#include <util/delay.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <stdbool.h>
#include <Arduino_FreeRTOS.h>
#include <task.h>
#include <semphr.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

const uint8_t LED_R_PIN = PB5;  // Red LED pin for manual mode
const uint8_t LED_G_PIN = PB4;  // Green LED pin for automatic mode
const uint8_t BUTTON_PIN = PD2; // Button pin for toggling modes
const uint8_t PIR_PIN = PD0;    // PIR motion sensor pin for motion detection
const uint8_t SWITCH_PIN = PD6; // Switch pin for manual mode control

const uint8_t LCD_ADDR = 0x27;  // I2C address of the LCD
const uint8_t LCD_COLS = 16;    // Number of LCD columns
const uint8_t LCD_ROWS = 2;     // Number of LCD rows

volatile bool manualMode = true; 
SemaphoreHandle_t xMutexLCD;     
QueueHandle_t xButtonQueue;      

LiquidCrystal_I2C lcd(LCD_ADDR, LCD_COLS, LCD_ROWS);

ISR(INT0_vect) {
    // Minimal ISR; processing is handled in tasks
}

void setup() {
    
    DDRB |= (1 << LED_R_PIN) | (1 << LED_G_PIN); 
    PORTB &= ~((1 << LED_R_PIN) | (1 << LED_G_PIN));
    DDRD &= ~((1 << BUTTON_PIN) | (1 << PIR_PIN) | (1 << SWITCH_PIN));
    PORTD |= (1 << BUTTON_PIN) | (1 << PIR_PIN) | (1 << SWITCH_PIN);  

    
    EICRA |= (1 << ISC01); 
    EIMSK |= (1 << INT0);  
    sei();                 


    lcd.begin(LCD_COLS, LCD_ROWS);
    lcd.backlight(); 
    lcd.setCursor(0, 0); 
    lcd.print("Manual Mode");

    
    xMutexLCD = xSemaphoreCreateMutex();
    if (xMutexLCD == NULL) {
       while (1); 
    }

    // Create Queue for Button Events
    xButtonQueue = xQueueCreate(5, sizeof(bool));
    if (xButtonQueue == NULL) {
        while (1); 
    }

    
    xTaskCreate(vModeManagerTask, "Mode Manager", 128, NULL, 2, NULL);
    xTaskCreate(vLEDControlTask, "LED Control", 128, NULL, 1, NULL);
    xTaskCreate(vButtonHandlerTask, "Button Handler", 128, NULL, 3, NULL);

}

void loop() {//The Arduino loop is unused as FreeRTOS manages task scheduling.
}

void vModeManagerTask(void *pvParameters) {
    bool buttonEvent;
    while (1) {
        if (xQueueReceive(xButtonQueue, &buttonEvent, portMAX_DELAY) == pdTRUE) {
            manualMode = !manualMode; // Toggle mode
            if (xSemaphoreTake(xMutexLCD, portMAX_DELAY)) {
                lcd.clear();
                lcd.setCursor(0, 0);
                lcd.print(manualMode ? "Manual Mode" : "Automatic Mode");
                xSemaphoreGive(xMutexLCD);
            }
        }
    }
}

void vLEDControlTask(void *pvParameters) {
    TickType_t xLastWakeTime = xTaskGetTickCount();
    while (1) {
        if (manualMode) {
            PORTB |= (1 << LED_R_PIN);
            if (PIND & (1 << SWITCH_PIN)) {
                PORTB |= (1 << LED_G_PIN);
            } else {
                PORTB &= ~(1 << LED_G_PIN);
            }
        } else {
            PORTB &= ~(1 << LED_R_PIN);
            if (PIND & (1 << PIR_PIN)) {
                PORTB |= (1 << LED_G_PIN);
            } else {
                PORTB &= ~(1 << LED_G_PIN);
            }
        }
        vTaskDelayUntil(&xLastWakeTime, 50 / portTICK_PERIOD_MS);
    }
}


void vButtonHandlerTask(void *pvParameters) {
    bool buttonEvent = true;
    while (1) {
        if (!(PIND & (1 << BUTTON_PIN))) {
            _delay_ms(20);
            if (!(PIND & (1 << BUTTON_PIN))) {
                xQueueSend(xButtonQueue, &buttonEvent, portMAX_DELAY);
                while (!(PIND & (1 << BUTTON_PIN)));
            }
        }
        vTaskDelay(20 / portTICK_PERIOD_MS);
    }
}