/*      $OpenBSD: uniq.c,v 1.33 2022/01/01 18:20:52 cheloha Exp $       */
/*      $NetBSD: uniq.c,v 1.7 1995/08/31 22:03:48 jtc Exp $     */

/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Case Larsen.
 *
 * 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 <ctype.h>
#include <err.h>
#include <limits.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <wchar.h>
#include <wctype.h>

long long numchars, numfields;
unsigned long long repeats;
int cflag, dflag, iflag, uflag;

void     show(const char *);
char    *skip(char *);
void     obsolete(char *[]);
__dead void     usage(void);

int
main(int argc, char *argv[])
{
        const char *errstr;
        char *p, *prevline, *t, *thisline, *tmp;
        size_t prevsize, thissize, tmpsize;
        ssize_t len;
        int ch;

        setlocale(LC_CTYPE, "");

        if (pledge("stdio rpath wpath cpath", NULL) == -1)
                err(1, "pledge");

        obsolete(argv);
        while ((ch = getopt(argc, argv, "cdf:is:u")) != -1) {
                switch (ch) {
                case 'c':
                        cflag = 1;
                        break;
                case 'd':
                        dflag = 1;
                        break;
                case 'f':
                        numfields = strtonum(optarg, 0, LLONG_MAX, &errstr);
                        if (errstr)
                                errx(1, "fields is %s: %s", errstr, optarg);
                        break;
                case 'i':
                        iflag = 1;
                        break;
                case 's':
                        numchars = strtonum(optarg, 0, LLONG_MAX, &errstr);
                        if (errstr)
                                errx(1, "chars is %s: %s", errstr, optarg);
                        break;
                case 'u':
                        uflag = 1;
                        break;
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        /* If neither -d nor -u are set, default is -d -u. */
        if (!dflag && !uflag)
                dflag = uflag = 1;

        if (argc > 2)
                usage();
        if (argc >= 1 && strcmp(argv[0], "-") != 0) {
                if (freopen(argv[0], "r", stdin) == NULL)
                        err(1, "%s", argv[0]);
        }
        if (argc == 2 && strcmp(argv[1], "-") != 0) {
                if (freopen(argv[1], "w", stdout) == NULL)
                        err(1, "%s", argv[1]);
        }

        if (pledge("stdio", NULL) == -1)
                err(1, "pledge");

        prevsize = 0;
        prevline = NULL;
        if ((len = getline(&prevline, &prevsize, stdin)) == -1) {
                free(prevline);
                if (ferror(stdin))
                        err(1, "getline");
                return 0;
        }
        if (prevline[len - 1] == '\n')
                prevline[len - 1] = '\0';
        if (numfields || numchars)
                p = skip(prevline);
        else
                p = prevline;
        
        thissize = 0;
        thisline = NULL;
        while ((len = getline(&thisline, &thissize, stdin)) != -1) {
                if (thisline[len - 1] == '\n')
                        thisline[len - 1] = '\0';

                /* If requested get the chosen fields + character offsets. */
                if (numfields || numchars)
                        t = skip(thisline);
                else
                        t = thisline;

                /* If different, print; set previous to new value. */
                if ((iflag ? strcasecmp : strcmp)(p, t)) {
                        show(prevline);
                        tmp = prevline;
                        prevline = thisline;
                        thisline = tmp;
                        tmp = p;
                        p = t;
                        t = tmp;
                        tmpsize = prevsize;
                        prevsize = thissize;
                        thissize = tmpsize;
                        repeats = 0;
                } else
                        ++repeats;
        }
        free(thisline);
        if (ferror(stdin))
                err(1, "getline");

        show(prevline);
        free(prevline);

        return 0;
}

/*
 * show --
 *      Output a line depending on the flags and number of repetitions
 *      of the line.
 */
void
show(const char *str)
{
        if ((dflag && repeats) || (uflag && !repeats)) {
                if (cflag)
                        printf("%4llu %s\n", repeats + 1, str);
                else
                        printf("%s\n", str);
        }
}

char *
skip(char *str)
{
        long long nchars, nfields;
        wchar_t wc;
        int len;
        int field_started;

        for (nfields = numfields; nfields && *str; nfields--) {
                /* Skip one field, including preceding blanks. */
                for (field_started = 0; *str != '\0'; str += len) {
                        if ((len = mbtowc(&wc, str, MB_CUR_MAX)) == -1) {
                                (void)mbtowc(NULL, NULL, MB_CUR_MAX);
                                wc = L'?';
                                len = 1;
                        }
                        if (iswblank(wc)) {
                                if (field_started)
                                        break;
                        } else
                                field_started = 1;
                }
        }

        /* Skip some additional characters. */
        for (nchars = numchars; nchars-- && *str != '\0'; str += len)
                if ((len = mblen(str, MB_CUR_MAX)) == -1)
                        len = 1;

        return (str);
}

void
obsolete(char *argv[])
{
        size_t len;
        char *ap, *p, *start;

        while ((ap = *++argv)) {
                /* Return if "--" or not an option of any form. */
                if (ap[0] != '-') {
                        if (ap[0] != '+')
                                return;
                } else if (ap[1] == '-')
                        return;
                if (!isdigit((unsigned char)ap[1]))
                        continue;
                /*
                 * Digit signifies an old-style option.  Malloc space for dash,
                 * new option and argument.
                 */
                len = strlen(ap) + 3;
                if ((start = p = malloc(len)) == NULL)
                        err(1, "malloc");
                *p++ = '-';
                *p++ = ap[0] == '+' ? 's' : 'f';
                (void)strlcpy(p, ap + 1, len - 2);
                *argv = start;
        }
}

__dead void
usage(void)
{
        fprintf(stderr,
            "usage: %s [-ci] [-d | -u] [-f fields] [-s chars] [input_file [output_file]]\n",
            getprogname());
        exit(1);
}