/* -------------------------------------------------------------------------- */
/* --- DEPENDANCIES --------------------------------------------------------- */

#include <errno.h>
#include <fcntl.h>             /* open */
#include <stdlib.h>            /* malloc free */
#include <string.h>            /* memset */
#include "mts_fpga_reg.h"      /* register functions*/
#include "mts_error_codes.h"   /* error codes*/
#include "mts_fpga_hash.h"     /* compute fiel hash*/
#include "mts_fpga_spi.h"      /* spi interface commands*/
/* -------------------------------------------------------------------------- */
/* --- PRIVATE MACROS ------------------------------------------------------- */

#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
#if DEBUG_REG == 1
#define DEBUG_MSG(str) fprintf(stderr, str)
#define DEBUG_PRINTF(fmt, args...)                                             \
  fprintf(stderr, "%s:%d: " fmt, __FUNCTION__, __LINE__, args)
#define CHECK_NULL(a)                                                          \
  if (a == NULL) {                                                             \
    fprintf(stderr, "%s:%d: ERROR: NULL POINTER AS ARGUMENT\n", __FUNCTION__,  \
            __LINE__);                                                         \
    return MTAC_REG_ERROR;                                                     \
  }
#else
#define DEBUG_MSG(str)
#define DEBUG_PRINTF(fmt, args...)
#define CHECK_NULL(a)                                                          \
  if (a == NULL) {                                                             \
    return MTAC_REG_ERROR;                                                     \
  }
#endif

/* -------------------------------------------------------------------------- */
/* --- PRIVATE CONSTANTS ---------------------------------------------------- */

const char *valid_hw[] = {MTCDT, MTCAP};
static const uint8_t fpga_version[] = {28, 31, 33, 35, 37};
static const struct mtac_reg_s loregs[3] = {
    {-1, 0, 0, 0, 2, 0, 0},  /* PAGE_REG */
    {-1, 0, 7, 0, 1, 0, 0},  /* SOFT_RESET */
    {-1, 1, 0, 0, 8, 1, 103} /* VERSION */
};
/* -------------------------------------------------------------------------- */
/* --- PRIVATE VARIABLES ---------------------------------------------------- */

void *mtac_spi_target = NULL;  /*! generic pointer to the SPI device */
uint8_t mtac_spi_mux_mode = 0; /*! current SPI mux mode used */
/* -------------------------------------------------------------------------- */
/* --- PUBLIC FUNCTIONS DEFINITION ------------------------------------------ */

void print_supported_versions() {
  int i;
  printf("Supported FPGA Versions: \n");
  for (i = 0; i < (int)(sizeof fpga_version); i++) {
    printf("%d\n", fpga_version[i]);
  }
}

/* check the version of the fpga is within the supported list */
bool check_fpga_version(uint8_t version) {
  int i;
  for (i = 0; i < (int)(sizeof fpga_version); i++) {
    if (fpga_version[i] == version) {
      printf("Valid FPGA version: %u\n", version);
      return true;
    }
  }
  printf("Invalid FPGA version: %u\n", version);
  return false;
}

/* Make sure no device is using the spidev bus to prevent contention*/
int bus_contention() {
  char number[1024];
  FILE *f = popen("lsof", "r");
  while (fgets(number, 1024, f) != NULL) {
    if (strstr(number, "spidev") != NULL) {
      printf("The accesory card is being used by another process: \n %sPlease "
             "close all LoRaWAN processes and try again.\n",
             number);
      pclose(f);
      return MTAC_OPEN_FILES;
    }
  }
  pclose(f);
  return MTAC_SUCCESS;
}

/* write to creset pin */
int mtac_creset_write(mts_hw *mts, char num) {
  int fd = open(mts->creset, O_WRONLY);
  if (fd < 0) {
    printf("Unable to lock file, are you root?\n");
    return MTAC_LOCK_FAILURE;
  }
  write(fd, &num, 1);
  close(fd);
  return MTAC_SUCCESS;
}

int hw_check(mts_hw *mts) {
  FILE *fp;
  fp = fopen(HW_FILE, "r");

  if (fp == NULL) {
    printf("Unable to lock file, are you root?\n");
    return MTAC_LOCK_FAILURE;
  }
  fscanf(fp, "%[^\n]", mts->dev_hw);
  fclose(fp);
  if (strstr(mts->dev_hw, "MTCAP")) {
    if (mts->path != 0) {
      printf("Path argument is not supported on this device. Exiting.\n");
      return MTAC_INVALID_HARDWARE;
    } else {
      strcpy(mts->spi_path, SPI_DEV_PATH_MTCAP);
      strcpy(mts->mtac_hw, MTAC_HW_VERSION);
      strcpy(mts->creset, CRESET);
      return MTAC_SUCCESS;
    }
  } else if (strstr(mts->dev_hw, "MTCDT3")) {
    if (mts->path == 0) {
      strcpy(mts->mtac_hw, MTCDT3_HW_VERSION_AP1);
      strcpy(mts->spi_path, SPI_DEV_PATH_MTCDT3_AP1);
      strcpy(mts->creset, MTCDT3_CRESET_AP1);
      return MTAC_SUCCESS;
    } else if (mts->path == 1) {
      strcpy(mts->mtac_hw, MTCDT3_HW_VERSION_AP1);
      strcpy(mts->spi_path, SPI_DEV_PATH_MTCDT3_AP1);
      strcpy(mts->creset, MTCDT3_CRESET_AP1);
      return MTAC_SUCCESS;
    } else if (mts->path == 2) {
      strcpy(mts->mtac_hw, MTCDT3_HW_VERSION_AP2);
      strcpy(mts->spi_path, SPI_DEV_PATH_MTCDT3_AP2);
      strcpy(mts->creset, MTCDT3_CRESET_AP2);
      return MTAC_SUCCESS;
    }
  } else if (strstr(mts->dev_hw, "MTCDT")) {
    if (mts->path == 0) {
      strcpy(mts->spi_path, SPI_DEV_PATH_MTCDT);
      strcpy(mts->mtac_hw, MTAC_HW_VERSION);
      strcpy(mts->creset, CRESET);
      return MTAC_SUCCESS;
    } else if (mts->path == 1) {
      strcpy(mts->mtac_hw, MTAC_HW_VERSION_AP1);
      strcpy(mts->spi_path, SPI_DEV_PATH_AP1);
      strcpy(mts->creset, CRESET_AP1);
      return MTAC_SUCCESS;
    } else if (mts->path == 2) {
      strcpy(mts->mtac_hw, MTAC_HW_VERSION_AP2);
      strcpy(mts->spi_path, SPI_DEV_PATH_AP2);
      strcpy(mts->creset, CRESET_AP2);
      return MTAC_SUCCESS;
    }
  } else
    printf("This software is licensed only for supported MultiTech products.\n");
  return MTAC_INVALID_HARDWARE;
}

/* check mtac hardware compatibility */
int mtac_check(mts_hw *mts) {
  int i;
  char buff[255];
  FILE *fptr;
  /* verify that the device to be flashed exists */
  if ((fptr = fopen(mts->mtac_hw, "r")) == NULL) {
    printf("Could not connect to hardware. Verify accessory port argument?\n");
    return MTAC_HW_NOT_FOUND;
  }
  fscanf(fptr, "%s", &buff);
  for (i = 0; i < (int)(sizeof valid_hw); i++) {
    if (valid_hw[i] == buff) {
      printf("Found Valid Hardware: %s\n", buff);
      strcpy(mts->mtac_hw, buff);
      fclose(fptr);
      return MTAC_SUCCESS;
    }
  }
  printf("\nInvalid Hardware: %s. Cannot Upgrade FPGA.\n", buff);
  fclose(fptr);
  return MTAC_INVALID_HARDWARE;
}

/* connect to the oncentrator to get the fpga version */
int mtac_get_version(int path) {
  uint8_t u = 0;
  int ret;
  mts_hw mts;
  mts.path = path;
  /* check MTAC Hardware Compatibility */
  printf("Checking hardware compatibility\n");
  ret = hw_check(&mts);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }

  ret = mtac_check(&mts);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }

  if (strstr(mts.mtac_hw, MTCAP)) {
    strcpy(mts.spi_path, "/dev/spidev0.0");
  }
  /* open the SPI link */
  ret = mtac_creset_write(&mts, '1');
  sleep(2);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  ret = mtac_spi_open(mts.spi_path, &mtac_spi_target);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  /* detect if the gateway has an FPGA with SPI mux header support */
  ret = mtac_spi_r(mtac_spi_target, MTAC_SPI_MUX_MODE1, MTAC_FPGA,
                   loregs[MTAC_VERSION].addr, &u);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  if (check_fpga_version(u) != true) {
    printf("INFO: no FPGA detected or version not supported (v%u)\n", u);
    return MTAC_INVALID_FPGA_VERSION;
  } else {
    mtac_spi_mux_mode = MTAC_SPI_MUX_MODE1;
    /* FPGA Soft Reset */
    mtac_spi_w(mtac_spi_target, mtac_spi_mux_mode, MTAC_FPGA, 0, 1);
    mtac_spi_w(mtac_spi_target, mtac_spi_mux_mode, MTAC_FPGA, 0, 0);
  }

  /* check SX1301 version */
  ret = mtac_spi_r(mtac_spi_target, mtac_spi_mux_mode, MTAC_SX1301,
                   loregs[MTAC_VERSION].addr, &u);
  if (ret != MTAC_SUCCESS) {
    return MTAC_SX1301_VERSION_FAILURE;
  }

  /* write 0 to the page/reset register */
  ret = mtac_spi_w(mtac_spi_target, mtac_spi_mux_mode, MTAC_SX1301,
                   loregs[MTAC_PAGE_REG].addr, 0);
  if (ret != MTAC_SUCCESS) {
    return MTAC_FPGA_REG_ERROR;
  }
  mtac_disconnect();
  return MTAC_SUCCESS;
}

/* setup and upgrade the mtac card with the file specified */
int mtac_upgrade(char *input_file, int path) {
  int ret;
  mts_hw mts;
  mts.path = path;
  /* check that no other device is using the bus */
  ret = bus_contention();
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  /* check MTAC Hardware Compatibility */
  printf("Checking hardware compatibility\n");
  ret = hw_check(&mts);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }

  ret = mtac_check(&mts);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  if (!input_file) {
    if (strstr(mts.dev_hw, "MTCDT")) {
      input_file = strdup(MTCDT_DEFAULT_FILE);
    } else if (strstr(mts.mtac_hw, MTCAP)) {
      input_file = strdup(MTCAP_DEFAULT_FILE);
    }
  }
  /* check input file checksum */
  ret = sha256_file(mts.mtac_hw, input_file);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }

  /* check SPI link status */
  if (mtac_spi_target != NULL) {
    printf("WARNING: concentrator was connected\n");
    mtac_spi_close(mtac_spi_target);
  }

  /* pull creset down to access spi flash */
  ret = mtac_creset_write(&mts, '0');
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  sleep(1);

  /* erase chip before flashing new firmware */
  ret = mtac_erase(&mts);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }

  /* program user specified firmware */
  printf("Programming flash\n");
  ret = mtac_program(&mts, input_file);
  if (ret != MTAC_SUCCESS) {
    return ret;
  } else {
    printf("Write Complete. Resetting FPGA\n");
  }
  /* pull creset up to access FPGA */
  ret = mtac_creset_write(&mts, '1');
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  sleep(5);
  printf("Reading New FPGA configuration\n");
  ret = mtac_get_version(path);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  return MTAC_SUCCESS;
}

/* erase entire flash */
int mtac_erase(mts_hw *mts) {
  int ret;
  printf("Erasing flash\n");
  /* pull device out of powerdown state */
  ret = mtac_release(mts->spi_path, mtac_spi_target);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }

  /* enable writing to flash */
  ret = write_enable(mts->spi_path, mtac_spi_target);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }

  /* send chip erase command to flash */
  ret = chip_erase(mts->spi_path, mtac_spi_target);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  /* pull device out of powerdown state */
  mtac_release(mts->spi_path, mtac_spi_target);
  if (ret != MTAC_SUCCESS) {
    return ret;
  }
  return MTAC_SUCCESS;
}

/* write to mtac card with input file */
int mtac_program(mts_hw *mts, char input_file[]) {
  FILE *f;
  struct stat st;
  size_t file_size;
  int i = 0;
  int ret = MTAC_SUCCESS;
  int index, result;
  uint32_t offset, page_address, no_pages, page_data[256];
  uint8_t adr_lower, adr_higher;

  /* get data array from file to be writen */
  f = fopen(input_file, "r");
  stat(input_file, &st);
  file_size = st.st_size;
  uint8_t *p_array;
  p_array = (uint8_t *)malloc(sizeof(uint8_t) * file_size);
  unsigned int data[file_size];
  while ((result = fscanf(f, "%x ", data + i)) == 1) {
    i++;
  }
  fclose(f);
  no_pages = ceil(i / 256.0);

  /* program one page at a time */
  for (page_address = 0x00; page_address < no_pages; page_address++) {
    /* mask page address */
    adr_higher = (page_address >> 8) & 0xff;
    adr_lower = page_address & 0xff;
    /* calculate initial data offset */
    offset = page_address * 256;
    /* enable writing to flash */
    ret = write_enable(mts->spi_path, mtac_spi_target);
    if (ret != MTAC_SUCCESS) {
      free(p_array);
      break;
    }
    /* assign data for page to be written */
    for (index = 0; index < 256; index++) {
      page_data[index] = index + offset > i ? 0xff : data[index + offset];
    }
    /* program single page*/
    ret = page_program(mts->spi_path, mtac_spi_target, adr_lower, adr_higher, page_data);
    if (ret != MTAC_SUCCESS) {
      free(p_array);
      break;
    }
    /* release device from page program powerdown */
    ret = mtac_release(mts->spi_path, mtac_spi_target);
    if (ret != MTAC_SUCCESS) {
      free(p_array);
      break;
    }
  }
  free(p_array);
  return ret;
}

/* Concentrator disconnect */
int mtac_disconnect(void) {
  if (mtac_spi_target != NULL) {
    mtac_spi_close(mtac_spi_target);
    mtac_spi_target = NULL;
    DEBUG_MSG("Note: success disconnecting the concentrator\n");
    return MTAC_SUCCESS;
  } else {
    DEBUG_MSG("WARNING: concentrator was already disconnected\n");
    return MTAC_SPI_CLOSE_FAILURE;
  }
}