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

#define PIR_PIN 5
#define BUZZER_PIN 18
#define LED_PIN 19
#define BUTTON_PIN 21
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

const char* ssid = "Wokwi WiFi";
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

bool motionDetected = false;

void setup() {
    Serial.begin(115200);
    pinMode(PIR_PIN, INPUT);
    pinMode(BUZZER_PIN, OUTPUT);
    pinMode(LED_PIN, OUTPUT);
    pinMode(BUTTON_PIN, INPUT_PULLUP);

    // Initialize OLED
    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
        Serial.println("SSD1306 allocation failed");
        for (;;);
    }
    display.clearDisplay();
    
    setup_wifi();
    client.setServer(mqtt_server, 1883);
}

void setup_wifi() {
    Serial.print("Connecting to WiFi...");
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(1000);
        Serial.print(".");
    }
    Serial.println("Connected to WiFi!");
}

void loop() {
    if (!client.connected()) {
        reconnect_mqtt();
    }
    client.loop();

    int motion = digitalRead(PIR_PIN);
    if (motion == HIGH && !motionDetected) {
        motionDetected = true;
        Serial.println("🚨 Motion Detected! Sending Alert...");
        digitalWrite(BUZZER_PIN, HIGH);
        digitalWrite(LED_PIN, HIGH);
        client.publish("surveillance/alert", "Motion Detected!");

        // Display message on OLED
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(10, 30);
        display.println("INTRUDER!");
        display.display();

        delay(3000);
        digitalWrite(BUZZER_PIN, LOW);
    }

    if (digitalRead(BUTTON_PIN) == LOW) {
        Serial.println("🔄 Resetting Alert...");
        motionDetected = false;
        digitalWrite(LED_PIN, LOW);
        display.clearDisplay();
        display.display();
    }
}

void reconnect_mqtt() {
    while (!client.connected()) {
        Serial.print("Connecting to MQTT...");
        if (client.connect("ESP32Client")) {
            Serial.println("Connected to MQTT!");
        } else {
            Serial.print("Failed, rc=");
            Serial.print(client.state());
            Serial.println(" retrying in 5 seconds...");
            delay(5000);
        }
    }
}