#include "fatfs.h"
#include "usbd_cdc_if.h"
#include "firmware.pb.h"
#include "cls_device.pb.h"
#include "usb.pb.h"
#include "cmsis_os2.h"
#include <pb_encode.h>
#include "UsbDataHandler.h"
#include "crc.h"
#include "FirmwareUpdate.h"
#include "stdbool.h"
#include "CLS.h"
#include "stdbool.h"
#include "ram_loader.h"

// static memory only for decoding messages
static cls_firmware_Start msg_cls_firmware_Start;
static cls_firmware_Package msg_cls_firmware_Package;
static cls_firmware_PackageAck msg_cls_firmware_PackageAck;
static cls_firmware_Done msg_cls_firmware_Done;
static cls_firmware_FileCheck msg_cls_firmware_FileCheck;
static UsbDataPacket pack_cls_firmware_Package;


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

/**
 * @brief This function builds and sends a cls_firmware_PackageAck 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_cls_firmware_PackageAck.ack = ack;
  msg_cls_firmware_PackageAck.counter= counter;
  msg_cls_firmware_PackageAck.crc_pac = crc;
  msg_cls_firmware_PackageAck.device_id =device;

  UsbDataPacketSendMessage(cls_usb_PackageType_FIRMWAREPACKAGEACK, &pack_cls_firmware_Package, cls_firmware_PackageAck_fields, &msg_cls_firmware_PackageAck);
}


void DataSend_FirmwareFileCheck(uint32_t crc, uint32_t device_id, bool ready_for_data, UINT size, char* name) {
  msg_cls_firmware_FileCheck.crc_fw = crc;
  msg_cls_firmware_FileCheck.device_id = device_id;
  msg_cls_firmware_FileCheck.ready_for_data = ready_for_data;
  msg_cls_firmware_FileCheck.size = size;
  memcpy(msg_cls_firmware_FileCheck.name, name, sizeof(msg_cls_firmware_FileCheck.name));

  UsbDataPacketSendMessage(cls_usb_PackageType_FIRMWAREFILECHECK, &pack_cls_firmware_Package, cls_firmware_FileCheck_fields, &msg_cls_firmware_FileCheck);
}


#define CHUNK_SIZE 256  // Change this to the size of chunks you want to read
static uint8_t crc_buffer[CHUNK_SIZE];


void fw_Start_Slave( cls_firmware_Start * msg)  {

  uint32_t crc = 0;
  UINT totalRead = 0;
  UINT bytesRead = 0;
  
  // Check if file already exists
  if(f_open(&FwFile, msg->name, FA_READ) == FR_OK) {

    __HAL_CRC_DR_RESET(&hcrc);
    do {
      f_read(&FwFile, crc_buffer, CHUNK_SIZE, &bytesRead);
      crc = HAL_CRC_Accumulate(&hcrc, (uint32_t *)crc_buffer, bytesRead);
      totalRead+=bytesRead;
    } while(bytesRead == CHUNK_SIZE);
    f_close(&FwFile);

    if(crc == msg->crc_fw) { 
      // CRC matches, no need for transfer
      DataSend_FirmwareFileCheck(crc, msg->device_id, false, totalRead, msg->name);
      return;
    }
  }

  fresult_open = f_open(&FwFile, msg->name, FA_CREATE_ALWAYS | FA_WRITE);
  FileOpen=true;
  DataSend_FirmwareFileCheck(crc, msg->device_id, fresult_open==FR_OK, totalRead, msg->name);
}

void fw_Start_Master( cls_firmware_Start * msg) {
  fresult_open = f_open(&FwFile, "firm.bin", FA_CREATE_ALWAYS | FA_WRITE);
  FileOpen=true;
  DataSend_FirmwareFileCheck(0, msg->device_id, fresult_open==FR_OK, 0, msg->name);
}

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

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

  if(msg_cls_firmware_Start.device_id == gCLS_DEVICE_ADDRESS) {
    fw_Start_Master(&msg_cls_firmware_Start);
  } else {
    fw_Start_Slave(&msg_cls_firmware_Start);
  }
}


void DataClbk_cls_firmware_Package(void *msg, uint32_t length) {
  DATA_CLBK_SETUP(cls_firmware_Package);

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

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

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

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

void DataClbk_cls_firmware_Done(void *msg, uint32_t length) {
  DATA_CLBK_SETUP(cls_firmware_Done);

  // check CRC and Package counter

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

  if(msg_cls_firmware_Done.device_id == gCLS_DEVICE_ADDRESS) {
    RamLoader_LoadApplication();
  } else if (msg_cls_firmware_Done.device_id == gCLS_DEVICE_ADDRESS +1) {
      // send fw to display
      // todo !

    } {

      // send fw to slave
    FirmwareUpdateArgs args;
    args.device = msg_cls_firmware_Done.device_id;
    memcpy(args.name, msg_cls_firmware_Start.name, sizeof(args.name));

    FirmwareUpdateTask_start(args);
  }
}