#include "fatfs.h"
#include "usbd_cdc_if.h"
#include "firmware.pb.h"
#include "cmsis_os2.h"
#include <pb_encode.h>
#include "UsbDataHandler.h"
#include "crc.h"

// static memory only for decoding messages
static FirmwareStart msg_FirmwareStart;
static FirmwarePackage msg_FirmwarePackage;
static FirmwarePackageAck msg_FirmwarePackageAck;
static FirmwareDone msg_FirmwareDone;

static UsbDataPacket pack_FirmwarePackageAck;


static FIL FwFile = {0};
static bool FileOpen = false;
static FRESULT fresult_open =0;
static uint32_t fwStartTime = 0;
static uint32_t fwPackageCounter =0;

#define ASSERT_SIZE(x) \
  { \
    if (!(x)) \
      Error_Handler(); \
  }

#define DATA_CLBK_SETUP(name) \
  { \
    ASSERT_SIZE(length == sizeof(name)); \
    memcpy(&msg_##name, msg, sizeof(name)); \
  }


/**
 * @brief This function builds and sends a FirmwarePackageAck message over USB.
 *
 * @param ack A boolean flag indicating the acknowledgment status.
 * @param crc A 32-bit cyclic redundancy check (CRC) for the firmware package.
 * @param counter A 32-bit counter for the firmware packages.
 * @param device A 32-bit identifier for the device.
 */
void DataSend_FirmwarePackgeAck(bool ack, uint32_t crc, uint32_t counter, uint32_t device) {
  msg_FirmwarePackageAck.ack = ack;
  msg_FirmwarePackageAck.counter= counter;
  msg_FirmwarePackageAck.crc_pac = crc;
  msg_FirmwarePackageAck.device_id =device;


  pb_ostream_t ostream = pb_ostream_from_buffer(pack_FirmwarePackageAck.data,sizeof(pack_FirmwarePackageAck.data));
  bool status = pb_encode(&ostream, FirmwarePackageAck_fields, &msg_FirmwarePackageAck);

  pack_FirmwarePackageAck.head.length= ostream.bytes_written;
  pack_FirmwarePackageAck.head.type = 0xF04;
  pack_FirmwarePackageAck.head.check =  UsbDataPacket_head_sum(&pack_FirmwarePackageAck);

  if(status) {
    while (CDC_Transmit_HS((uint8_t*)&pack_FirmwarePackageAck, pack_FirmwarePackageAck.head.length + sizeof(UsbDataPacketHead) ) == USBD_BUSY)
    {
      osDelay(3);
    }
  } else {
    Error_Handler();
  }

}

void DataClbk_FirmwareStart(void *msg, uint32_t length) {
  DATA_CLBK_SETUP(FirmwareStart);
  fwStartTime = osKernelGetSysTimerCount();
  fwPackageCounter = 0;

  if(FileOpen) {
    f_close(&FwFile);
  }

  fresult_open = f_open(&FwFile, msg_FirmwareStart.name, FA_CREATE_ALWAYS | FA_WRITE);
  FileOpen=true;

}

// 0x58900205 python
// 0x2ACB825B stm32


void DataClbk_FirmwarePackage(void *msg, uint32_t length) {
  DATA_CLBK_SETUP(FirmwarePackage);

  // check CRC and Package counter
  uint32_t crc_check = HAL_CRC_Calculate(&hcrc,(uint32_t *)msg_FirmwarePackage.data.bytes, msg_FirmwarePackage.data.size);
  if(msg_FirmwarePackage.crc_pac != crc_check ) {
    DataSend_FirmwarePackgeAck(false, msg_FirmwarePackage.crc_pac, msg_FirmwarePackage.counter, msg_FirmwarePackage.device_id);
    return;
  }

  if(msg_FirmwarePackage.counter != fwPackageCounter) {
    DataSend_FirmwarePackgeAck(false, msg_FirmwarePackage.crc_pac, msg_FirmwarePackage.counter, msg_FirmwarePackage.device_id);
    return;
  }

  if(fresult_open != 0) {
    DataSend_FirmwarePackgeAck(false, 0, 0, msg_FirmwarePackage.device_id);
    return;
  }
  
  unsigned int bytes_written =0;
  f_write(&FwFile,msg_FirmwarePackage.data.bytes, msg_FirmwarePackage.data.size, &bytes_written);
  fwPackageCounter++;
  DataSend_FirmwarePackgeAck(true, msg_FirmwarePackage.crc_pac, msg_FirmwarePackage.counter, msg_FirmwarePackage.device_id);
}

void DataClbk_FirmwarePackageAck(void *msg, uint32_t length) {
  DATA_CLBK_SETUP(FirmwarePackageAck);
  // Does notthing for the Master
}

void DataClbk_FirmwareDone(void *msg, uint32_t length) {
  DATA_CLBK_SETUP(FirmwareDone);

  // check CRC and Package counter

  f_close(&FwFile);
  fresult_open = 0xFF;
  FileOpen=false;


  // Spawn Task to Send this File over CAN

}