/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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 <sys/capsicum.h>

#include <capsicum_helpers.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <limits.h>
#include <locale.h>
#include <nl_types.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <wchar.h>
#include <wctype.h>

static enum { DF_NONE, DF_NOSEP, DF_PRESEP, DF_POSTSEP } Dflag;
static bool cflag, dflag, uflag, iflag;
static long long numchars, numfields, repeats;

static const struct option long_opts[] =
{
        {"all-repeated",optional_argument,      NULL, 'D'},
        {"count",       no_argument,            NULL, 'c'},
        {"repeated",    no_argument,            NULL, 'd'},
        {"skip-fields", required_argument,      NULL, 'f'},
        {"ignore-case", no_argument,            NULL, 'i'},
        {"skip-chars",  required_argument,      NULL, 's'},
        {"unique",      no_argument,            NULL, 'u'},
        {NULL,          no_argument,            NULL, 0}
};

static FILE     *file(const char *, const char *);
static wchar_t  *convert(const char *);
static int       inlcmp(const char *, const char *);
static void      show(FILE *, const char *);
static wchar_t  *skip(wchar_t *);
static void      obsolete(char *[]);
static void      usage(void);

int
main (int argc, char *argv[])
{
        wchar_t *tprev, *tthis;
        FILE *ifp, *ofp;
        int ch, comp;
        size_t prevbuflen, thisbuflen, b1;
        char *prevline, *thisline, *p;
        const char *errstr, *ifn, *ofn;
        cap_rights_t rights;

        (void) setlocale(LC_ALL, "");

        obsolete(argv);
        while ((ch = getopt_long(argc, argv, "+D::cdif:s:u", long_opts,
            NULL)) != -1)
                switch (ch) {
                case 'D':
                        if (optarg == NULL || strcasecmp(optarg, "none") == 0)
                                Dflag = DF_NOSEP;
                        else if (strcasecmp(optarg, "prepend") == 0)
                                Dflag = DF_PRESEP;
                        else if (strcasecmp(optarg, "separate") == 0)
                                Dflag = DF_POSTSEP;
                        else
                                usage();
                        break;
                case 'c':
                        cflag = true;
                        break;
                case 'd':
                        dflag = true;
                        break;
                case 'i':
                        iflag = true;
                        break;
                case 'f':
                        numfields = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr)
                                errx(1, "field skip value is %s: %s", errstr, optarg);
                        break;
                case 's':
                        numchars = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr != NULL)
                                errx(1, "character skip value is %s: %s", errstr, optarg);
                        break;
                case 'u':
                        uflag = true;
                        break;
                case '?':
                default:
                        usage();
                }

        argc -= optind;
        argv += optind;

        if (argc > 2)
                usage();

        if (Dflag && dflag)
                dflag = false;

        ifp = stdin;
        ifn = "stdin";
        ofp = stdout;
        ofn = "stdout";
        if (argc > 0 && strcmp(argv[0], "-") != 0)
                ifp = file(ifn = argv[0], "r");
        cap_rights_init(&rights, CAP_FSTAT, CAP_READ);
        if (caph_rights_limit(fileno(ifp), &rights) < 0)
                err(1, "unable to limit rights for %s", ifn);
        cap_rights_init(&rights, CAP_FSTAT, CAP_WRITE);
        if (argc > 1)
                ofp = file(ofn = argv[1], "w");
        else
                cap_rights_set(&rights, CAP_IOCTL);
        if (caph_rights_limit(fileno(ofp), &rights) < 0) {
                err(1, "unable to limit rights for %s",
                    argc > 1 ? argv[1] : "stdout");
        }
        if (cap_rights_is_set(&rights, CAP_IOCTL)) {
                unsigned long cmd;

                cmd = TIOCGETA; /* required by isatty(3) in printf(3) */

                if (caph_ioctls_limit(fileno(ofp), &cmd, 1) < 0) {
                        err(1, "unable to limit ioctls for %s",
                            argc > 1 ? argv[1] : "stdout");
                }
        }

        caph_cache_catpages();
        if (caph_enter() < 0)
                err(1, "unable to enter capability mode");

        prevbuflen = thisbuflen = 0;
        prevline = thisline = NULL;

        if (getline(&prevline, &prevbuflen, ifp) < 0) {
                if (ferror(ifp))
                        err(1, "%s", ifn);
                exit(0);
        }
        if (!cflag && !Dflag && !dflag && !uflag)
                show(ofp, prevline);
        tprev = convert(prevline);

        tthis = NULL;
        while (getline(&thisline, &thisbuflen, ifp) >= 0) {
                if (tthis != NULL)
                        free(tthis);
                tthis = convert(thisline);

                if (tthis == NULL && tprev == NULL)
                        comp = inlcmp(thisline, prevline);
                else if (tthis == NULL || tprev == NULL)
                        comp = 1;
                else
                        comp = wcscoll(tthis, tprev);

                if (comp) {
                        /* If different, print; set previous to new value. */
                        if (Dflag == DF_POSTSEP && repeats > 0)
                                fputc('\n', ofp);
                        if (!cflag && !Dflag && !dflag && !uflag)
                                show(ofp, thisline);
                        else if (!Dflag &&
                            (!dflag || (cflag && repeats > 0)) &&
                            (!uflag || repeats == 0))
                                show(ofp, prevline);
                        p = prevline;
                        b1 = prevbuflen;
                        prevline = thisline;
                        prevbuflen = thisbuflen;
                        if (tprev != NULL)
                                free(tprev);
                        tprev = tthis;
                        thisline = p;
                        thisbuflen = b1;
                        tthis = NULL;
                        repeats = 0;
                } else {
                        if (Dflag) {
                                if (repeats == 0) {
                                        if (Dflag == DF_PRESEP)
                                                fputc('\n', ofp);
                                        show(ofp, prevline);
                                }
                        } else if (dflag && !cflag) {
                                if (repeats == 0)
                                        show(ofp, prevline);
                        }
                        ++repeats;
                        if (Dflag)
                                show(ofp, thisline);
                }
        }
        if (ferror(ifp))
                err(1, "%s", ifn);
        if (!cflag && !Dflag && !dflag && !uflag)
                /* already printed */ ;
        else if (!Dflag &&
            (!dflag || (cflag && repeats > 0)) &&
            (!uflag || repeats == 0))
                show(ofp, prevline);
        if (fflush(ofp) != 0)
                err(1, "%s", ofn);
        exit(0);
}

static wchar_t *
convert(const char *str)
{
        size_t n;
        wchar_t *buf, *ret, *p;

        if ((n = mbstowcs(NULL, str, 0)) == (size_t)-1)
                return (NULL);
        if (SIZE_MAX / sizeof(*buf) < n + 1)
                errx(1, "conversion buffer length overflow");
        if ((buf = malloc((n + 1) * sizeof(*buf))) == NULL)
                err(1, "malloc");
        if (mbstowcs(buf, str, n + 1) != n)
                errx(1, "internal mbstowcs() error");
        /* The last line may not end with \n. */
        if (n > 0 && buf[n - 1] == L'\n')
                buf[n - 1] = L'\0';

        /* If requested get the chosen fields + character offsets. */
        if (numfields || numchars) {
                if ((ret = wcsdup(skip(buf))) == NULL)
                        err(1, "wcsdup");
                free(buf);
        } else
                ret = buf;

        if (iflag) {
                for (p = ret; *p != L'\0'; p++)
                        *p = towlower(*p);
        }

        return (ret);
}

static int
inlcmp(const char *s1, const char *s2)
{
        int c1, c2;

        while (*s1 == *s2++)
                if (*s1++ == '\0')
                        return (0);
        c1 = (unsigned char)*s1;
        c2 = (unsigned char)*(s2 - 1);
        /* The last line may not end with \n. */
        if (c1 == '\n')
                c1 = '\0';
        if (c2 == '\n')
                c2 = '\0';
        return (c1 - c2);
}

/*
 * show --
 *      Output a line depending on the flags and number of repetitions
 *      of the line.
 */
static void
show(FILE *ofp, const char *str)
{
        if (cflag)
                (void)fprintf(ofp, "%4lld %s", repeats + 1, str);
        else
                (void)fprintf(ofp, "%s", str);
}

static wchar_t *
skip(wchar_t *str)
{
        long long nchars, nfields;

        for (nfields = 0; *str != L'\0' && nfields++ != numfields; ) {
                while (iswblank(*str))
                        str++;
                while (*str != L'\0' && !iswblank(*str))
                        str++;
        }
        for (nchars = numchars; nchars-- && *str != L'\0'; ++str)
                ;
        return(str);
}

static FILE *
file(const char *name, const char *mode)
{
        FILE *fp;

        if ((fp = fopen(name, mode)) == NULL)
                err(1, "%s", name);
        return(fp);
}

static void
obsolete(char *argv[])
{
        char *ap, *p;

        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.
                 */
                if (asprintf(&p, "-%c%s", ap[0] == '+' ? 's' : 'f', ap + 1) < 0)
                        err(1, "malloc");
                *argv = p;
        }
}

static void
usage(void)
{
        (void)fprintf(stderr, "usage: uniq [-cdiu] [-D[septype]] "
            "[-f fields] [-s chars] [input [output]]\n");
        exit(1);
}