#define ArrLen(x)         (sizeof(x)/sizeof(x[0]))

char buf_input[64];
bool led_state, header_mode, stdin_mode;
char header[32];
String buf;

const char* ll = "1713636000";
String s = "1713636000";

void setup() {
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);

  Serial.println();
  unsigned long x = strtol(ll, 0, 10);
  Serial.print("long: "); Serial.println(x);
  stdin_mode = false;
}

typedef enum : uint8_t {
  HEAD_TYPE,
  HEAD_ACTION,
  HEAD_PARAMS,
  HEAD_DATA,
  HEAD_ENUM_N
} header_enum;

struct header_t {
  header_enum  id;
  const char*  label;
  char         data[16];
  void reset() { memset(data, '\0',16); }
}
header_data[HEAD_ENUM_N] = {
  {HEAD_TYPE,  "Type",   {'\0'}},
  {HEAD_ACTION,"Action", {'\0'}},
  {HEAD_PARAMS,"Params", {'\0'}},
  {HEAD_DATA,  "Data",   {'\0'}},
};

// -------------------------------------

void checkHeader(char* str) {
  uint8_t index = 0;

  if (str) {
    for (int i=0; i<HEAD_ENUM_N; i++) 
      header_data[i].reset();
    
    if (strchr(str, ' ')) {
      char *token = strtok(str, " ");
      do {
        strncpy( header_data[index].data, token, 16 );
        token = strtok(nullptr, " ");
      } while (token && (++index < HEAD_ENUM_N));
    }
  }
}

void loop() {
  if (Serial.available()) {
    if (Serial.find("#HEAD ")) {
      memset(header, '\0', sizeof(header)-1);
      
      int n = Serial.readBytesUntil('\n', header, sizeof(header)-1); header[n] = '\0';

      if (n > 0) 
        checkHeader(header);
    }
  }
  else if (stdin_mode)
    if (!(millis()%1000))
      digitalWrite(LED_BUILTIN, led_state=!led_state);
}