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

#include "utils.h"

char *listStrDataNames[] = {"path_to_serial_port", "path_to_gpio_chip",
                            "network_username", "network_password",
                            "network_auth"};
char *listIntDataNames[] = {"pin_pwr_key", "pin_status"};

int checkPinVal(char *pathToChip, int pinNum) {
  int pinVal = -1;
  struct gpiod_chip *chip;
  struct gpiod_line *line;

  chip = gpiod_chip_open(pathToChip);
  if (!chip) {
    perror("Error opening GPIO chip");
    return -1;
  }

  line = gpiod_chip_get_line(chip, pinNum);
  if (!line) {
    perror("Error getting GPIO line");
    gpiod_chip_close(chip);
    return -1;
  }

  if (gpiod_line_request_input(line, "pin status") < 0) {
    perror("Error setting GPIO line as input");
    gpiod_chip_close(chip);
    return -1;
  }

  pinVal = gpiod_line_get_value(line);
  if (pinVal < 0) {
    perror("Error getting GPIO line value");
    gpiod_chip_close(chip);
    return -1;
  }

  gpiod_chip_close(chip);
  return pinVal;
}

int readCfg(listCfgData cfgData, const char *pathExe) {
  char strBuffer[BUFSIZ];
  char *pathCfg, *pathDirEnd, *tmpPtr = NULL;
  const char *filenameCfg = "network_monitor.cfg";
  int sizePathDir, idx, idx2;
  unsigned long numCharRead;
  FILE *fileCfg;

  /* Form config filepath string. */
  pathDirEnd = strrchr(pathExe, '/');
  sizePathDir = pathDirEnd - pathExe;
  if (pathDirEnd == NULL) {
    printf("Cannot obtain the executable directory.\n");
    return 1;
  }
  pathCfg = malloc(sizeof(char) * (sizePathDir + strlen(filenameCfg) + 2));
  strncpy(pathCfg, pathExe, sizePathDir + 1);
  strcat(pathCfg, filenameCfg);

  /* Open the config file. */
  fileCfg = fopen(pathCfg, "r");
  if (fileCfg == NULL) {
    printf("Cannot open config file \"%s\".\n", pathCfg);
    free(pathCfg);
    return 1;
  }

  /* Check that it is not empty. */
  if (fgets(strBuffer, BUFSIZ, fileCfg) == NULL) {
    printf("Config file is empty.\n");
    fclose(fileCfg);
    free(pathCfg);
    return 1;
  }

  /* Allocate memory for the config data list. */
  cfgData.strDataList = malloc(STR_LIST_LENGTH * sizeof(strData));
  cfgData.intDataList = malloc(INT_LIST_LENGTH * sizeof(intData));

  /* Read the file and populate the config string data. */
  for (idx = 0; idx < STR_LIST_LENGTH; idx++) {
    cfgData.strDataList[idx].name =
        malloc(sizeof(char) * (strlen(listStrDataNames[idx]) + 1));
    strcpy(cfgData.strDataList[idx].name, listStrDataNames[idx]);
    cfgData.strDataList[idx].value = NULL;

    rewind(fileCfg);
    do {
      fgets(strBuffer, BUFSIZ, fileCfg);
      tmpPtr = strtok(strBuffer, " =\n\t\r");
      if (tmpPtr == NULL)
        continue;
      if (strcmp(cfgData.strDataList[idx].name, tmpPtr) != 0)
        continue;

      tmpPtr = strtok(NULL, " =\n\t\r");
      if (tmpPtr == NULL || *tmpPtr != '\"')
        continue;

      tmpPtr = strtok(tmpPtr, "\"");
      if (tmpPtr == NULL)
        continue;

      cfgData.strDataList[idx].value =
          malloc(sizeof(char) * (strlen(tmpPtr) + 1));
      strcpy(cfgData.strDataList[idx].value, tmpPtr);
      break;
    } while (feof(fileCfg) == 0);
    if (cfgData.strDataList[idx].value == NULL && idx < NETWORK_USERNAME_POS) {
      printf("Could not find the \"%s\" variable.\n",
             cfgData.strDataList[idx].name);
      for (idx2 = 0; idx2 <= idx; idx2++) {
        free(cfgData.strDataList[idx2].name);
        free(cfgData.strDataList[idx2].value);
      }
      fclose(fileCfg);
      free(pathCfg);
      return 1;
    }
  }

  /* Populate the config integer data names. */
  for (idx = 0; idx < INT_LIST_LENGTH; idx++) {
    cfgData.intDataList[idx].name =
        malloc(sizeof(char) * (strlen(listIntDataNames[idx]) + 1));
    strcpy(cfgData.intDataList[idx].name, listIntDataNames[idx]);
    cfgData.intDataList[idx].value = -1;

    rewind(fileCfg);
    do {
      fgets(strBuffer, BUFSIZ, fileCfg);
      tmpPtr = strtok(strBuffer, " =\n\t\r");
      if (tmpPtr == NULL)
        continue;
      if (strcmp(cfgData.intDataList[idx].name, tmpPtr) != 0)
        continue;

      tmpPtr = strtok(NULL, " =\n\t\r");
      if (tmpPtr == NULL || *tmpPtr != '\"')
        continue;

      tmpPtr = strtok(tmpPtr, "\"");
      if (tmpPtr == NULL)
        continue;

      sscanf(tmpPtr, "%d%ln", &cfgData.intDataList[idx].value, &numCharRead);
      if ((numCharRead != strlen(tmpPtr)) ||
          (strtok(NULL, " =\n\t\r\"") != NULL)) {
        printf("Format error for \"%s\".\n", cfgData.intDataList[idx].name);
        for (idx2 = 0; idx2 <= idx; idx2++) {
          free(cfgData.intDataList[idx2].name);
        }
        fclose(fileCfg);
        free(pathCfg);
        return 1;
      }
      break;
    } while (feof(fileCfg) == 0);
    if (cfgData.intDataList[idx].value == -1) {
      printf("Error parsing the config file.\nCould not find the "
             "\"%s\" variable.\n",
             cfgData.intDataList[idx].name);
      for (idx2 = 0; idx2 <= idx; idx2++) {
        free(cfgData.intDataList[idx2].name);
      }
      fclose(fileCfg);
      free(pathCfg);
      return 1;
    }
  }

  free(pathCfg);
  fclose(fileCfg);
  return 0;
}

/* Do not call this before initializing dataCfg with readCfg(). */
int freeCfgData(listCfgData cfgData) {
  int idx;
  for (idx = 0; idx < STR_LIST_LENGTH; idx++) {
    free(cfgData.strDataList[idx].name);
    free(cfgData.strDataList[idx].value);
  }
  free(cfgData.strDataList);

  for (idx = 0; idx < INT_LIST_LENGTH; idx++) {
    free(cfgData.intDataList[idx].name);
    cfgData.intDataList[idx].value = -1;
  }
  free(cfgData.intDataList);
  return 0;
}