#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include <Wire.h>
#include <Adafruit_BMP085.h>
#include <OneWire.h>
#include <DallasTemperature.h>

// --- WiFi & MQTT Configuration ---
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.emqx.io"; // Change to AWS Endpoint later
const int mqtt_port = 1883;

// --- Hardware Pin Mapping ---
#define TEMP_PIN 4      // DS18B20
#define VIB_PIN 18      // SW-420 (Slide Switch)
#define CURRENT_PIN 34  // ACS712 (Potentiometer)

// --- Sensor Objects ---
Adafruit_BMP085 bmp;
OneWire oneWire(TEMP_PIN);
DallasTemperature tempSensors(&oneWire);

// --- Global Variables ---
WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastPublishTime = 0;
const int publishInterval = 5000; // 5 seconds

// Vibration Interrupt Logic
volatile bool vibrationDetected = false;
void IRAM_ATTR handleVibration() {
  vibrationDetected = true;
}

// --- Functions ---

void setup_wifi() {
  delay(10);
  Serial.print("\nConnecting to WiFi: ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi Connected! IP: " + WiFi.localIP().toString());
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT Broker...");
    // Create a random client ID
    String clientId = "ESP32Client-" + String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("Connected!");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" Retrying in 5s...");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  
  // 1. Initialize Hardware
  if (!bmp.begin()) {
    Serial.println("Could not find BMP180 sensor!");
  }
  tempSensors.begin();
  
  // 2. Setup Vibration Interrupt
  pinMode(VIB_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(VIB_PIN), handleVibration, FALLING);
  
  // 3. Setup Networking
  setup_wifi();
  client.setServer(mqtt_server, mqtt_port);
}

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

  unsigned long now = millis();
  if (now - lastPublishTime > publishInterval) {
    lastPublishTime = now;

    // --- A. Read All Sensors ---
    tempSensors.requestTemperatures();
    float temp = tempSensors.getTempCByIndex(0);
    long pressure = bmp.readPressure();
    
    // Convert 12-bit ADC (0-4095) to 0-30 Amps
    float current = (analogRead(CURRENT_PIN) / 4095.0) * 30.0;
    
    // Check vibration status
    bool vibStatus = vibrationDetected;
    if (vibrationDetected) vibrationDetected = false; // Reset flag after reading

    // --- B. Defect Detection logic (Local) ---
    if (temp > 50.0) Serial.println("LOCAL ALERT: High Temperature!");
    if (current > 20.0) Serial.println("LOCAL ALERT: Overcurrent!");

    // --- C. Create JSON Payload (AWS Style) ---
    StaticJsonDocument<256> doc;
    doc["device_id"] = "ESP32_IND_01";
    doc["temperature"] = temp;
    doc["pressure"] = pressure;
    doc["current_amps"] = current;
    doc["vibration_fault"] = vibStatus;
    doc["timestamp"] = now;

    char buffer[256];
    serializeJson(doc, buffer);

    // --- D. Publish to Cloud ---
    Serial.print("Publishing to MQTT: ");
    Serial.println(buffer);
    client.publish("industrial/monitor/test", buffer);
  }
}