#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Servo.h>

// ---------------------- OLED Setup ----------------------
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// ---------------------- Pins ----------------------
#define POT_PIN A0      // Slider / potentiometer
#define SOLAR_PIN A1    // Simulated solar sensor
#define SERVO_PIN 9     // Servo PWM signal

// ---------------------- Servo & Constants ----------------------
Servo panelServo;
const float CURRENT_SCALING = 0.05; // Current per % sunlight
const float VOLTAGE = 5.0;          // Example voltage of solar panel

// ---------------------- Functions ----------------------
int readPotentiometer() {
  return analogRead(POT_PIN); // 0-1023
}

int readSolarSensor(int potValue) {
  // Simulate solar sensor with small variation
  float variation = random(-50, 50) / 100.0; // -0.5% to +0.5%
  int solar = potValue / 1023.0 * 100 + variation;
  if (solar < 0) solar = 0;
  if (solar > 100) solar = 100;
  return solar;
}

int calculatePanelAngleIST(int hour, int minute) {
  // Map 6:00 AM -> 0°, 6:00 PM -> 180°
  int totalMinutes = hour * 60 + minute;
  int angle = map(totalMinutes, 6*60, 18*60, 0, 180);
  if (angle < 0) angle = 0;
  if (angle > 180) angle = 180;
  return angle;
}

// ---------------------- Setup ----------------------
void setup() {
  Serial.begin(9600);
  panelServo.attach(SERVO_PIN);

  Wire.begin();
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.clearDisplay();
}

// ---------------------- Main Loop ----------------------
void loop() {
  // ---------- Simulated Time ----------
  int hour = 9;      // Example: 9 AM
  int minute = 30;   // Example: 9:30 AM

  // ---------- Panel Angle ----------
  int panelAngle = calculatePanelAngleIST(hour, minute);
  panelServo.write(panelAngle);

  // ---------- Read Sunlight ----------
  int potValue = readPotentiometer();       // Slider % sunlight
  int solarValue = readSolarSensor(potValue); // Simulated solar sensor %

  // ---------- Calculate Current & Power ----------
  float current = solarValue * CURRENT_SCALING; // A
  float power = VOLTAGE * current;             // W

  // ---------- Display on OLED ----------
  display.clearDisplay();
  display.setCursor(0,0);
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.println("Smart Solar Tracker");

  display.print("Pot: "); display.println(potValue);
  display.print("Solar: "); display.println(solarValue);
  display.print("Angle: "); display.println(panelAngle);
  display.print("Current: "); display.println(current, 2);
  display.print("Power: "); display.println(power, 2);

  display.display();

  delay(500); // Update every 0.5 sec
}