#include <PubSubClient.h>
#include <WiFi.h>

//2-configuration du point d accés
const char* ssid = "Wokwi-GUEST";
const char* password = "";

//3-configuration du broker EMQX PORT 1883
const char* mqttServer = "broker.emqx.io";
int port = 1883;

char clientId[50];

//4-configuration d un clien mqtt (publisher)
WiFiClient espClient;
PubSubClient client(espClient);
//config thingspeak
/*const int myChannelNumber = 2693900;
const char* myApiKey = "YGOS4LAEN3HA3FVQ";
const char* server = "api.thingspeak.com";*/

int buz=17;
int led=4;
void setup() {
Serial.begin(115200);
  pinMode(buz, OUTPUT);
  pinMode(led, OUTPUT);
   // 5-initialisation du wifi
  initWiFi();

  // 6-initialisation du broker mqtt
  initMQTT();
  client.setCallback(callback);
 //  ThingSpeak.begin(espClient);
}
void initWiFi(void)
{
  delay(10);
  Serial.println("------cnx WI-FI------");
  Serial.print("Cnx ready: ");
  Serial.println(ssid);
  Serial.println("ok");
//reconnection en cas de perte de connexion
  reconnectWiFi();
}

void initMQTT(void)
{
  client.setServer(mqttServer, port); 
 
}

//en cas de probleme de connexion 
void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    long r = random(1000);
    sprintf(clientId, "clientId-%ld", r);
    if (client.connect(clientId)) {
      Serial.print(clientId);
      Serial.println(" connected");
     client.subscribe("gaz");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

//
void checkWiFIAndMQTT(void)
{
  if (!client.connected())
    reconnectMQTT(); 
    reconnectWiFi(); 
}

void reconnectWiFi(void)
{
  if (WiFi.status() == WL_CONNECTED)
    return;

  WiFi.begin(ssid, password); // Conecta na rede WI-FI

  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }

  Serial.println();
  Serial.print("Cnx success ");
  Serial.print(ssid);
  Serial.println("IP adresse: ");
  Serial.println(WiFi.localIP());
}
//lire le topic
void callback(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String stMessage;
  //lire bit par bit
  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    stMessage += (char)message[i];
  }
  Serial.println();

    if (String(topic) == "gaz") {
    Serial.print("Changing output to ");
   /* ThingSpeak.setField(1,stMessage.toInt());
    int x = ThingSpeak.writeFields(myChannelNumber,myApiKey);
  
  if(x == 200){
    Serial.println("Data pushed successfull");
  }else{
    Serial.println("Push error" + String(x));
  }*/
   if(stMessage.toInt() > 200){
      Serial.println("alerte gaz");
      for(int i=0;i<3;i++)
      {
      digitalWrite(led,1);
      delay(500);
      digitalWrite(led,0);
      delay(500);    
      }
      tone(buz,500,2000);
    }
    else {
      Serial.println("etat ok");
      digitalWrite(led,0);
      noTone(buz);
    }
  }
}

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