/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved. The Berkeley Software License Agreement
 * specifies the terms and conditions for redistribution.
 */

/*
 * This module provides with system/library function substitutes for tchar
 * datatype. This also includes two conversion functions between tchar and
 * char arrays.
 *
 * T. Kurosaka, Palo Alto, California, USA
 * March 1989
 *
 * Implementation Notes:
 *      Many functions defined here use a "char" buffer chbuf[].  In the
 * first attempt, there used to be only one chbuf defined as static
 * (private) variable and shared by these functions.  csh linked with that
 * version of this file misbehaved in interpreting "eval `tset ....`".
 * (in general, builtin function with back-quoted expression).
 *      This bug seemed to be caused by sharing of chbuf
 * by these functions simultanously (thru vfork() mechanism?).  We could not
 * identify which two functions interfere each other so we decided to
 * have each of these function its private instance of chbuf.
 * The size of chbuf[] might be much bigger than necessary for some functions.
 */
#ifdef DBG
#include <stdio.h>      /* For <assert.h> needs stderr defined. */
#else /* !DBG */
#define NDEBUG          /* Disable assert(). */
#endif /* !DBG */

#include <assert.h>
#include "sh.h"

#ifdef MBCHAR
#include <widec.h>      /* For wcsetno() */
#endif

#include <sys/param.h>  /* MAXPATHLEN */
#include <fcntl.h>
#include <unistd.h>

bool    cflg;

/*
 * strtots(to, from): convert a char string 'from' into a tchar buffer 'to'.
 *      'to' is assumed to have the enough size to hold the conversion result.
 *      When 'to' is NOSTR(=(tchar *)0), strtots() attempts to allocate a space
 *      automatically using xalloc().  It is caller's responsibility to
 *      free the space allocated in this way, by calling xfree(ptr).
 *      In either case, strtots() returns the pointer to the conversion
 *      result (i.e. 'to', if 'to' wasn't NOSTR, or the allocated space.).
 *      When a conversion or allocateion failed,  NOSTR is returned.
 */

tchar   *
strtots(tchar *to, char *from)
{
        int     i;

        if (to == NOSTR) {      /* Need to xalloc(). */
                int     i;

                i = mbstotcs(NOSTR, from, 0);
                if (i < 0) {
                        return (NOSTR);
                }

                /* Allocate space for the resulting tchar array. */
                to = (tchar *)xalloc(i * sizeof (tchar));
        }
        i = mbstotcs(to, from, INT_MAX);
        if (i < 0) {
                return (NOSTR);
        }
        return (to);
}

char    *
tstostr(char *to, tchar *from)
{
        tchar   *ptc;
        wchar_t wc;
        char    *pmb;
        int     len;

        if (to == (char *)NULL) {       /* Need to xalloc(). */
                int     i;
                int     i1;
                char    junk[MB_LEN_MAX];

                /* Get sum of byte counts for each char in from. */
                i = 0;
                ptc = from;
                while (wc = (wchar_t)((*ptc++)&TRIM)) {
                        if ((i1 = wctomb(junk, wc)) <= 0) {
                                i1 = 1;
                        }
                        i += i1;
                }

                /* Allocate that much. */
                to = (char *)xalloc(i + 1);
        }

        ptc = from;
        pmb = to;
        while (wc = (wchar_t)((*ptc++)&TRIM)) {
                if ((len = wctomb(pmb, wc)) <= 0) {
                        *pmb = (unsigned char)wc;
                        len = 1;
                }
                pmb += len;
        }
        *pmb = (char)0;
        return (to);
}

/*
 * mbstotcs(to, from, tosize) is similar to strtots() except that
 * this returns # of tchars of the resulting tchar string.
 * When NULL is give as the destination, no real conversion is carried out,
 * and the function reports how many tchar characters would be made in
 * the converted result including the terminating 0.
 *      tchar   *to;    - Destination buffer, or NULL.
 *      char    *from;  - Source string.
 *      int     tosize; - Size of to, in terms of # of tchars.
 */
int
mbstotcs(tchar *to, char *from, int tosize)
{
        tchar   *ptc = to;
        char    *pmb = from;
        wchar_t wc;
        int     chcnt = 0;
        int     j;


        /* Just count how many tchar would be in the result. */
        if (to == (tchar *)NULL) {
                while (*pmb) {
                        if ((j = mbtowc(&wc, pmb, MB_CUR_MAX)) <= 0) {
                                j = 1;
                        }
                        pmb += j;
                        chcnt++;
                }
                chcnt++;        /* For terminator. */
                return (chcnt); /* # of chars including terminating zero. */
        } else {        /* Do the real conversion. */
                while (*pmb) {
                        if ((j = mbtowc(&wc, pmb, MB_CUR_MAX)) <= 0) {
                                wc = (unsigned char)*pmb;
                                j = 1;
                        }
                        pmb += j;
                        *(ptc++) = (tchar)wc;
                        if (++chcnt >= tosize) {
                                break;
                        }
                }
                /* Terminate with zero only when space is left. */
                if (chcnt < tosize) {
                        *ptc = (tchar)0;
                        ++chcnt;
                }
                return (chcnt); /* # of chars including terminating zero. */
        }
}


/* tchar version of STRING functions. */

/*
 * Returns the number of
 * non-NULL tchar elements in tchar string argument.
 */
int
strlen_(tchar *s)
{
        int n;

        n = 0;
        while (*s++) {
                n++;
        }
        return (n);
}

/*
 * Concatenate tchar string s2 on the end of s1.  S1's space must be large
 * enough.  Return s1.
 */
tchar *
strcat_(tchar *s1, tchar *s2)
{
        tchar *os1;

        os1 = s1;
        while (*s1++)
                ;
        --s1;
        while (*s1++ = *s2++)
                ;
        return (os1);
}

/*
 * Compare tchar strings:  s1>s2: >0  s1==s2: 0  s1<s2: <0
 * BUGS: Comparison between two characters are done by subtracting two chars
 *      after converting each to an unsigned long int value.  It might not make
 *      a whole lot of sense to do that if the characters are in represented
 *      as wide characters and the two characters belong to different codesets.
 *      Therefore, this function should be used only to test the equallness.
 */
int
strcmp_(tchar *s1, tchar *s2)
{
        while (*s1 == *s2++) {
                if (*s1++ == (tchar)0) {
                        return (0);
                }
        }
        return (((unsigned long)*s1) - ((unsigned long)*(--s2)));
}

/*
 * This is only used in sh.glob.c for sorting purpose.
 */
int
strcoll_(tchar *s1, tchar *s2)
{
        char buf1[BUFSIZ];
        char buf2[BUFSIZ];

        tstostr(buf1, s1);
        tstostr(buf2, s2);
        return (strcoll(buf1, buf2));
}

/*
 * Copy tchar string s2 to s1.  s1 must be large enough.
 * return s1
 */
tchar *
strcpy_(tchar *s1, tchar *s2)
{
        tchar *os1;

        os1 = s1;
        while (*s1++ = *s2++)
                ;
        return (os1);
}

/*
 * Return the ptr in sp at which the character c appears;
 * NULL if not found
 */
tchar *
index_(tchar *sp, tchar c)
{

        do {
                if (*sp == c) {
                        return (sp);
                }
        } while (*sp++);
        return (NULL);
}

/*
 * Return the ptr in sp at which the character c last
 * appears; NOSTR if not found
 */

tchar *
rindex_(tchar *sp, tchar c)
{
        tchar *r;

        r = NOSTR;
        do {
                if (*sp == c) {
                        r = sp;
                }
        } while (*sp++);
        return (r);
}

/* Additional misc functions. */

/* Calculate the display width of a string.  */
int
tswidth(tchar *ts)
{
#ifdef MBCHAR
        wchar_t tc;
        int     w = 0;
        int     p_col;

        while (tc = *ts++) {
                if ((p_col = wcwidth((wchar_t)tc)) > 0)
                        w += p_col;
        }
        return (w);
#else /* !MBCHAR --- one char always occupies one column. */
        return (strlen_(ts));
#endif
}

/*
 * Two getenv() substitute functions.  They differ in the type of arguments.
 * BUGS: Both returns the pointer to an allocated space where the env var's
 *      values is stored.  This space is freed automatically on the successive
 *      call of either function.  Therefore the caller must copy the contents
 *      if it needs to access two env vars.  There is an arbitary limitation
 *      on the number of chars of a env var name.
 */
#define LONGEST_ENVVARNAME      256             /* Too big? */
tchar *
getenv_(tchar *name_)
{
        char    name[LONGEST_ENVVARNAME * MB_LEN_MAX];

        assert(strlen_(name_) < LONGEST_ENVVARNAME);
        return (getenvs_(tstostr(name, name_)));
}

tchar *
getenvs_(char *name)
{
        static tchar    *pbuf = (tchar *)NULL;
        char    *val;

        if (pbuf) {
                xfree(pbuf);
                pbuf = NOSTR;
        }
        val = getenv(name);
        if (val == (char *)NULL) {
                return (NOSTR);
        }
        return (pbuf = strtots(NOSTR, val));
}

/* Followings are the system call interface for tchar strings. */

/*
 * creat() and open() replacement.
 * BUGS: An unusually long file name could be dangerous.
 */
int
creat_(tchar *name_, int mode)
{
        int fd;
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */

        tstostr(chbuf, name_);
        fd = creat((char *)chbuf, mode);
        if (fd != -1) {
                setfd(fd);
        }
        return (fd);
}

/*VARARGS2*/
int
open_(path_, flags, mode)
        tchar   *path_;
        int     flags;
        int     mode; /* May be omitted. */
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */
        int fd;

        tstostr(chbuf, path_);
        fd = open((char *)chbuf, flags, mode);
        if (fd != -1) {
                setfd(fd);
        }
        return (fd);
}

/*
 * mkstemp replacement
 */
int
mkstemp_(tchar *name_)
{
        int fd;
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */

        tstostr(chbuf, name_);
        fd = mkstemp((char *)chbuf);
        if (fd != -1) {
                setfd(fd);
                strtots(name_, chbuf);
        }
        return (fd);
}

/*
 * read() and write() reaplacement.
 *      int        d;
 *      tchar      *buf;  - where the result be stored.  Not NULL terminated.
 *      int        nchreq; - # of tchars requrested.
 */
int
read_(int d, tchar *buf, int nchreq)
{
        unsigned char chbuf[BUFSIZ * MB_LEN_MAX]; /* General use buffer. */
#ifdef MBCHAR
        /*
         * We would have to read more than tchar bytes
         * when there are multibyte characters in the file.
         */
        int     i, j, fflags;
        unsigned char   *s;     /* Byte being scanned for a multibyte char. */
        /* Points to the pos where next read() to read the data into. */
        unsigned char   *p;
        tchar   *t;
        wchar_t         wc;
        int             b_len;
        int             nchread = 0; /* Count how many bytes has been read. */
        int             nbytread = 0; /* Total # of bytes read. */
        /* # of bytes needed to complete the last char just read. */
        int             delta;
        unsigned char   *q;     /* q points to the first invalid byte. */
        int             mb_cur_max = MB_CUR_MAX;
#ifdef DBG
        tprintf("Entering read_(d=%d, buf=0x%x, nchreq=%d);\n",
            d, buf, nchreq);
#endif /* DBG */
        /*
         *      Step 1: We collect the exact number of bytes that make
         *      nchreq characters into chbuf.
         *      We must be careful not to read too many bytes as we
         *      cannot push back such over-read bytes.
         *      The idea we use here is that n multibyte characters are stored
         *      in no less than n but less than n*MB_CUR_MAX bytes.
         */
        assert(nchreq <= BUFSIZ);
        delta = 0;
        p = s = chbuf;
        t = buf;
        while (nchread < nchreq) {
                int             m;  /* # of bytes to try to read this time. */
                int             k;  /* # of bytes successfully read. */

retry:
                /*
                 * Let's say the (N+1)'th byte bN is actually the first
                 * byte of a three-byte character c.
                 * In that case, p, s, q look like this:
                 *
                 *              /-- already read--\ /-- not yet read --\
                 * chbuf[]:     b0 b1 ..... bN bN+1 bN+2 bN+2 ...
                 *              ^               ^       ^
                 *              |               |       |
                 *              p               s       q
                 *                              \----------/
                 *                              c hasn't been completed
                 *
                 * Just after the next read(), p and q will be adavanced to:
                 *
                 *      /-- already read-----------------------\ /-- not yet -
                 * chbuf[]: b0 b1 ..... bN bN+1 bN+2 bN+2 ... bX bX+1 bX+2...
                 *                      ^       ^                ^
                 *                      |       |                |
                 *                      s       p                q
                 *                      \----------/
                 *                       c has been completed
                 *                       but hasn't been scanned
                 */
                m = nchreq - nchread;
                assert(p + m < chbuf + sizeof (chbuf));
                k = read(d, p, m);
                /*
                 * when child sets O_NDELAY or O_NONBLOCK on stdin
                 * and exits and we are interactive then turn the modes off
                 * and retry
                 */
                if (k == 0) {
                        if ((intty && !onelflg && !cflg) &&
                            ((fflags = fcntl(d, F_GETFL, 0)) & O_NDELAY)) {
                                fflags &= ~O_NDELAY;
                                fcntl(d, F_SETFL, fflags);
                                goto retry;
                        }
                } else if (k < 0) {
                        if (errno == EAGAIN) {
                                fflags = fcntl(d, F_GETFL, 0);
                                fflags &= ~O_NONBLOCK;
                                fcntl(d, F_SETFL, fflags);
                                goto retry;
                        }
                        return (-1);
                }
                nbytread += k;
                q = p + k;
                delta = 0;

                /* Try scaning characters in s..q-1 */
                while (s < q) {
                        /* Convert the collected bytes into tchar array. */
                        if (*s == 0) {
                                /* NUL is treated as a normal char here. */
                                *t++ = 0;
                                s++;
                                nchread++;
                                continue;
                        }

                        if ((b_len = q - s) > mb_cur_max) {
                                b_len = mb_cur_max;
                        }
                        if ((j = mbtowc(&wc, (char *)s, b_len)) <=  0) {
                                if (mb_cur_max > 1 && b_len < mb_cur_max) {
                                        /*
                                         * Needs more byte to complete this char
                                         * In order to read() more than delta
                                         * bytes.
                                         */
                                        break;
                                }
                                wc = (unsigned char)*s;
                                j = 1;
                        }

                        *t++ = wc;
                        nchread++;
                        s += j;
                }

                if (k < m) {
                        /* We've read as many bytes as possible. */
                        while (s < q) {
                                if ((b_len = q - s) > mb_cur_max) {
                                        b_len = mb_cur_max;
                                }
                                if ((j = mbtowc(&wc, (char *)s, b_len)) <=  0) {
                                        wc = (unsigned char)*s;
                                        j = 1;
                                }
                                *t++ = wc;
                                nchread++;
                                s += j;
                        }
                        return (nchread);
                }

                p = q;
        }

        if (mb_cur_max == 1 || (delta = q - s) == 0) {
                return (nchread);
        }

        /*
         * We may have (MB_CUR_MAX - 1) unread data in the buffer.
         * Here, the last converted data was an illegal character which was
         * treated as one byte character. We don't know at this point
         * whether or not the remaining data is in legal sequence.
         * We first attempt to convert the remaining data.
         */
        do {
                if ((j = mbtowc(&wc, (char *)s, delta)) <= 0)
                        break;
                *t++ = wc;
                nchread++;
                s += j;
                delta -= j;
        } while (delta > 0);

        if (delta == 0)
                return (nchread);

        /*
         * There seem to be ugly sequence in the buffer. Fill up till
         * mb_cur_max and see if we can get a right sequence.
         */
        while (delta < mb_cur_max) {
                assert((q + 1) < (chbuf + sizeof (chbuf)));
                if (read(d, q, 1) != 1)
                        break;
                delta++;
                q++;
                if (mbtowc(&wc, (char *)s, delta) > 0) {
                        *t = wc;
                        return (nchread + 1);
                }
        }

        /*
         * no luck. we have filled MB_CUR_MAX bytes in the buffer.
         * Ideally we should return with leaving such data off and
         * put them into a local buffer for next read, but we don't
         * have such.
         * So, stop reading further, and treat them as all single
         * byte characters.
         */
        while (s < q) {
                b_len = q - s;
                if ((j = mbtowc(&wc, (char *)s, b_len)) <=  0) {
                        wc = (unsigned char)*s;
                        j = 1;
                }
                *t++ = wc;
                nchread++;
                s += j;
        }
        return (nchread);

#else /* !MBCHAR */
        /* One byte always represents one tchar.  Easy! */
        int             i;
        unsigned char   *s;
        tchar           *t;
        int             nchread;

#ifdef DBG
        tprintf("Entering read_(d=%d, buf=0x%x, nchreq=%d);\n",
            d, buf, nchreq);
#endif /* DBG */
        assert(nchreq <= BUFSIZ);
retry:
        nchread = read(d, (char *)chbuf, nchreq);
        /*
         * when child sets O_NDELAY or O_NONBLOCK on stdin
         * and exits and we are interactive then turn the modes off
         * and retry
         */
        if (nchread == 0) {
                if ((intty && !onelflg && !cflg) &&
                    ((fflags = fcntl(d, F_GETFL, 0)) & O_NDELAY)) {
                        fflags &= ~O_NDELAY;
                        fcntl(d, F_SETFL, fflags);
                        goto retry;
                }
        } else if (nchread < 0) {
                if (errno == EAGAIN) {
                        fflags = fcntl(d, F_GETFL, 0);
                        fflags &= ~O_NONBLOCK;
                        fcntl(d, F_SETFL, fflags);
                        goto retry;
                }
                len = 0;
        } else {
                for (i = 0, t = buf, s = chbuf; i < nchread; ++i) {
                    *t++ = ((tchar)*s++);
                }
        }
        return (nchread);
#endif
}

/*
 * BUG: write_() returns -1 on failure, or # of BYTEs it has written.
 *      For consistency and symmetry, it should return the number of
 *      characters it has actually written, but that is technically
 *      difficult although not impossible.  Anyway, the return
 *      value of write() has never been used by the original csh,
 *      so this bug should be OK.
 */
int
write_(int d, tchar *buf, int nch)
{
        unsigned char chbuf[BUFSIZ*MB_LEN_MAX]; /* General use buffer. */
#ifdef MBCHAR
        tchar           *pt;
        unsigned char   *pc;
        wchar_t         wc;
        int             i, j;

#ifdef  DBG
        tprintf("Entering write_(d=%d, buf=0x%x, nch=%d);\n",
            d, buf, nch); /* Hope printf() doesn't call write_() itself! */
#endif /* DBG */
        assert(nch * MB_CUR_MAX < sizeof (chbuf));
        i = nch;
        pt = buf;
        pc = chbuf;
        while (i--) {
                /*
                 * Convert to tchar string.
                 * NUL is treated as normal char here.
                 */
                wc = (wchar_t)((*pt++)&TRIM);
                if (wc == (wchar_t)0) {
                        *pc++ = 0;
                } else {
                        if ((j = wctomb((char *)pc, wc)) <= 0) {
                                *pc = (unsigned char)wc;
                                j = 1;
                        }
                        pc += j;
                }
        }
        return (write(d, chbuf, pc - chbuf));
#else /* !MBCHAR */
        /* One byte always represents one tchar.  Easy! */
        int     i;
        unsigned char   *s;
        tchar   *t;

#ifdef  DBG
        tprintf("Entering write_(d=%d, buf=0x%x, nch=%d);\n",
            d, buf, nch); /* Hope printf() doesn't call write_() itself! */
#endif /* DBG */
        assert(nch <= sizeof (chbuf));
        for (i = 0, t = buf, s = chbuf; i < nch; ++i) {
            *s++ = (char)((*t++)&0xff);
        }
        return (write(d, (char *)chbuf, nch));
#endif
}

#undef chbuf

#include <sys/types.h>
#include <sys/stat.h>   /* satruct stat */
#include <dirent.h>     /* DIR */

extern DIR *Dirp;

int
stat_(tchar *path, struct stat *buf)
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */

        tstostr(chbuf, path);
        return (stat((char *)chbuf, buf));
}

int
lstat_(tchar *path, struct stat *buf)
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */

        tstostr(chbuf, path);
        return (lstat((char *)chbuf, buf));
}

int
chdir_(tchar *path)
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */

        tstostr(chbuf, path);
        return (chdir((char *)chbuf));
}

tchar *
getwd_(tchar *path)
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */
        int     rc;

        rc = (int)getwd((char *)chbuf);
        if (rc == 0) {
                return (0);
        } else {
                return (strtots(path, chbuf));
        }
}

int
unlink_(tchar *path)
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */

        tstostr(chbuf, path);
        return (unlink((char *)chbuf));
}

DIR *
opendir_(tchar *dirname)
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */

        extern DIR *opendir();
        DIR     *dir;

        dir = opendir(tstostr(chbuf, dirname));
        if (dir != NULL) {
                setfd(dir->dd_fd);
        }
        return (Dirp = dir);
}

int
closedir_(DIR *dirp)
{
        int ret;
        extern int closedir();

        ret = closedir(dirp);
        Dirp = NULL;
        return (ret);
}

int
gethostname_(tchar *name, int namelen)
{
        char chbuf[BUFSIZ * MB_LEN_MAX]; /* General use buffer. */

        assert(namelen < BUFSIZ);
        if (gethostname((char *)chbuf, sizeof (chbuf)) != 0) {
                return (-1);
        }
        if (mbstotcs(name, chbuf, namelen) < 0) {
                return (-1);
        }
        return (0); /* Succeeded. */
}

int
readlink_(tchar *path, tchar *buf, int bufsiz)
{
        char chbuf[MAXPATHLEN * MB_LEN_MAX]; /* General use buffer. */
        char    chpath[MAXPATHLEN + 1];
        int     i;

        tstostr(chpath, path);
        i = readlink(chpath, (char *)chbuf, sizeof (chbuf));
        if (i < 0) {
                return (-1);
        }
        chbuf[i] = (char)0;     /* readlink() doesn't put NULL. */
        i = mbstotcs(buf, chbuf, bufsiz);
        if (i < 0) {
                return (-1);
        }
        return (i - 1); /* Return # of tchars EXCLUDING the terminating NULL. */
}

/* checks that it's a number */

int
chkalldigit_(tchar *str)
{
        char chbuf[BUFSIZ * MB_LEN_MAX]; /* General use buffer. */
        char *c = chbuf;

        (void) tstostr(chbuf, str);

        while (*c)
                if (!isdigit(*(c++)))
                        return (-1);

        return (0);
}

int
atoi_(tchar *str)
{
        char chbuf[BUFSIZ * MB_LEN_MAX]; /* General use buffer. */

        tstostr(chbuf, str);
        return (atoi((char *)chbuf));
}

tchar *
simple(tchar *s)
{
        tchar *sname = s;

        while (1) {
                if (any('/', sname)) {
                        while (*sname++ != '/')
                                ;
                } else {
                        return (sname);
                }
        }
}