#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include <WiFi.h>


/* ESP32 S3 WROOM, and SSD1306 I2C OLED Display */
/**************************************************************************
 Domain: IoT, RTOS, Embedded
 Author : Ravi K
 sta_code: AB1202

 Description: This is a brief demo of using Wokwi to simulate ESP32 S3 driving I2C based OLED, 
              using mixed style of FreeRTOS + basic Arduino Framework type of OLED access
 
 Issues: No issues
 **************************************************************************/

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 myOled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

String oledline[9]; //One line of text per OLED row. For textsize of 1 there are 8 OLED rows/lines

char sta_code[11] = "AB1201";
char boardWifiMAC[31];
char tmpBuffer[64];

  TickType_t currMillis, prevMillis;
int cnt = 0;

static TaskHandle_t count_display_task_handle = NULL;


void displayTextOLED(String oledline[]) {
  int jj;
  myOled.clearDisplay();
  myOled.setTextSize(1);
  myOled.setTextColor(SSD1306_WHITE);
  myOled.setCursor(0, 0);

  for (jj=1; jj<=8; jj++) { 
    myOled.println(oledline[jj]);
    }
  
  myOled.display();  
}


void getMacWifiShield(char *macWifiShield) 
{
    byte mac[6];

    WiFi.macAddress(mac);
    sprintf(macWifiShield, "%02X%02X%02X%02X%02X%02X", mac[5], mac[4], mac[3], mac[2], mac[1], mac[0]);
};




/* Just counts each time and displays incremented counter on the OLED */
void do_count_display_task(void *pvParameters){

while(1)
{
  currMillis = xTaskGetTickCount(); // Get current tick count
if (currMillis - prevMillis > pdMS_TO_TICKS(2000)) {
  
    cnt++;
 oledline[3] = String("OLED display cnt: ") + cnt;

    displayTextOLED(oledline);

    prevMillis = currMillis;
 
 }//millis diff > 1000

 // Small delay to avoid excessive CPU usage
 vTaskDelay(pdMS_TO_TICKS(50)); 

} //while(1)

} //do_count_display_task();

/* Init function: 
      Initialize Serial Port,
      initialize OLED,
      Get Wifi interface MAC on the ESP32,
      and
      Spawn the display counter task 
*/

void init_system() {
  pinMode(RGB_BUILTIN, OUTPUT);
  Serial.begin(921600);

  Wire.begin(18, 17); //SDA, SCK
  // Make sure to use the correct I2C address. Address 0x3C for 128x64
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!myOled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println("SSD1306 allocation failed");
    for(;;); // Don't proceed, loop forever
  }

  getMacWifiShield(boardWifiMAC);
  oledline[1] = String("Station ID:") + sta_code;
  oledline[2] = String(boardWifiMAC);
  int jj; for (jj=2; jj<=8; jj++){ oledline[jj]=""; }

  displayTextOLED(oledline);

 printf("init_system() is done !\n");

  vTaskDelay(pdMS_TO_TICKS(3 * 1000));

  xTaskCreate(do_count_display_task, "Count display Task", 4096, NULL, 2, 	&count_display_task_handle);


}

void app_main()
{
   init_system();

}


/* ********* Wokwi, dont cry \!******* */

void setup()
{
  // Nothing to do here
  //I just call the ESP IDF's app_main()
   app_main();
}

void loop() {
  // Nothing to do here
}