#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// WARNING //GPIO2 and GPIO0 can’t be set to LOW at boot time, do not change!!!
// GPIO0 relay7 is uncommented in this sketch
// PAY ATTENTION // Actual Pin numbers D0-D16 dont match GPIO numbers
// NOT all GPIO pins can be used on ESP8266-12E board 

// Change the credentials below, so your ESP8266 connects to your router
const char* ssid = "YOUR-SSID";
const char* password = "YOUR-PASSWORD";

// Change the variable to your Raspberry Pi IP address, so it connects to your MQTT broker
const char* mqtt_server = "IP OR HOST NAME OF YOUR MQTT BROKER";

// Initializes the espClient. You should change the espClient name if you have multiple ESPs running in your home automation system
WiFiClient espClient;
PubSubClient client(espClient);

// relay1 - GPIO 5 = D1 on ESP-12E NodeMCU board
const int relay1 = 5;

// relay2 - GPIO 4 = D2 on ESP-12E NodeMCU board
const int relay2 = 4;

// relay3 - GPIO 14 = D5 on ESP-12E NodeMCU board
const int relay3 = 14;

// relay4 - GPIO 12 = D6 on6 ESP-12E NodeMCU board
const int relay4 = 12;

// relay5 - GPIO 13 = D7 on ESP-12E NodeMCU board
const int relay5 = 13;

// GPIO2 can’t be LOW at boot, do not change!!!
// Add pull up resistor in range 2K-10K on pins 3V3 and D4 
// Relay6 will activate for 100msec during boot
// relay6 - GPIO 2 = D4 on ESP-12E NodeMCU board
const int relay6 = 2;

// GPIO0 can’t be LOW at boot, do not change!!!
// Add pull up resistor in range 2K-10K on pins 3V3 and D3 
// WARNING: GPIO0 is needs to be grounded to get into programming mode.
// If your sketch is driving it HIGH, grounding it can damage you ESP8266 chip.
// The safe way to reprogram the ESP8266 when your code drives the GPIO0 output is to
// a) Power down the board
// b) short GPIO0 to gnd
// c) power up the board which goes into program mode due to the short on GPIO0
// d) remove the short from GPIO0 so you don't short out the output when the program runs
// e) reprogram the board
// f) power cycle the board if necessary.
// Credits to Matthew Ford https://www.forward.com.au/pfod/ESP8266/GPIOpins/index.html
// relay7 - GPIO 0 = D3 on ESP-12E NodeMCU board
// Uncomment command below at your own risk. 
// const int relay6 = 0;


// Timers auxiliar variables
long now = millis();
long lastMeasure = 0;

// Don't change the function below. This functions connects your ESP8266 to your router
void setup_wifi() {
 delay(10);
 // We start by connecting to a WiFi network
 Serial.println();
 Serial.print("Connecting to ");
 Serial.println(ssid);
 WiFi.begin(ssid, password);
 while (WiFi.status() != WL_CONNECTED) {
   delay(500);
   Serial.print(".");}
 Serial.println("");
 Serial.print("WiFi connected - ESP IP address: ");
 Serial.println(WiFi.localIP());
}

// This functions is executed when some device publishes a message to a topic that your ESP8266 is subscribed to
// Change the function below to add logic to your program, so when a device publishes a message to a topic that 
// your ESP8266 is subscribed you can actually do something
void callback(String topic, byte* message, unsigned int length) {
 Serial.print("Message arrived on topic: ");
 Serial.print(topic);
 Serial.print(". Message: ");
 String messageTemp;
 
 for (int i = 0; i < length; i++) {
   Serial.print((char)message[i]);
   messageTemp += (char)message[i];
 }
 Serial.println();

 // Feel free to add more if statements to control more GPIOs with MQTT

  // Topic esp01/relay1
  // Turns GPIO5 according to the message
 if(topic=="esp01/relay1"){
     Serial.print("Changing esp01 relay1 to ");
     if(messageTemp == "on"){
       digitalWrite(relay1, LOW);
       Serial.print("On");
     }
     else if(messageTemp == "off"){
       digitalWrite(relay1, HIGH);
       Serial.print("Off");
     }
 }
 Serial.println();

 // Topic esp01/relay2
 // Turns the GPIO4 according to the message
 if(topic=="esp01/relay2"){
     Serial.print("Changing esp01 relay2 to ");
     if(messageTemp == "on"){
       digitalWrite(relay2, LOW);
       Serial.print("On");
     }
     else if(messageTemp == "off"){
       digitalWrite(relay2, HIGH);
       Serial.print("Off");
     } 
 }
 Serial.println();

 // Topic esp01/relay3
 // Turns the relay3 GPIO14 according to the message
 if(topic=="esp01/relay3"){
     Serial.print("Changing esp01 relay3 to ");
     if(messageTemp == "on"){
       digitalWrite(relay3, LOW);
       Serial.print("On");
     }
     else if(messageTemp == "off"){
       digitalWrite(relay3, HIGH);
       Serial.print("Off");
     } 
 }
 Serial.println();

 // Topic esp01/relay4
 // Turns the relay4 GPIO12 according to the message
 if(topic=="esp01/relay4"){
     Serial.print("Changing esp01 relay4 to ");
     if(messageTemp == "on"){
       digitalWrite(relay4, LOW);
       Serial.print("On");
     }
     else if(messageTemp == "off"){
       digitalWrite(relay4, HIGH);
       Serial.print("Off");
     } 
 }
 Serial.println();

 // Topic esp01/relay5
 // Turns the relay5 GPIO13 according to the message
 if(topic=="esp01/relay5"){
     Serial.print("Changing esp01 relay5 to ");
     if(messageTemp == "on"){
       digitalWrite(relay5, LOW);
       Serial.print("On");
     }
     else if(messageTemp == "off"){
       digitalWrite(relay5, HIGH);
       Serial.print("Off");
     } 
 }
 Serial.println();

   //GPIO2 can’t be LOW at boot, do not change!!!
   // Topic esp01/relay6
 // Turns the relay6 GPIO2 according to the message
 if(topic=="esp01/relay6"){
     Serial.print("Changing esp01 relay6 to ");
     if(messageTemp == "on"){
       digitalWrite(relay6, LOW);
       Serial.print("On");
     }
     else if(messageTemp == "off"){
       digitalWrite(relay6, HIGH);
       Serial.print("Off");
     } 
 }
 Serial.println();

    //GPIO0 can’t be LOW at boot, do not change!!!
   // Topic esp01/relay7
 // Turns the relay7 GPIO0 according to the message
 //if(topic=="esp01/relay7"){
 //    Serial.print("Changing esp01 relay7 to ");
 //    if(messageTemp == "on"){
 //      digitalWrite(relay7, LOW);
 //      Serial.print("On");
 //    }
 //    else if(messageTemp == "off"){
 //      digitalWrite(relay7, HIGH);
 //      Serial.print("Off");
 //    } 
// }
// Serial.println();
 
}

 // This functions reconnects your ESP8266 to your MQTT broker
 // Change the function below if you want to subscribe to more topics with your ESP8266 
void reconnect() {
 // Loop until we're reconnected
 while (!client.connected()) {
   Serial.print("Attempting MQTT connection...");
   // Attempt to connect
   /*
    YOU MIGHT NEED TO CHANGE THIS LINE, IF YOU'RE HAVING PROBLEMS WITH MQTT MULTIPLE CONNECTIONS
    To change the ESP device ID, you will have to give a new name to the ESP8266.
     */
   if (client.connect("ESP8266Client")) {
     Serial.println("connected");  
     // Subscribe or resubscribe to a topic
     // You can subscribe to more topics (to control more LEDs in this example)
     client.subscribe("esp01/relay1");
     client.subscribe("esp01/relay2");
     client.subscribe("esp01/relay3");
     client.subscribe("esp01/relay4");
     client.subscribe("esp01/relay5");
     client.subscribe("esp01/relay6");
     //client.subscribe("esp01/relay7");
   } else {
     Serial.print("failed, rc=");
     Serial.print(client.state());
     Serial.println(" try again in 5 seconds");
     // Wait 5 seconds before retrying
     delay(5000);
   }    
 }
}

 // The setup function sets your ESP GPIOs to Outputs, starts the serial communication at a baud rate of 115200
 // Sets your mqtt broker and sets the callback function
 // The callback function is what receives messages and actually controls the LEDs
void setup() {
 
 pinMode(relay1, OUTPUT);
 digitalWrite(relay1, HIGH);

 pinMode(relay2, OUTPUT);
 digitalWrite(relay2, HIGH);

 pinMode(relay3, OUTPUT);
 digitalWrite(relay3, HIGH);

 pinMode(relay4, OUTPUT);
 digitalWrite(relay4, HIGH);

 pinMode(relay5, OUTPUT);
 digitalWrite(relay5, HIGH);

 //GPIO2 can’t be LOW at boot, do not change!!!
 pinMode(relay6, OUTPUT);
 digitalWrite(relay6, HIGH);

 //GPIO0 can’t be LOW at boot, do not change!!!
 // pinMode(relay7, OUTPUT);
 // digitalWrite(relay7, HIGH);

 
 Serial.begin(115200);
 setup_wifi();
 client.setServer(mqtt_server, 1883);
 client.setCallback(callback);

}

// For this project, you don't need to change anything in the loop function. Basically it ensures that you ESP is connected to your broker
void loop() {

 if (!client.connected()) {
   reconnect();
 }
 if(!client.loop())
   client.connect("ESP8266Client");

 now = millis();
 
}