// my solution to lesson 4

// Learned so far
// - writing task
// - task scheduling
// - memory managament

// Challenge

// Write 2 tasks.

// task 1 : get input from serial monitor 
//          after getting a enter , put it into heap memory 
//          signal to task2 that there is something on the heap 

// task2 :  read input from the heap if the task 1 signal that there is a message
//          display it on the serial monitor 
//          free the memory

#if CONFIG_FREERTOS_UNICORE
static const BaseType_t app_cpu = 0 ;
#else
static const BaseType_t app_cpu = 1;
#endif

// Pins
static const int led_pin = 2;
bool volatile messageFlag = false; 
char * message_ptr; 


// Our task is to read in a message 
void readMessageFromMonitor(void * parameter) {
  char ch;
  char buff[40];
  int idx = 0;
  
  memset(buff, 0, 20);
  while (1) {
    if (Serial.available() > 0) {
      ch = Serial.read();
       

      if (ch == '\n') {
      
        if(idx != 0 )
        {  // clear buffer
        
          buff[idx] = '\0'; 
          idx++;   
          // make room on the heap for the message  
          message_ptr = (char *) pvPortMalloc(idx * sizeof(char));
          // Place the message on the heap  
          memcpy(message_ptr, buff, idx); 
          // set the flag 
          messageFlag = true;
          idx = 0 ; 
          memset(buff, 0, 20); 
        }
        else
        {
          /* Ignore the empty buffer.  */
        }
      } else {
        if (idx < 39) {
           
          buff[idx] = ch;

                 
          idx++;
        }
      }
    }
  }
}

void displayMessage(void * parameter) { 
  while(1) {
  if (messageFlag) {
    Serial.print("Task2 reads :");
    Serial.println(message_ptr);
    vPortFree(message_ptr); 
    messageFlag = false ;  
  }}
}


void setup() {
  pinMode(led_pin, OUTPUT);
  Serial.begin(9600);
  Serial.println("RW");

  // Task to run forever
  xTaskCreatePinnedToCore(
    readMessageFromMonitor,    // Function to be called
    "Read Message",  // name of the function
    1024,         // stack size
    NULL,         // parameter to pass to the function
    1,            // priority
    NULL,         // task handle
    app_cpu
  );

  xTaskCreatePinnedToCore(
    displayMessage,    // Function to be called
    "Display Message",  // name of the function
    1024,         // stack size
    NULL,         // parameter to pass to the function
    1,            // priority
    NULL,         // task handle
    app_cpu
  );
  vTaskDelete(NULL);
}

void loop() {
  
}