#include <Arduino.h>
#include <LiquidCrystal.h>
#include <Arduino_FreeRTOS.h>
#include <semphr.h>

// LCD pins (adapt to your wiring)
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

// LEDs
#define LED1 2
#define LED2 3

// Buttons
#define BTN_TOGGLE 4
#define BTN_INC    5
#define BTN_DEC    6

// ---------------- Global Variables ----------------
// Global variable used for LED1 state, updated by 
// ButtonLedTask and read by ReportTask.
volatile bool led1State = false;

// Global variable used to store blinking delay time 
// in milliseconds, modified by ControlTask.
volatile int blinkDelay = 500;

// Global variable used as a signal when a button 
// event occurs, consumed by ReportTask.
volatile bool buttonEvent = false;

// Global semaphore used for provider/consumer 
// synchronization between tasks.
SemaphoreHandle_t xSemaphore;

// ---------------- TASK 1 ----------------
// Toggle LED1 state when button is pressed.
void ButtonLedTask(void *pvParameters) {
	(void) pvParameters;

	for (;;) {
		if (digitalRead(BTN_TOGGLE) == LOW) {
			led1State = !led1State;
			digitalWrite(LED1, led1State);

			buttonEvent = true;
			xSemaphoreGive(xSemaphore);

			vTaskDelay(pdMS_TO_TICKS(300)); // debounce
		}
		vTaskDelay(pdMS_TO_TICKS(50));
	}
}

// ---------------- TASK 2 ----------------
// Blink LED2 only when LED1 is turned off.
void LedBlinkTask(void *pvParameters) {
	(void) pvParameters;

	for (;;) {
		if (!led1State) {
			digitalWrite(LED2, HIGH);
			vTaskDelay(pdMS_TO_TICKS(blinkDelay));
			digitalWrite(LED2, LOW);
			vTaskDelay(pdMS_TO_TICKS(blinkDelay));
		} else {
			digitalWrite(LED2, LOW);
			vTaskDelay(pdMS_TO_TICKS(200));
		}
	}
}

// ---------------- TASK 3 ----------------
// Increase or decrease blinking delay with buttons.
void ControlTask(void *pvParameters) {
	(void) pvParameters;

	for (;;) {
		if (digitalRead(BTN_INC) == LOW) {
			blinkDelay += 100;
			if (blinkDelay > 2000) {
				blinkDelay = 2000;
			}
			buttonEvent = true;
			xSemaphoreGive(xSemaphore);

			vTaskDelay(pdMS_TO_TICKS(300));
		}
		if (digitalRead(BTN_DEC) == LOW) {
			blinkDelay -= 100;
			if (blinkDelay < 100) {
				blinkDelay = 100;
			}
			buttonEvent = true;
			xSemaphoreGive(xSemaphore);

			vTaskDelay(pdMS_TO_TICKS(300));
		}
		vTaskDelay(pdMS_TO_TICKS(50));
	}
}

// ---------------- TASK 4 ----------------
// Report current system state to LCD and Serial.
void ReportTask(void *pvParameters) {
	(void) pvParameters;

	for (;;) {
		if (xSemaphoreTake(xSemaphore, portMAX_DELAY) 
		    == pdTRUE) {
			lcd.clear();
			lcd.setCursor(0, 0);
			lcd.print("LED1: ");
			lcd.print(led1State ? "ON " : "OFF");

			lcd.setCursor(0, 1);
			lcd.print("BlinkDelay:");
			lcd.print(blinkDelay);

			if (buttonEvent) {
				Serial.println("Button pressed -> event logged!");
				buttonEvent = false;
			}
		}
		vTaskDelay(pdMS_TO_TICKS(200));
	}
}

// ---------------- SETUP ----------------
void setup(void) {
	pinMode(LED1, OUTPUT);
	pinMode(LED2, OUTPUT);

	pinMode(BTN_TOGGLE, INPUT_PULLUP);
	pinMode(BTN_INC, INPUT_PULLUP);
	pinMode(BTN_DEC, INPUT_PULLUP);

	Serial.begin(9600);
	lcd.begin(16, 2);

	xSemaphore = xSemaphoreCreateBinary();

	xTaskCreate(ButtonLedTask, "BtnLED", 128, NULL, 1, NULL);
	xTaskCreate(LedBlinkTask, "LedBlink", 128, NULL, 1, NULL);
	xTaskCreate(ControlTask, "Control", 128, NULL, 1, NULL);
	xTaskCreate(ReportTask, "Report", 256, NULL, 1, NULL);

	vTaskStartScheduler();
}

// ---------------- LOOP ----------------
void loop(void) {
	// Not used in FreeRTOS applications.
}