#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"

#define HEARTBEAT_LED_PIN GPIO_NUM_4 // use GPIO4 for the LED

// blink task function
void heartbeat_task(void *pvParameters){
  int heartbeatState = 0; //start with LED off
  TickType_t lastTime = 0; 

  while(1){
    TickType_t now = xTaskGetTickCount();
    //prints the period of the function 
    printf("LED toggled at %lu ms (Δ = %lu ms)\n",
           (unsigned long)(now * portTICK_PERIOD_MS),
           (unsigned long)((now - lastTime) * portTICK_PERIOD_MS));
    lastTime = now;

    gpio_set_level(HEARTBEAT_LED_PIN, heartbeatState);
    heartbeatState = !heartbeatState; // toggle on/off

    //delays for 250 ms
    vTaskDelay(pdMS_TO_TICKS(250));
    vTaskDelay(pdMS_TO_TICKS(50));  // experimentation section
  }
  vTaskDelete(NULL);
}

//prints a message every 10s
void vitals_task(void * pvParameters){
   TickType_t lastTime = 0;
  while(1){
    TickType_t now = xTaskGetTickCount();
    //generate psuedo heart rate of 60-100 bpm
    int heartRate = (rand() % 41 + 60);

      //prints the period of the function 
    printf("Vitals printed at %lu ms (Δ = %lu ms) | Heart Rate: %d bpm\n",
           (unsigned long)(now * portTICK_PERIOD_MS),
           (unsigned long)((now - lastTime) * portTICK_PERIOD_MS),
           heartRate);

    lastTime = now;

    printf("Patient's heart is beating, Time = %lu ms | Heart Rate: %d bpm \n", (unsigned long)(xTaskGetTickCount()*portTICK_PERIOD_MS), heartRate); 
    vTaskDelay(pdMS_TO_TICKS(15000));
  }
  vTaskDelete(NULL);
}

void app_main() {
  //LED GPIO pin set up
  gpio_reset_pin(HEARTBEAT_LED_PIN);
  gpio_set_direction(HEARTBEAT_LED_PIN, GPIO_MODE_OUTPUT); 

  xTaskCreate(heartbeat_task, "HeartbeatTask", 2048, NULL, 1, NULL);
  xTaskCreate(vitals_task, "VitalsTask", 2048, NULL, 2, NULL);
  }