// audioguard.ino - BitDogLab / RP2040 Wokwi
// Potenciômetro GP28 → ADC → OLED + MQTT

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

// ── Display ──────────────────────────────
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define SCREEN_ADDR 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// ── ADC (Microfone simulado) ──────────────
#define MIC_PIN 28
#define SAMPLE_INTERVAL_MS 1
#define BUFFER_SIZE 50
int sampleBuffer[BUFFER_SIZE];
int bufferIdx = 0;
unsigned long totalSamples = 0;
unsigned long lastSample = 0;

// ── WiFi ─────────────────────────────────
const char* ssid     = "Wokwi-GUEST";
const char* password = "";

// ── MQTT (HiveMQ público - sem TLS) ──────
const char* mqtt_server = "broker.hivemq.com";
const int   mqtt_port   = 1883;
const char* mqtt_topic  = "audioguard/samples";
const char* mqtt_status = "audioguard/status";
const char* clientId    = "bitdoglab-001";

WiFiClient   wifiClient;
PubSubClient mqtt(wifiClient);

// ── Estado ───────────────────────────────
unsigned long lastPublish  = 0;
unsigned long packetsSent  = 0;
const int    PUBLISH_EVERY = 2000;
bool mqttConnected = false;

// ─────────────────────────────────────────
void drawDisplay(int raw, float vol, bool wifi, bool mqtt_ok) {
  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);

  // Título
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.print("AUDIOGUARD v1.0");
  display.drawLine(0, 9, 127, 9, SSD1306_WHITE);

  // ADC value
  display.setCursor(0, 12);
  display.print("ADC: ");
  display.print(raw);
  display.print(" / 4095");

  // Volume bar
  display.setCursor(0, 22);
  display.print("Vol: ");
  int barW = (int)(vol * 80);
  display.drawRect(35, 22, 80, 8, SSD1306_WHITE);
  display.fillRect(35, 22, barW, 8, SSD1306_WHITE);
  display.setCursor(118, 22);
  display.print((int)(vol*100));

  // Amostras
  display.setCursor(0, 33);
  display.print("Amostras: ");
  display.print(totalSamples);

  // Status WiFi/MQTT
  display.setCursor(0, 43);
  display.print("WiFi:");
  display.print(wifi ? " OK" : " --");
  display.print("  MQTT:");
  display.print(mqtt_ok ? " OK" : " --");

  // Pacotes enviados
  display.setCursor(0, 54);
  display.print("Env: ");
  display.print(packetsSent);
  display.print(" pacotes");

  display.display();
}

void connectWifi() {
  Serial.print("Conectando WiFi");
  WiFi.begin(ssid, password);
  int tries = 0;
  while (WiFi.status() != WL_CONNECTED && tries < 20) {
    delay(500);
    Serial.print(".");
    tries++;
  }
  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("\nWiFi OK: " + WiFi.localIP().toString());
  }
}

void connectMQTT() {
  mqtt.setServer(mqtt_server, mqtt_port);
  int attempts = 0;
  while (!mqtt.connected() && attempts < 3) {
    Serial.print("MQTT conectando...");
    if (mqtt.connect(clientId)) {
      Serial.println("OK");
      mqttConnected = true;
      mqtt.publish(mqtt_status, "{\"status\":\"online\",\"device\":\"bitdoglab\"}");
    } else {
      Serial.print("falhou rc=");
      Serial.println(mqtt.state());
      delay(2000);
      attempts++;
    }
  }
}

void setup() {
  Serial.begin(115200);
  analogReadResolution(12);
  Wire.begin();

  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDR)) {
    Serial.println("OLED falhou!");
    while (true);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10, 10);
  display.println("AudioGuard");
  display.setTextSize(1);
  display.setCursor(20, 40);
  display.println("Iniciando...");
  display.display();
  delay(1500);

  connectWifi();
  connectMQTT();
  Serial.println("Sistema pronto.");
}

void loop() {
  // Reconecta MQTT se necessário
  if (!mqtt.connected()) {
    mqttConnected = false;
    connectMQTT();
  }
  mqtt.loop();

  unsigned long now = millis();

  // Coleta amostra ADC
  if (now - lastSample >= SAMPLE_INTERVAL_MS) {
    lastSample = now;
    int raw = analogRead(MIC_PIN);
    sampleBuffer[bufferIdx % BUFFER_SIZE] = raw;
    bufferIdx++;
    totalSamples++;
    float vol = raw / 4095.0f;
    drawDisplay(raw, vol, WiFi.status() == WL_CONNECTED, mqttConnected);
  }

  // Publica pacote MQTT a cada 2 segundos
  if (now - lastPublish >= PUBLISH_EVERY && mqttConnected) {
    lastPublish = now;

    // Calcula média e pico do buffer
    long sum = 0;
    int peak = 0;
    int count = min((int)totalSamples, BUFFER_SIZE);
    for (int i = 0; i < count; i++) {
      sum += sampleBuffer[i];
      if (sampleBuffer[i] > peak) peak = sampleBuffer[i];
    }
    float avg = (count > 0) ? (sum / (float)count) : 0;

    // Monta JSON
    StaticJsonDocument<256> doc;
    doc["device"]     = clientId;
    doc["ts"]         = now;
    doc["avg_raw"]    = (int)avg;
    doc["peak_raw"]   = peak;
    doc["avg_v"]      = avg / 4095.0f * 3.3f;
    doc["total"]     = totalSamples;
    doc["vol_pct"]   = (int)((peak / 4095.0f) * 100);

    // Serializa e publica
    char jsonBuf[256];
    serializeJson(doc, jsonBuf);
    if (mqtt.publish(mqtt_topic, jsonBuf)) {
      packetsSent++;
      Serial.print("[MQTT] Publicado #");
      Serial.print(packetsSent);
      Serial.print(" avg=");
      Serial.println((int)avg);
    }
  }
}