/**************************************************************************/
/*!
    @file     InternalFS.cpp
    @author   hathach (tinyusb.org)

    @section LICENSE

    Software License Agreement (BSD License)

    Copyright (c) 2018, Adafruit Industries (adafruit.com)
    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 holders 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 ''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 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 <Arduino.h>
#include <string.h>
#include "InternalFS.h"
#include "flash/flash_nrf5x.h"

#ifdef NRF52840_XXAA
#define LFS_FLASH_ADDR        0xED000
#else
#define LFS_FLASH_ADDR        0x6D000
#endif

#define LFS_FLASH_TOTAL_SIZE  (7*FLASH_NRF52_PAGE_SIZE)
#define LFS_BLOCK_SIZE        128

//--------------------------------------------------------------------+
// LFS Disk IO
//--------------------------------------------------------------------+

#if !CFG_DEBUG

#define VERIFY_LFS(...)       _GET_3RD_ARG(__VA_ARGS__, VERIFY_ERR_2ARGS, VERIFY_ERR_1ARGS)(__VA_ARGS__, NULL)
#define PRINT_LFS_ERR(_err)

#else

#define VERIFY_LFS(...)       _GET_3RD_ARG(__VA_ARGS__, VERIFY_ERR_2ARGS, VERIFY_ERR_1ARGS)(__VA_ARGS__, dbg_strerr_lfs)
#define PRINT_LFS_ERR(_err)   VERIFY_MESS(_err, dbg_strerr_lfs)

static const char* dbg_strerr_lfs (int32_t err)
{
  switch ( err )
  {
    case LFS_ERR_OK:
      return "LFS_ERR_OK";

    case LFS_ERR_IO:
      return "LFS_ERR_IO";

    case LFS_ERR_CORRUPT:
      return "LFS_ERR_CORRUPT";

    case LFS_ERR_NOENT:
      return "LFS_ERR_NOENT";

    case LFS_ERR_EXIST:
      return "LFS_ERR_EXIST";

    case LFS_ERR_NOTDIR:
      return "LFS_ERR_NOTDIR";

    case LFS_ERR_ISDIR:
      return "LFS_ERR_ISDIR";

    case LFS_ERR_NOTEMPTY:
      return "LFS_ERR_NOTEMPTY";

    case LFS_ERR_BADF:
      return "LFS_ERR_BADF";

    case LFS_ERR_INVAL:
      return "LFS_ERR_INVAL";

    case LFS_ERR_NOSPC:
      return "LFS_ERR_NOSPC";

    case LFS_ERR_NOMEM:
      return "LFS_ERR_NOMEM";

    default:
    {
      static char errcode[10];
      sprintf(errcode, "%d", err);
      return errcode;
    }
  }
}

#endif

static inline uint32_t lba2addr(uint32_t block)
{
  return ((uint32_t) LFS_FLASH_ADDR) + block * LFS_BLOCK_SIZE;
}

static int _iflash_read (const struct lfs_config *c, lfs_block_t block, lfs_off_t off, void *buffer, lfs_size_t size)
{
  (void) c;

  uint32_t addr = lba2addr(block) + off;
  flash_nrf5x_read(buffer, addr, size);

  return 0;
}

// Program a region in a block. The block must have previously
// been erased. Negative error codes are propogated to the user.
// May return LFS_ERR_CORRUPT if the block should be considered bad.
static int _iflash_prog (const struct lfs_config *c, lfs_block_t block, lfs_off_t off, const void *buffer,
                         lfs_size_t size)
{
  (void) c;

  uint32_t addr = lba2addr(block) + off;
  flash_nrf5x_write(addr, buffer, size);

  return 0;
}

// Erase a block. A block must be erased before being programmed.
// The state of an erased block is undefined. Negative error codes
// are propogated to the user.
// May return LFS_ERR_CORRUPT if the block should be considered bad.
static int _iflash_erase (const struct lfs_config *c, lfs_block_t block)
{
  (void) c;

  uint32_t addr = lba2addr(block);

  // implement as write 0xff to whole block address
  for(int i=0; i <LFS_BLOCK_SIZE; i++)
  {
    flash_nrf5x_write8(addr + i, 0xFF);
  }

  // flash_nrf5x_flush();

  return 0;
}

// Sync the state of the underlying block device. Negative error codes
// are propogated to the user.
static int _iflash_sync (const struct lfs_config *c)
{
  (void) c;
  flash_nrf5x_flush();
  return 0;
}

//--------------------------------------------------------------------+
// Implementation
//--------------------------------------------------------------------+
LittleFS InternalFS;

LittleFS::LittleFS (void)
{
  varclr(&_lfs_cfg);
  _lfs_cfg.context = NULL;
  _lfs_cfg.read = _iflash_read;
  _lfs_cfg.prog = _iflash_prog;
  _lfs_cfg.erase = _iflash_erase;
  _lfs_cfg.sync = _iflash_sync;

  _lfs_cfg.read_size = LFS_BLOCK_SIZE;
  _lfs_cfg.prog_size = LFS_BLOCK_SIZE;
  _lfs_cfg.block_size = LFS_BLOCK_SIZE;
  _lfs_cfg.block_count = LFS_FLASH_TOTAL_SIZE / LFS_BLOCK_SIZE;
  _lfs_cfg.lookahead = 128;

  _begun = false;
}

LittleFS::~LittleFS ()
{

}

bool LittleFS::begin (void)
{
  if ( _begun ) return true;
  _begun = true;

  int err = lfs_mount(&_lfs, &_lfs_cfg);

  // reformat if we can't mount the filesystem
  if ( LFS_ERR_CORRUPT == err )
  {
    LOG_LV1("IFLASH", "Format internal file system");
    this->format(false);
  }

  return true;
}

bool LittleFS::format (bool eraseall)
{
  if ( eraseall )
  {
    for ( uint32_t addr = LFS_FLASH_ADDR; addr < LFS_FLASH_ADDR + LFS_FLASH_TOTAL_SIZE; addr += FLASH_NRF52_PAGE_SIZE )
    {
      flash_nrf5x_erase(addr);
    }
  }

  VERIFY_LFS(lfs_format(&_lfs, &_lfs_cfg), false);
  VERIFY_LFS(lfs_mount(&_lfs, &_lfs_cfg), false);

  return true;
}

BluefruitFS::File LittleFS::_open_file (char const *filepath, uint8_t mode)
{
  BluefruitFS::File file(*this);

  int flags = (mode == FILE_READ) ? LFS_O_RDONLY :
              (mode == FILE_WRITE) ? (LFS_O_RDWR | LFS_O_CREAT) : 0;

  if ( flags )
  {
    lfs_file_t* fhdl = (lfs_file_t*) rtos_malloc(sizeof(lfs_file_t));
    VERIFY(fhdl, file);

    int rc = lfs_file_open(&_lfs, fhdl, filepath, flags);

    if ( rc )
    {
      rtos_free(fhdl);
      PRINT_LFS_ERR(rc);
    }
    else
    {
      // move to end of file
      if ( mode == FILE_WRITE ) lfs_file_seek(&_lfs, fhdl, 0, LFS_SEEK_END);

      file._hdl = fhdl;
      file._is_dir = false;

      file._path = (char*) rtos_malloc(strlen(filepath) + 1);
      strcpy(file._path, filepath);
    }
  }

  return file;
}

BluefruitFS::File LittleFS::_open_dir (char const *filepath)
{
  BluefruitFS::File file(*this);

  lfs_dir_t* fhdl = (lfs_dir_t*) rtos_malloc(sizeof(lfs_dir_t));
  int rc = lfs_dir_open(&_lfs, fhdl, filepath);

  if ( rc )
  {
    rtos_free(fhdl);
    PRINT_LFS_ERR(rc);
  }
  else
  {
    file._hdl = fhdl;
    file._is_dir = true;

    file._path = (char*) rtos_malloc(strlen(filepath) + 1);
    strcpy(file._path, filepath);
  }

  return file;
}

BluefruitFS::File LittleFS::open (char const *filepath, uint8_t mode)
{
  BluefruitFS::File file(*this);
  struct lfs_info info;

  int rc = lfs_stat(&_lfs, filepath, &info);
  if ( LFS_ERR_OK == rc )
  {
    // file existed, open file or directory accordingly
    file = (info.type == LFS_TYPE_REG) ? _open_file(filepath, mode) : _open_dir(filepath);
  }
  else if ( LFS_ERR_NOENT == rc )
  {
    // file not existed, only proceed with FILE_WRITE mode
    if ( mode == FILE_WRITE ) file = _open_file(filepath, mode);
  }
  else
  {
    PRINT_LFS_ERR(rc);
  }

  return file;
}

bool LittleFS::exists (char const *filepath)
{
  struct lfs_info info;
  return 0 == lfs_stat(&_lfs, filepath, &info);
}

bool LittleFS::mkdir (char const *filepath)
{
  const char* slash = filepath;
  if ( slash[0] == '/' ) slash++;    // skip root '/'

  while ( NULL != (slash = strchr(slash, '/')) )
  {
    char parent[slash - filepath + 1] = { 0 };
    memcpy(parent, filepath, slash - filepath);

    // make intermediate parent
    int rc = lfs_mkdir(&_lfs, parent);
    if ( rc != LFS_ERR_OK && rc != LFS_ERR_EXIST )
    {
      PRINT_LFS_ERR(rc);
      return false;
    }

    slash++;
  }
  
  int rc = lfs_mkdir(&_lfs, filepath);
  if ( rc != LFS_ERR_OK && rc != LFS_ERR_EXIST )
  {
    PRINT_LFS_ERR(rc);
    return false;
  }

  return true;
}

bool LittleFS::remove (char const *filepath)
{
  VERIFY_LFS(lfs_remove(&_lfs, filepath), false);
  return true;
}

bool LittleFS::rmdir (char const *filepath)
{
  VERIFY_LFS(lfs_remove(&_lfs, filepath));
  return true;
}

bool LittleFS::rmdir_r (char const *filepath)
{
  /* adafruit: lfs is modified to remove non-empty folder,
   According to below issue, comment these 2 line won't corrupt filesystem
   https://github.com/ARMmbed/littlefs/issues/43 */
  VERIFY_LFS(lfs_remove(&_lfs, filepath));
  return true;
}

//--------------------------------------------------------------------+
// FILE API
//--------------------------------------------------------------------+
size_t LittleFS::_f_write (void* fhdl, uint8_t const *buf, size_t size)
{
  lfs_ssize_t wrcount = lfs_file_write(&_lfs, (lfs_file_t*) fhdl, buf, size);
  VERIFY(wrcount > 0, 0);
  return wrcount;
}

void LittleFS::_f_flush (void* fhdl)
{
  VERIFY_LFS(lfs_file_sync(&_lfs, (lfs_file_t* ) fhdl),);
}

int LittleFS::_f_read (void* fhdl, void *buf, uint16_t nbyte)
{
  return lfs_file_read(&_lfs, (lfs_file_t*) fhdl, buf, nbyte);
}

bool LittleFS::_f_seek (void* fhdl, uint32_t pos)
{
  return lfs_file_seek(&_lfs, (lfs_file_t*) fhdl, pos, LFS_SEEK_SET) >= 0;
}

uint32_t LittleFS::_f_position (void* fhdl)
{
  return lfs_file_tell(&_lfs, (lfs_file_t*) fhdl);
}

uint32_t LittleFS::_f_size (void* fhdl)
{
  return lfs_file_size(&_lfs, (lfs_file_t*) fhdl);
}

void LittleFS::_f_close (void* fhdl, bool is_dir)
{
  if ( is_dir )
  {
    lfs_dir_close(&_lfs, (lfs_dir_t *) fhdl);
  }
  else
  {
    lfs_file_close(&_lfs, (lfs_file_t*) fhdl);
  }
}

File LittleFS::_f_openNextFile (void* fhdl, char const* cwd, uint8_t mode)
{
  BluefruitFS::File file(*this);
  struct lfs_info info;

  int rc;

  // lfs_dir_read return 0 when reaching end of directory, 1 if found an entry
  // skip "." and ".." entries
  do
  {
    rc = lfs_dir_read(&_lfs, (lfs_dir_t *) fhdl, &info);
  } while ( rc == 1 && (!strcmp(".", info.name) || !strcmp("..", info.name)) );

  if ( rc == 1 )
  {
    // string cat name with current folder
    char filepath[strlen(cwd) + 1 + strlen(info.name) + 1];

    strcpy(filepath, cwd);
    if ( !(cwd[0] == '/' && cwd[1] == 0) ) strcat(filepath, "/");    // only add '/' if cwd is not root
    strcat(filepath, info.name);

    file = (info.type == LFS_TYPE_REG) ? _open_file(filepath, mode) : _open_dir(filepath);
  }
  else if ( rc < 0 )
  {
    PRINT_LFS_ERR(rc);
  }

  return file;
}

void LittleFS::_f_rewindDirectory (void* fhdl)
{
  VERIFY_LFS(lfs_dir_rewind(&_lfs, (lfs_dir_t* ) fhdl),);
}