#include "WiFi.h"
#include "PubSubClient.h"
#include "DHT.h"
#include "Wire.h" // For I2C communication with BMP180

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

// MQTT Broker Configuration
const char* MQTTServer = "broker.hivemq.com";
const char* MQTT_ID = "1cd878b0-5820-4178-8f03-cb5728416b3e";
const int Port = 1883;

// MQTT Topics
const char* topic_humidity = "sensors/humidity";
const char* topic_temperature = "sensors/temperature";
const char* topic_rain = "sensors/rain";
const char* topic_flow_rate = "sensors/flow_rate";
const char* topic_water_level = "sensors/water_level";
const char* topic_ph = "sensors/ph";
const char* topic_bmp_temperature = "sensors/bmp_temperature";
const char* topic_bmp_pressure = "sensors/bmp_pressure";

const char* alert_level1 = "sensors/level1";
const char* alert_level2 = "sensors/level2";
const char* alert_level3 = "sensors/level3";

// MQTT Client
WiFiClient espClient;
PubSubClient client(espClient);

// DHT22 Configuration
#define DHTPIN 15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// GPIO Pins
#define RAIN_AO_PIN 34          // Analog output from rain sensor
#define RAIN_DO_PIN 35          // Digital output from rain sensor
#define FLOW_SENSOR_PIN 13      // Flow sensor digital output
#define TRIG_PIN 4              // HC-SR04 Trigger pin
#define ECHO_PIN 5              // HC-SR04 Echo pin
#define PH_SENSOR_PIN 36        // pH sensor analog output
#define BMP_SCL_PIN 22          // BMP180 SCL
#define BMP_SDA_PIN 21          // BMP180 SDA
#define LED_CONNECTED 25
#define LED_DISCONNECTED 26

unsigned long lastSensorReadTime = 0;
const unsigned long sensorInterval = 100; // 100ms interval

// --------- WiFi Connection ---------
void connectWiFi() {
  pinMode(LED_CONNECTED, OUTPUT);
  pinMode(LED_DISCONNECTED, OUTPUT);

  digitalWrite(LED_CONNECTED, LOW);
  digitalWrite(LED_DISCONNECTED, HIGH);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }

  digitalWrite(LED_DISCONNECTED, LOW);
  digitalWrite(LED_CONNECTED, HIGH);
}

// --------- MQTT Connection ---------
void reconnectMQTT() {
  while (!client.connected()) {
    digitalWrite(LED_CONNECTED, LOW);
    digitalWrite(LED_DISCONNECTED, HIGH);

    if (client.connect(MQTT_ID)) {
      digitalWrite(LED_DISCONNECTED, LOW);
      digitalWrite(LED_CONNECTED, HIGH);
    } else {
      delay(5000);
    }
  }
}

// --------- Sensor Data Reading ---------
float readWaterLevel() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH, 10000); // Timeout 10ms
  if (duration == 0) return -1; // No signal
  return duration * 0.034 / 2; // Convert to distance (cm)
}

float readPH() {
  int analogValue = analogRead(PH_SENSOR_PIN);
  return (analogValue * (14.0 / 4095.0)); // Convert analog value to pH
}

int readRainSensor() {
  return analogRead(RAIN_AO_PIN); // Read rain sensor as analog value
}

int readFlowRate() {
  int flowValue = pulseIn(FLOW_SENSOR_PIN, HIGH, 10000); // Timeout 10ms
  return (flowValue > 0) ? flowValue : -1; // Return -1 if no signal
}

float readBMPSimTemperature() {
  Wire.beginTransmission(0x77); // Address of BMP180
  // Simulated I2C commands for temperature read
  return 25.0; // Replace with actual read logic if necessary
}

float readBMPSimPressure() {
  Wire.beginTransmission(0x77); // Address of BMP180
  // Simulated I2C commands for pressure read
  return 101325; // Replace with actual read logic if necessary
}

void sendSensorData() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  int rainAmount = readRainSensor();
  int flowRate = readFlowRate();
  float waterLevel = readWaterLevel();
  float phValue = readPH();
  float bmpTemperature = readBMPSimTemperature();
  float bmpPressure = readBMPSimPressure();

  // Publish data to MQTT
  if (!isnan(humidity)) client.publish(topic_humidity, String(humidity).c_str());
  if (!isnan(temperature)) client.publish(topic_temperature, String(temperature).c_str());
  client.publish(topic_rain, String(rainAmount).c_str());
  if (flowRate >= 0) client.publish(topic_flow_rate, String(flowRate).c_str());
  if (waterLevel >= 0) client.publish(topic_water_level, String(waterLevel).c_str());
  client.publish(topic_ph, String(phValue).c_str());
  client.publish(topic_bmp_temperature, String(bmpTemperature).c_str());
  client.publish(topic_bmp_pressure, String(bmpPressure).c_str());
}

void processAlerts(int rainAmount, float waterLevel, int flowRate) {
  if (waterLevel < 50 && rainAmount > 500 && flowRate < 15) {
    client.publish(alert_level1, "Cảnh báo nhẹ: Điều kiện ổn định nhưng cần theo dõi.");
  } else if (waterLevel >= 20 && waterLevel < 50 && rainAmount > 500 && flowRate >= 15 && flowRate < 25) {
    client.publish(alert_level2, "Cảnh báo trung bình: Có nguy cơ lũ.");
  } else if (waterLevel < 20 && rainAmount > 500 && flowRate >= 25) {
    client.publish(alert_level3, "Cảnh báo nghiêm trọng: Lũ lụt có nguy cơ xảy ra.");
  }
}

// --------- Main Setup and Loop ---------
void setup() {
  Serial.begin(115200);
  Serial.println("Khởi động cảm biến...");
  dht.begin();
  Wire.begin(BMP_SDA_PIN, BMP_SCL_PIN); // Initialize I2C

  pinMode(RAIN_AO_PIN, INPUT);
  pinMode(RAIN_DO_PIN, INPUT);
  pinMode(FLOW_SENSOR_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(PH_SENSOR_PIN, INPUT);

  connectWiFi();
  client.setServer(MQTTServer, Port);
}

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

  unsigned long currentMillis = millis();
  if (currentMillis - lastSensorReadTime >= sensorInterval) {
    lastSensorReadTime = currentMillis;

    // Read and send data
    sendSensorData();

    // Process alerts
    int rainAmount = readRainSensor();
    float waterLevel = readWaterLevel();
    int flowRate = readFlowRate();
    processAlerts(rainAmount, waterLevel, flowRate);
  }
}