// Mohamad Amin Mohamadi
#include <OneWire.h>
#include <DallasTemperature.h>

#define LDR_sen A0
#define heater 4
#define fan 5
// if the value falls lower than the definition below, then we assume it's night and vice versa
#define NightOrDay 400
#define HotOrCold 30
#define ONE_WIRE_BUS 2

int i;
bool flag = 0;

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

void setup() {
  Serial.begin(9600);
  pinMode(heater, OUTPUT);
  pinMode(fan, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  sensors.begin();
}

void loop() {
  // this section is used to pick a random LED that's constantly powered throughout the night
  int LDR_val = analogRead(LDR_sen);
  if(LDR_val <= NightOrDay){
    if(flag == 0){
      int random_led = random(7, 11);
      digitalWrite(random_led, HIGH);
      for(i=7; i<11; i++){
        if(i!=random_led){
          digitalWrite(i, LOW);
        }
      }
      flag = 1;
    }
  }
  else {
    if(flag == 1){
      flag = 0;
    }
    for(i=7;i<11;i++){
      digitalWrite(i, LOW);
    }
  }
  // this section turns the fan or the heater on depending on the temperature
  sensors.requestTemperatures();
  float temp = sensors.getTempCByIndex(0);
  if (temp != DEVICE_DISCONNECTED_C) {
    if(temp <= HotOrCold){
      //if the temp drops below 30 then we assume it's cold and we turn the heater on
      digitalWrite(heater, HIGH);
      digitalWrite(fan, LOW);
    }
    else{
      digitalWrite(fan, HIGH);
      digitalWrite(heater, LOW);
    }
  } 
  else {
    Serial.println("Error");
  }
  delay(1000);
}