#define TRIG_PIN 26
#define ECHO_PIN 25
#define NODEID 2
float levelDanger = 300; //muc nuoc nguy hiem
float rateChangeDanger = 25; // toc do thay doi muc nuoc nguy hiem

float bottomToSensor = 400;
float levelSum=0;
float levelM,rateChange;
float levelMBefore=-1;  //muc nuoc trung binh giay truoc do
unsigned long timeC=-1;
unsigned long previousMillis = 0;
const unsigned long hour = 3600000; 
String value;
void setup() {
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}
void readData(){
  if (Serial.available() > 0) {
    String data = Serial.readString();
    if (data.substring(0, 2) == "CD") { //yeu cau thay gia tri nguy hiem
      float num1, num2;
      sscanf(data.c_str(), "CD%d%d", &num1, &num2);
      if(num1>0&&num1<400&&num2>0&&num2<100){ // kiem tra gia tri duoc thay doi
        levelDanger=num1;
        rateChangeDanger=num2;
        Serial.println("Change value danger:");
        Serial.print("Water level danger cm: ");
        Serial.println(levelDanger);
        Serial.print("Rate of water level change cm/s: ");
        Serial.println(rateChangeDanger);
        Serial.println();
      }
    }
    if (data == "CV") { //kiem tra muc nuoc va toc do thay doi muc nuoc hien tai
      sendData(1,value);
    }
  }
}
void sendData(int toNode,String data){
  Serial.print(NODEID);
  Serial.print(" sending to node ");
  Serial.print(toNode);
  Serial.print(": ");
  Serial.println(data);
  Serial.println();

}
void loop() {
  readData();

  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(5);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH);
  long distance = duration * 0.034 / 2;

  float level=bottomToSensor - distance;
  timeC++;
  if(timeC>0)
  levelSum+=level;
  if(timeC==5){
    levelM=levelSum/5;
    if(levelMBefore>-1){
      rateChange=levelM-levelMBefore;
      value=String(levelM,2)+" "+String(rateChange,2);
      Serial.print("Chieu cao muc nuoc hien tai: ");
      Serial.println(levelM);
      Serial.print("Toc do thay doi muc nuoc: ");
      Serial.println(rateChange);
      Serial.println();
    }
    levelMBefore=levelM;
    levelSum=0;
    timeC=0;
    if(levelM>=levelDanger||rateChange>rateChangeDanger){
      Serial.println("Flash flood warning:");
      sendData(1,value);
    }
  }
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= hour) {
    previousMillis = currentMillis;
    Serial.print("Gui tinh trang tram hien tai moi gio: ");
    sendData(1,value);
  }
  delay(200);
}