//
// The guts of the virtual FAT16 are implemented here.
// This is taken from DAPLink and some memory-wasting bits are commented out or removed.
//

/**
 * @file    virtual_fs.h
 * @brief   FAT 12/16 filesystem handling
 *
 * DAPLink Interface Firmware
 * Copyright (c) 2009-2016, ARM Limited, All Rights Reserved
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef VIRTUAL_FS_H
#define VIRTUAL_FS_H

#include "platform.h"

#ifdef __cplusplus
extern "C" {
#endif

// Toggleable debug funcs
#if DEBUG_VFS
#define vfs_printf(...)  do { dbg(__VA_ARGS__); } while(0)
#define vfs_printf_nonl(...)  do { PRINTF(__VA_ARGS__); } while(0)
#define vfs_puts(buf)  do { PUTS(buf); } while(0)
#define vfs_putsn(buf, n)  do { PUTSN(buf, n); } while(0)
#else
#define vfs_printf(...) do { } while(0)
#define vfs_printf_nonl(...)  do { } while(0)
#define vfs_puts(buf)  do { } while(0)
#define vfs_putsn(buf, n)  do { } while(0)
#endif

#define VFS_CLUSTER_SIZE        0x1000
#define VFS_SECTOR_SIZE         512
#define VFS_SECTORS_PER_CLUSTER         8
#define VFS_INVALID_SECTOR      0xFFFFFFFF
#define VFS_FILE_INVALID        0
#define VFS_MAX_FILES           16
#define VFS_DISK_SIZE MB(32)

/** Filename typedef */
typedef char vfs_filename_t[11];

typedef enum {
    VFS_FILE_ATTR_READ_ONLY     = (1 << 0),
    VFS_FILE_ATTR_HIDDEN        = (1 << 1),
    VFS_FILE_ATTR_SYSTEM        = (1 << 2),
    VFS_FILE_ATTR_VOLUME_LABEL  = (1 << 3),
    VFS_FILE_ATTR_SUB_DIR       = (1 << 4),
    VFS_FILE_ATTR_ARCHIVE       = (1 << 5),
    VFS_FILE_ATTR_LFN = 0x0F, // composite special
} vfs_file_attr_bit_t;

typedef enum {
    VFS_FILE_CREATED = 0,   /*!< A new file was created */
    VFS_FILE_DELETED,       /*!< An existing file was deleted */
    VFS_FILE_CHANGED,       /*!< Some attribute of the file changed.
                                  Note: when a file is deleted or
                                  created a file changed
                                  notification will also occur*/
} vfs_file_change_t;

/** File typedef */
typedef void *vfs_file_t;

/** Sector struct typedef */
typedef uint32_t vfs_sector_t;

/**
 * Callback for when data is written to a file on the virtual filesystem
 */
typedef void (*vfs_write_cb_t)(uint32_t sector_offset, const uint8_t *data, uint32_t num_sectors);

/**
 * Callback for when data is ready from the virtual filesystem
 */
typedef uint32_t (*vfs_read_cb_t)(uint32_t sector_offset, uint8_t *data, uint32_t num_sectors);

/**
 * Callback for when a file's attributes are changed on the virtual filesystem.
 * Note that the 'file' parameter can be saved and compared to other files to see if
 * they are referencing the same object. The same cannot be done with new_file_data
 * since it points to a temporary buffer.
 */
typedef void (*vfs_file_change_cb_t)(const vfs_filename_t filename, vfs_file_change_t change,
                                     vfs_file_t file, vfs_file_t new_file_data);

/**
 * Initialize the filesystem with the given size and name
 *
 * @param drive_name
 * @param disk_size
 */
void vfs_init(const vfs_filename_t drive_name, uint32_t disk_size);

/**
 * Get the total size of the virtual filesystem
 */
uint32_t vfs_get_total_size(void);

/**
 * Add a file to the virtual FS and return a handle to this file.
 * This must be called before vfs_read or vfs_write are called.
 * Adding a new file after vfs_read or vfs_write have been called results in undefined behavior.
 *
 * @param filename
 * @param read_cb
 * @param write_cb
 * @param len
 * @return
 */
vfs_file_t vfs_create_file(const vfs_filename_t filename,
                           vfs_read_cb_t read_cb, vfs_write_cb_t write_cb,
                           uint32_t len);

/**
 * Set the attributes of a file
 *
 * @param file
 * @param attr
 */
void vfs_file_set_attr(vfs_file_t file, vfs_file_attr_bit_t attr);

/**
 * Get the starting sector of this file.
 * NOTE - If the file size is 0 there is no starting
 * sector so VFS_INVALID_SECTOR will be returned.
 *
 * @param file
 * @return
 */
vfs_sector_t vfs_file_get_start_sector(vfs_file_t file);

/**
 * Get the size of the file.
 *
 * @param file
 * @return
 */
uint32_t vfs_file_get_size(vfs_file_t file);

/**
 * Get the attributes of a file
 *
 * @param file
 * @return
 */
vfs_file_attr_bit_t vfs_file_get_attr(vfs_file_t file);

/**
 * Set the callback when a file is created, deleted or has atributes changed.
 *
 * @param cb
 */
void vfs_set_file_change_callback(vfs_file_change_cb_t cb);

/**
 * Read one or more sectors from the virtual filesystem
 *
 * @param sector
 * @param buf
 * @param num_of_sectors
 */
void vfs_read(uint32_t sector, uint8_t *buf, uint32_t num_of_sectors);

/**
 * Write one or more sectors to the virtual filesystem
 *
 * @param sector
 * @param buf
 * @param num_of_sectors
 */
void vfs_write(uint32_t sector, const uint8_t *buf, uint32_t num_of_sectors);

bool vfs_find_file(uint32_t start_sector, vfs_filename_t *destFilename, vfs_file_t **destFile);

#ifdef __cplusplus
}
#endif

#endif// VIRTUAL_FS_H