#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
#include <LiquidCrystal.h>
#include <Wire.h>
#include "Arduino_FreeRTOS.h"
#include <task.h>
#include <queue.h>


LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
const byte buttonPin = 6;

float num1 = 0.0;
float num2 = 0.0;
char op = '0'; // if Operation=0 no button was pressed

char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  {'1', '2', '3', '+'},
  {'4', '5', '6', '-'},
  {'7', '8', '9', '*'},
  {'.', '0', '=', '/'}
};

byte rowPins[KEYPAD_ROWS] = {5, 4, 3, 2};
byte colPins[KEYPAD_COLS] = {A3, A2, A1, A0};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);


void updateCursor() {
  if (millis() / 250 % 2 == 0 ) {
    lcd.cursor();
  } else {
    lcd.noCursor();
  }
}

TaskHandle_t buttonTaskHandle;
void showSpalshScreenTask(void* pvParameters) {
  vTaskSuspend(buttonTaskHandle);
  lcd.print("FreeRTOS");
  lcd.setCursor(3, 1);
  String message = "Calculator";
  for (byte i = 0; i < message.length(); i++) {
    lcd.print(message[i]);
    delay(50);
  }

  vTaskDelay(pdMS_TO_TICKS(500));
  lcd.clear();
  vTaskResume(buttonTaskHandle);
  vTaskDelete(NULL);
}

void keypadTask(void* pvParameters) {
  for (;;) {
    char k = keypad.getKey();

    if (k) {
      lcd.print(k);

      if (k == '+')
        op = '+';
      else if (k == '-')
        op = '-';
      else if (k == '*')
        op = '*';
      else if (k == '/')
        op = '/';

      if (isDigit(k) && op == '0') {
        num1 = (num1 * 10.0) + (k - '0');
      } else if (isDigit(k) && op != '0') {
        num2 = (num2 * 10.0) + (k - '0');
      }

      if (k == '=') {
        lcd.setCursor(0, 1);
        switch (op) {
          case '+':
            lcd.print(num1 + num2);
            break;
          case '-':
            lcd.print(num1 - num2);
            break;
          case '*':
            lcd.print(num1 * num2);
            break;
          case '/':
            if (num2 != 0.0)
              lcd.print(num1 / num2);
            else
              lcd.print("Error");
            break;
        }

        op = '0';
        num1 = 0.0;
        num2 = 0.0;


       
      }
    }

    vTaskDelay(pdMS_TO_TICKS(100)); // Adjust the delay as needed
  }
}

void buttonCheckTask(void* pvParameters) {
  bool buttonPressed = false;
  for (;;) {
    if (!buttonPressed && digitalRead(buttonPin) == LOW) {
      lcd.clear();

      // Set flag to true indicating button press
      buttonPressed = true;

      // Wait until the button is released
      while (digitalRead(buttonPin) == LOW) {
        vTaskDelay(pdMS_TO_TICKS(50)); // Adjust delay time as needed
      }

      // Set flag back to false when button is released
      buttonPressed = false;
    }
    vTaskDelay(pdMS_TO_TICKS(50)); // Adjust delay time as needed
  }
}


void setup() {
  lcd.begin(16, 2);
  lcd.clear();
  lcd.cursor();
  lcd.setCursor(1, 0);

 xTaskCreate(showSpalshScreenTask, "SplashScreenTask", 128, NULL, 1, NULL);

  xTaskCreate(keypadTask, "KeypadTask", 128, NULL, 1, NULL);

  xTaskCreate(buttonCheckTask, "ButtonCheckTask", 128, NULL, 1, &buttonTaskHandle);

  vTaskStartScheduler(); // Start the FreeRTOS scheduler
}

void loop() {
  // Empty
}