/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1987, 1991, 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/capsicum.h>
#include <sys/param.h>
#include <sys/stat.h>

#include <capsicum_helpers.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <locale.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wchar.h>
#include <wctype.h>
#include <libxo/xo.h>

#include <libcasper.h>
#include <casper/cap_fileargs.h>

#define WC_XO_VERSION "1"

static const char *stdin_filename = "stdin";

static fileargs_t *fa;
static uintmax_t tlinect, twordct, tcharct, tlongline;
static bool doline, doword, dochar, domulti, dolongline;
static volatile sig_atomic_t siginfo;
static xo_handle_t *stderr_handle;

static void     show_cnt(const char *file, uintmax_t linect, uintmax_t wordct,
                    uintmax_t charct, uintmax_t llct);
static int      cnt(const char *);
static void     usage(void);

static void
siginfo_handler(int sig __unused)
{

        siginfo = 1;
}

static void
reset_siginfo(void)
{

        signal(SIGINFO, SIG_DFL);
        siginfo = 0;
}

int
main(int argc, char *argv[])
{
        int ch, errors, total;
        cap_rights_t rights;

        (void) setlocale(LC_CTYPE, "");

        argc = xo_parse_args(argc, argv);
        if (argc < 0)
                exit(EXIT_FAILURE);

        while ((ch = getopt(argc, argv, "clmwL")) != -1)
                switch((char)ch) {
                case 'l':
                        doline = true;
                        break;
                case 'w':
                        doword = true;
                        break;
                case 'c':
                        dochar = true;
                        domulti = false;
                        break;
                case 'L':
                        dolongline = true;
                        break;
                case 'm':
                        domulti = true;
                        dochar = false;
                        break;
                case '?':
                default:
                        usage();
                }
        argv += optind;
        argc -= optind;

        fa = fileargs_init(argc, argv, O_RDONLY, 0,
            cap_rights_init(&rights, CAP_READ, CAP_FSTAT), FA_OPEN);
        if (fa == NULL)
                xo_err(EXIT_FAILURE, "Unable to initialize casper");
        caph_cache_catpages();
        if (caph_limit_stdio() < 0)
                xo_err(EXIT_FAILURE, "Unable to limit stdio");
        if (caph_enter_casper() < 0)
                xo_err(EXIT_FAILURE, "Unable to enter capability mode");

        /* Wc's flags are on by default. */
        if (!(doline || doword || dochar || domulti || dolongline))
                doline = doword = dochar = true;

        stderr_handle = xo_create_to_file(stderr, XO_STYLE_TEXT, 0);

        xo_set_version(WC_XO_VERSION);
        xo_open_container("wc");
        xo_open_list("file");

        (void)signal(SIGINFO, siginfo_handler);
        errors = 0;
        total = 0;
        if (argc == 0) {
                xo_open_instance("file");
                if (cnt(NULL) != 0)
                        ++errors;
                xo_close_instance("file");
        } else {
                while (argc--) {
                        xo_open_instance("file");
                        if (cnt(*argv++) != 0)
                                ++errors;
                        xo_close_instance("file");
                        ++total;
                }
        }

        xo_close_list("file");

        if (total > 1) {
                xo_open_container("total");
                show_cnt("total", tlinect, twordct, tcharct, tlongline);
                xo_close_container("total");
        }

        fileargs_free(fa);
        xo_close_container("wc");
        if (xo_finish() < 0)
                xo_err(EXIT_FAILURE, "stdout");
        exit(errors == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
}

static void
show_cnt(const char *file, uintmax_t linect, uintmax_t wordct,
    uintmax_t charct, uintmax_t llct)
{
        xo_handle_t *xop;

        if (!siginfo)
                xop = NULL;
        else {
                xop = stderr_handle;
                siginfo = 0;
        }

        if (doline)
                xo_emit_h(xop, " {:lines/%7ju/%ju}", linect);
        if (doword)
                xo_emit_h(xop, " {:words/%7ju/%ju}", wordct);
        if (dochar || domulti)
                xo_emit_h(xop, " {:characters/%7ju/%ju}", charct);
        if (dolongline)
                xo_emit_h(xop, " {:long-lines/%7ju/%ju}", llct);
        if (file != stdin_filename)
                xo_emit_h(xop, " {:filename/%s}\n", file);
        else
                xo_emit_h(xop, "\n");
}

static int
cnt(const char *file)
{
        static char buf[MAXBSIZE];
        struct stat sb;
        mbstate_t mbs;
        const char *p;
        uintmax_t linect, wordct, charct, llct, tmpll;
        ssize_t len;
        size_t clen;
        int fd;
        wchar_t wch;
        bool gotsp, warned;

        linect = wordct = charct = llct = tmpll = 0;
        if (file == NULL) {
                fd = STDIN_FILENO;
                file = stdin_filename;
        } else if ((fd = fileargs_open(fa, file)) < 0) {
                xo_warn("%s: open", file);
                return (1);
        }
        if (doword || (domulti && MB_CUR_MAX != 1))
                goto word;
        /*
         * If all we need is the number of characters and it's a regular file,
         * just stat it.
         */
        if (doline == 0 && dolongline == 0) {
                if (fstat(fd, &sb)) {
                        xo_warn("%s: fstat", file);
                        (void)close(fd);
                        return (1);
                }
                /* pseudo-filesystems advertize a zero size */
                if (S_ISREG(sb.st_mode) && sb.st_size > 0) {
                        reset_siginfo();
                        charct = sb.st_size;
                        show_cnt(file, linect, wordct, charct, llct);
                        tcharct += charct;
                        (void)close(fd);
                        return (0);
                }
        }
        /*
         * For files we can't stat, or if we need line counting, slurp the
         * file.  Line counting is split out because it's a lot faster to get
         * lines than to get words, since the word count requires locale
         * handling.
         */
        while ((len = read(fd, buf, sizeof(buf))) != 0) {
                if (len < 0) {
                        xo_warn("%s: read", file);
                        (void)close(fd);
                        return (1);
                }
                if (siginfo)
                        show_cnt(file, linect, wordct, charct, llct);
                charct += len;
                if (doline || dolongline) {
                        for (p = buf; len > 0; --len, ++p) {
                                if (*p == '\n') {
                                        if (tmpll > llct)
                                                llct = tmpll;
                                        tmpll = 0;
                                        ++linect;
                                } else {
                                        tmpll++;
                                }
                        }
                }
        }
        reset_siginfo();
        if (doline)
                tlinect += linect;
        if (dochar)
                tcharct += charct;
        if (dolongline && llct > tlongline)
                tlongline = llct;
        show_cnt(file, linect, wordct, charct, llct);
        (void)close(fd);
        return (0);

        /* Do it the hard way... */
word:   gotsp = true;
        warned = false;
        memset(&mbs, 0, sizeof(mbs));
        while ((len = read(fd, buf, sizeof(buf))) != 0) {
                if (len < 0) {
                        xo_warn("%s: read", file);
                        (void)close(fd);
                        return (1);
                }
                p = buf;
                while (len > 0) {
                        if (siginfo)
                                show_cnt(file, linect, wordct, charct, llct);
                        if (!domulti || MB_CUR_MAX == 1) {
                                clen = 1;
                                wch = (unsigned char)*p;
                        } else if ((clen = mbrtowc(&wch, p, len, &mbs)) == 0) {
                                clen = 1;
                        } else if (clen == (size_t)-1) {
                                if (!warned) {
                                        errno = EILSEQ;
                                        xo_warn("%s", file);
                                        warned = true;
                                }
                                memset(&mbs, 0, sizeof(mbs));
                                clen = 1;
                                wch = (unsigned char)*p;
                        } else if (clen == (size_t)-2) {
                                break;
                        }
                        charct++;
                        if (wch != L'\n')
                                tmpll++;
                        len -= clen;
                        p += clen;
                        if (wch == L'\n') {
                                if (tmpll > llct)
                                        llct = tmpll;
                                tmpll = 0;
                                ++linect;
                        }
                        if (iswspace(wch)) {
                                gotsp = true;
                        } else if (gotsp) {
                                gotsp = false;
                                ++wordct;
                        }
                }
        }
        reset_siginfo();
        if (domulti && MB_CUR_MAX > 1) {
                if (mbrtowc(NULL, NULL, 0, &mbs) == (size_t)-1 && !warned)
                        xo_warn("%s", file);
        }
        if (doline)
                tlinect += linect;
        if (doword)
                twordct += wordct;
        if (dochar || domulti)
                tcharct += charct;
        if (dolongline && llct > tlongline)
                tlongline = llct;
        show_cnt(file, linect, wordct, charct, llct);
        (void)close(fd);
        return (0);
}

static void
usage(void)
{
        xo_error("usage: wc [-c | -m] [-Llw] [file ...]\n");
        exit(EXIT_FAILURE);
}