#include <Wire.h>
#include <LiquidCrystal_I2C.h>

#define LDR_PIN A0
#define LED_HIJAU 8
#define LED_KUNING 9
#define LED_MERAH 10
#define BUTTON_PIN 7

LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows

int bufferValue = 0; // Buffer untuk menyimpan nilai LDR
bool decreaseLight = false;
int lastLdrValue = 0; // Variabel untuk menyimpan nilai LDR sebelumnya

void setup() {
    pinMode(LDR_PIN, INPUT);
    pinMode(LED_HIJAU, OUTPUT);
    pinMode(LED_KUNING, OUTPUT);
    pinMode(LED_MERAH, OUTPUT);
    pinMode(BUTTON_PIN, INPUT_PULLUP);
    
    lcd.init();
    lcd.backlight();
    
    Serial.begin(9600);
}

void loop() {
    int ldrValue = analogRead(LDR_PIN);
    int adjustedLdrValue = 1023 - ldrValue; // Membalikkan nilai LDR

    if (!decreaseLight) {
        if (abs(adjustedLdrValue - lastLdrValue) > 50) { // Periksa perubahan signifikan
            bufferValue = adjustedLdrValue; // Update buffer dengan nilai LDR yang baru dibaca
            lastLdrValue = adjustedLdrValue;
        }
    }

    Serial.println(bufferValue);

    // Threshold values for the LED indicators
    int thresholdGreen = 300;
    int thresholdYellow = 600;

    if (bufferValue < thresholdGreen) {
        digitalWrite(LED_HIJAU, HIGH);
        digitalWrite(LED_KUNING, LOW);
        digitalWrite(LED_MERAH, LOW);
        lcd.clear();
        lcd.print(bufferValue);
        lcd.print(":Cahaya Aman!");
    } else if (bufferValue < thresholdYellow) {
        digitalWrite(LED_HIJAU, LOW);
        digitalWrite(LED_KUNING, HIGH);
        digitalWrite(LED_MERAH, LOW);
        lcd.clear();
        lcd.print(bufferValue);
        lcd.print(":Cahaya Siaga!");
    } else {
        digitalWrite(LED_HIJAU, LOW);
        digitalWrite(LED_KUNING, LOW);
        digitalWrite(LED_MERAH, HIGH);
        lcd.clear();
        lcd.print(bufferValue);
        lcd.print(":Tidak Aman!");
        lcd.setCursor(0, 1);
        lcd.print("Kurangi Cahaya!");

        if (digitalRead(BUTTON_PIN) == LOW) { // Button pressed
            lcd.clear();
            lcd.print("Proses Pengurangan!");
            decreaseLight = true;
        }
    }

    if (decreaseLight) {
        bufferValue -= 100;
        if (bufferValue < 0) bufferValue = 0; // Ensure value does not go negative

        // Update LED status and LCD display
        if (bufferValue < thresholdGreen) {
            digitalWrite(LED_HIJAU, HIGH);
            digitalWrite(LED_KUNING, LOW);
            digitalWrite(LED_MERAH, LOW);
            lcd.clear();
            lcd.print(bufferValue);
            lcd.print(":Cahaya Aman!");
            decreaseLight = false;
        } else if (bufferValue < thresholdYellow) {
            digitalWrite(LED_HIJAU, LOW);
            digitalWrite(LED_KUNING, HIGH);
            digitalWrite(LED_MERAH, LOW);
            lcd.clear();
            lcd.print(bufferValue);
            lcd.print(":Cahaya Siaga!");
        } else {
            digitalWrite(LED_HIJAU, LOW);
            digitalWrite(LED_KUNING, LOW);
            digitalWrite(LED_MERAH, HIGH);
            lcd.clear();
            lcd.print(bufferValue);
            lcd.print(":Tidak Aman!");
            lcd.setCursor(0, 1);
            lcd.print("Proses Pengurangan!");
        }

        delay(1000); // Simulate delay in light reduction
    }

    delay(1000); // Delay 1 second
}