#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <OneWire.h>
#include <DallasTemperature.h>

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

// Pin definitions
#define ONE_WIRE_BUS PB1  // DS18B20 data pin
#define PHOTO_PIN PA1     // Photoresistor analog input
#define LED_PIN PC13      // Built-in LED
#define BUTTON_PIN PB0    // Pushbutton

// Sensor setup
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

// Thresholds
float tempThreshold = 25.0;    // Default temperature threshold (°C)
int lightThreshold = 500;      // Default light threshold (ADC value)
bool alertActive = false;
bool overrideMode = false;
unsigned long lastButtonPress = 0;

void setup() {
  // Initialize pins
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLDOWN);  // Use internal pull-down
  
  // Initialize serial for debugging
  Serial.begin(9600);
  
  // Initialize temperature sensor
  sensors.begin();
  
  // Initialize OLED
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while(1); // Don't proceed if display failed
  }
  
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.println("Sensor Panel Init");
  display.display();
  delay(2000);
}

void loop() {
  // Read sensors
  sensors.requestTemperatures();
  float temperature = sensors.getTempCByIndex(0);
  int lightLevel = analogRead(PHOTO_PIN);
  
  // Check button for override with debounce
  if(digitalRead(BUTTON_PIN)) {
    if(millis() - lastButtonPress > 300) { // 300ms debounce
      overrideMode = !overrideMode;
      lastButtonPress = millis();
    }
    while(digitalRead(BUTTON_PIN)); // Wait for button release
  }
  
  // Determine alert state if not in override
  if(!overrideMode) {
    alertActive = (temperature > tempThreshold) || (lightLevel > lightThreshold);
  }
  
  // Control LED
  digitalWrite(LED_PIN, alertActive ? HIGH : LOW);
  
  // Update display
  updateDisplay(temperature, lightLevel, alertActive, overrideMode);
  
  delay(500); // Update twice per second
}

void updateDisplay(float temp, int light, bool alert, bool override) {
  display.clearDisplay();
  display.setCursor(0,0);
  
  // Display temperature
  display.print("Temp: ");
  display.print(temp, 1);
  display.println(" C");
  
  // Display light level
  display.print("Light: ");
  display.println(light);
  
  // Display thresholds
  display.print("Thresholds: ");
  display.print(tempThreshold, 0);
  display.print("C/");
  display.print(lightThreshold);
  display.println("L");
  
  // Display status
  display.println();
  if(override) {
    display.println("MANUAL OVERRIDE");
    display.print("Alert: ");
    display.println(alert ? "ON" : "OFF");
  } else {
    display.println("AUTO MODE");
    if(alert) {
      display.println("ALERT ACTIVE!");
    }
  }
  
  display.display();
}