/*
 * file.c
 *
 * Mini "VFS" by Marcus Sundberg
 *
 * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
 * 2003-03-10 - kharris@nexus-tech.net - ported to uboot
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <config.h>
#include <malloc.h>
#include <fat.h>
#include <linux/stat.h>
#include <linux/time.h>

/* Supported filesystems */
static const struct filesystem filesystems[] = {
        { file_fat_detectfs,  file_fat_ls,  file_fat_read,  "FAT" },
};
#define NUM_FILESYS     (sizeof(filesystems)/sizeof(struct filesystem))

/* The filesystem which was last detected */
static int current_filesystem = FSTYPE_NONE;

/* The current working directory */
#define CWD_LEN         511
char file_cwd[CWD_LEN+1] = "/";

const char *
file_getfsname(int idx)
{
        if (idx < 0 || idx >= NUM_FILESYS)
                return NULL;

        return filesystems[idx].name;
}

static void
pathcpy(char *dest, const char *src)
{
        char *origdest = dest;

        do {
                if (dest-file_cwd >= CWD_LEN) {
                        *dest = '\0';
                        return;
                }
                *(dest) = *(src);
                if (*src == '\0') {
                        if (dest-- != origdest && ISDIRDELIM(*dest)) {
                                *dest = '\0';
                        }
                        return;
                }
                ++dest;

                if (ISDIRDELIM(*src))
                        while (ISDIRDELIM(*src)) src++;
                else
                        src++;
        } while (1);
}

int
file_cd(const char *path)
{
        if (ISDIRDELIM(*path)) {
                while (ISDIRDELIM(*path)) path++;
                strncpy(file_cwd+1, path, CWD_LEN-1);
        } else {
                const char *origpath = path;
                char *tmpstr = file_cwd;
                int back = 0;

                while (*tmpstr != '\0') tmpstr++;
                do {
                        tmpstr--;
                } while (ISDIRDELIM(*tmpstr));

                while (*path == '.') {
                        path++;
                        while (*path == '.') {
                                path++;
                                back++;
                        }
                        if (*path != '\0' && !ISDIRDELIM(*path)) {
                                path = origpath;
                                back = 0;
                                break;
                        }
                        while (ISDIRDELIM(*path)) path++;
                        origpath = path;
                }

                while (back--) {
                        /* Strip off path component */
                        while (!ISDIRDELIM(*tmpstr)) {
                                tmpstr--;
                        }
                        if (tmpstr == file_cwd) {
                                /* Incremented again right after the loop. */
                                tmpstr--;
                                break;
                        }
                        /* Skip delimiters */
                        while (ISDIRDELIM(*tmpstr)) tmpstr--;
                }
                tmpstr++;
                if (*path == '\0') {
                        if (tmpstr == file_cwd) {
                                *tmpstr = '/';
                                tmpstr++;
                        }
                        *tmpstr = '\0';
                        return 0;
                }
                *tmpstr = '/';
                pathcpy(tmpstr+1, path);
        }

        return 0;
}

int
file_detectfs(void)
{
        int i;

        current_filesystem = FSTYPE_NONE;

        for (i = 0; i < NUM_FILESYS; i++) {
                if (filesystems[i].detect() == 0) {
                        strcpy(file_cwd, "/");
                        current_filesystem = i;
                        break;
                }
        }

        return current_filesystem;
}

int
file_ls(const char *dir)
{
        char fullpath[1024];
        const char *arg;

        if (current_filesystem == FSTYPE_NONE) {
                printf("Can't list files without a filesystem!\n");
                return -1;
        }

        if (ISDIRDELIM(*dir)) {
                arg = dir;
        } else {
                sprintf(fullpath, "%s/%s", file_cwd, dir);
                arg = fullpath;
        }
        return filesystems[current_filesystem].ls(arg);
}

long
file_read(const char *filename, void *buffer, unsigned long maxsize)
{
        char fullpath[1024];
        const char *arg;

        if (current_filesystem == FSTYPE_NONE) {
                printf("Can't load file without a filesystem!\n");
                return -1;
        }

        if (ISDIRDELIM(*filename)) {
                arg = filename;
        } else {
                sprintf(fullpath, "%s/%s", file_cwd, filename);
                arg = fullpath;
        }

        return filesystems[current_filesystem].read(arg, buffer, maxsize);
}