/* mbed Microcontroller Library
 * Copyright (c) 2006-2012 ARM Limited
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef MBED_FATFILESYSTEM_H
#define MBED_FATFILESYSTEM_H

#include "FileSystem.h"
#include "BlockDevice.h"
#include "FileHandle.h"
#include "ff.h"
#include <stdint.h>
#include "PlatformMutex.h"

using namespace mbed;

/**
 * FATFileSystem based on ChaN's Fat Filesystem library v0.8
 */
class FATFileSystem : public FileSystem {
public:
    /** Lifetime of the FATFileSystem
     *
     *  @param name     Name to add filesystem to tree as
     *  @param bd       BlockDevice to mount, may be passed instead to mount call
     */
    FATFileSystem(const char *name = NULL, BlockDevice *bd = NULL);
    virtual ~FATFileSystem();
    
    /** Formats a logical drive, FDISK partitioning rule.
     *
     *  The block device to format should be mounted when this function is called.
     *
     *  @param bd
     *    This is the block device that will be formatted.
     *
     *  @param cluster_size
     *    This is the number of bytes per cluster. A larger cluster size will decrease
     *    the overhead of the FAT table, but also increase the minimum file size. The
     *    cluster_size must be a multiple of the underlying device's allocation unit
     *    and is currently limited to a max of 32,768 bytes. If zero, a cluster size
     *    will be determined from the device's allocation unit. Defaults to zero.
     *   
     *  @return         0 on success, negative error code on failure
     */
    static int format(BlockDevice *bd, bd_size_t cluster_size = 0);

    /** Mounts a filesystem to a block device
     *
     *  @param bd       BlockDevice to mount to
     *  @return         0 on success, negative error code on failure
     */
    virtual int mount(BlockDevice *bd);

    /** Unmounts a filesystem from the underlying block device
     *
     *  @return         0 on success, negative error code on failure
     */
    virtual int unmount();

    /** Reformats a filesystem, results in an empty and mounted filesystem
     *
     *  @param bd
     *      BlockDevice to reformat and mount. If NULL, the mounted
     *      block device will be used.
     *      Note: if mount fails, bd must be provided.
     *      Default: NULL
     *
     *  @param allocation_unit
     *      This is the number of bytes per cluster size. The valid value is N
     *      times the sector size. N is a power of 2 from 1 to 128 for FAT
     *      volume and upto 16MiB for exFAT volume. If zero is given,
     *      the default allocation unit size is selected by the underlying
     *      filesystem, which depends on the volume size.
     *
     *  @return         0 on success, negative error code on failure
     */
    virtual int reformat(BlockDevice *bd, int allocation_unit);

    /** Reformats a filesystem, results in an empty and mounted filesystem
     *
     *  @param bd       BlockDevice to reformat and mount. If NULL, the mounted
     *                  block device will be used.
     *                  Note: if mount fails, bd must be provided.
     *                  Default: NULL
     *  @return         0 on success, negative error code on failure
     */
    virtual int reformat(BlockDevice *bd = NULL)
    {
        // required for virtual inheritance shenanigans
        return reformat(bd, 0);
    }

    /** Remove a file from the filesystem.
     *
     *  @param path     The name of the file to remove.
     *  @return         0 on success, negative error code on failure
     */
    virtual int remove(const char *path);

    /** Rename a file in the filesystem.
     *
     *  @param path     The name of the file to rename.
     *  @param newpath  The name to rename it to
     *  @return         0 on success, negative error code on failure
     */
    virtual int rename(const char *path, const char *newpath);

    /** Store information about the file in a stat structure
     *
     *  @param path     The name of the file to find information about
     *  @param st       The stat buffer to write to
     *  @return         0 on success, negative error code on failure
     */
    virtual int stat(const char *path, struct stat *st);

    /** Create a directory in the filesystem.
     *
     *  @param path     The name of the directory to create.
     *  @param mode     The permissions with which to create the directory
     *  @return         0 on success, negative error code on failure
     */
    virtual int mkdir(const char *path, mode_t mode);

protected:
    /** Open a file on the filesystem
     *
     *  @param file     Destination for the handle to a newly created file
     *  @param path     The name of the file to open
     *  @param flags    The flags to open the file in, one of O_RDONLY, O_WRONLY, O_RDWR,
     *                  bitwise or'd with one of O_CREAT, O_TRUNC, O_APPEND
     *  @return         0 on success, negative error code on failure
     */
    virtual int file_open(fs_file_t *file, const char *path, int flags);

    /** Close a file
     *
     *  @param file     File handle
     *  @return         0 on success, negative error code on failure
     */
    virtual int file_close(fs_file_t file);

    /** Read the contents of a file into a buffer
     *
     *  @param file     File handle
     *  @param buffer   The buffer to read in to
     *  @param len      The number of bytes to read
     *  @return         The number of bytes read, 0 at end of file, negative error on failure
     */
    virtual ssize_t file_read(fs_file_t file, void *buffer, size_t len);

    /** Write the contents of a buffer to a file
     *
     *  @param file     File handle
     *  @param buffer   The buffer to write from
     *  @param len      The number of bytes to write 
     *  @return         The number of bytes written, negative error on failure
     */
    virtual ssize_t file_write(fs_file_t file, const void *buffer, size_t len);

    /** Flush any buffers associated with the file
     *
     *  @param file     File handle
     *  @return         0 on success, negative error code on failure
     */
    virtual int file_sync(fs_file_t file);

    /** Move the file position to a given offset from from a given location
     *
     *  @param file     File handle
     *  @param offset   The offset from whence to move to
     *  @param whence   The start of where to seek
     *      SEEK_SET to start from beginning of file,
     *      SEEK_CUR to start from current position in file,
     *      SEEK_END to start from end of file
     *  @return         The new offset of the file
     */
    virtual off_t file_seek(fs_file_t file, off_t offset, int whence);

    /** Get the file position of the file
     *
     *  @param file     File handle
     *  @return         The current offset in the file
     */
    virtual off_t file_tell(fs_file_t file);

    /** Get the size of the file
     *
     *  @param file     File handle
     *  @return         Size of the file in bytes
     */
    virtual off_t file_size(fs_file_t file);

    /** Open a directory on the filesystem
     *
     *  @param dir      Destination for the handle to the directory
     *  @param path     Name of the directory to open
     *  @return         0 on success, negative error code on failure
     */
    virtual int dir_open(fs_dir_t *dir, const char *path);

    /** Close a directory
     *
     *  @param dir      Dir handle
     *  @return         0 on success, negative error code on failure
     */
    virtual int dir_close(fs_dir_t dir);

    /** Read the next directory entry
     *
     *  @param dir      Dir handle
     *  @param ent      The directory entry to fill out
     *  @return         1 on reading a filename, 0 at end of directory, negative error on failure
     */
    virtual ssize_t dir_read(fs_dir_t dir, struct dirent *ent);

    /** Set the current position of the directory
     *
     *  @param dir      Dir handle
     *  @param offset   Offset of the location to seek to,
     *                  must be a value returned from dir_tell
     */
    virtual void dir_seek(fs_dir_t dir, off_t offset);

    /** Get the current position of the directory
     *
     *  @param dir      Dir handle
     *  @return         Position of the directory that can be passed to dir_rewind
     */
    virtual off_t dir_tell(fs_dir_t dir);

    /** Rewind the current position to the beginning of the directory
     *
     *  @param dir      Dir handle
     */
    virtual void dir_rewind(fs_dir_t dir);
    
private:
    FATFS _fs; // Work area (file system object) for logical drive
    char _fsid[sizeof("0:")];
    int _id;

protected:
    virtual void lock();
    virtual void unlock();
    virtual int mount(BlockDevice *bd, bool mount);
};

#endif
