#include "sdkconfig.h"
#if CONFIG_USB_ENABLED


#include <stdlib.h>
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"
#include "tinyusb.h"

static const char *TAG = "example";

#if CONFIG_USB_MSC_ENABLED

#define README_CONTENTS "This is tinyusb's MassStorage Class demo.\r\n\r\nIf you find any bugs or get any questions, feel free to file an\r\nissue at github.com/hathach/tinyusb"

enum
{
  DISK_BLOCK_NUM  = 2 * 140, // 8KB is the smallest size that windows allow to mount
  DISK_BLOCK_SIZE = 512
};

#ifdef CFG_EXAMPLE_MSC_READONLY
const
#endif
uint8_t msc_disk[DISK_BLOCK_NUM][DISK_BLOCK_SIZE] =
{
  //------------- Block0: Boot Sector -------------//
  // byte_per_sector    = DISK_BLOCK_SIZE; fat12_sector_num_16  = DISK_BLOCK_NUM;
  // sector_per_cluster = 1; reserved_sectors = 1;
  // fat_num            = 1; fat12_root_entry_num = 16;
  // sector_per_fat     = 1; sector_per_track = 1; head_num = 1; hidden_sectors = 0;
  // drive_number       = 0x80; media_type = 0xf8; extended_boot_signature = 0x29;
  // filesystem_type    = "FAT12   "; volume_serial_number = 0x1234; volume_label = "TinyUSB MSC";
  // FAT magic code at offset 510-511
  {
    0xEB, 0x3C, 0x90, 0x4D, 0x53, 0x44, 0x4F, 0x53, 0x35, 0x2E, 0x30, 0x00, 0x02, 0x01, 0x01, 0x00,
    0x01, 0x10, 0x00, 0x10, 0x00, 0xF8, 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x80, 0x00, 0x29, 0x34, 0x12, 0x00, 0x00, 'E' , 'S' , 'P' , '3' , '2' ,
    'S' , '2' , ' ' , 'M' , 'S' , 'C' , 0x46, 0x41, 0x54, 0x31, 0x32, 0x20, 0x20, 0x20, 0x00, 0x00,

    // Zero up to 2 last bytes of FAT magic code
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0xAA
  },

  //------------- Block1: FAT12 Table -------------//
  {
    0xF8, 0xFF, 0xFF, 0xFF, 0x0F // // first 2 entries must be F8FF, third entry is cluster end of readme file
  },

  //------------- Block2: Root Directory -------------//
  {
    // first entry is volume label
    'E' , 'S' , 'P' , '3' , '2' , 'S' , '2' , ' ' , 'M' , 'S' , 'C' , 0x08, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4F, 0x6D, 0x65, 0x43, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    // second entry is readme file
    'R' , 'E' , 'A' , 'D' , 'M' , 'E' , ' ' , ' ' , 'T' , 'X' , 'T' , 0x20, 0x00, 0xC6, 0x52, 0x6D,
    0x65, 0x43, 0x65, 0x43, 0x00, 0x00, 0x88, 0x6D, 0x65, 0x43, 0x02, 0x00,
    sizeof(README_CONTENTS) - 1, 0x00, 0x00, 0x00 // readme's files size (4 Bytes)
  },

  //------------- Block3: Readme Content -------------//
  README_CONTENTS
};

// Invoked when received SCSI_CMD_INQUIRY
// Application fill vendor id, product id and revision with string up to 8, 16, 4 characters respectively
void tud_msc_inquiry_cb(uint8_t lun, uint8_t vendor_id[8], uint8_t product_id[16], uint8_t product_rev[4])
{
  (void) lun;

  const char vid[] = "Espressif";
  const char pid[] = "Mass Storage";
  const char rev[] = "1.0";

  memcpy(vendor_id  , vid, strlen(vid));
  memcpy(product_id , pid, strlen(pid));
  memcpy(product_rev, rev, strlen(rev));
  ESP_LOGI(__func__, "");
}

// Invoked when received Test Unit Ready command.
// return true allowing host to read/write this LUN e.g SD card inserted
bool tud_msc_test_unit_ready_cb(uint8_t lun)
{
  (void) lun;
  ESP_LOGI(__func__, "");

  return true; // RAM disk is always ready
}

// Invoked when received SCSI_CMD_READ_CAPACITY_10 and SCSI_CMD_READ_FORMAT_CAPACITY to determine the disk size
// Application update block count and block size
void tud_msc_capacity_cb(uint8_t lun, uint32_t* block_count, uint16_t* block_size)
{
  (void) lun;
  ESP_LOGI(__func__, "");

  *block_count = DISK_BLOCK_NUM;
  *block_size  = DISK_BLOCK_SIZE;
}

// Invoked when received Start Stop Unit command
// - Start = 0 : stopped power mode, if load_eject = 1 : unload disk storage
// - Start = 1 : active mode, if load_eject = 1 : load disk storage
bool tud_msc_start_stop_cb(uint8_t lun, uint8_t power_condition, bool start, bool load_eject)
{
  (void) lun;
  (void) power_condition;
  ESP_LOGI(__func__, "");

  if ( load_eject )
  {
    if (start)
    {
      // load disk storage
    } else
    {
      // unload disk storage
    }
  }

  return true;
}

// Callback invoked when received READ10 command.
// Copy disk's data to buffer (up to bufsize) and return number of copied bytes.
int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buffer, uint32_t bufsize)
{
  (void) lun;
  ESP_LOGI(__func__, "");

  uint8_t const* addr = msc_disk[lba] + offset;
  memcpy(buffer, addr, bufsize);

  return bufsize;
}

// Callback invoked when received WRITE10 command.
// Process data in buffer to disk's storage and return number of written bytes
int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset, uint8_t* buffer, uint32_t bufsize)
{
  (void) lun;
  ESP_LOGI(__func__, "");

#ifndef CFG_EXAMPLE_MSC_READONLY
  uint8_t* addr = msc_disk[lba] + offset;
  memcpy(addr, buffer, bufsize);
#else
  (void) lba; (void) offset; (void) buffer;
#endif

  return bufsize;
}

// Callback invoked when received an SCSI command not in built-in list below
// - READ_CAPACITY10, READ_FORMAT_CAPACITY, INQUIRY, MODE_SENSE6, REQUEST_SENSE
// - READ10 and WRITE10 has their own callbacks
int32_t tud_msc_scsi_cb (uint8_t lun, uint8_t const scsi_cmd[16], void* buffer, uint16_t bufsize)
{
  // read10 & write10 has their own callback and MUST not be handled here
  ESP_LOGI(__func__, "");

  void const* response = NULL;
  uint16_t resplen = 0;

  // most scsi handled is input
  bool in_xfer = true;

  switch (scsi_cmd[0])
  {
    case SCSI_CMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
      // Host is about to read/write etc ... better not to disconnect disk
      resplen = 0;
      break;

    default:
      // Set Sense = Invalid Command Operation
      tud_msc_set_sense(lun, SCSI_SENSE_ILLEGAL_REQUEST, 0x20, 0x00);

      // negative means error -> tinyusb could stall and/or response with failed status
      resplen = -1;
      break;
  }

  // return resplen must not larger than bufsize
  if ( resplen > bufsize ) resplen = bufsize;

  if ( response && (resplen > 0) )
  {
    if (in_xfer)
    {
      memcpy(buffer, response, resplen);
    } else
    {
      // SCSI output
    }
  }

  return resplen;
}

#endif /* CONFIG_USB_MSC_ENABLED */

#if CONFIG_USB_CDC_ENABLED
void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
  if (dtr && rts) {
    tud_cdc_write_str("Welcome to tinyUSB CDC example!!!\r\n");
  }
}
#endif /* CONFIG_USB_CDC_ENABLED */

// USB Device Driver task
// This top level thread processes all usb events and invokes callbacks
void usb_device_task(void *param) {
  (void)param;
  ESP_LOGI(TAG, "USB task started");
  while (1) {
    tud_task(); // RTOS forever loop
  }
}

void cloop() {
#if CONFIG_USB_CDC_ENABLED
  if (tud_cdc_connected()) {
    // connected and there are data available
    if ( tud_cdc_available() ) {
      uint8_t buf[64];
      // read and echo back
      uint32_t count = tud_cdc_read(buf, sizeof(buf));
      for (uint32_t i = 0; i < count; i++) {
        tud_cdc_write_char(buf[i]);
        if ( buf[i] == '\r' ) {
          tud_cdc_write_str("\n > ");
        }
      }
      tud_cdc_write_flush();
    }
  }
#endif /* CONFIG_USB_CDC_ENABLED */
}

void csetup() {
  tinyusb_config_t tusb_cfg = {
    .descriptor = NULL,
    .string_descriptor = NULL,
    .external_phy = false
  };

  ESP_ERROR_CHECK(tinyusb_driver_install(&tusb_cfg));
  xTaskCreate(usb_device_task, "usbd", 4096, NULL, 24, NULL);
}

#endif /* CONFIG_USB_ENABLED */