// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// 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.

#include "vfs_api.h"
extern "C" {
#include "esp_vfs_fat.h"
#include "diskio.h"
#include "diskio_wl.h"
#include "vfs_fat_internal.h"
}
#include "FFat.h"

using namespace fs;

F_Fat::F_Fat(FSImplPtr impl) : FS(impl) {}

const esp_partition_t *check_ffat_partition(const char *label) {
  const esp_partition_t *ck_part = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_FAT, label);
  if (!ck_part) {
    log_e("No FAT partition found with label %s", label);
    return NULL;
  }
  return ck_part;
}

bool F_Fat::begin(bool formatOnFail, const char *basePath, uint8_t maxOpenFiles, const char *partitionLabel) {
  if (_wl_handle != WL_INVALID_HANDLE) {
    log_w("Already Mounted!");
    return true;
  }

  if (!check_ffat_partition(partitionLabel)) {
    log_e("No fat partition found on flash");
    return false;
  }

  esp_vfs_fat_mount_config_t conf = {
    .format_if_mount_failed = formatOnFail,
    .max_files = maxOpenFiles,
    .allocation_unit_size = CONFIG_WL_SECTOR_SIZE,
    .disk_status_check_enable = false,
    .use_one_fat = false
  };
  esp_err_t err = esp_vfs_fat_spiflash_mount_rw_wl(basePath, partitionLabel, &conf, &_wl_handle);
  if (err) {
    log_e("Mounting FFat partition failed! Error: %d", err);
    esp_vfs_fat_spiflash_unmount_rw_wl(basePath, _wl_handle);
    _wl_handle = WL_INVALID_HANDLE;
    return false;
  }
  _impl->mountpoint(basePath);
  return true;
}

void F_Fat::end() {
  if (_wl_handle != WL_INVALID_HANDLE) {
    esp_err_t err = esp_vfs_fat_spiflash_unmount_rw_wl(_impl->mountpoint(), _wl_handle);
    if (err) {
      log_e("Unmounting FFat partition failed! Error: %d", err);
      return;
    }
    _wl_handle = WL_INVALID_HANDLE;
    _impl->mountpoint(NULL);
  }
}

bool F_Fat::format(bool full_wipe, char *partitionLabel) {
  esp_err_t result;
  bool res = true;
  if (_wl_handle != WL_INVALID_HANDLE) {
    log_w("Already Mounted!");
    return false;
  }
  wl_handle_t temp_handle;
  // Attempt to mount to see if there is already data
  const esp_partition_t *ffat_partition = check_ffat_partition(partitionLabel);
  if (!ffat_partition) {
    log_w("No partition!");
    return false;
  }
  result = wl_mount(ffat_partition, &temp_handle);

  if (result == ESP_OK) {
    // Wipe disk- quick just wipes the FAT. Full zeroes the whole disk
    uint32_t wipe_size = full_wipe ? wl_size(temp_handle) : 16384;
    wl_erase_range(temp_handle, 0, wipe_size);
    wl_unmount(temp_handle);
  } else {
    res = false;
    log_w("wl_mount failed!");
  }
  // Now do a mount with format_if_fail (which it will)
  esp_vfs_fat_mount_config_t conf = {
    .format_if_mount_failed = true, .max_files = 1, .allocation_unit_size = CONFIG_WL_SECTOR_SIZE, .disk_status_check_enable = false, .use_one_fat = false
  };
  result = esp_vfs_fat_spiflash_mount_rw_wl("/format_ffat", partitionLabel, &conf, &temp_handle);
  esp_vfs_fat_spiflash_unmount_rw_wl("/format_ffat", temp_handle);
  if (result != ESP_OK) {
    res = false;
    log_w("esp_vfs_fat_spiflash_mount_rw_wl failed!");
  }
  return res;
}

size_t F_Fat::totalBytes() {
  FATFS *fs;
  DWORD free_clust, tot_sect, sect_size;

  BYTE pdrv = ff_diskio_get_pdrv_wl(_wl_handle);
  char drv[3] = {(char)(48 + pdrv), ':', 0};
  if (f_getfree(drv, &free_clust, &fs) != FR_OK) {
    return 0;
  }
  tot_sect = (fs->n_fatent - 2) * fs->csize;
  sect_size = CONFIG_WL_SECTOR_SIZE;
  return tot_sect * sect_size;
}

size_t F_Fat::usedBytes() {
  FATFS *fs;
  DWORD free_clust, used_sect, sect_size;

  BYTE pdrv = ff_diskio_get_pdrv_wl(_wl_handle);
  char drv[3] = {(char)(48 + pdrv), ':', 0};
  if (f_getfree(drv, &free_clust, &fs) != FR_OK) {
    return 0;
  }
  used_sect = (fs->n_fatent - 2 - free_clust) * fs->csize;
  sect_size = CONFIG_WL_SECTOR_SIZE;
  return used_sect * sect_size;
}

size_t F_Fat::freeBytes() {

  FATFS *fs;
  DWORD free_clust, free_sect, sect_size;

  BYTE pdrv = ff_diskio_get_pdrv_wl(_wl_handle);
  char drv[3] = {(char)(48 + pdrv), ':', 0};
  if (f_getfree(drv, &free_clust, &fs) != FR_OK) {
    return 0;
  }
  free_sect = free_clust * fs->csize;
  sect_size = CONFIG_WL_SECTOR_SIZE;
  return free_sect * sect_size;
}

F_Fat FFat = F_Fat(FSImplPtr(new VFSImpl()));