/* $NetBSD: file.c,v 1.34 2024/04/24 15:49:03 nia Exp $ */

/*-
 * Copyright (c) 1980, 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/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)file.c      8.2 (Berkeley) 3/19/94";
#else
__RCSID("$NetBSD: file.c,v 1.34 2024/04/24 15:49:03 nia Exp $");
#endif
#endif /* not lint */

#ifdef FILEC

#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/tty.h>

#include <dirent.h>
#include <pwd.h>
#include <termios.h>
#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>

#ifndef SHORT_STRINGS
#include <string.h>
#endif /* SHORT_STRINGS */

#include "csh.h"
#include "extern.h"

/*
 * Tenex style file name recognition, .. and more.
 * History:
 *      Author: Ken Greer, Sept. 1975, CMU.
 *      Finally got around to adding to the Cshell., Ken Greer, Dec. 1981.
 */

#define ON      1
#define OFF     0
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif

#define ESC '\033'

typedef enum {
    LIST, RECOGNIZE
}       COMMAND;

static void setup_tty(int);
static void back_to_col_1(void);
static int pushback(Char *);
static void catn(Char *, Char *, size_t);
static void copyn(Char *, Char *, size_t);
static Char filetype(Char *, Char *);
static void print_by_column(Char *, Char *[], size_t);
static Char *tilde(Char *, Char *);
static void retype(void);
static void beep(void);
static void print_recognized_stuff(Char *);
static void extract_dir_and_name(Char *, Char *, Char *);
static Char *getentry(DIR *, int);
static void free_items(Char **, size_t);
static size_t tsearch(Char *, COMMAND, size_t);
static int recognize(Char *, Char *, size_t, size_t);
static int is_prefix(Char *, Char *);
static int is_suffix(Char *, Char *);
static int ignored(Char *);

/*
 * Put this here so the binary can be patched with adb to enable file
 * completion by default.  Filec controls completion, nobeep controls
 * ringing the terminal bell on incomplete expansions.
 */
int filec = 0;

static void
setup_tty(int on)
{
    struct termios tchars;

    (void)tcgetattr(SHIN, &tchars);

    if (on) {
        tchars.c_cc[VEOL] = ESC;
        if (tchars.c_lflag & ICANON)
            on = TCSADRAIN;
        else {
            tchars.c_lflag |= ICANON;
            on = TCSAFLUSH;
        }
    }
    else {
        tchars.c_cc[VEOL] = _POSIX_VDISABLE;
        on = TCSADRAIN;
    }

    (void)tcsetattr(SHIN, on, &tchars);
}

/*
 * Move back to beginning of current line
 */
static void
back_to_col_1(void)
{
    struct termios tty, tty_normal;
    sigset_t nsigset, osigset;

    sigemptyset(&nsigset);
    (void)sigaddset(&nsigset, SIGINT);
    (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
    (void)tcgetattr(SHOUT, &tty);
    tty_normal = tty;
    tty.c_iflag &= ~INLCR;
    tty.c_oflag &= ~ONLCR;
    (void)tcsetattr(SHOUT, TCSADRAIN, &tty);
    (void)write(SHOUT, "\r", 1);
    (void)tcsetattr(SHOUT, TCSADRAIN, &tty_normal);
    (void)sigprocmask(SIG_SETMASK, &osigset, NULL);
}

/*
 * Push string contents back into tty queue
 */
static int
pushback(Char *string)
{
    struct termios tty, tty_normal;
    char buf[64], svchars[sizeof(buf)];
    sigset_t nsigset, osigset;
    Char *p;
    size_t bufidx, i, len_str, nbuf, nsv, onsv, retrycnt;
    char c;

    nsv = 0;
    sigemptyset(&nsigset);
    (void)sigaddset(&nsigset, SIGINT);
    (void)sigprocmask(SIG_BLOCK, &nsigset, &osigset);
    (void)tcgetattr(SHOUT, &tty);
    tty_normal = tty;
    tty.c_lflag &= ~(ECHOKE | ECHO | ECHOE | ECHOK | ECHONL | ECHOPRT | ECHOCTL);
    /* FIONREAD works only in noncanonical mode. */
    tty.c_lflag &= ~ICANON;
    tty.c_cc[VMIN] = 0;
    (void)tcsetattr(SHOUT, TCSADRAIN, &tty);

    for (retrycnt = 5; ; retrycnt--) {
        /*
         * Push back characters.
         */
        for (p = string; (c = (char)*p) != '\0'; p++)
            (void)ioctl(SHOUT, TIOCSTI, (ioctl_t) &c);
        for (i = 0; i < nsv; i++)
            (void)ioctl(SHOUT, TIOCSTI, (ioctl_t) &svchars[i]);

        if (retrycnt == 0)
            break;              /* give up salvaging characters */

        len_str = (size_t)(p - string);

        if (ioctl(SHOUT, FIONREAD, (ioctl_t) &nbuf) ||
            nbuf <= len_str + nsv ||    /* The string fit. */
            nbuf > sizeof(buf))         /* For future binary compatibility
                                           (and safety). */
            break;

        /*
         * User has typed characters before the pushback finished.
         * Salvage the characters.
         */

        /* This read() should be in noncanonical mode. */
        if (read(SHOUT, &buf, nbuf) != (ssize_t)nbuf)
            continue;           /* hangup? */

        onsv = nsv;
        for (bufidx = 0, i = 0; bufidx < nbuf; bufidx++, i++) {
            c = buf[bufidx];
            if ((i < len_str) ? c != (char)string[i] :
                        (i < len_str + onsv) ? c != svchars[i - len_str] : 1) {
                /* Salvage a character. */
                if (nsv < (int)(sizeof svchars / sizeof svchars[0])) {
                    svchars[nsv++] = c;
                    i--;        /* try this comparison with the next char */
                } else
                    break;      /* too many */
            }
        }
    }

#if 1
    /*
     * XXX  Is this a bug or a feature of kernel tty driver?
     *
     * FIONREAD in canonical mode does not return correct byte count
     * in tty input queue, but this is required to avoid unwanted echo.
     */
    tty.c_lflag |= ICANON;
    (void)tcsetattr(SHOUT, TCSADRAIN, &tty);
    (void)ioctl(SHOUT, FIONREAD, (ioctl_t) &i);
#endif
    (void)tcsetattr(SHOUT, TCSADRAIN, &tty_normal);
    (void)sigprocmask(SIG_SETMASK, &osigset, NULL);

    return (int)nsv;
}

/*
 * Concatenate src onto tail of des.
 * Des is a string whose maximum length is count.
 * Always null terminate.
 */
static void
catn(Char *des, Char *src, size_t count)
{
    while (count-- > 0 && *des)
        des++;
    while (count-- > 0)
        if ((*des++ = *src++) == 0)
            return;
    *des = '\0';
}

/*
 * Like strncpy but always leave room for trailing \0
 * and always null terminate.
 */
static void
copyn(Char *des, Char *src, size_t count)
{
    while (count-- > 0)
        if ((*des++ = *src++) == 0)
            return;
    *des = '\0';
}

static Char
filetype(Char *dir, Char *file)
{
    struct stat statb;
    Char path[MAXPATHLEN];

    catn(Strcpy(path, dir), file, sizeof(path) / sizeof(Char));
    if (lstat(short2str(path), &statb) == 0) {
        switch (statb.st_mode & S_IFMT) {
        case S_IFDIR:
            return ('/');
        case S_IFLNK:
            if (stat(short2str(path), &statb) == 0 &&   /* follow it out */
                S_ISDIR(statb.st_mode))
                return ('>');
            else
                return ('@');
        case S_IFSOCK:
            return ('=');
        default:
            if (statb.st_mode & 0111)
                return ('*');
        }
    }
    return (' ');
}

static struct winsize win;

/*
 * Print sorted down columns
 */
static void
print_by_column(Char *dir, Char *items[], size_t count)
{
    size_t c, columns, i, maxwidth, r, rows;

    maxwidth = 0;

    if (ioctl(SHOUT, TIOCGWINSZ, (ioctl_t) & win) < 0 || win.ws_col == 0)
        win.ws_col = 80;
    for (i = 0; i < count; i++)
        maxwidth = maxwidth > (r = Strlen(items[i])) ? maxwidth : r;
    maxwidth += 2;              /* for the file tag and space */
    columns = win.ws_col / maxwidth;
    if (columns == 0)
        columns = 1;
    rows = (count + (columns - 1)) / columns;
    for (r = 0; r < rows; r++) {
        for (c = 0; c < columns; c++) {
            i = c * rows + r;
            if (i < count) {
                size_t w;

                (void)fprintf(cshout, "%s", vis_str(items[i]));
                (void)fputc(dir ? filetype(dir, items[i]) : ' ', cshout);
                if (c < columns - 1) {  /* last column? */
                    w = Strlen(items[i]) + 1;
                    for (; w < maxwidth; w++)
                        (void) fputc(' ', cshout);
                }
            }
        }
        (void)fputc('\r', cshout);
        (void)fputc('\n', cshout);
    }
}

/*
 * Expand file name with possible tilde usage
 *      ~person/mumble
 * expands to
 *      home_directory_of_person/mumble
 */
static Char *
tilde(Char *new, Char *old)
{
    static Char person[40];
    struct passwd *pw;
    Char *o, *p;

    if (old[0] != '~')
        return (Strcpy(new, old));

    for (p = person, o = &old[1]; *o && *o != '/'; *p++ = *o++)
        continue;
    *p = '\0';
    if (person[0] == '\0')
        (void)Strcpy(new, value(STRhome));
    else {
        pw = getpwnam(short2str(person));
        if (pw == NULL)
            return (NULL);
        (void)Strcpy(new, str2short(pw->pw_dir));
    }
    (void)Strcat(new, o);
    return (new);
}

/*
 * Cause pending line to be printed
 */
static void
retype(void)
{
    struct termios tty;

    (void)tcgetattr(SHOUT, &tty);
    tty.c_lflag |= PENDIN;
    (void)tcsetattr(SHOUT, TCSADRAIN, &tty);
}

static void
beep(void)
{
    if (adrof(STRnobeep) == 0)
        (void)write(SHOUT, "\007", 1);
}

/*
 * Erase that silly ^[ and
 * print the recognized part of the string
 */
static void
print_recognized_stuff(Char *recognized_part)
{
    /* An optimized erasing of that silly ^[ */
    (void)fputc('\b', cshout);
    (void)fputc('\b', cshout);
    switch (Strlen(recognized_part)) {
    case 0:                     /* erase two Characters: ^[ */
        (void)fputc(' ', cshout);
        (void)fputc(' ', cshout);
        (void)fputc('\b', cshout);
        (void)fputc('\b', cshout);
        break;
    case 1:                     /* overstrike the ^, erase the [ */
        (void)fprintf(cshout, "%s", vis_str(recognized_part));
        (void)fputc(' ', cshout);
        (void)fputc('\b', cshout);
        break;
    default:                    /* overstrike both Characters ^[ */
        (void)fprintf(cshout, "%s", vis_str(recognized_part));
        break;
    }
    (void)fflush(cshout);
}

/*
 * Parse full path in file into 2 parts: directory and file names
 * Should leave final slash (/) at end of dir.
 */
static void
extract_dir_and_name(Char *path, Char *dir, Char *name)
{
    Char *p;

    p = Strrchr(path, '/');
    if (p == NULL) {
        copyn(name, path, MAXNAMLEN);
        dir[0] = '\0';
    }
    else {
        copyn(name, ++p, MAXNAMLEN);
        copyn(dir, path, (size_t)(p - path));
    }
}

static Char *
getentry(DIR *dir_fd, int looking_for_lognames)
{
    struct dirent *dirp;
    struct passwd *pw;

    if (looking_for_lognames) {
        if ((pw = getpwent()) == NULL)
            return (NULL);
        return (str2short(pw->pw_name));
    }
    if ((dirp = readdir(dir_fd)) != NULL)
        return (str2short(dirp->d_name));
    return (NULL);
}

static void
free_items(Char **items, size_t numitems)
{
    size_t i;

    for (i = 0; i < numitems; i++)
        free(items[i]);
    free(items);
}

#define FREE_ITEMS(items, numitems) { \
        sigset_t nsigset, osigset;\
\
        sigemptyset(&nsigset);\
        (void) sigaddset(&nsigset, SIGINT);\
        (void) sigprocmask(SIG_BLOCK, &nsigset, &osigset);\
        free_items(items, numitems);\
        (void) sigprocmask(SIG_SETMASK, &osigset, NULL);\
}

/*
 * Perform a RECOGNIZE or LIST command on string "word".
 */
static size_t
tsearch(Char *word, COMMAND command, size_t max_word_length)
{
    Char dir[MAXPATHLEN + 1], extended_name[MAXNAMLEN + 1];
    Char name[MAXNAMLEN + 1], tilded_dir[MAXPATHLEN + 1];
    DIR *dir_fd;
    Char *entry;
    int ignoring, looking_for_lognames;
    size_t name_length, nignored, numitems;
    Char **items = NULL;
    size_t maxitems = 0;

    numitems = 0;
    ignoring = TRUE;
    nignored = 0;

    looking_for_lognames = (*word == '~') && (Strchr(word, '/') == NULL);
    if (looking_for_lognames) {
        (void)setpwent();
        copyn(name, &word[1], MAXNAMLEN);       /* name sans ~ */
        dir_fd = NULL;
    }
    else {
        extract_dir_and_name(word, dir, name);
        if (tilde(tilded_dir, dir) == 0)
            return (0);
        dir_fd = opendir(*tilded_dir ? short2str(tilded_dir) : ".");
        if (dir_fd == NULL)
            return (0);
    }

again:                          /* search for matches */
    name_length = Strlen(name);
    for (numitems = 0; (entry = getentry(dir_fd, looking_for_lognames)) != NULL;) {
        if (!is_prefix(name, entry))
            continue;
        /* Don't match . files on null prefix match */
        if (name_length == 0 && entry[0] == '.' &&
            !looking_for_lognames)
            continue;
        if (command == LIST) {
            if ((size_t)numitems >= maxitems) {
                maxitems += 1024;
                items = xreallocarray(items, sizeof(*items), maxitems);
            }
            items[numitems] = xreallocarray(NULL,
                (size_t) (Strlen(entry) + 1), sizeof(Char));
            copyn(items[numitems], entry, MAXNAMLEN);
            numitems++;
        }
        else {                  /* RECOGNIZE command */
            if (ignoring && ignored(entry))
                nignored++;
            else if (recognize(extended_name,
                entry, name_length, ++numitems))
                break;
        }
    }
    if (ignoring && numitems == 0 && nignored > 0) {
        ignoring = FALSE;
        nignored = 0;
        if (looking_for_lognames)
            (void)setpwent();
        else
            rewinddir(dir_fd);
        goto again;
    }

    if (looking_for_lognames)
        (void)endpwent();
    else
        (void)closedir(dir_fd);
    if (numitems == 0)
        return (0);
    if (command == RECOGNIZE) {
        if (looking_for_lognames)
            copyn(word, STRtilde, 1);
        else
            /* put back dir part */
            copyn(word, dir, max_word_length);
        /* add extended name */
        catn(word, extended_name, max_word_length);
        return (numitems);
    }
    else {                      /* LIST */
        qsort(items, numitems, sizeof(items[0]), 
                (int (*) (const void *, const void *)) sortscmp);
        print_by_column(looking_for_lognames ? NULL : tilded_dir,
                        items, numitems);
        if (items != NULL)
            FREE_ITEMS(items, numitems);
    }
    return (0);
}

/*
 * Object: extend what user typed up to an ambiguity.
 * Algorithm:
 * On first match, copy full entry (assume it'll be the only match)
 * On subsequent matches, shorten extended_name to the first
 * Character mismatch between extended_name and entry.
 * If we shorten it back to the prefix length, stop searching.
 */
static int
recognize(Char *extended_name, Char *entry, size_t name_length, size_t numitems)
{
    if (numitems == 1)          /* 1st match */
        copyn(extended_name, entry, MAXNAMLEN);
    else {                      /* 2nd & subsequent matches */
        Char *ent, *x;
        size_t len = 0;

        x = extended_name;
        for (ent = entry; *x && *x == *ent++; x++, len++)
            continue;
        *x = '\0';              /* Shorten at 1st Char diff */
        if (len == name_length) /* Ambiguous to prefix? */
            return (-1);        /* So stop now and save time */
    }
    return (0);
}

/*
 * Return true if check matches initial Chars in template.
 * This differs from PWB imatch in that if check is null
 * it matches anything.
 */
static int
is_prefix(Char *check, Char *template)
{
    do
        if (*check == 0)
            return (TRUE);
    while (*check++ == *template++);
    return (FALSE);
}

/*
 *  Return true if the Chars in template appear at the
 *  end of check, I.e., are its suffix.
 */
static int
is_suffix(Char *check, Char *template)
{
    Char *c, *t;

    for (c = check; *c++;)
        continue;
    for (t = template; *t++;)
        continue;
    for (;;) {
        if (t == template)
            return 1;
        if (c == check || *--t != *--c)
            return 0;
    }
}

ssize_t
tenex(Char *inputline, size_t inputline_size)
{
    char tinputline[BUFSIZE];
    ssize_t num_read;
    size_t numitems;

    setup_tty(ON);

    while ((num_read = read(SHIN, tinputline, BUFSIZE)) > 0) {
        size_t i, nr = (size_t) num_read;


        static Char delims[] = {' ', '\'', '"', '\t', ';', '&', '<',
        '>', '(', ')', '|', '^', '%', '\0'};
        Char *str_end, *word_start, last_Char, should_retype;
        size_t space_left;
        COMMAND command;

        for (i = 0; i < nr; i++)
            inputline[i] = (unsigned char) tinputline[i];
        last_Char = inputline[nr - 1] & ASCII;

        if (last_Char == '\n' || nr == inputline_size)
            break;
        command = (last_Char == ESC) ? RECOGNIZE : LIST;
        if (command == LIST)
            (void)fputc('\n', cshout);
        str_end = &inputline[nr];
        if (last_Char == ESC)
            --str_end;          /* wipeout trailing cmd Char */
        *str_end = '\0';
        /*
         * Find LAST occurrence of a delimiter in the inputline. The word start
         * is one Character past it.
         */
        for (word_start = str_end; word_start > inputline; --word_start)
            if (Strchr(delims, word_start[-1]))
                break;
        space_left = inputline_size - (size_t)(word_start - inputline) - 1;
        numitems = tsearch(word_start, command, space_left);

        if (command == RECOGNIZE) {
            /* print from str_end on */
            print_recognized_stuff(str_end);
            if (numitems != 1)  /* Beep = No match/ambiguous */
                beep();
        }

        /*
         * Tabs in the input line cause trouble after a pushback. tty driver
         * won't backspace over them because column positions are now
         * incorrect. This is solved by retyping over current line.
         */
        should_retype = FALSE;
        if (Strchr(inputline, '\t')) {  /* tab Char in input line? */
            back_to_col_1();
            should_retype = TRUE;
        }
        if (command == LIST)    /* Always retype after a LIST */
            should_retype = TRUE;
        if (pushback(inputline))
            should_retype = TRUE;
        if (should_retype) {
            if (command == RECOGNIZE)
                (void) fputc('\n', cshout);
            printprompt();
        }
        if (should_retype)
            retype();
    }
    setup_tty(OFF);
    return num_read;
}

static int
ignored(Char *entry)
{
    struct varent *vp;
    Char **cp;

    if ((vp = adrof(STRfignore)) == NULL || (cp = vp->vec) == NULL)
        return (FALSE);
    for (; *cp != NULL; cp++)
        if (is_suffix(entry, *cp))
            return (TRUE);
    return (FALSE);
}
#endif                          /* FILEC */