#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <IRremote.hpp>
#include <RTClib.h>

// LCD
LiquidCrystal_I2C lcd(0x27, 20, 4);

// RTC (DS1307 for simulation)
RTC_DS1307 rtc;

// IR
#define IR_RECEIVE_PIN 7

// IR Remote codes
#define BTN_UP     0x18 // 2
#define BTN_DOWN   0x4A // 8
#define BTN_LEFT   0x10 // 4
#define BTN_RIGHT  0x5A // 6
#define BTN_OK     0xA8 // OK or PLAY in Wokwi

// Photodiodes
const int pdTop = A0;
const int pdBottom = A1;
const int pdLeft = A2;
const int pdRight = A3;

// Stepper X (horizontal)
#define DIR_X 2
#define STEP_X 3

// Stepper Y (vertical)
#define DIR_Y 4
#define STEP_Y 5

// Settings
int delayTime = 3; // stepping delay
int stepSize = 10; // degrees per manual press
int threshold = 100; // photodiode light difference threshold
int lightThreshold = 200; // if all photodiodes < this, fallback to RTC

bool autoMode = true;

void setup() {
  Serial.begin(9600);
  lcd.begin(20, 4);
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Solar Tracker Ready");

  // Initialize IR receiver
  IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);
  
  // Setup pins
  pinMode(DIR_X, OUTPUT);
  pinMode(STEP_X, OUTPUT);
  pinMode(DIR_Y, OUTPUT);
  pinMode(STEP_Y, OUTPUT);

  // RTC start
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC!");
    lcd.setCursor(0, 1);
    lcd.print("RTC Not Found");
  }

  if (!rtc.isrunning()) {
    Serial.println("RTC is NOT running, setting to compile time");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

void loop() {
  if (IrReceiver.decode()) {
    uint32_t value = IrReceiver.decodedIRData.command;
    Serial.print("IR Code: 0x"); Serial.println(value, HEX);

    if (value == BTN_OK) {
      autoMode = !autoMode;
      lcd.setCursor(0, 2);
      lcd.print("Mode: ");
      lcd.print(autoMode ? "AUTO  " : "MANUAL");
    }

    if (!autoMode) {
      if (value == BTN_UP) moveStepper(STEP_Y, DIR_Y, HIGH, stepSize);
      if (value == BTN_DOWN) moveStepper(STEP_Y, DIR_Y, LOW, stepSize);
      if (value == BTN_LEFT) moveStepper(STEP_X, DIR_X, LOW, stepSize);
      if (value == BTN_RIGHT) moveStepper(STEP_X, DIR_X, HIGH, stepSize);
    }

    IrReceiver.resume(); // ready to receive next
  }

  if (autoMode) {
    int top = analogRead(pdTop);
    int bottom = analogRead(pdBottom);
    int left = analogRead(pdLeft);
    int right = analogRead(pdRight);

    lcd.setCursor(0, 1);
    lcd.print("T:");
    lcd.print(top);
    lcd.print(" B:");
    lcd.print(bottom);

    lcd.setCursor(0, 3);
    lcd.print("L:");
    lcd.print(left);
    lcd.print(" R:");
    lcd.print(right);

    bool lowLight = (top < lightThreshold && bottom < lightThreshold &&
                     left < lightThreshold && right < lightThreshold);

    if (lowLight) {
      // Use RTC to control
      DateTime now = rtc.now();
      int hour = now.hour();
      int minute = now.minute();

      // Horizontal movement by hour
      int hourSteps = map(hour, 6, 18, 0, 200); // 6 AM to 6 PM
      moveToPosition(STEP_X, DIR_X, hourSteps);

      // Vertical movement by minute (optional)
      int minuteSteps = map(minute, 0, 59, 0, 100);
      moveToPosition(STEP_Y, DIR_Y, minuteSteps);

    } else {
      // Top/Bottom
      if (abs(top - bottom) > threshold) {
        if (top > bottom)
          moveStepper(STEP_Y, DIR_Y, LOW, 1);
        else
          moveStepper(STEP_Y, DIR_Y, HIGH, 1);
      }

      // Left/Right
      if (abs(left - right) > threshold) {
        if (left > right)
          moveStepper(STEP_X, DIR_X, LOW, 1);
        else
          moveStepper(STEP_X, DIR_X, HIGH, 1);
      }
    }
  }

  delay(100);
}

void moveStepper(int stepPin, int dirPin, bool direction, int steps) {
  digitalWrite(dirPin, direction);
  for (int i = 0; i < steps; i++) {
    digitalWrite(stepPin, HIGH);
    delay(delayTime);
    digitalWrite(stepPin, LOW);
    delay(delayTime);
  }
}

void moveToPosition(int stepPin, int dirPin, int targetStep) {
  // You can implement this based on a position tracking system if needed
  // For now, this function is a placeholder
}