/*
  EEPROM.cpp - ASR650x EEPROM emulation

  Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.
  This file is part of the esp8266 core for Arduino environment.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

/*
 * note that the chip has 1K user flash.;
 * the size of user flash row is 256; 
 * user flash row 0-2 can be edited;
 * user flash row 3 is reservated, must not be edited;
 *
 * CY_FLASH_SIZEOF_ROW is 256 , CY_SFLASH_USERBASE is 0x0ffff400
 *
 */

#include "Arduino.h"
#include "EEPROM.h"
#include "debug.h"

#ifdef DEBUG_ASR_CORE
#define DEBUGV(fmt, ...) ::printf((PGM_P)PSTR(fmt), ## __VA_ARGS__)
#endif

#ifndef DEBUGV
#define DEBUGV(...) do { (void)0; } while (0)
#endif

#define _EEPROM_SIZE              (CY_FLASH_SIZEOF_ROW * 3)

EEPROMClass::EEPROMClass(uint32_t baddr)
: _baddr(baddr)
, _data(0)
, _size(0)
, _dirty(false)
{
}

EEPROMClass::EEPROMClass(void)
: _baddr(CY_SFLASH_USERBASE)
, _data(0)
, _size(0)
, _dirty(false)
{
}

void EEPROMClass::begin(size_t size) {
  if (size <= 0) {
    DEBUGV("EEPROMClass::begin error, size == 0\n");
    return;
  }
  if (size > _EEPROM_SIZE) {
    DEBUGV("EEPROMClass::begin error, %d > %d\n", size, _EEPROM_SIZE);
    size = _EEPROM_SIZE;
  }

  size = (size + 3) & (~3);

  //In case begin() is called a 2nd+ time, don't reallocate if size is the same
  if(_data && size != _size) {
    delete[] _data;
    _data = new uint8_t[size];
  } else if(!_data) {
    _data = new uint8_t[size];
  }

  _size = size;

  if (FLASH_read_at(_baddr, reinterpret_cast<uint8_t *>(_data), _size) == -1) {
    DEBUGV("EEPROMClass::begin flash read failed\n");
  }

  _dirty = false; //make sure dirty is cleared in case begin() is called 2nd+ time
}

void EEPROMClass::end() {
  if (!_size)
    return;

  commit();
  if(_data) {
    delete[] _data;
  }
  _data = 0;
  _size = 0;
  _dirty = false;
}


uint8_t EEPROMClass::read(int const address) {
  if (address < 0 || (size_t)address >= _size) {
    DEBUGV("EEPROMClass::read error, address %d > %d or %d < 0\n", address, _size, address);
    return 0;
  }
  if (!_data) {
    DEBUGV("EEPROMClass::read without ::begin\n");
    return 0;
  }

  return _data[address];
}

void EEPROMClass::write(int const address, uint8_t const value) {
  if (address < 0 || (size_t)address >= _size) {
    DEBUGV("EEPROMClass::write error, address %d > %d or %d < 0\n", address, _size, address);
    return;
  }
  if(!_data) {
    DEBUGV("EEPROMClass::read without ::begin\n");
    return;
  }

  // Optimise _dirty. Only flagged if data written is different.
  uint8_t* pData = &_data[address];
  if (*pData != value)
  {
    *pData = value;
    _dirty = true;
  }
}

bool EEPROMClass::commit() {
  if (!_size)
    return false;
  if(!_dirty)
    return true;
  if(!_data)
    return false;

  if (FLASH_update(_baddr, reinterpret_cast<const void *>(_data), _size) == 0) {
    _dirty = false;
    return true;
  }

  DEBUGV("EEPROMClass::commit failed\n");
  return false;
}

uint8_t * EEPROMClass::getDataPtr() {
  _dirty = true;
  return &_data[0];
}

uint8_t const * EEPROMClass::getConstDataPtr() const {
  return &_data[0];
}

#if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_EEPROM)
EEPROMClass EEPROM;
#endif

