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/*

 * Copyright (c) 2008 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - 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.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.

 */

/** @addtogroup fs

 * @{

 */

/**

 * @file    fat_dentry.c

 * @brief   Functions that work with FAT directory entries.

 */

#include "fat_dentry.h"

#include <ctype.h>

#include <string.h>

static bool is_d_char(const char ch)

{

    if (isalnum(ch) || ch == '_')

        return true;

    else

        return false;

}

/** Compare path component with the name read from the dentry.

 *

 * This function compares the path component with the name read from the dentry.

 * The comparison is case insensitive and tolerates a mismatch on the trailing

 * dot character at the end of the name (i.e. when there is a dot, but no

 * extension).

 *

 * @param name      Node name read from the dentry.

 * @param component Path component.

 *

 * @return      Zero on match, non-zero otherwise.

 */

int fat_dentry_namecmp(char *name, const char *component)

{

    int rc;

    size_t size;

    if (!(rc = stricmp(name, component)))

        return rc;

    if (!str_chr(name, '.')) {

        /*

         * There is no '.' in the name, so we know that there is enough

         * space for appending an extra '.' to name.

         */

        size = str_size(name);

        name[size] = '.';

        name[size + 1] = '\0';

        rc = stricmp(name, component);

    }

    return rc;

}

bool fat_dentry_name_verify(const char *name)

{

    unsigned i, dot;

    bool dot_found = false;

    for (i = 0; name[i]; i++) {

        if (name[i] == '.') {

            if (dot_found) {

                return false;

            } else {

                dot_found = true;

                dot = i;

            }

        } else {

            if (!is_d_char(name[i]))

                return false;

        }

    }

    if (dot_found) {

        if (dot > FAT_NAME_LEN)

            return false;

        if (i - dot > FAT_EXT_LEN + 1)

            return false;

    } else {

        if (i > FAT_NAME_LEN)

            return false;

    }

    return true;

}

void fat_dentry_name_get(const fat_dentry_t *d, char *buf)

{

    unsigned int i;

    for (i = 0; i < FAT_NAME_LEN; i++) {

        if (d->name[i] == FAT_PAD)

            break;

        if (d->name[i] == FAT_DENTRY_E5_ESC)

            *buf++ = 0xe5;

        else {

            if (d->lcase & FAT_LCASE_LOWER_NAME)

                *buf++ = tolower(d->name[i]);

            else

                *buf++ = d->name[i];

        }

    }

    if (d->ext[0] != FAT_PAD)

        *buf++ = '.';

    for (i = 0; i < FAT_EXT_LEN; i++) {

        if (d->ext[i] == FAT_PAD) {

            *buf = '\0';

            return;

        }

        if (d->ext[i] == FAT_DENTRY_E5_ESC)

            *buf++ = 0xe5;

        else {

            if (d->lcase & FAT_LCASE_LOWER_EXT)

                *buf++ = tolower(d->ext[i]);

            else

                *buf++ = d->ext[i];

        }

    }

    *buf = '\0';

}

void fat_dentry_name_set(fat_dentry_t *d, const char *name)

{

    unsigned int i;

    const char fake_ext[] = "   ";

    bool lower_name = true;

    bool lower_ext = true;

    for (i = 0; i < FAT_NAME_LEN; i++) {

        switch ((uint8_t) *name) {

        case 0xe5:

            d->name[i] = FAT_DENTRY_E5_ESC;

            name++;

            break;

        case '\0':

        case '.':

            d->name[i] = FAT_PAD;

            break;

        default:

            if (isalpha(*name)) {

                if (!islower(*name))

                    lower_name = false;

            }

            d->name[i] = toupper(*name++);

            break;

        }

    }

    if (*name++ != '.')

        name = fake_ext;

    for (i = 0; i < FAT_EXT_LEN; i++) {

        switch ((uint8_t) *name) {

        case 0xe5:

            d->ext[i] = FAT_DENTRY_E5_ESC;

            name++;

            break;

        case '\0':

            d->ext[i] = FAT_PAD;

            break;

        default:

            if (isalpha(*name)) {

                if (!islower(*name))

                    lower_ext = false;

            }

            d->ext[i] = toupper(*name++);

            break;

        }

    }

    if (lower_name)

        d->lcase |= FAT_LCASE_LOWER_NAME;

    else

        d->lcase &= ~FAT_LCASE_LOWER_NAME;

    if (lower_ext)

        d->lcase |= FAT_LCASE_LOWER_EXT;

    else

        d->lcase &= ~FAT_LCASE_LOWER_EXT;

}

fat_dentry_clsf_t fat_classify_dentry(const fat_dentry_t *d)

{

    if (d->attr & FAT_ATTR_VOLLABEL) {

        /* volume label entry */

        return FAT_DENTRY_SKIP;

    }

    if (d->name[0] == FAT_DENTRY_ERASED) {

        /* not-currently-used entry */

        return FAT_DENTRY_FREE;

    }

    if (d->name[0] == FAT_DENTRY_UNUSED) {

        /* never used entry */

        return FAT_DENTRY_LAST;

    }

    if (d->name[0] == FAT_DENTRY_DOT) {

        /*

         * Most likely '.' or '..'.

         * It cannot occur in a regular file name.

         */

        return FAT_DENTRY_SKIP;

    }

    return FAT_DENTRY_VALID;

}

/**

 * @}

 */