#include <Wire.h>
#include <BH1750.h>
#include <DHT.h>

// Light Sensors for Solar Tracking
BH1750 lightNorth;
BH1750 lightSouth;

// Motor Driver Pins
#define IN1 5
#define IN2 6
#define ENA 9  

// Movement Settings
const int maxSpeed = 255;
const int minSpeed = 20;

// Sunlight Thresholds
const int cloudDrop = 100;  
const int noSunThreshold = 20;  

int luxNorth = 0, luxSouth = 0;
int previousLux = 0;
unsigned long cloudDetectedTime = 0;

// Temperature & Power Measurement
#define DHTPIN 2  
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

#define VOLTAGE_SENSOR A0  
#define CURRENT_SENSOR A1  

float voltage = 0, current = 0, power = 0;
float temperature_air = 0;

void setup() {
  Serial.begin(9600);
  Wire.begin();

  // Initialize Sensors
  lightNorth.begin(BH1750::CONTINUOUS_HIGH_RES_MODE);
  lightSouth.begin(BH1750::CONTINUOUS_HIGH_RES_MODE);
  dht.begin();

  // Motor Control Pins
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(ENA, OUTPUT);

  Serial.println("Solar Tracker + Power vs. Temperature Monitoring Initialized...");
}

void loop() {
  // Read light intensity for tracking
  luxNorth = lightNorth.readLightLevel();
  luxSouth = lightSouth.readLightLevel();
  int luxDifference = luxNorth - luxSouth;

  Serial.print("Lux North: "); Serial.print(luxNorth);
  Serial.print("\t Lux South: "); Serial.print(luxSouth);
  Serial.print("\t Difference: "); Serial.println(luxDifference);

  // Move Solar Tracker
  if (luxNorth > luxSouth) {  
    int speed = constrain(map(abs(luxDifference), 0, 500, minSpeed, maxSpeed), minSpeed, 255);
    Serial.print("Moving South at Speed: "); Serial.println(speed);
    movePiston("South", speed);
  } 
  else if (abs(previousLux - luxSouth) > cloudDrop) {
    Serial.println("🌥 Cloud Detected → Pausing...");
    cloudDetectedTime = millis();
    stopPiston();
  }
  else if (millis() - cloudDetectedTime < 5000) {
    Serial.println("Waiting for cloud to pass...");
  }
  else if (abs(luxNorth - luxSouth) < 10) {  
    Serial.println("☀ Sunlight Balanced → Returning to North");
    movePiston("North", maxSpeed);
  }
  else {
    Serial.println("✔ Stable Sunlight → Stopping");
    stopPiston();
  }

  previousLux = luxSouth;

  // Measure Power & Temperature
  temperature_air = dht.readTemperature();
  voltage = readVoltage();
  current = readCurrent();
  power = voltage * current;

  // Print Data for Arduino Serial Plotter
  Serial.print("T_Air:"); Serial.print(temperature_air);
  Serial.print("\tPower:"); Serial.println(power);

  delay(2000);
}

// Move Piston Function
void movePiston(String direction, int speed) {
  if (direction == "South") {
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);
  } else if (direction == "North") {
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, HIGH);
  }
  analogWrite(ENA, speed);
}

// Stop Piston Function
void stopPiston() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 0);
}

// Read Voltage
float readVoltage() {
  int sensorValue = analogRead(VOLTAGE_SENSOR);
  return (sensorValue / 1023.0) * 5.0 * 11;  // Adjust for voltage divider
}

// Read Current
float readCurrent() {
  int sensorValue = analogRead(CURRENT_SENSOR);
  float voltage = (sensorValue / 1023.0) * 5.0;
  return (voltage - 2.5) / 0.185;  // ACS712 (5A version)
}