#include <WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <ArduinoJson.h>
#include <WiFiUdp.h>
#include <NTPClient.h>
#include <SPIFFS.h>
#include <RTClib.h> // Para DS3231
#include <Wire.h> // Para I2C

#define SENSOR_PIN 4    // DS18B20 no GPIO4
#define RELE_PIN 5      // Relé no GPIO5
#define SDA_PIN 21      // DS3231 SDA no GPIO21
#define SCL_PIN 20      // DS3231 SCL no GPIO20
#define WIFI_SSID "Wokwi-GUEST"  // Wi-Fi simulado do Wokwi
#define WIFI_PASSWORD ""
#define MQTT_SERVER "broker.hivemq.com"  // MQTT público para simulação
#define MQTT_PORT 1883
#define MQTT_USER ""
#define MQTT_PASS ""

WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "pool.ntp.org", -10800); // UTC-3 (Brasil)
OneWire oneWire(SENSOR_PIN);
DallasTemperature sensors(&oneWire);
WiFiClient espClient;
PubSubClient client(espClient);
RTC_DS3231 rtc;
unsigned long lastSyncTime = 0;
unsigned long savedEpochTime = 0; // Para armazenar o último tempo salvo
bool timeSynced = false;
bool useRTC = true; // Para DS3231

void setup() {
  Serial.begin(115200);
  pinMode(RELE_PIN, OUTPUT);
  digitalWrite(RELE_PIN, LOW);
  sensors.begin();
  Wire.begin(SDA_PIN, SCL_PIN); // I2C com SDA no GPIO21, SCL no GPIO20
  SPIFFS.begin(true);
  timeClient.begin();
  if (useRTC && rtc.begin()) {
    if (rtc.lostPower()) {
      Serial.println("RTC perdeu energia, sincronizando com NTP...");
      syncRTCwithNTP();
    }
  } else {
    useRTC = false;
  }
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  if (WiFi.waitForConnectResult() == WL_CONNECTED) {
    Serial.println("Wi-Fi conectado!");
    timeClient.update();
    lastSyncTime = millis();
    timeSynced = true;
    savedEpochTime = timeClient.getEpochTime();
    saveLastSyncTime(savedEpochTime);
    if (useRTC) syncRTCwithNTP();
  } else {
    Serial.println("Wi-Fi desconectado, usando RTC interno ou DS3231!");
    loadLastSyncTime();
  }
  client.setServer(MQTT_SERVER, MQTT_PORT);
  client.setCallback(callback);
  reconnect();
}

void loop() {
  if (WiFi.status() == WL_CONNECTED) {
    if (!client.connected()) reconnect();
    client.loop();
    timeClient.update();
    lastSyncTime = millis();
    timeSynced = true;
    savedEpochTime = timeClient.getEpochTime();
    saveLastSyncTime(savedEpochTime);
    if (useRTC) syncRTCwithNTP();
  }
  unsigned long now = getCurrentTime();
  sensors.requestTemperatures();
  float temp = sensors.getTempCByIndex(0);
  if (temp != DEVICE_DISCONNECTED_C && temp >= 15 && temp <= 30) {
    int dose = calculateDose(temp, 100, 0.5); // 100 peixes, 0.5kg
    if (isScheduledTime(now) || !timeSynced) {
      digitalWrite(RELE_PIN, HIGH);
      delay(dose * 1000); // Dose em segundos
      digitalWrite(RELE_PIN, LOW);
      saveToFlash(temp, dose, now);
    }
    if (WiFi.status() == WL_CONNECTED) {
      StaticJsonDocument<200> doc;
      doc["tanque"] = 1;
      doc["temperatura"] = temp;
      doc["dose"] = dose;
      doc["hora"] = now;
      char buffer[200];
      serializeJson(doc, buffer);
      client.publish("piscicultura/dados", buffer);
      Serial.println("Dados enviados: T=" + String(temp) + "°C, Dose=" + String(dose) + "g");
    }
  } else {
    Serial.println("Erro: DS18B20 desconectado ou temperatura inválida!");
  }
  delay(60000); // Lê a cada 1 minuto
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message;
  for (int i = 0; i < length; i++) message += (char)payload[i];
  StaticJsonDocument<200> doc;
  deserializeJson(doc, message);
  if (doc["comando"] == "alimentar") {
    int dose = doc["dose"];
    digitalWrite(RELE_PIN, HIGH);
    delay(dose * 1000);
    digitalWrite(RELE_PIN, LOW);
  }
}

void reconnect() {
  while (!client.connected() && WiFi.status() == WL_CONNECTED) {
    if (client.connect("ESP32_Piscicultura")) {
      Serial.println("MQTT conectado!");
      client.subscribe("piscicultura/comandos");
    } else {
      Serial.println("Falha no MQTT, tentando novamente...");
      delay(5000);
    }
  }
}

int calculateDose(float temp, int numPeixes, float pesoMedio) {
  float percent = (temp > 25) ? 0.03 : (temp < 20) ? 0.02 : 0.025; // EMBRAPA
  return (numPeixes * pesoMedio * percent) / 0.006; // 6g/s
}

bool isScheduledTime(unsigned long now) {
  int hour = (now % 86400) / 3600; // Horas do dia
  return (hour == 8 || hour == 12 || hour == 15 || hour == 18); // 4x/dia
}

void saveToFlash(float temp, int dose, unsigned long hora) {
  File file = SPIFFS.open("/dados.txt", "a");
  file.printf("{\"tanque\":1,\"temperatura\":%.1f,\"dose\":%d,\"hora\":%lu}\n", temp, dose, hora);
  file.close();
}

void saveLastSyncTime(unsigned long epochTime) {
  File file = SPIFFS.open("/lastSync.txt", "w");
  file.println(epochTime);
  file.close();
}

void loadLastSyncTime() {
  File file = SPIFFS.open("/lastSync.txt", "r");
  if (file) {
    savedEpochTime = file.readString().toInt();
    lastSyncTime = millis();
    timeSynced = true;
    file.close();
  }
}

unsigned long getCurrentTime() {
  if (useRTC && !rtc.lostPower()) {
    return rtc.now().unixtime();
  }
  return timeSynced ? (savedEpochTime + (millis() - lastSyncTime) / 1000) : (millis() / 1000);
}

void syncRTCwithNTP() {
  if (WiFi.status() == WL_CONNECTED) {
    timeClient.update();
    rtc.adjust(DateTime(timeClient.getEpochTime()));
  }
}