/*
 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. 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 copyright holder 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 "lfs_api.h"

lfs_t g_lfs;
FileDirInfo g_lfsDir[LFS_MAX_OPEN_DIRS] = {0};

FileOpInfo g_fsOp;
static LittleFsHandleStruct g_handle[LITTLE_FS_MAX_OPEN_FILES] = {0};
struct dirent g_nameValue;
static pthread_mutex_t g_FslocalMutex = PTHREAD_MUTEX_INITIALIZER;

FileOpInfo GetFsOpInfo(void)
{
    return g_fsOp;
}

LittleFsHandleStruct *LfsAllocFd(const char *fileName, int *fd)
{
    int len = strlen(fileName) + 1;

    pthread_mutex_lock(&g_FslocalMutex);
    for (int i = 0; i < LITTLE_FS_MAX_OPEN_FILES; i++) {
        if (g_handle[i].useFlag == 0) {
            *fd = i;
            g_handle[i].useFlag = 1;
            g_handle[i].pathName = (char *)malloc(len);
            if (g_handle[i].pathName) {
                memcpy_s(g_handle[i].pathName, LITTLE_FS_MAX_NAME_LEN, fileName, len);
            }
            pthread_mutex_unlock(&g_FslocalMutex);
            return &(g_handle[i]);
        }
    }
    pthread_mutex_unlock(&g_FslocalMutex);
    *fd = INVALID_FD;
    return NULL;
}

BOOL CheckFileIsOpen(const char *fileName)
{
    for (int i = 0; i < LITTLE_FS_MAX_OPEN_FILES; i++) {
        if (g_handle[i].useFlag == 1) {
            if (strcmp(g_handle[i].pathName, fileName) == 0) {
                return TRUE;
            }
        }
    }

    return FALSE;
}

lfs_dir_t *GetFreeDir()
{
    pthread_mutex_lock(&g_FslocalMutex);
    for (int i = 0; i < LFS_MAX_OPEN_DIRS; i++) {
        if (g_lfsDir[i].useFlag == 0) {
            g_lfsDir[i].useFlag = 1;
            pthread_mutex_unlock(&g_FslocalMutex);
            return &(g_lfsDir[i].dir);
        }
    }
    pthread_mutex_unlock(&g_FslocalMutex);
    return NULL;
}

const struct MountOps g_lfsMnt = {
    .Mount = LfsMount,
    .Umount = LfsUmount,
};

const struct FileOps g_lfsFops = {
    .Mkdir = LfsMkdir,
    .Unlink = LfsUnlink,
    .Rmdir = LfsRmdir,
    .Opendir = LfsOpendir,
    .Readdir = LfsReaddir,
    .Closedir = LfsClosedir,
    .Open = LfsOpen,
    .Close = LfsClose,
    .Write = LfsWrite,
    .Read = LfsRead,
    .Seek = LfsSeek,
    .Rename = LfsRename,
    .Getattr = LfsStat,
    .Fsync = LfsFsync,
};

int LfsMount(const char *source, const char *target, const char *fileSystemType, unsigned long mountflags,
    const void *data)
{
    int ret;

    g_fsOp.fsVops = &g_lfsVops;
    ret = lfs_mount(&g_lfs, (struct lfs_config*)data);

    return ret;
}

int LfsUmount(const char *target)
{
    return lfs_unmount(&g_lfs);
}

int LfsUnlink(const char *fileName)
{
    return lfs_remove(&g_lfs, fileName);
}

int LfsMkdir(const char *dirName, mode_t mode)
{
    return lfs_mkdir(&g_lfs, dirName);
}

int LfsRmdir(const char *dirName)
{
    return lfs_remove(&g_lfs, dirName);
}

DIR *LfsOpendir(const char *dirName)
{
    int ret;

    lfs_dir_t *dir = GetFreeDir();
    if (dir == NULL) {
        return NULL;
    }

    ret = lfs_dir_open(&g_lfs, dir, dirName);

    if (ret == 0) {
        return (DIR *)dir;
    } else {
        return NULL;
    }
}

struct dirent *LfsReaddir(DIR *dir)
{
    int ret;
    struct lfs_info lfsInfo;

    ret = lfs_dir_read(&g_lfs, (lfs_dir_t *)dir, &lfsInfo);
    if (ret == 0) {
        pthread_mutex_lock(&g_FslocalMutex);
        (void)memcpy_s(g_nameValue.d_name, sizeof(g_nameValue.d_name), lfsInfo.name, strlen(lfsInfo.name) + 1);
        if (lfsInfo.type == LFS_TYPE_DIR) {
            g_nameValue.d_type = DT_DIR;
        } else if (lfsInfo.type == LFS_TYPE_REG) {
            g_nameValue.d_type = DT_REG;
        }

        g_nameValue.d_reclen = lfsInfo.size;
        pthread_mutex_unlock(&g_FslocalMutex);

        return &g_nameValue;
    }

    return NULL;
}

int LfsClosedir(const DIR *dir)
{
    return lfs_dir_close(&g_lfs, (lfs_dir_t *)dir);
}

int LfsOpen(const char *pathName, int openFlag, int mode)
{
    int fd = INVALID_FD;

    // if file is already open, return invalid fd
    if (pathName == NULL || CheckFileIsOpen(pathName)) {
        goto errout;
    }

    LittleFsHandleStruct *fsHandle = LfsAllocFd(pathName, &fd);
    if (fd == INVALID_FD) {
        goto errout;
    }

    int err = lfs_file_open(&g_lfs, &(fsHandle->file), pathName, openFlag);
    if (err != 0) {
        goto errout;
    }

    return fd;
errout:
    return INVALID_FD;
}

int LfsRead(int fd, void *buf, unsigned int len)
{
    if (fd >= LITTLE_FS_MAX_OPEN_FILES && fd < 0) {
        return VFS_ERROR;
    }

    return lfs_file_read(&g_lfs, &(g_handle[fd].file), buf, len);
}

int LfsWrite(int fd, const void *buf, unsigned int len)
{
    if (fd >= LITTLE_FS_MAX_OPEN_FILES && fd < 0) {
        return VFS_ERROR;
    }

    return lfs_file_write(&g_lfs, &(g_handle[fd].file), buf, len);
}

int LfsSeek(int fd, off_t offset, int whence)
{
    if (fd >= LITTLE_FS_MAX_OPEN_FILES && fd < 0) {
        return VFS_ERROR;
    }

    return lfs_file_seek(&g_lfs, &(g_handle[fd].file), offset, whence);
}

int LfsClose(int fd)
{
    int ret = VFS_ERROR;

    if (fd >= LITTLE_FS_MAX_OPEN_FILES && fd < 0) {
        return ret;
    }

    pthread_mutex_lock(&g_FslocalMutex);
    ret = lfs_file_close(&g_lfs, &(g_handle[fd].file));
    g_handle[fd].useFlag = 0;
    if (g_handle[fd].pathName != NULL) {

        free(g_handle[fd].pathName);
        g_handle[fd].pathName = NULL;
    }
    pthread_mutex_unlock(&g_FslocalMutex);

    return ret;    
}

int LfsRename(const char *oldName, const char *newName)
{
    return lfs_rename(&g_lfs, oldName, newName);
}

int LfsStat(const char *path, struct stat *buf)
{
    int ret;
    struct lfs_info info;

    ret = lfs_stat(&g_lfs, path, &info);
    if (ret == 0) {
        buf->st_size = info.size;
    }

    return ret;    
}

int LfsFsync(int fd)
{
    return lfs_file_sync(&g_lfs, &(g_handle[fd].file));
}