/*
 * File Name:       pthread_dht11.c
 * Workflow:        periodically rw from coordinator, get TH data, push
 * 					it to shared memory
 * Return Value:    NULL always
 */

/* Header files */
#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/types.h>

#include "debug.h"
#include "proto.h"

/* external variables */
extern pthread_mutex_t mutex_zigbee_coordinator;
extern volatile sig_atomic_t should_exit;

/* thread start routine function*/
void *pthread_dht11(void *args) {
  ARG_STRUCT *p_resource_struct = malloc(sizeof(ARG_STRUCT));
  SHM_STRUCT *p_shm_struct = malloc(sizeof(SHM_STRUCT));
  char tmp[7];
  ssize_t rwRetCount;

  // get resources from main
  p_resource_struct = args;
  DebugLog("[DEBUG-INFO %s:%d]: Get read/write fd: %d.\n", __FUNCTION__,
           __LINE__, p_resource_struct->rw_fd);
  DebugLog("[DEBUG-INFO %s:%d]: Get shared memory ID: %d.\n", __FUNCTION__,
           __LINE__, p_resource_struct->shm_id);

  // attach shared memory to local
  p_shm_struct = shmat(p_resource_struct->shm_id, NULL, 0);

  // prepare buffer to get TH data
  memset(tmp, '\0', 7);

  // modify shared memory
  while (!should_exit) {
    pthread_mutex_lock(&mutex_zigbee_coordinator);
    rwRetCount = write(p_resource_struct->rw_fd, "TH", sizeof("TH"));
    // write failure retry
    if (rwRetCount == -1) {
      pthread_mutex_unlock(&mutex_zigbee_coordinator);
      continue;
    }
    DebugLog("[DEBUG-INFO %s:%d]: write(\"TH\") to coordinator, %zd Byte(s) "
             "written.\n",
             __FUNCTION__, __LINE__, rwRetCount);

    // zigbee end-device reaction time wait
    sleep(3);

    rwRetCount = read(p_resource_struct->rw_fd, tmp, 7);
    DebugLog("[DEBUG-INFO %s:%d]: read() from coordinator, %zd Byte(s) read.\n",
             __FUNCTION__, __LINE__, rwRetCount);

    if (rwRetCount == -1) {
      p_shm_struct->tempNow = 0;
      DebugLog("[DEBUG-INFO %s:%d]: Nothing read, set temperature to 0.\n",
               __FUNCTION__, __LINE__);

      p_shm_struct->humiNow = 0;
      DebugLog("[DEBUG-INFO %s:%d]: Nothing read, set humidity to 0.\n",
               __FUNCTION__, __LINE__);
    } else {
      p_shm_struct->tempNow =
          ((int)(tmp[0] - '0')) * 10 + ((int)(tmp[1] - '0')) * 1;
      DebugLog("[DEBUG-INFO %s:%d]: Current temperature: %d.\n", __FUNCTION__,
               __LINE__, p_shm_struct->tempNow);

      p_shm_struct->humiNow =
          ((int)(tmp[4] - '0')) * 10 + ((int)(tmp[5] - '0')) * 1;
      DebugLog("[DEBUG-INFO %s:%d]: Current humidity: %d.\n", __FUNCTION__,
               __LINE__, p_shm_struct->humiNow);
    }

    pthread_mutex_unlock(&mutex_zigbee_coordinator);
  }

  pthread_exit(NULL);
}