/* 
 * The MIT License (MIT)
 *
 * Copyright (c) 2019 Ha Thach (tinyusb.org)
 * Copyright (c) 2022 King Kévin <kingkevin@cuvoodoo.info>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "bsp/board.h"
#include "tusb.h"

#if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
  // ESP-IDF need "freertos/" prefix in include path.
  // CFG_TUSB_OS_INC_PATH should be defined accordingly.
  #include "freertos/FreeRTOS.h"
  #include "freertos/semphr.h"
  #include "freertos/queue.h"
  #include "freertos/task.h"
  #include "freertos/timers.h"
  #include "esp_log.h"
  #include "esp_partition.h"
  #include "esp_ota_ops.h"

  #define USBD_STACK_SIZE     4096
#else
  #include "FreeRTOS.h"
  #include "semphr.h"
  #include "queue.h"
  #include "task.h"
  #include "timers.h"

  // Increase stack size when debug log is enabled
  #define USBD_STACK_SIZE    (3*configMINIMAL_STACK_SIZE/2) * (CFG_TUSB_DEBUG ? 2 : 1)
#endif

static const char* TAG = "DFU";

//--------------------------------------------------------------------+
// MACRO CONSTANT TYPEDEF PROTYPES
//--------------------------------------------------------------------+
/* Blink pattern (in ms) */
enum  {
  BLINK_IDLE = 1000,
  BLINK_DOWNLOAD = 250,
  BLINK_SUSPENDED = 2500,
};

// static timer
StaticTimer_t blinky_tmdef;
TimerHandle_t blinky_tm;

// static task
StackType_t  usb_device_stack[USBD_STACK_SIZE];
StaticTask_t usb_device_taskdef;

// static task for cdc
#define CDC_STACK_SZIE      configMINIMAL_STACK_SIZE
StackType_t  cdc_stack[CDC_STACK_SZIE];
StaticTask_t cdc_taskdef;


void led_blinky_cb(TimerHandle_t xTimer);
void usb_device_task(void* param);

// used to download image onto OTA partition
esp_ota_handle_t ota_handle = 0;

// how to program the downloaded data (0 = using OTA tools, 1 = using partition tools)
static uint8_t dl_method = 0;

// download blocks to program
static uint8_t dl_block[CFG_TUD_DFU_XFER_BUFSIZE] = {0};
static uint16_t dl_block_len = 0;
static uint16_t dl_block_num = 0;

// task taking care of flashing during download
// note: esp_ota_begin erase flash, which takes too long to be in tud_dfu_download_cb, causing a USB timeout, thus it's in a task
static void dl_task(void* arg)
{
  esp_err_t rc;
  while (true) {
    if (dl_block_len) { // we received a new block
      const esp_partition_t *ota_part = esp_ota_get_next_update_partition(NULL);
      if (NULL == ota_part) {
        ESP_LOGE(TAG, "OTA not found");
        tud_dfu_finish_flashing(DFU_STATUS_ERR_PROG);
        continue;
      }
      if (0 == dl_method) { // using OTA tools
        // get handle for OTA update
        if (0 == ota_handle) {
          ESP_LOGD(TAG, "init OTA flash");
          rc = esp_ota_begin(ota_part, OTA_SIZE_UNKNOWN, &ota_handle);
          if (ESP_OK != rc) {
            ESP_LOGE(TAG, "init OTA failed");
            esp_ota_abort(ota_handle);
            ota_handle = 0;
            tud_dfu_finish_flashing(DFU_STATUS_ERR_ERASE);
            continue;
          }
        }

        // write data to partition
        rc = esp_ota_write_with_offset(ota_handle, dl_block, dl_block_len, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE);
        if (ESP_OK != rc) {
          ESP_LOGE(TAG, "writing OTA failed");
          esp_ota_abort(ota_handle);
          ota_handle = 0;
          tud_dfu_finish_flashing(DFU_STATUS_ERR_WRITE);
          continue;
        }

        tud_dfu_finish_flashing(DFU_STATUS_OK); // flashing op for download complete without error
      } else if (1 == dl_method) { // using partition tools
        // read current data
        uint8_t flash_block[CFG_TUD_DFU_XFER_BUFSIZE];
        rc = esp_partition_read(ota_part, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE, flash_block, dl_block_len);
        if (ESP_OK != rc) {
          ESP_LOGE(TAG, "reading range failed");
          tud_dfu_finish_flashing(DFU_STATUS_ERR_CHECK_ERASED);
          continue;
        }
        if (0 == memcmp(dl_block, flash_block, dl_block_len)) { // data is the same
          dl_block_len = 0; // ready for next block
          tud_dfu_finish_flashing(DFU_STATUS_OK); // flashing op for download complete without error
          continue;
        }
        if (0 == (dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE) % 4096) { // new page
          rc = esp_partition_erase_range(ota_part, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE, 4096); // erase page (block is smaller than page
          if (ESP_OK != rc) {
            ESP_LOGE(TAG, "erase range failed");
            tud_dfu_finish_flashing(DFU_STATUS_ERR_ERASE);
            continue;
          }
        }
        rc = esp_partition_write(ota_part, dl_block_num * CFG_TUD_DFU_XFER_BUFSIZE, flash_block, dl_block_len); // write new data
        if (ESP_OK != rc) {
          ESP_LOGE(TAG, "writing range failed");
          tud_dfu_finish_flashing(DFU_STATUS_ERR_WRITE);
          continue;
        }
        ESP_LOGD(TAG, "writing range OK");
        dl_block_len = 0; // ready for next block
        tud_dfu_finish_flashing(DFU_STATUS_OK); // flashing op for download complete without error
      } else { // unknown method
        tud_dfu_finish_flashing(DFU_STATUS_ERR_TARGET);
      }
      dl_block_len = 0; // ready for next block
    } else { // no new block
      vTaskDelay(1); // allow other tasks to run (and watchdog reset)
    }
  }
}

// task to complete flashing, used when entering manifestation
static void complete_task(void* arg)
{
  esp_err_t rc;

  // finish flashing
  if (ota_handle) {
    rc = esp_ota_end(ota_handle);
    ota_handle = 0;
    if (ESP_OK != rc) {
      ESP_LOGE(TAG, "close OTA failed");
      tud_dfu_finish_flashing(DFU_STATUS_ERR_PROG);
      vTaskDelete(NULL); // close task
    }
  }

  // switch to OTA app
  const esp_partition_t *ota = esp_ota_get_next_update_partition(NULL);
  esp_app_desc_t ota_desc;
  esp_ota_get_partition_description(ota, &ota_desc);
  if (ESP_APP_DESC_MAGIC_WORD == ota_desc.magic_word) {
    ESP_LOGI(TAG, "set boot to valid app");
    esp_ota_set_boot_partition(ota);
    xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_IDLE), 0);
    tud_dfu_finish_flashing(DFU_STATUS_OK);
  } else {
    ESP_LOGI(TAG, "no valid app");
    tud_dfu_finish_flashing(DFU_STATUS_ERR_VERIFY);
  }

  vTaskDelete(NULL); // close task
}

//--------------------------------------------------------------------+
// Main
//--------------------------------------------------------------------+

int main(void)
{
  board_init();

  const esp_partition_t *next = esp_ota_get_next_update_partition(NULL);
  esp_app_desc_t next_desc;
  esp_ota_get_partition_description(next, &next_desc);

  if (ESP_APP_DESC_MAGIC_WORD == next_desc.magic_word) {
    ESP_LOGI(TAG, "set app for next boot");
    esp_ota_set_boot_partition(next);
  } else {
    ESP_LOGI(TAG, "no valid app");
  }

  // soft timer for blinky
  blinky_tm = xTimerCreateStatic(NULL, pdMS_TO_TICKS(BLINK_IDLE), true, NULL, led_blinky_cb, &blinky_tmdef);
  xTimerStart(blinky_tm, 0);

  // Create a task for tinyusb device stack
  (void) xTaskCreateStatic( usb_device_task, "usbd", USBD_STACK_SIZE, NULL, configMAX_PRIORITIES-1, usb_device_stack, &usb_device_taskdef);

  // skip starting scheduler (and return) for ESP32-S2 or ESP32-S3
#if !TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
  vTaskStartScheduler();
#endif

  // create task to handle download progress
  xTaskCreate(dl_task, "dl_task", 2 * 1024, NULL, 8, NULL);

  ESP_LOGI(TAG, "DFU mode");

  return 0;
}

#if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
void app_main(void)
{
  main();
}
#endif

// USB Device Driver task
// This top level thread process all usb events and invoke callbacks
void usb_device_task(void* param)
{
  (void) param;

  // This should be called after scheduler/kernel is started.
  // Otherwise it could cause kernel issue since USB IRQ handler does use RTOS queue API.
  tusb_init();

  // RTOS forever loop
  while (1)
  {
    // tinyusb device task
    tud_task();
  }
}

//--------------------------------------------------------------------+
// Device callbacks
//--------------------------------------------------------------------+

// Invoked when usb bus is suspended
// remote_wakeup_en : if host allow us  to perform remote wakeup
// Within 7ms, device must draw an average of current less than 2.5 mA from bus
void tud_suspend_cb(bool remote_wakeup_en)
{
  (void) remote_wakeup_en;
  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_SUSPENDED), 0);
}

// Invoked when usb bus is resumed
void tud_resume_cb(void)
{
  xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_IDLE), 0);
}

//--------------------------------------------------------------------+
// DFU callbacks
// Note: alt is used as the partition number, in order to support multiple partitions like FLASH, EEPROM, etc.
//--------------------------------------------------------------------+

// Invoked right before tud_dfu_download_cb() (state=DFU_DNBUSY) or tud_dfu_manifest_cb() (state=DFU_MANIFEST)
// Application return timeout in milliseconds (bwPollTimeout) for the next download/manifest operation.
// During this period, USB host won't try to communicate with us.
uint32_t tud_dfu_get_timeout_cb(uint8_t alt, uint8_t state)
{
  if ( state == DFU_DNBUSY )
  {
    return 3; // SPI flash Page Program Time 0.7-3 ms
  }
  else if (state == DFU_MANIFEST)
  {
    // since we don't buffer entire image and do any flashing in manifest stage
    return 0;
  }

  return 0;
}

// Invoked when received DFU_DNLOAD (wLength>0) following by DFU_GETSTATUS (state=DFU_DNBUSY) requests
// This callback could be returned before flashing op is complete (async).
// Once finished flashing, application must call tud_dfu_finish_flashing()
void tud_dfu_download_cb(uint8_t alt, uint16_t block_num, uint8_t const* data, uint16_t length)
{
  esp_err_t rc;
  static bool dl_started = false;

  ESP_LOGD(TAG, "download, alt=%u block=%u", alt, block_num);

  if (alt > 1) {
    ESP_LOGW(TAG, "download to invalid alt %u", alt);
    tud_dfu_finish_flashing(DFU_STATUS_ERR_ADDRESS);
    return;
  }

  if (0 == length) { // there is nothing to program
    // finish flashing
    if (ota_handle) {
      rc = esp_ota_end(ota_handle);
      ota_handle = 0;
      if (ESP_OK != rc) {
        ESP_LOGE(TAG, "close OTA failed");
        tud_dfu_finish_flashing(DFU_STATUS_ERR_PROG);
        return;
      }
    }
    dl_started = false;
    tud_dfu_finish_flashing(DFU_STATUS_OK); // flashing op for download complete without error
  } else if (length > CFG_TUD_DFU_XFER_BUFSIZE) { // more data than we can handle
    tud_dfu_finish_flashing(DFU_STATUS_ERR_PROG);
  } else if (dl_block_len) { // there is already a block to program
    tud_dfu_finish_flashing(DFU_STATUS_ERR_STALLEDPKT);
  } else { // all is fine to program
    if (!dl_started) {
      xTimerChangePeriod(blinky_tm, pdMS_TO_TICKS(BLINK_DOWNLOAD), 0);
      dl_started = true;
    }
    memcpy(dl_block, data, length); // copy data for dl_task
    dl_method = alt; // remember how to flash
    dl_block_num = block_num; // remember offset
    dl_block_len = length; // notify dl_task block is ready
  }
}

// Invoked when download process is complete, received DFU_DNLOAD (wLength=0) following by DFU_GETSTATUS (state=Manifest)
// Application can do checksum, or actual flashing if buffered entire image previously.
// Once finished flashing, application must call tud_dfu_finish_flashing()
void tud_dfu_manifest_cb(uint8_t alt)
{
  (void)alt; // not used
  ESP_LOGI(TAG, "download completed, enter manifestation");
  xTaskCreate(complete_task, "complete_task", 3 * 1024, NULL, 8, NULL);
}

// Invoked when received DFU_UPLOAD request
// Application must populate data with up to length bytes and
// Return the number of written bytes
uint16_t tud_dfu_upload_cb(uint8_t alt, uint16_t block_num, uint8_t* data, uint16_t length)
{
  uint16_t xfer_len = 0;

  if (alt > 0) {
    ESP_LOGW(TAG, "upload unknown alt %u", alt);
    return 0;
  }

  ESP_LOGD(TAG, "upload, alt=%u block=%u", alt, block_num);
  const esp_partition_t * part  = esp_partition_find_first(ESP_PARTITION_TYPE_APP, ESP_PARTITION_SUBTYPE_APP_OTA_0, NULL);
  esp_err_t rc = esp_partition_read(part, block_num * CFG_TUD_DFU_XFER_BUFSIZE, data, length);
  if (ESP_OK == rc) {
    xfer_len = length;
  } else {
    xfer_len = 0;
    ESP_LOGW(TAG, "reading flash failed");
  }

  return xfer_len;
}

// Invoked when the Host has terminated a download or upload transfer
void tud_dfu_abort_cb(uint8_t alt)
{
  (void) alt;
  ESP_LOGI(TAG, "host aborted transfer");
  blinky_tm = xTimerCreateStatic(NULL, pdMS_TO_TICKS(BLINK_IDLE), true, NULL, led_blinky_cb, &blinky_tmdef);
}

// Invoked when a DFU_DETACH request is received
void tud_dfu_detach_cb(void)
{
  ESP_LOGI(TAG, "host detach -> reboot");
  esp_restart();
}

//--------------------------------------------------------------------+
// BLINKING TASK
//--------------------------------------------------------------------+
void led_blinky_cb(TimerHandle_t xTimer)
{
  (void) xTimer;
  static bool led_state = false;

  board_led_write(led_state);
  led_state = 1 - led_state; // toggle
}