp -= len;
        else
                while (len--)
                        term_vspace(p);

        roff_term_pre_br(p, n);
}

static void
roff_term_pre_ta(ROFF_TERM_ARGS)
{
        term_tab_set(p, NULL);
        for (n = n->child; n != NULL; n = n->next)
                term_tab_set(p, n->string);
}

static void
roff_term_pre_ti(ROFF_TERM_ARGS)
{
        struct roffsu    su;
        const char      *cp;      /* Request argument. */
        size_t           maxoff;  /* Maximum indentation in basic units. */
        int              len;     /* Request argument in basic units. */
        int              sign;

        roff_term_pre_br(p, n);

        if (n->child == NULL)
                return;
        cp = n->child->string;
        if (*cp == '+') {
                sign = 1;
                cp++;
        } else if (*cp == '-') {
                sign = -1;
                cp++;
        } else
                sign = 0;

        if (a2roffsu(cp, &su, SCALE_EM) == NULL)
                return;
        len = term_hspan(p, &su);
        maxoff = term_len(p, 72);

        switch (sign) {
        case 1:
                if (p->tcol->offset + len <= maxoff)
                        p->ti = len;
                else if (p->tcol->offset < maxoff)
                        p->ti = maxoff - p->tcol->offset;
                else
                        p->ti = 0;
                break;
        case -1:
                if ((size_t)len < p->tcol->offset)
                        p->ti = -len;
                else
                        p->ti = -p->tcol->offset;
                break;
        default:
                if ((size_t)len > maxoff)
                        len = maxoff;
                p->ti = len - p->tcol->offset;
                break;
        }
        p->tcol->offset += p->ti;
}