#include <Arduino.h>
#include <SoftwareSerial.h>
#include <inttypes.h>

#define PD0  5
#define PD1  4
char c=' ';


static char recv_buf[512];
static bool is_exist = false;
static bool is_join = false;
static int led = 0;

class mySerial : public SoftwareSerial {

  public:
    mySerial(uint8_t receivePin, uint8_t transmitPin,
             bool inverse_logic = false) :
      SoftwareSerial(receivePin, transmitPin, inverse_logic) {}

    virtual size_t write(uint8_t byte) {
      return SoftwareSerial::write(byte);
    }

    int printf(char* fmt, ...) {
      char buff[256];
      va_list args;
      va_start(args, fmt);
      int return_status = vsnprintf(buff, sizeof(buff), fmt, args);
      va_end(args);
      uint8_t *s = (uint8_t *)&buff;
      while (*s) write(*s++);
      return return_status;
    }
};

mySerial SerialE5(PD0, PD1);

static int at_send_check_response(char *p_ack, int timeout_ms, char *p_cmd, ...)
{
  int ch;
  int num = 0;
  int index = 0;
  int startMillis = 0;
  va_list args;
  memset(recv_buf, 0, sizeof(recv_buf));
  va_start(args, p_cmd);
  SerialE5.printf(p_cmd, args);
  Serial.printf(p_cmd, args);
  va_end(args);
  delay(200);
  startMillis = millis();

  if (p_ack == NULL)
  {
    return 0;
  }

  do
  {
    while (SerialE5.available() > 0)
    {
      ch = SerialE5.read();
      recv_buf[index++] = ch;
      Serial.print((char)ch);
      delay(2);
    }

    if (strstr(recv_buf, p_ack) != NULL)
    {
      return 1;
    }

  } while (millis() - startMillis < timeout_ms);
  return 0;
}

static void recv_prase(char *p_msg)
{
  if (p_msg == NULL)
  {
    return;
  }
  char *p_start = NULL;
  int data = 0;
  int rssi = 0;
  int snr = 0;

  p_start = strstr(p_msg, "RX");
  if (p_start && (1 == sscanf(p_start, "RX: \"%d\"\r\n", &data)))
  {
    Serial.println(data);

  }

  p_start = strstr(p_msg, "RSSI");
  if (p_start && (1 == sscanf(p_start, "RSSI %d,", &rssi)))
  {

    Serial.print("rssi:");
    Serial.println(rssi);
  }
  p_start = strstr(p_msg, "SNR");
  if (p_start && (1 == sscanf(p_start, "SNR %d", &snr)))
  {

    Serial.print("snr :");
    Serial.println(snr);
  }
}

void setup(void)
{

  Serial.begin(9600);
  SerialE5.begin(9600);
  Serial.print("E5 LORAWAN TEST\r\n");

  if (at_send_check_response("+AT: OK", 100, "AT\r\n"))
  {
    is_exist = true;
        at_send_check_response("+ID: AppEui", 1000, "AT+ID\r\n");
        at_send_check_response("+MODE: LWOTAA", 1000, "AT+MODE=LWOTAA\r\n");
        at_send_check_response("+DR: EU868", 1000, "AT+DR=EU868\r\n");
        at_send_check_response("+CH: NUM", 1000, "AT+CH=NUM,0-2\r\n");
        at_send_check_response("+KEY: APPKEY", 1000, "AT+KEY=APPKEY,\"2B7E151628AED2A6ABF7158809CF4F3C\"\r\n");
        at_send_check_response("+CLASS: C", 1000, "AT+CLASS=A\r\n");
        at_send_check_response("+PORT: 8", 1000, "AT+PORT=8\r\n");
    delay(200);

    is_join = true;
  }
  else
  {
    is_exist = false;
    Serial.print("No E5 module found.\r\n");

  }
}
void loop(void)
{
  if (is_exist)
  {
    int ret = 0;
    if (is_join)
    {

      ret = at_send_check_response("+JOIN: Network joined", 12000, "AT+JOIN\r\n");
      if (ret)
      {
        is_join = false;
      }
      else
      {
        at_send_check_response("+ID: AppEui", 1000, "AT+ID\r\n");
        Serial.print("JOIN failed!\r\n\r\n");
        delay(5000);
      }
    }
    else
    //Ex: Copy and Paste --> AT+MSGHEX="68 65 6c 6c 6f 20 77 6f 72 6c 64" <--  to serial monitor
    {
      if (SerialE5.available())
      {
        c = SerialE5.read();
        Serial.write(c);
      }
      if (Serial.available())
      {
        c = Serial.read();
        SerialE5.write(c);
      }
    }
  }
  else
  {
    delay(1000);
  }
}