/*
  The code here is based on code by Mark Adler et al. which is
  Copyright (c) 1990-2005 Info-ZIP.  Specifically, it derives from zip
  version 2.31.  Modifications are by Allin Cottrell, March, 2006.
  Please see the included file "LICENSE" which contains the Info-ZIP
  license information.
*/

#include "zunz_private.h"

#include <time.h>
#include <utime.h>
#include <dirent.h>

#define FNAME_DEBUG 0

#if (!defined(S_IWRITE) && defined(S_IWUSR))
# define S_IWRITE S_IWUSR
#endif

#ifdef WIN32

static int lsstat (const char *fname, struct stat *buf, zfile *zf)
{
    return gretl_stat(fname, buf);
}

/* below: "fname" is as given by caller; "zname" is contructed using
   internal_to_external().  On win32 we standardize on backslash as
   dir separator in internal_to_external(), so here we need to ensure
   we have a version of fname that also uses backslashes for
   comparison (and we're not sure that the caller used backslashes).
*/

#define FNMAX 1024

int wanted_namecmp (const char *fname, const char *zname)
{
    char tmp[FNMAX];
    int i;

    *tmp = 0;
    strncat(tmp, fname, FNMAX - 1);

    for (i=0; tmp[i] != 0; i++) {
	if (tmp[i] == '/') {
	    tmp[i] = '\\';
	}
    }

    return fnamecmp(tmp, zname);
}

#else /* !WIN32 */

static int lsstat (const char *fname, struct stat *buf, zfile *zf)
{
    if (put_links(zf->opt)) {
	return lstat(fname, buf);
    } else {
	return stat(fname, buf);
    }
}

#endif /* WIN32? */

/* Process a (supposed) disk filename, which may refer to nothing, to
   a regular file, a symlink, or a directory.  Recurse into
   directories if this is wanted.  Return an error code in the ZE_
   class.
*/

int add_filenames (const char *fname, zfile *zf)
{
    struct stat s;
    int err = 0;

     if (lsstat(fname, &s, zf)) {
	/* Not a file or directory */
	trace(2, "add_filenames: couldn't stat '%s'\n", fname);
	return ZE_MISS;
    }

    if ((s.st_mode & S_IFREG) == S_IFREG) {
	trace(2, "add_filenames: running newname on file '%s'\n", fname);
	return newname(fname, zf);
    }

#ifndef WIN32
    if ((s.st_mode & S_IFLNK) == S_IFLNK) {
	trace(2, "add_filenames: running newname on symlink '%s'\n", fname);
	return newname(fname, zf);
    }
#endif

    if ((s.st_mode & S_IFDIR) == S_IFDIR) {
	char *path, *dpath;
	const gchar *dirname;
        int sz, n = strlen(fname);
	GDir *d;

	trace(2, "add_filenames: running newname on directory '%s'\n", fname);

        sz = (n + 2 < 8)? 8 : n + 2;
	path = calloc(sz, 1);
	if (path == NULL) {
	    return ZE_MEM;
	}

	if (!strcmp(fname, ".")) {
	    ;  /* avoid "./" prefix and do not create zip entry */
	} else {
	    /* ensure trailing / on the directory name */
	    strcpy(path, fname);
	    if (path[n-1] != '/') {
		strcat(path, "/");
	    }
	    err = newname(path, zf);
	}

	/* recurse into directory */
	if (!err && recurse(zf->opt) && (d = gretl_opendir(fname)) != NULL) {
	    while (!err && (dirname = g_dir_read_name(d)) != NULL) {
		if (strcmp(dirname, ".") && strcmp(dirname, "..")) {
		    dpath = malloc(strlen(path) + strlen(dirname) + 1);
		    if (dpath == NULL) {
			err = ZE_MEM;
		    } else {
			strcat(strcpy(dpath, path), dirname);
			err = add_filenames(dpath, zf);
			free(dpath);
		    }
		}
	    }
	    g_dir_close(d);
	}
	free(path);
    } /* (s.st_mode & S_IFDIR) */

    return err;
}

#ifdef WIN32

static char *reslash (const char *fname)
{
    char *s, *newname = g_strdup(fname);

    if (newname != NULL) {
	s = newname;
	while (*s) {
	    if (*s == '\\') *s = '/';
	    s++;
	}
    }

    return newname;
}

#endif

static gchar *gretl_filename_to_utf8 (const char *fname, GError **gerr)
{
    gsize bytes;
    gchar *ret = NULL;

    if (g_utf8_validate(fname, -1, NULL)) {
	ret = g_strdup(fname);
    } else {
	/* On Windows, with GTK >= 2.6, the GLib filename
	   encoding is UTF-8; however, filenames coming from
	   a native Windows file dialog will be in the
	   locale charset
	*/
#ifdef WIN32
	ret = g_locale_to_utf8(fname, -1, NULL, &bytes, gerr);
#else
	ret = g_filename_to_utf8(fname, -1, NULL, &bytes, gerr);
#endif
    }

    return ret;
}

/* Convert the external file name to an internal zipfile name,
   returning the allocated string */

char *external_to_internal (const char *name, zfile *zf, GError **gerr)
{
    const char *xname = name;
    char *iname = NULL;
    const char *t = NULL;
    const char *p;

#ifdef WIN32
    char *tmp = reslash(xname);

    if (tmp == NULL) {
	return NULL;
    }
    xname = tmp;
#endif

    /* Find starting point in name before copying:
       strip "//host/share/" part of a UNC name
    */
    if (!strncmp(xname, "//", 2) && (xname[2] != '\0' && xname[2] != '/')) {
	p = xname + 2;
	while (*p != '\0' && *p != '/') {
	    p++; /* strip host name */
	}
	if (*p != '\0') {
	    p++;
	    while (*p != '\0' && *p != '/') {
		p++; /* strip 'share' name */
	    }
	}
	if (*p != '\0') {
	    t = p + 1;
	}
    } else {
	t = xname;
    }

    while (*t == '/') {
	t++; /* strip leading '/' chars to get a relative path */
    }

    while (*t == '.' && t[1] == '/') {
	t += 2; /* strip redundant leading "./" sections */
    }

    /* ensure UTF-8 for internal name */
    iname = gretl_filename_to_utf8(t, gerr);

#if FNAME_DEBUG
    fprintf(stderr, "external_to_internal\n '%s' -> '%s'\n", xname, iname);
#endif

#ifdef WIN32
    free(tmp);
#endif

    return iname;
}

#ifdef WIN32

/* convert @from src to a printable ASCII version in @targ, either
   processing @n bytes of @src or all of it if @n < 0
*/

static void asciify (char *targ, const char *src, int n)
{
    int c, i, j = 0;

    if (n < 0) {
	n = strlen(src);
    }

    while (*targ) targ++;

    for (i=0; i<n; i++) {
        c = src[i];
        if (c >= 32 && c < 128 && isprint(c)) {
            targ[j++] = c;
        }
    }
}

/* g_locale_from_utf8 failed on @iname, so now we try desperate
   measures
*/

static char *remedial_convert (const char *iname)
{
    char *xname = g_malloc0(strlen(iname) + 1);

    if (xname == NULL) {
        return NULL;
    }

    if (strchr(iname, '/') == NULL) {
	asciify(xname, iname, -1);
    } else {
	/* do it by parts */
        const char *p = strchr(iname, '/');
        int m = p - iname + 1;
        gchar *tmp;
        gsize b;

        tmp = g_locale_from_utf8(iname, m, NULL, &b, NULL);
        if (tmp != NULL) {
            /* converted first part OK */
            strcat(xname, tmp);
            g_free(tmp);
        } else {
            asciify(xname, iname, m);
        }

        tmp = g_locale_from_utf8(p + 1, -1, NULL, &b, NULL);
        if (tmp != NULL) {
            /* converted second part OK */
            strcat(xname, tmp);
            g_free(tmp);
        } else {
            asciify(xname, p + 1, -1);
        }
    }

    if (*xname == '\0') {
        free(xname);
        xname = NULL;
    } else {
        fprintf(stderr, "remedial convert: '%s' -> '%s'\n", iname, xname);
    }

    return xname;
}

#endif

/* Convert a zipfile internal name to an external file name,
   returning the allocated string: we convert from forward
   slashes to backslashes on MS Windows.
*/

char *internal_to_external (const char *iname)
{
    char *xname = g_strdup(iname);

#ifdef WIN32
    if (xname != NULL) {
	char *s = xname;

	while (*s) {
	    if (*s == '/') *s = '\\';
	    s++;
	}
    }
#endif

#if FNAME_DEBUG
    fprintf(stderr, "internal_to_external\n '%s' -> '%s'\n", iname, xname);
#endif

    return xname;
}

/* Set last updated and accessed time of file to the given DOS time */

void time_stamp_file (const char *fname, guint32 dost)
{
    struct utimbuf u;

    u.actime = u.modtime = dos2unixtime(dost);
    utime(fname, &u);
}

/* If file @fname does not exist, return 0.  Else, return the file's
   last modified date and time as an MSDOS date and time, that is, an
   unsigned 32-bit value with the date most significant to allow
   unsigned integer comparison of absolute times.  Also, if @attr is
   not NULL, store the file attributes there, with the high two bytes
   being the Unix attributes, and the low byte being a mapping of that
   to DOS attributes.  If @fsize is not NULL, store the file size
   there.  If @t is not NULL, the file's access, modification and
   creation times are stored there as UNIX time_t values.
*/

guint32 file_mod_time (const char *fname, guint32 *attr, long *fsize,
		       iztimes *t, zfile *zf)
{
    struct stat s;
    char *tmp;
    int len = strlen(fname);

    if (fname == NULL) {
	if (attr != NULL) {
	    *attr = 0;
	}
	if (fsize != NULL) {
	    *fsize = -2L; /* convention for a label name (??) */
	}
	if (t != NULL) {
	    t->atime = t->mtime = t->ctime = 0;
	}
	return 0;
    }

    tmp = g_strdup(fname);
    if (tmp[len-1] == '/') {
	tmp[len-1] = '\0';
    }

    if (lsstat(tmp, &s, zf) != 0) {
	free(tmp);
	return 0;
    }

    free(tmp);

    if (attr != NULL) {
	*attr = ((guint32) s.st_mode << 16) | !(s.st_mode & S_IWRITE);
	if ((s.st_mode & S_IFMT) == S_IFDIR) {
	    *attr |= MSDOS_DIR_ATTR;
	}
    }

    if (fsize != NULL) {
	*fsize = (s.st_mode & S_IFMT) == S_IFREG ? s.st_size : -1L;
    }

    if (t != NULL) {
	t->atime = s.st_atime;
	t->mtime = s.st_mtime;
	t->ctime = t->mtime; /* best guess, (s.st_ctime: last status change!!) */
    }

    return unix2dostime(&s.st_mtime);
}

#define EB_L_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(2))
#define EB_C_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(1))
#define EB_L_UX2_SIZE   (EB_HEADSIZE + EB_UX2_MINLEN)
#define EB_C_UX2_SIZE    EB_HEADSIZE
#define EF_L_UNIX_SIZE  (EB_L_UT_SIZE + EB_L_UX2_SIZE)
#define EF_C_UNIX_SIZE  (EB_C_UT_SIZE + EB_C_UX2_SIZE)

/* store full data in local header but just modification time stamp info
   in central header
*/

int set_extra_field (zfile *zf, zlist *z, iztimes *z_utim)
{
    int len = strlen(z->name);
    struct stat s;
    char *name;

    /* For the full sized UT local field including the UID/GID fields, we
       have to stat the file again. */

    /* not all systems allow stat'ing a file with / appended */
    name = g_strdup(z->name);
    if (name[len - 1] == '/') {
	name[len - 1] = '\0';
    }

    if (lsstat(name, &s, zf)) {
	g_free(name);
	return ZE_OPEN;
    }

    g_free(name);

    z->extra = malloc(EF_L_UNIX_SIZE);
    z->cextra = malloc(EF_C_UNIX_SIZE);

    if (z->extra == NULL || z->cextra == NULL) {
	return ZE_MEM;
    }

    z->extra[0]  = 'U';
    z->extra[1]  = 'T';
    z->extra[2]  = (char) EB_UT_LEN(2);    /* length of data part of local e.f. */
    z->extra[3]  = 0;
    z->extra[4]  = EB_UT_FL_MTIME | EB_UT_FL_ATIME; /* st_ctime != creation */
    z->extra[5]  = (char) (s.st_mtime);
    z->extra[6]  = (char) (s.st_mtime >> 8);
    z->extra[7]  = (char) (s.st_mtime >> 16);
    z->extra[8]  = (char) (s.st_mtime >> 24);
    z->extra[9]  = (char) (s.st_atime);
    z->extra[10] = (char) (s.st_atime >> 8);
    z->extra[11] = (char) (s.st_atime >> 16);
    z->extra[12] = (char) (s.st_atime >> 24);
    z->extra[13] = 'U';
    z->extra[14] = 'x';
    z->extra[15] = (char) EB_UX2_MINLEN;   /* length of data part of local e.f. */
    z->extra[16] = 0;
    z->extra[17] = (char) (s.st_uid);
    z->extra[18] = (char) (s.st_uid >> 8);
    z->extra[19] = (char) (s.st_gid);
    z->extra[20] = (char) (s.st_gid >> 8);
    z->extlen = EF_L_UNIX_SIZE;

    memcpy(z->cextra, z->extra, EB_C_UT_SIZE);
    z->cextra[EB_LEN] = (char) EB_UT_LEN(1);
    memcpy(z->cextra + EB_C_UT_SIZE, z->extra + EB_L_UT_SIZE, EB_C_UX2_SIZE);
    z->cextra[EB_LEN + EB_C_UT_SIZE] = 0;
    z->cextlen = EF_C_UNIX_SIZE;

    return ZE_OK;
}