/* $OpenBSD: out.c,v 1.59 2025/07/16 14:23:55 schwarze Exp $ */
/*
 * Copyright (c) 2011, 2014, 2015, 2017, 2018, 2019, 2021, 2025
 *               Ingo Schwarze <schwarze@openbsd.org>
 * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * 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 <ctype.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "mandoc_aux.h"
#include "mandoc.h"
#include "tbl.h"
#include "out.h"

struct  tbl_colgroup {
        struct tbl_colgroup     *next;
        size_t                   wanted;
        int                      startcol;
        int                      endcol;
};

static  size_t  tblcalc_data(struct rofftbl *, struct roffcol *,
                        const struct tbl_opts *, const struct tbl_dat *,
                        size_t);
static  size_t  tblcalc_literal(struct rofftbl *, struct roffcol *,
                        const struct tbl_dat *, size_t);
static  size_t  tblcalc_number(struct rofftbl *, struct roffcol *,
                        const struct tbl_opts *, const struct tbl_dat *);


/*
 * Parse the *src string and store a scaling unit into *dst.
 * If the string doesn't specify the unit, use the default.
 * If no default is specified, fail.
 * Return a pointer to the byte after the last byte used,
 * or NULL on total failure.
 */
const char *
a2roffsu(const char *src, struct roffsu *dst, enum roffscale def)
{
        char            *endptr;

        dst->unit = def == SCALE_MAX ? SCALE_BU : def;
        dst->scale = strtod(src, &endptr);
        if (endptr == src)
                return NULL;

        switch (*endptr++) {
        case 'c':
                dst->unit = SCALE_CM;
                break;
        case 'i':
                dst->unit = SCALE_IN;
                break;
        case 'f':
                dst->unit = SCALE_FS;
                break;
        case 'M':
                dst->unit = SCALE_MM;
                break;
        case 'm':
                dst->unit = SCALE_EM;
                break;
        case 'n':
                dst->unit = SCALE_EN;
                break;
        case 'P':
                dst->unit = SCALE_PC;
                break;
        case 'p':
                dst->unit = SCALE_PT;
                break;
        case 'u':
                dst->unit = SCALE_BU;
                break;
        case 'v':
                dst->unit = SCALE_VS;
                break;
        default:
                endptr--;
                if (SCALE_MAX == def)
                        return NULL;
                dst->unit = def;
                break;
        }
        return endptr;
}

/*
 * Calculate the abstract widths and decimal positions of columns in a
 * table.  This routine allocates the columns structures then runs over
 * all rows and cells in the table.  The function pointers in "tbl" are
 * used for the actual width calculations.
 */
void
tblcalc(struct rofftbl *tbl, const struct tbl_span *sp_first,
    size_t offset, size_t rmargin)
{
        const struct tbl_opts   *opts;
        const struct tbl_span   *sp;
        const struct tbl_dat    *dp;
        struct roffcol          *col;
        struct tbl_colgroup     *first_group, **gp, *g;

        /* Widths in basic units. */
        size_t  *colwidth; /* Widths of all columns. */
        size_t   min1;     /* Width of the narrowest column. */
        size_t   min2;     /* Width of the second narrowest column. */
        size_t   wanted;   /* For any of the narrowest columns. */
        size_t   xwidth;   /* Total width of columns not to expand. */
        size_t   ewidth;   /* Width of widest column to equalize. */
        size_t   width;    /* Width of the data in basic units. */
        size_t   enw;      /* Width of one EN unit. */

        int      icol;     /* Column number, starting at zero. */
        int      maxcol;   /* Number of last column. */
        int      necol;    /* Number of columns to equalize. */
        int      nxcol;    /* Number of columns to expand. */
        int      done;     /* Boolean: this group is wide enough. */
        int      quirkcol;

        /*
         * Allocate the master column specifiers.  These will hold the
         * widths and decimal positions for all cells in the column.  It
         * must be freed and nullified by the caller.
         */

        assert(tbl->cols == NULL);
        tbl->cols = mandoc_calloc((size_t)sp_first->opts->cols,
            sizeof(struct roffcol));
        opts = sp_first->opts;

        maxcol = -1;
        first_group = NULL;
        enw = (*tbl->len)(1, tbl->arg);
        for (sp = sp_first; sp != NULL; sp = sp->next) {
                if (sp->pos != TBL_SPAN_DATA)
                        continue;

                /*
                 * Account for the data cells in the layout, matching it
                 * to data cells in the data section.
                 */

                for (dp = sp->first; dp != NULL; dp = dp->next) {
                        icol = dp->layout->col;
                        while (maxcol < icol + dp->hspans)
                                tbl->cols[++maxcol].spacing = SIZE_MAX;
                        col = tbl->cols + icol;
                        col->flags |= dp->layout->flags;
                        if (dp->layout->flags & TBL_CELL_WIGN)
                                continue;

                        /* Handle explicit width specifications. */
                        if (col->width < dp->layout->width)
                                col->width = dp->layout->width;
                        if (dp->layout->spacing != SIZE_MAX &&
                            (col->spacing == SIZE_MAX ||
                             col->spacing < dp->layout->spacing))
                                col->spacing = dp->layout->spacing;

                        /*
                         * Calculate an automatic width.
                         * Except for spanning cells, apply it.
                         */

                        width = tblcalc_data(tbl,
                            dp->hspans == 0 ? col : NULL,
                            opts, dp,
                            dp->block == 0 ? 0 :
                            dp->layout->width ? dp->layout->width :
                            rmargin ? (rmargin / enw + sp->opts->cols / 2) /
                            (sp->opts->cols + 1) * enw : 0);
                        if (dp->hspans == 0)
                                continue;

                        /*
                         * Build a singly linked list
                         * of all groups of columns joined by spans,
                         * recording the minimum width for each group.
                         */

                        gp = &first_group;
                        while (*gp != NULL && ((*gp)->startcol != icol ||
                            (*gp)->endcol != icol + dp->hspans))
                                gp = &(*gp)->next;
                        if (*gp == NULL) {
                                g = mandoc_malloc(sizeof(*g));
                                g->next = *gp;
                                g->wanted = width;
                                g->startcol = icol;
                                g->endcol = icol + dp->hspans;
                                *gp = g;
                        } else if ((*gp)->wanted < width)
                                (*gp)->wanted = width;
                }
        }

        /*
         * The minimum width of columns explicitly specified
         * in the layout is 1n.
         */

        if (maxcol < sp_first->opts->cols - 1)
                maxcol = sp_first->opts->cols - 1;
        for (icol = 0; icol <= maxcol; icol++) {
                col = tbl->cols + icol;
                if (col->width < enw)
                        col->width = enw;

                /*
                 * Column spacings are needed for span width
                 * calculations, so set the default values now.
                 */

                if (col->spacing == SIZE_MAX || icol == maxcol)
                        col->spacing = 3;
        }

        /*
         * Replace the minimum widths with the missing widths,
         * and dismiss groups that are already wide enough.
         */

        gp = &first_group;
        while ((g = *gp) != NULL) {
                done = 0;
                for (icol = g->startcol; icol <= g->endcol; icol++) {
                        width = tbl->cols[icol].width;
                        if (icol < g->endcol)
                                width += (*tbl->len)(tbl->cols[icol].spacing,
                                    tbl->arg);
                        if (g->wanted <= width) {
                                done = 1;
                                break;
                        } else
                                g->wanted -= width;
                }
                if (done) {
                        *gp = g->next;
                        free(g);
                } else
                        gp = &g->next;
        }

        colwidth = mandoc_reallocarray(NULL, maxcol + 1, sizeof(*colwidth));
        while (first_group != NULL) {

                /*
                 * Rebuild the array of the widths of all columns
                 * participating in spans that require expansion.
                 */

                for (icol = 0; icol <= maxcol; icol++)
                        colwidth[icol] = SIZE_MAX;
                for (g = first_group; g != NULL; g = g->next)
                        for (icol = g->startcol; icol <= g->endcol; icol++)
                                colwidth[icol] = tbl->cols[icol].width;

                /*
                 * Find the smallest and second smallest column width
                 * among the columns which may need expamsion.
                 */

                min1 = min2 = SIZE_MAX;
                for (icol = 0; icol <= maxcol; icol++) {
                        width = colwidth[icol];
                        if (min1 > width) {
                                min2 = min1;
                                min1 = width;
                        } else if (min1 < width && min2 > width)
                                min2 = width;
                }

                /*
                 * Find the minimum wanted width
                 * for any one of the narrowest columns,
                 * and mark the columns wanting that width.
                 */

                wanted = min2;
                for (g = first_group; g != NULL; g = g->next) {
                        necol = 0;
                        for (icol = g->startcol; icol <= g->endcol; icol++)
                                if (colwidth[icol] == min1)
                                        necol++;
                        if (necol == 0)
                                continue;
                        width = min1 + (g->wanted - 1) / necol + 1;
                        if (width > min2)
                                width = min2;
                        if (wanted > width)
                                wanted = width;
                }

                /* Record the effect of the widening. */

                gp = &first_group;
                while ((g = *gp) != NULL) {
                        done = 0;
                        for (icol = g->startcol; icol <= g->endcol; icol++) {
                                if (colwidth[icol] != min1)
                                        continue;
                                if (g->wanted <= wanted - min1) {
                                        tbl->cols[icol].width += g->wanted;
                                        done = 1;
                                        break;
                                }
                                tbl->cols[icol].width = wanted;
                                g->wanted -= wanted - min1;
                        }
                        if (done) {
                                *gp = g->next;
                                free(g);
                        } else
                                gp = &g->next;
                }
        }
        free(colwidth);

        /*
         * Align numbers with text.
         * Count columns to equalize and columns to maximize.
         * Find maximum width of the columns to equalize.
         * Find total width of the columns *not* to maximize.
         */

        necol = nxcol = 0;
        ewidth = xwidth = 0;
        for (icol = 0; icol <= maxcol; icol++) {
                col = tbl->cols + icol;
                if (col->width > col->nwidth)
                        col->decimal += (col->width - col->nwidth) / 2;
                if (col->flags & TBL_CELL_EQUAL) {
                        necol++;
                        if (ewidth < col->width)
                                ewidth = col->width;
                }
                if (col->flags & TBL_CELL_WMAX)
                        nxcol++;
                else
                        xwidth += col->width;
        }

        /*
         * Equalize columns, if requested for any of them.
         * Update total width of the columns not to maximize.
         */

        if (necol) {
                for (icol = 0; icol <= maxcol; icol++) {
                        col = tbl->cols + icol;
                        if ( ! (col->flags & TBL_CELL_EQUAL))
                                continue;
                        if (col->width == ewidth)
                                continue;
                        if (nxcol && rmargin)
                                xwidth += ewidth - col->width;
                        col->width = ewidth;
                }
        }

        /*
         * If there are any columns to maximize, find the total
         * available width, deducting 3n margins between columns.
         * Distribute the available width evenly.
         */

        if (nxcol && rmargin) {
                xwidth += (*tbl->len)(3 * maxcol +
                    (opts->opts & (TBL_OPT_BOX | TBL_OPT_DBOX) ?
                     2 : !!opts->lvert + !!opts->rvert), tbl->arg);
                if (rmargin <= offset + xwidth)
                        return;
                xwidth = rmargin - offset - xwidth;

                /*
                 * Emulate a bug in GNU tbl width calculation that
                 * manifests itself for large numbers of x-columns.
                 * Emulating it for 5 x-columns gives identical
                 * behaviour for up to 6 x-columns.
                 */

                if (nxcol == 5) {
                        quirkcol = xwidth / enw % nxcol + 2;
                        if (quirkcol != 3 && quirkcol != 4)
                                quirkcol = -1;
                } else
                        quirkcol = -1;

                necol = 0;
                ewidth = 0;
                for (icol = 0; icol <= maxcol; icol++) {
                        col = tbl->cols + icol;
                        if ( ! (col->flags & TBL_CELL_WMAX))
                                continue;
                        col->width = (double)xwidth * ++necol / nxcol
                            - ewidth + 0.4995;
                        if (necol == quirkcol)
                                col->width -= enw;
                        ewidth += col->width;
                }
        }
}

static size_t
tblcalc_data(struct rofftbl *tbl, struct roffcol *col,
    const struct tbl_opts *opts, const struct tbl_dat *dp, size_t mw)
{
        size_t           sz;

        /* Branch down into data sub-types. */

        switch (dp->layout->pos) {
        case TBL_CELL_HORIZ:
        case TBL_CELL_DHORIZ:
                sz = (*tbl->len)(1, tbl->arg);
                if (col != NULL && col->width < sz)
                        col->width = sz;
                return sz;
        case TBL_CELL_LONG:
        case TBL_CELL_CENTRE:
        case TBL_CELL_LEFT:
        case TBL_CELL_RIGHT:
                return tblcalc_literal(tbl, col, dp, mw);
        case TBL_CELL_NUMBER:
                return tblcalc_number(tbl, col, opts, dp);
        case TBL_CELL_DOWN:
                return 0;
        default:
                abort();
        }
}

static size_t
tblcalc_literal(struct rofftbl *tbl, struct roffcol *col,
    const struct tbl_dat *dp, size_t mw)
{
        const char      *str;   /* Beginning of the first line. */
        const char      *beg;   /* Beginning of the current line. */
        char            *end;   /* End of the current line. */

        /* Widths in basic units. */
        size_t           lsz;   /* Of the current line. */
        size_t           wsz;   /* Of the current word. */
        size_t           msz;   /* Of the longest line. */
        size_t           enw;   /* Of one EN unit. */

        if (dp->string == NULL || *dp->string == '\0')
                return 0;
        str = mw ? mandoc_strdup(dp->string) : dp->string;
        msz = lsz = 0;
        for (beg = str; beg != NULL && *beg != '\0'; beg = end) {
                end = mw ? strchr(beg, ' ') : NULL;
                if (end != NULL) {
                        *end++ = '\0';
                        while (*end == ' ')
                                end++;
                }
                wsz = (*tbl->slen)(beg, tbl->arg);
                enw = (*tbl->len)(1, tbl->arg);
                if (mw && lsz && lsz + enw + wsz <= mw)
                        lsz += enw + wsz;
                else
                        lsz = wsz;
                if (msz < lsz)
                        msz = lsz;
        }
        if (mw)
                free((void *)str);
        if (col != NULL && col->width < msz)
                col->width = msz;
        return msz;
}

static size_t
tblcalc_number(struct rofftbl *tbl, struct roffcol *col,
                const struct tbl_opts *opts, const struct tbl_dat *dp)
{
        const char      *cp, *lastdigit, *lastpoint;
        size_t           totsz; /* Total width of the number in basic units. */
        size_t           intsz; /* Width of the integer part in basic units. */
        char             buf[2];

        if (dp->string == NULL || *dp->string == '\0')
                return 0;

        totsz = (*tbl->slen)(dp->string, tbl->arg);
        if (col == NULL)
                return totsz;

        /*
         * Find the last digit and
         * the last decimal point that is adjacent to a digit.
         * The alignment indicator "\&" overrides everything.
         */

        lastdigit = lastpoint = NULL;
        for (cp = dp->string; cp[0] != '\0'; cp++) {
                if (cp[0] == '\\' && cp[1] == '&') {
                        lastdigit = lastpoint = cp;
                        break;
                } else if (cp[0] == opts->decimal &&
                    (isdigit((unsigned char)cp[1]) ||
                     (cp > dp->string && isdigit((unsigned char)cp[-1]))))
                        lastpoint = cp;
                else if (isdigit((unsigned char)cp[0]))
                        lastdigit = cp;
        }

        /* Not a number, treat as a literal string. */

        if (lastdigit == NULL) {
                if (col != NULL && col->width < totsz)
                        col->width = totsz;
                return totsz;
        }

        /* Measure the width of the integer part. */

        if (lastpoint == NULL)
                lastpoint = lastdigit + 1;
        intsz = 0;
        buf[1] = '\0';
        for (cp = dp->string; cp < lastpoint; cp++) {
                buf[0] = cp[0];
                intsz += (*tbl->slen)(buf, tbl->arg);
        }

        /*
         * If this number has more integer digits than all numbers
         * seen on earlier lines, shift them all to the right.
         * If it has fewer, shift this number to the right.
         */

        if (intsz > col->decimal) {
                col->nwidth += intsz - col->decimal;
                col->decimal = intsz;
        } else
                totsz += col->decimal - intsz;

        /* Update the maximum total width seen so far. */

        if (totsz > col->nwidth)
                col->nwidth = totsz;
        if (col->nwidth > col->width)
                col->width = col->nwidth;
        return totsz;
}