/*      $NetBSD: ul.c,v 1.20 2019/02/03 03:19:30 mrg Exp $      */

/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1980, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)ul.c        8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: ul.c,v 1.20 2019/02/03 03:19:30 mrg Exp $");
#endif /* not lint */

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <term.h>
#include <unistd.h>
#include <util.h>

#define IESC    '\033'
#define SO      '\016'
#define SI      '\017'
#define HFWD    '9'
#define HREV    '8'
#define FREV    '7'
#define MAXBUF  512

#define NORMAL  000
#define ALTSET  001     /* Reverse */
#define SUPERSC 002     /* Dim */
#define SUBSC   004     /* Dim | Ul */
#define UNDERL  010     /* Ul */
#define BOLD    020     /* Bold */

static int      must_overstrike;

struct  CHAR    {
        char    c_mode;
        char    c_char;
} ;

static size_t col, maxcol;
static int      mode;
static int      halfpos;
static int      upln;
static int      iflag;

static void filter(FILE *);
static void flushln(struct CHAR *, size_t);
static void fwd(struct CHAR *, size_t);
static void iattr(struct CHAR *);
static void initbuf(struct CHAR *, size_t);
static void outc(int);
static int outchar(int);
static void overstrike(struct CHAR *);
static void reverse(struct CHAR *, size_t);
static void setulmode(int);
static void alloc_buf(struct CHAR **, size_t *);
static void set_mode(void);


#define PRINT(s)        if (s == NULL) /* void */; else tputs(s, 1, outchar)

int
main(int argc, char **argv)
{
        int c;
        const char *termtype;
        FILE *f;

        termtype = getenv("TERM");
        if (termtype == NULL || (argv[0][0] == 'c' && !isatty(1)))
                termtype = "lpr";
        while ((c=getopt(argc, argv, "it:T:")) != -1)
                switch(c) {

                case 't':
                case 'T': /* for nroff compatibility */
                                termtype = optarg;
                        break;
                case 'i':
                        iflag = 1;
                        break;

                default:
                        fprintf(stderr,
                                "usage: %s [ -i ] [ -tTerm ] file...\n",
                                argv[0]);
                        exit(1);
                }

        setupterm(termtype, 0, NULL);
        if ((over_strike && enter_bold_mode == NULL) ||
            (transparent_underline && enter_underline_mode == NULL &&
                underline_char == NULL)) {
                set_mode();
        }
        if (optind == argc)
                filter(stdin);
        else {
                for (; optind < argc; optind++) {
                        f = fopen(argv[optind], "r");
                        if (f == NULL)
                                err(EXIT_FAILURE, "Failed to open `%s'", argv[optind]);
                        filter(f);
                        fclose(f);
                }
        }
        exit(0);
}

static void
filter(FILE *f)
{
        int c;
        struct  CHAR *obuf = NULL;
        size_t obuf_size = 0;
        alloc_buf(&obuf, &obuf_size);

        while ((c = getc(f)) != EOF) switch(c) {

        case '\b':
                if (col > 0)
                        col--;
                continue;

        case '\t':
                col = (col+8) & ~07;
                if (col > maxcol)
                        maxcol = col;
                if (col >= obuf_size)
                        alloc_buf(&obuf, &obuf_size);
                continue;

        case '\r':
                col = 0;
                continue;

        case SO:
                mode |= ALTSET;
                continue;

        case SI:
                mode &= ~ALTSET;
                continue;

        case IESC:
                switch (c = getc(f)) {

                case HREV:
                        if (halfpos == 0) {
                                mode |= SUPERSC;
                                halfpos--;
                        } else if (halfpos > 0) {
                                mode &= ~SUBSC;
                                halfpos--;
                        } else {
                                halfpos = 0;
                                reverse(obuf, obuf_size);
                        }
                        continue;

                case HFWD:
                        if (halfpos == 0) {
                                mode |= SUBSC;
                                halfpos++;
                        } else if (halfpos < 0) {
                                mode &= ~SUPERSC;
                                halfpos++;
                        } else {
                                halfpos = 0;
                                fwd(obuf, obuf_size);
                        }
                        continue;

                case FREV:
                        reverse(obuf, obuf_size);
                        continue;

                default:
                        fprintf(stderr,
                                "Unknown escape sequence in input: %o, %o\n",
                                IESC, c);
                        exit(1);
                }

        case '_':
                if (obuf[col].c_char)
                        obuf[col].c_mode |= UNDERL | mode;
                else
                        obuf[col].c_char = '_';
                /* FALLTHROUGH */
        case ' ':
                col++;
                if (col > maxcol)
                        maxcol = col;
                if (col >= obuf_size)
                        alloc_buf(&obuf, &obuf_size);
                continue;

        case '\n':
                flushln(obuf, obuf_size);
                continue;

        case '\f':
                flushln(obuf, obuf_size);
                putchar('\f');
                continue;

        default:
                if (c < ' ')    /* non printing */
                        continue;
                if (obuf[col].c_char == '\0') {
                        obuf[col].c_char = c;
                        obuf[col].c_mode = mode;
                } else if (obuf[col].c_char == '_') {
                        obuf[col].c_char = c;
                        obuf[col].c_mode |= UNDERL|mode;
                } else if (obuf[col].c_char == c)
                        obuf[col].c_mode |= BOLD|mode;
                else
                        obuf[col].c_mode = mode;
                col++;
                if (col > maxcol)
                        maxcol = col;
                if (col >= obuf_size)
                        alloc_buf(&obuf, &obuf_size);
                continue;
        }
        if (maxcol)
                flushln(obuf, obuf_size);

        free(obuf);
}

static void
flushln(struct CHAR *obuf, size_t obuf_size)
{
        int lastmode;
        size_t i;
        int hadmodes = 0;

        lastmode = NORMAL;
        for (i=0; i<maxcol; i++) {
                if (obuf[i].c_mode != lastmode) {
                        hadmodes++;
                        setulmode(obuf[i].c_mode);
                        lastmode = obuf[i].c_mode;
                }
                if (obuf[i].c_char == '\0') {
                        if (upln) {
                                PRINT(cursor_right);
                        }
                        else {
                                outc(' ');
                        }
                } else
                        outc(obuf[i].c_char);
        }
        if (lastmode != NORMAL) {
                setulmode(0);
        }
        if (must_overstrike && hadmodes)
                overstrike(obuf);
        putchar('\n');
        if (iflag && hadmodes)
                iattr(obuf);
        (void)fflush(stdout);
        if (upln)
                upln--;
        initbuf(obuf, obuf_size);
}

/*
 * For terminals that can overstrike, overstrike underlines and bolds.
 * We don't do anything with halfline ups and downs, or Greek.
 */
static void
overstrike(struct CHAR *obuf)
{
        size_t i;
        char lbuf[256];
        char *cp = lbuf;
        int hadbold=0;

        /* Set up overstrike buffer */
        for (i=0; i<maxcol; i++)
                switch (obuf[i].c_mode) {
                case NORMAL:
                default:
                        *cp++ = ' ';
                        break;
                case UNDERL:
                        *cp++ = '_';
                        break;
                case BOLD:
                        *cp++ = obuf[i].c_char;
                        hadbold=1;
                        break;
                }
        putchar('\r');
        for (*cp=' '; *cp==' '; cp--)
                *cp = 0;
        for (cp=lbuf; *cp; cp++)
                putchar(*cp);
        if (hadbold) {
                putchar('\r');
                for (cp=lbuf; *cp; cp++)
                        putchar(*cp=='_' ? ' ' : *cp);
                putchar('\r');
                for (cp=lbuf; *cp; cp++)
                        putchar(*cp=='_' ? ' ' : *cp);
        }
}

static void
iattr(struct CHAR *obuf)
{
        size_t i;
        char lbuf[256];
        char *cp = lbuf;

        for (i=0; i<maxcol; i++)
                switch (obuf[i].c_mode) {
                case NORMAL:    *cp++ = ' '; break;
                case ALTSET:    *cp++ = 'g'; break;
                case SUPERSC:   *cp++ = '^'; break;
                case SUBSC:     *cp++ = 'v'; break;
                case UNDERL:    *cp++ = '_'; break;
                case BOLD:      *cp++ = '!'; break;
                default:        *cp++ = 'X'; break;
                }
        for (*cp=' '; *cp==' '; cp--)
                *cp = 0;
        for (cp=lbuf; *cp; cp++)
                putchar(*cp);
        putchar('\n');
}

static void
initbuf(struct CHAR *obuf, size_t obuf_size)
{

        memset(obuf, 0, obuf_size * sizeof(*obuf));     /* depends on NORMAL == 0 */
        col = 0;
        maxcol = 0;
        set_mode();
}

static void
set_mode(void)
{
        mode &= ALTSET;
}

static void
fwd(struct CHAR *obuf, size_t obuf_size)
{
        int oldcol, oldmax;

        oldcol = col;
        oldmax = maxcol;
        flushln(obuf, obuf_size);
        col = oldcol;
        maxcol = oldmax;
}

static void
reverse(struct CHAR *obuf, size_t obuf_size)
{
        upln++;
        fwd(obuf, obuf_size);
        PRINT(cursor_up);
        PRINT(cursor_up);
        upln++;
}

static int
outchar(int c)
{
        return (putchar(c & 0177));
}

static int curmode = 0;

static void
outc(int c)
{
        putchar(c);
        if (underline_char && !enter_underline_mode && (curmode & UNDERL)) {
                if (cursor_left)
                        PRINT(cursor_left);
                else
                        putchar('\b');
                PRINT(underline_char);
        }
}

static void
setulmode(int newmode)
{
        if (!iflag) {
                if (curmode != NORMAL && newmode != NORMAL)
                        setulmode(NORMAL);
                switch (newmode) {
                case NORMAL:
                        switch(curmode) {
                        case NORMAL:
                                break;
                        case UNDERL:
                                if (enter_underline_mode)
                                        PRINT(exit_underline_mode);
                                else
                                        PRINT(exit_standout_mode);
                                break;
                        default:
                                /* This includes standout */
                                if (exit_attribute_mode)
                                        PRINT(exit_attribute_mode);
                                else
                                        PRINT(exit_standout_mode);
                                break;
                        }
                        break;
                case ALTSET:
                        if (enter_reverse_mode)
                                PRINT(enter_reverse_mode);
                        else
                                PRINT(enter_standout_mode);
                        break;
                case SUPERSC:
                        /*
                         * This only works on a few terminals.
                         * It should be fixed.
                         */
                        PRINT(enter_underline_mode);
                        PRINT(enter_dim_mode);
                        break;
                case SUBSC:
                        if (enter_dim_mode)
                                PRINT(enter_dim_mode);
                        else
                                PRINT(enter_standout_mode);
                        break;
                case UNDERL:
                        if (enter_underline_mode)
                                PRINT(enter_underline_mode);
                        else
                                PRINT(enter_standout_mode);
                        break;
                case BOLD:
                        if (enter_bold_mode)
                                PRINT(enter_bold_mode);
                        else
                                PRINT(enter_reverse_mode);
                        break;
                default:
                        /*
                         * We should have some provision here for multiple modes
                         * on at once.  This will have to come later.
                         */
                        PRINT(enter_standout_mode);
                        break;
                }
        }
        curmode = newmode;
}

/*
 * Reallocates the buffer pointed to by *buf and sets
 * the newly allocated set of bytes to 0.
 */
static void
alloc_buf(struct CHAR **buf, size_t *size)
{
        size_t osize = *size;
        *size += MAXBUF;
        ereallocarr(buf, *size, sizeof(**buf));
        memset(*buf + osize, 0, (*size - osize) * sizeof(**buf));
}