#include <Wire.h>
#include "RTClib.h"

RTC_DS1307 rtc;           // <-- use RTC_DS1307 for DS1307 module

const int LDR_Pin  = A0;
const int Relay_Pin = 7;
const int threshold = 500;  // tune this

void setup() {
  Serial.begin(9600);
  pinMode(LDR_Pin, INPUT);
  pinMode(Relay_Pin, OUTPUT);

  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  // If RTC has lost power, set the time once.
  if (!rtc.isrunning()) {
    Serial.println("RTC is NOT running, setting time!");
    // Set to compile time — run once, then comment out the next line
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

void loop() {
  DateTime now = rtc.now();
  int hour = now.hour();
  int lightValue = analogRead(LDR_Pin);

  Serial.print("Hour: "); Serial.print(hour);
  Serial.print(" | LDR: "); Serial.println(lightValue);

  // The hour should be either above 18 or below 6.
  if (hour >= 18 || hour < 6)
  {
    if (lightValue < threshold)
    {
      digitalWrite(Relay_Pin, HIGH);
    } else {
      digitalWrite(Relay_Pin, LOW);
    }
  }
  delay(1000);
}