#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <WiFi.h>
#include <PubSubClient.h>

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

// Pins
#define LDR_PIN 34
#define PIR_PIN 27
#define LED1 26
#define LED2 25
#define LED3 33

// Thresholds
int lightThreshold = 500;
bool motionDetected = false;

// Wi-Fi + MQTT
const char* ssid = "YOUR_WIFI";
const char* password = "YOUR_PASS";
const char* mqtt_server = "broker.hivemq.com";
WiFiClient espClient;
PubSubClient client(espClient);

// Function to connect to MQTT
void reconnectMQTT() {
  while (!client.connected()) {
    if (client.connect("StreetLightESP32")) {
      client.subscribe("streetlight/control"); 
    } else {
      delay(2000);
    }
  }
}

// Emergency flashing mode
void emergencyFlash() {
  for (int i=0;i<3;i++){
    analogWrite(LED1,255); analogWrite(LED2,255); analogWrite(LED3,255);
    delay(200);
    analogWrite(LED1,0); analogWrite(LED2,0); analogWrite(LED3,0);
    delay(200);
  }
}

void setup() {
  Serial.begin(115200);

  // OLED init
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setCursor(0,0);
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.println("Advanced Street Light Init...");
  display.display();
  delay(2000);

  // Pins
  pinMode(LDR_PIN, INPUT);
  pinMode(PIR_PIN, INPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);

  // Wi-Fi connect
  WiFi.begin(ssid,password);
  while(WiFi.status()!=WL_CONNECTED){ delay(500); Serial.print("."); }
  Serial.println("WiFi connected");

  client.setServer(mqtt_server,1883);
}

void loop() {
  if (!client.connected()) reconnectMQTT();
  client.loop();

  int ldrValue = analogRead(LDR_PIN);
  motionDetected = digitalRead(PIR_PIN);

  // --- Automatic street light control ---
  int brightness = 0;
  if (ldrValue < lightThreshold) {   // Nighttime
    brightness = motionDetected ? 255 : 100; // Full if motion, dim otherwise
  } else {
    brightness = 0; // Daytime OFF
  }

  // --- PWM control for LEDs ---
  analogWrite(LED1, brightness);
  analogWrite(LED2, brightness);
  analogWrite(LED3, brightness);

  // --- Emergency Mode Example ---
  if (ldrValue < 100 && motionDetected && brightness == 255) { // optional condition
    emergencyFlash();
  }

  // --- Display on OLED ---
  display.clearDisplay();
  display.setCursor(0,0);
  display.println("Advanced Street Light");
  display.print("LDR: "); display.println(ldrValue);
  display.print("Motion: "); display.println(motionDetected ? "Yes":"No");
  display.print("Brightness: "); display.println(brightness);
  display.display();

  // --- Publish to MQTT ---
  String msg = "LDR:"+String(ldrValue)+" Motion:"+String(motionDetected)+" Bright:"+String(brightness);
  client.publish("streetlight/status", msg.c_str());

  delay(500);
}