/*
 * 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.
 *
 * @(#) Copyright (c) 1980, 1993 The Regents of the University of California.  All rights reserved.
 * @(#)colcrt.c 8.1 (Berkeley) 6/6/93
 * $FreeBSD: head/usr.bin/colcrt/colcrt.c 227158 2011-11-06 08:14:28Z ed $
 */

#include <err.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wchar.h>

/*
 * colcrt - replaces col for crts with new nroff esp. when using tbl.
 * Bill Joy UCB July 14, 1977
 *
 * This filter uses a screen buffer, 267 half-lines by 132 columns.
 * It interprets the up and down sequences generated by the new
 * nroff when used with tbl and by \u \d and \r.
 * General overstriking doesn't work correctly.
 * Underlining is split onto multiple lines, etc.
 *
 * Option - suppresses all underlining.
 * Option -2 forces printing of all half lines.
 */

static wchar_t  page[267][132];

static int      outline = 1;
static int      outcol;

static char     suppresul;
static char     printall;

static void     move(int, int);
static void     pflush(int);
static int      plus(wchar_t, wchar_t);
static void     usage(void);

int
main(int argc, char *argv[])
{
        wint_t c;
        wchar_t *cp, *dp;
        int ch, i, w;

        setlocale(LC_ALL, "");

        while ((ch = getopt(argc, argv, "-2")) != -1)
                switch (ch) {
                case '-':
                        suppresul = 1;
                        break;
                case '2':
                        printall = 1;
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        do {
                if (argc > 0) {
                        if (freopen(argv[0], "r", stdin) == NULL) {
                                fflush(stdout);
                                err(1, "%s", argv[0]);
                        }
                        argc--;
                        argv++;
                }
                for (;;) {
                        c = getwc(stdin);
                        if (c == WEOF) {
                                pflush(outline);
                                fflush(stdout);
                                break;
                        }
                        switch (c) {
                        case '\n':
                                if (outline >= 265)
                                        pflush(62);
                                outline += 2;
                                outcol = 0;
                                continue;
                        case '\016':
                        case '\017':
                                continue;
                        case 033:
                                c = getwc(stdin);
                                switch (c) {
                                case '9':
                                        if (outline >= 266)
                                                pflush(62);
                                        outline++;
                                        continue;
                                case '8':
                                        if (outline >= 1)
                                                outline--;
                                        continue;
                                case '7':
                                        outline -= 2;
                                        if (outline < 0)
                                                outline = 0;
                                        continue;
                                default:
                                        continue;
                                }
                        case '\b':
                                if (outcol)
                                        outcol--;
                                continue;
                        case '\t':
                                outcol += 8;
                                outcol &= ~7;
                                outcol--;
                                c = ' ';
                                /* FALLTHROUGH */
                        default:
                                if ((w = wcwidth(c)) <= 0)
                                        w = 1;  /* XXX */
                                if (outcol + w > 132) {
                                        outcol += w;
                                        continue;
                                }
                                cp = &page[outline][outcol];
                                outcol += w;
                                if (c == '_') {
                                        if (suppresul)
                                                continue;
                                        cp += 132;
                                        c = '-';
                                }
                                if (*cp == 0) {
                                        for (i = 0; i < w; i++)
                                                cp[i] = c;
                                        dp = cp - (outcol - w);
                                        for (cp--; cp >= dp && *cp == 0; cp--)
                                                *cp = ' ';
                                } else {
                                        if (plus(c, *cp) || plus(*cp, c))
                                                *cp = '+';
                                        else if (*cp == ' ' || *cp == 0) {
                                                for (i = 1; i < w; i++)
                                                        if (cp[i] != ' ' &&
                                                            cp[i] != 0)
                                                                goto cont;
                                                for (i = 0; i < w; i++)
                                                        cp[i] = c;
                                        }
                                }
cont:
                                continue;
                        }
                }
                if (ferror(stdin))
                        err(1, NULL);
        } while (argc > 0);
        fflush(stdout);
        exit(0);
}

static void
usage(void)
{
        fprintf(stderr, "usage: colcrt [-] [-2] [file ...]\n");
        exit(1);
}

static int
plus(wchar_t c, wchar_t d)
{

        return ((c == '|' && d == '-') || d == '_');
}

static void
pflush(int ol)
{
        static int first;
        int i;
        wchar_t *cp;
        char lastomit;
        int l, w;

        l = ol;
        lastomit = 0;
        if (l > 266)
                l = 266;
        else
                l |= 1;
        for (i = first | 1; i < l; i++) {
                move(i, i - 1);
                move(i, i + 1);
        }
        for (i = first; i < l; i++) {
                cp = page[i];
                if (printall == 0 && lastomit == 0 && *cp == 0) {
                        lastomit = 1;
                        continue;
                }
                lastomit = 0;
                while (*cp != L'\0') {
                        if ((w = wcwidth(*cp)) > 0) {
                                putwchar(*cp);
                                cp += w;
                        } else
                                cp++;
                }
                putwchar(L'\n');
        }
        wmemcpy(page[0], page[ol], (267 - ol) * 132);
        wmemset(page[267- ol], L'\0', ol * 132);
        outline -= ol;
        outcol = 0;
        first = 1;
}

static void
move(int l, int m)
{
        wchar_t *cp, *dp;

        for (cp = page[l], dp = page[m]; *cp; cp++, dp++) {
                switch (*cp) {
                        case '|':
                                if (*dp != ' ' && *dp != '|' && *dp != 0)
                                        return;
                                break;
                        case ' ':
                                break;
                        default:
                                return;
                }
        }
        if (*cp == 0) {
                for (cp = page[l], dp = page[m]; *cp; cp++, dp++)
                        if (*cp == '|')
                                *dp = '|';
                        else if (*dp == 0)
                                *dp = ' ';
                page[l][0] = 0;
        }
}