/*
 * This file is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This file 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
#include <AP_HAL/AP_HAL.h>
#include <AP_BoardConfig/AP_BoardConfig.h>
#include "Storage.h"

//#define STORAGEDEBUG 1

using namespace ESP32;

extern const AP_HAL::HAL& hal;

void Storage::_storage_open(void)
{
    if (_initialised) {
        return;
    }
#ifdef STORAGEDEBUG
    printf("%s:%d _storage_open \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    _dirty_mask.clearall();
    p = esp_partition_find_first((esp_partition_type_t)0x45, ESP_PARTITION_SUBTYPE_ANY, nullptr);
    // load from storage backend
    _flash_load();
    _initialised = true;
}

/*
  mark some lines as dirty. Note that there is no attempt to avoid
  the race condition between this code and the _timer_tick() code
  below, which both update _dirty_mask. If we lose the race then the
  result is that a line is written more than once, but it won't result
  in a line not being written.
*/
void Storage::_mark_dirty(uint16_t loc, uint16_t length)
{
#ifdef STORAGEDEBUG
    printf("%s:%d \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    uint16_t end = loc + length;
    for (uint16_t line=loc>>STORAGE_LINE_SHIFT;
         line <= end>>STORAGE_LINE_SHIFT;
         line++) {
        _dirty_mask.set(line);
    }
}

void Storage::read_block(void *dst, uint16_t loc, size_t n)
{
    if (loc >= sizeof(_buffer)-(n-1)) {
#ifdef STORAGEDEBUG
        printf("%s:%d read_block failed \n", __PRETTY_FUNCTION__, __LINE__);
#endif
        return;
    }
    _storage_open();
    memcpy(dst, &_buffer[loc], n);
}

void Storage::write_block(uint16_t loc, const void *src, size_t n)
{
    if (loc >= sizeof(_buffer)-(n-1)) {
#ifdef STORAGEDEBUG
        printf("%s:%d write_block failed \n", __PRETTY_FUNCTION__, __LINE__);
#endif
        return;
    }
    if (memcmp(src, &_buffer[loc], n) != 0) {
        _storage_open();
        memcpy(&_buffer[loc], src, n);
        _mark_dirty(loc, n);
    }
}

void Storage::_timer_tick(void)
{
    if (!_initialised) {
        return;
    }
    if (_dirty_mask.empty()) {
        _last_empty_ms = AP_HAL::millis();
        return;
    }

    // write out the first dirty line. We don't write more
    // than one to keep the latency of this call to a minimum
    uint16_t i;
    for (i=0; i<STORAGE_NUM_LINES; i++) {
        if (_dirty_mask.get(i)) {
            break;
        }
    }
    if (i == STORAGE_NUM_LINES) {
        // this shouldn't be possible
        return;
    }

    // save to storage backend
    _flash_write(i);
}

/*
  load all data from flash
 */
void Storage::_flash_load(void)
{
#ifdef STORAGEDEBUG
    printf("%s:%d \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    if (!_flash.init()) {
        AP_HAL::panic("unable to init flash storage");
    }
}

/*
  write one storage line. This also updates _dirty_mask.
*/
void Storage::_flash_write(uint16_t line)
{
#ifdef STORAGEDEBUG
    printf("%s:%d \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    if (_flash.write(line*STORAGE_LINE_SIZE, STORAGE_LINE_SIZE)) {
        // mark the line clean
        _dirty_mask.clear(line);
    }
}

/*
  callback to write data to flash
 */
bool Storage::_flash_write_data(uint8_t sector, uint32_t offset, const uint8_t *data, uint16_t length)
{
#ifdef STORAGEDEBUG
    printf("%s:%d  \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    size_t address = sector * STORAGE_SECTOR_SIZE + offset;
    bool ret = esp_partition_write(p, address, data, length) == ESP_OK;
    if (!ret && _flash_erase_ok()) {
        // we are getting flash write errors while disarmed. Try
        // re-writing all of flash
        uint32_t now = AP_HAL::millis();
        if (now - _last_re_init_ms > 5000) {
            _last_re_init_ms = now;
            bool ok = _flash.re_initialise();
            hal.console->printf("Storage: failed at %u:%u for %u - re-init %u\n",
                                (unsigned)sector, (unsigned)offset, (unsigned)length, (unsigned)ok);
#ifdef STORAGEDEBUG
            printf("Storage: failed at %u:%u for %u - re-init %u\n",
                   (unsigned)sector, (unsigned)offset, (unsigned)length, (unsigned)ok);
#endif
        }
    }
    return ret;
}

/*
  callback to read data from flash
 */
bool Storage::_flash_read_data(uint8_t sector, uint32_t offset, uint8_t *data, uint16_t length)
{
    size_t address = sector * STORAGE_SECTOR_SIZE + offset;
#ifdef STORAGEDEBUG
    printf("%s:%d  -> sec:%u off:%d len:%d addr:%d\n", __PRETTY_FUNCTION__, __LINE__,sector,offset,length,address);
#endif
    esp_partition_read(p, address, data, length);
    return true;
}

/*
  callback to erase flash sector
 */
bool Storage::_flash_erase_sector(uint8_t sector)
{
#ifdef STORAGEDEBUG
    printf("%s:%d  \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    size_t address = sector * STORAGE_SECTOR_SIZE;
    return esp_partition_erase_range(p, address, STORAGE_SECTOR_SIZE) == ESP_OK;
}

/*
  callback to check if erase is allowed
 */
bool Storage::_flash_erase_ok(void)
{
#ifdef STORAGEDEBUG
    printf("%s:%d  \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    // only allow erase while disarmed
    return !hal.util->get_soft_armed();
}

/*
  consider storage healthy if we have nothing to write sometime in the
  last 2 seconds
 */
bool Storage::healthy(void)
{
#ifdef STORAGEDEBUG
    printf("%s:%d  \n", __PRETTY_FUNCTION__, __LINE__);
#endif
    return _initialised && AP_HAL::millis() - _last_empty_ms < 2000;
}