/*      $OpenBSD: file.c,v 1.40 2020/10/06 01:40:43 deraadt Exp $       */
/*      $NetBSD: file.c,v 1.11 1996/11/08 19:34:37 christos 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/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <dirent.h>
#include <errno.h>
#include <limits.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

#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.
 */

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

#define ESC             '\033'
#define TABWIDTH        8

typedef enum {
        LIST,
        RECOGNIZE
} COMMAND;

struct cmdline {
        int      fdin;
        int      fdout;
        int      istty;
        int      flags;
#define CL_ALTWERASE    0x1
#define CL_PROMPT       0x2
        char    *buf;
        size_t   len;
        size_t   size;
        size_t   cursor;
};

/* Command line auxiliary functions. */
static void      cl_beep(struct cmdline *);
static void      cl_flush(struct cmdline *);
static int       cl_getc(struct cmdline *);
static Char     *cl_lastw(struct cmdline *);
static void      cl_putc(struct cmdline *, int);
static void      cl_visc(struct cmdline *, int);

/* Command line editing functions. */
static int      cl_abort(struct cmdline *, int);
static int      cl_erasec(struct cmdline *, int);
static int      cl_erasew(struct cmdline *, int);
static int      cl_insert(struct cmdline *, int);
static int      cl_kill(struct cmdline *, int);
static int      cl_list(struct cmdline *, int);
static int      cl_literal(struct cmdline *, int);
static int      cl_recognize(struct cmdline *, int);
static int      cl_reprint(struct cmdline *, int);
static int      cl_status(struct cmdline *, int);

static const struct termios     *setup_tty(int);

static void      catn(Char *, Char *, int);
static void      copyn(Char *, Char *, int);
static Char      filetype(Char *, Char *);
static void      print_by_column(Char *, Char *[], int);
static Char     *tilde(Char *, Char *);
static void      extract_dir_and_name(Char *, Char *, Char *);
static Char     *getentry(DIR *, int);
static void      free_items(Char **, int);
static int       tsearch(Char *, COMMAND, int);
static int       recognize(Char *, Char *, int, int);
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.
 */
bool    filec = 0;

static void
cl_flush(struct cmdline *cl)
{
        size_t  i, len;
        int     c;

        if (cl->flags & CL_PROMPT) {
                cl->flags &= ~CL_PROMPT;
                printprompt();
        }

        if (cl->cursor < cl->len) {
                for (; cl->cursor < cl->len; cl->cursor++)
                        cl_visc(cl, cl->buf[cl->cursor]);
        } else if (cl->cursor > cl->len) {
                len = cl->cursor - cl->len;
                for (i = len; i > 0; i--) {
                        c = cl->buf[--cl->cursor];
                        if (c == '\t')
                                len += TABWIDTH - 1;
                        else if (iscntrl(c))
                                len++;  /* account for leading ^ */
                }
                for (i = 0; i < len; i++)
                        cl_putc(cl, '\b');
                for (i = 0; i < len; i++)
                        cl_putc(cl, ' ');
                for (i = 0; i < len; i++)
                        cl_putc(cl, '\b');
                cl->cursor = cl->len;
        }
}

static int
cl_getc(struct cmdline *cl)
{
        ssize_t         n;
        unsigned char   c;

        for (;;) {
                n = read(cl->fdin, &c, 1);
                switch (n) {
                case -1:
                        if (errno == EINTR)
                                continue;
                        /* FALLTHROUGH */
                case 0:
                        return 0;
                default:
                        return c & 0x7F;
                }
        }
}

static Char *
cl_lastw(struct cmdline *cl)
{
        static Char              word[BUFSIZ];
        const unsigned char     *delimiters = " '\"\t;&<>()|^%";
        Char                    *cp;
        size_t                   i;

        for (i = cl->len; i > 0; i--)
                if (strchr(delimiters, cl->buf[i - 1]) != NULL)
                        break;

        cp = word;
        for (; i < cl->len; i++)
                *cp++ = cl->buf[i];
        *cp = '\0';

        return word;
}

static void
cl_putc(struct cmdline *cl, int c)
{
        unsigned char   cc = c;

        write(cl->fdout, &cc, 1);
}

static void
cl_visc(struct cmdline *cl, int c)
{
#define UNCNTRL(x)      ((x) == 0x7F ? '?' : ((x) | 0x40))
        int     i;

        if (c == '\t') {
                for (i = 0; i < TABWIDTH; i++)
                        cl_putc(cl, ' ');
        } else if (c != '\n' && iscntrl(c)) {
                cl_putc(cl, '^');
                cl_putc(cl, UNCNTRL(c));
        } else {
                cl_putc(cl, c);
        }
}

static int
cl_abort(struct cmdline *cl, int c)
{
        cl_visc(cl, c);

        /* Abort while/foreach loop prematurely. */
        if (whyles) {
                if (cl->istty)
                        setup_tty(0);
                kill(getpid(), SIGINT);
        }

        cl_putc(cl, '\n');
        cl->len = cl->cursor = 0;
        cl->flags |= CL_PROMPT;

        return 0;
}

static int
cl_erasec(struct cmdline *cl, int c)
{
        if (cl->len > 0)
                cl->len--;

        return 0;
}

static int
cl_erasew(struct cmdline *cl, int c)
{
        const unsigned char     *ws = " \t";

        for (; cl->len > 0; cl->len--)
                if (strchr(ws, cl->buf[cl->len - 1]) == NULL &&
                    ((cl->flags & CL_ALTWERASE) == 0 ||
                     isalpha(cl->buf[cl->len - 1])))
                        break;
        for (; cl->len > 0; cl->len--)
                if (strchr(ws, cl->buf[cl->len - 1]) != NULL ||
                    ((cl->flags & CL_ALTWERASE) &&
                     !isalpha(cl->buf[cl->len - 1])))
                        break;

        return 0;
}

static void
cl_beep(struct cmdline *cl)
{
        if (adrof(STRnobeep) == 0)
                cl_putc(cl, '\007');
}

static int
cl_insert(struct cmdline *cl, int c)
{
        if (cl->len == cl->size)
                return 1;

        cl->buf[cl->len++] = c;

        if (c == '\n')
                return 1;

        return 0;
}

static int
cl_kill(struct cmdline *cl, int c)
{
        cl->len = 0;

        return 0;
}

static int
cl_list(struct cmdline *cl, int c)
{
        Char    *word;
        size_t   len;

        if (adrof(STRignoreeof) || cl->len > 0)
                cl_visc(cl, c);

        if (cl->len == 0)
                return 1;

        cl_putc(cl, '\n');
        cl->cursor = 0;
        cl->flags |= CL_PROMPT;

        word = cl_lastw(cl);
        len = Strlen(word);
        tsearch(word, LIST, BUFSIZ - len - 1);  /* NUL */

        return 0;
}

static int
cl_literal(struct cmdline *cl, int c)
{
        int     literal;

        literal = cl_getc(cl);
        if (literal == '\n')
                literal = '\r';
        cl_insert(cl, literal);

        return 0;
}

static int
cl_recognize(struct cmdline *cl, int c)
{
        Char    *word;
        size_t   len;
        int      nitems;

        if (cl->len == 0) {
                cl_beep(cl);
                return 0;
        }

        word = cl_lastw(cl);
        len = Strlen(word);
        nitems = tsearch(word, RECOGNIZE, BUFSIZ - len - 1);    /* NUL */
        for (word += len; *word != '\0'; word++)
                cl_insert(cl, *word);
        if (nitems != 1)
                cl_beep(cl);

        return 0;
}

static int
cl_reprint(struct cmdline *cl, int c)
{
        cl_visc(cl, c);
        cl_putc(cl, '\n');
        cl->cursor = 0;

        return 0;
}

static int
cl_status(struct cmdline *cl, int c)
{
        cl->cursor = 0;
        if (cl->istty)
                ioctl(cl->fdin, TIOCSTAT);

        return 0;
}

const struct termios *
setup_tty(int on)
{
        static struct termios   newtio, oldtio;

        if (on) {
                tcgetattr(SHIN, &oldtio);

                newtio = oldtio;
                newtio.c_lflag &= ~(ECHO | ICANON | ISIG);
                newtio.c_cc[VEOL] = ESC;
                newtio.c_cc[VLNEXT] = _POSIX_VDISABLE;
                newtio.c_cc[VMIN] = 1;
                newtio.c_cc[VTIME] = 0;
        } else {
                newtio = oldtio;
        }

        tcsetattr(SHIN, TCSADRAIN, &newtio);

        /*
         * Since VLNEXT is disabled, restore its previous value in order to make
         * the key detectable.
         */
        newtio.c_cc[VLNEXT] = oldtio.c_cc[VLNEXT];

        return &newtio;
}

/*
 * 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, int count)
{
    while (--count >= 0 && *des)
        des++;
    while (--count >= 0)
        if ((*des++ = *src++) == 0)
            return;
    *des = '\0';
}

/*
 * Places Char's like strlcpy, but no special return value.
 */
static void
copyn(Char *des, Char *src, int count)
{
    while (--count >= 0)
        if ((*des++ = *src++) == 0)
            return;
    *des = '\0';
}

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

    Strlcpy(path, dir, sizeof path/sizeof(Char));
    catn(path, 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 (' ');
}

/*
 * Print sorted down columns
 */
static void
print_by_column(Char *dir, Char *items[], int count)
{
    struct winsize win;
    int i, rows, r, c, maxwidth = 0, columns;

    if (ioctl(SHOUT, TIOCGWINSZ, (ioctl_t) & win) == -1 || 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) {
                int 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)
{
    Char *o, *p;
    struct passwd *pw;
    static Char person[40];

    if (old[0] != '~') {
        Strlcpy(new, old, PATH_MAX);
        return new;
    }

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

/*
 * 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, p - path);
    }
}

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

    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, int numitems)
{
    int i;

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

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

/*
 * Perform a RECOGNIZE or LIST command on string "word".
 */
static int
tsearch(Char *word, COMMAND command, int max_word_length)
{
    DIR *dir_fd;
    int numitems = 0, ignoring = TRUE, nignored = 0;
    int name_length, looking_for_lognames;
    Char    tilded_dir[PATH_MAX], dir[PATH_MAX];
    Char    name[MAXNAMLEN + 1], extended_name[MAXNAMLEN + 1];
    Char   *entry;
    Char   **items = NULL;
    size_t  maxitems = 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 (numitems >= maxitems) {
                maxitems += 1024;
                items = xreallocarray(items, maxitems, sizeof(*items));
            }
            items[numitems] = xreallocarray(NULL, (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), sortscmp);
        print_by_column(looking_for_lognames ? NULL : tilded_dir,
                        items, numitems);
        if (items != NULL)
            FREE_ITEMS(items);
    }
    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, int name_length, int numitems)
{
    if (numitems == 1)          /* 1st match */
        copyn(extended_name, entry, MAXNAMLEN);
    else {                      /* 2nd & subsequent matches */
        Char *x, *ent;
        int 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;
    }
}

int
tenex(Char *inputline, int inputline_size)
{
        static struct {
                int     (*fn)(struct cmdline *, int);
                int     idx;
        }                        keys[] = {
                { cl_abort,     VINTR },
                { cl_erasec,    VERASE },
                { cl_erasew,    VWERASE },
                { cl_kill,      VKILL },
                { cl_list,      VEOF },
                { cl_literal,   VLNEXT },
                { cl_recognize, VEOL },
                { cl_reprint,   VREPRINT },
                { cl_status,    VSTATUS },
                { cl_insert,    -1 }
        };
        unsigned char            buf[BUFSIZ];
        const struct termios    *tio;
        struct cmdline           cl;
        size_t                   i;
        int                      c, ret;

        memset(&cl, 0, sizeof(cl));
        cl.fdin = SHIN;
        cl.fdout = SHOUT;
        cl.istty = isatty(SHIN);

        if (cl.istty)
                tio = setup_tty(1);

        cl.buf = buf;
        cl.size = sizeof(buf);
        if (inputline_size < cl.size)
                cl.size = inputline_size;
        if (cl.istty && tio->c_lflag & ALTWERASE)
                cl.flags |= CL_ALTWERASE;
        if (needprompt) {
                needprompt = 0;
                cl.flags |= CL_PROMPT;
                cl_flush(&cl);
        }

        for (;;) {
                if ((c = cl_getc(&cl)) == 0)
                        break;

                for (i = 0; keys[i].idx >= 0; i++)
                        if (cl.istty && CCEQ(tio->c_cc[keys[i].idx], c))
                                break;
                ret = keys[i].fn(&cl, c);
                cl_flush(&cl);
                if (ret)
                        break;
        }

        if (cl.istty)
                setup_tty(0);

        for (i = 0; i < cl.len; i++)
                inputline[i] = cl.buf[i];
        /*
         * NUL-terminating the buffer implies that it contains a complete
         * command ready to be executed. Therefore, don't terminate if the
         * buffer is full since more characters must be read in order to form a
         * complete command.
         */
        if (i < cl.size)
                inputline[i] = '\0';

        return cl.len;
}

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);
}