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

// NOTE: Source code is based on nummerous other projects, it's not my own, neither is it clearly from one other author.
// Considering it GPL would be best I assume.

#define D0              16        //WAKE  =>  16
#define D1              5         //IOS   =>  5
#define D2              4         //      =>  4
#define D3              0         //      =>  0
#define D4              2         //      =>  2
#define D5              14        //CLK   =>  14
#define D6              12        //MISO  =>  12
#define D7              13        //MOSI  =>  13
#define D8              15        //CS    =>  15
#define D9              3         //RX    =>  3
#define RELAY_PIN       D6 //D6 == default on SonOFF
#define TOGGLE_PIN      D3 //D3 == default on SonOFF
#define LED_PIN         D7 //D7 == default on SonOFF

#define MQTT_VERSION    MQTT_VERSION_3_1_1
#define MQTT_SERVER "192.168.XXXX.XXXX"  //you MQTT IP Address
const PROGMEM uint16_t  MQTT_SERVER_PORT          = 1883;
const PROGMEM char*     MQTT_CLIENT_ID            = "sonoff";
const char*             MQTT_LIGHT_STATE_TOPIC    = "/house/switchConfirm6/";
const char*             MQTT_LIGHT_COMMAND_TOPIC  = "/house/switch6/";
boolean                 m_relay_state             = false;
boolean                 fDebug                    = true;
long                    lastMsg                   = 0;
long unsigned int       pause                     = 5000;
int                     chk;
int                     TOGGLE_COUNT              = 0;

void callback(char* topic, byte* payload, unsigned int length);
void setRelay(char payload);

const char* ssid = "bergman_U";
const char* password = "gastvrij";
const char* mqtt_username= "mqtt_username";
const char* mqtt_password = "XXXXSECRETHEREXXXX";


WiFiClient wifiClient;
PubSubClient client(MQTT_SERVER, 1883, callback, wifiClient);

void setup() {
  //initialize the switch as an output and set to HIGH (on) (default)
  pinMode(LED_PIN, OUTPUT); // Led 1
  digitalWrite(LED_PIN, HIGH); // Led 1
  pinMode(RELAY_PIN, OUTPUT); // Relay Switch 1
  digitalWrite(RELAY_PIN, LOW); //  Relay Switch 1
  pinMode(TOGGLE_PIN, INPUT); // Toggle Button

  ArduinoOTA.setHostname("My Arduino SONOFF"); // A name given to your ESP8266 module when discovering it as a port in ARDUINO IDE
  ArduinoOTA.begin(); // OTA initialization

  //start the serial line for debugging
  Serial.begin(115200);
  delay(100);

  //start wifi subsystem
  WiFi.begin(ssid, password);
  //attempt to connect to the WIFI network and then connect to the MQTT server
  reconnect();

  //wait a bit before starting the main loop
      delay(2000);
}

void loop(){
  //reconnect if connection is lost
  if (!client.connected() && WiFi.status() == 3) {reconnect();}
  // insert button actions here;

  //check for button actions
  if (digitalRead(TOGGLE_PIN) == LOW) {
    m_relay_state = !m_relay_state; // switch state and setRelay accordingly
    if(m_relay_state == true){
      setRelay('1');
    }else{
      setRelay('0');
    }
    delay(1000);
  }

  //maintain MQTT connection
  client.loop();

  //MUST delay to allow ESP8266 WIFI functions to run
  delay(20);
  ArduinoOTA.handle();
}

void setRelay(char payload){
    if(payload == '1'){
      Serial.print("Set 1");
      digitalWrite(RELAY_PIN, HIGH);
      digitalWrite(LED_PIN, LOW);
      m_relay_state = true;
      client.publish(MQTT_LIGHT_STATE_TOPIC, "1");
    }
    //turn the switch off if the payload is '0' and publish to the MQTT server a confirmation message
    else if (payload == '0'){
      Serial.print("Set 0");
      digitalWrite(RELAY_PIN, LOW);
      digitalWrite(LED_PIN, HIGH);
      m_relay_state = false;
      client.publish(MQTT_LIGHT_STATE_TOPIC, "0");
    }
}

void callback(char* topic, byte* payload, unsigned int length) {
  //convert topic to string to make it easier to work with
  String topicStr = topic;
  //EJ: Note:  the "topic" value gets overwritten everytime it receives confirmation (callback) message from MQTT

  //Print out some debugging info
  Serial.println("Callback update.");
  Serial.print("Topic: ");
  Serial.println(topicStr);
  Serial.print("Payload: ");
  Serial.println(payload[0]);

  if (topicStr == MQTT_LIGHT_COMMAND_TOPIC){
    Serial.print(MQTT_LIGHT_COMMAND_TOPIC);
     //turn the switch on if the payload is '1' and publish to the MQTT server a confirmation message
    setRelay(payload[0]);
  }
}

void reconnect() {
  //attempt to connect to the wifi if connection is lost
  if(WiFi.status() != WL_CONNECTED){
    //debug printing
    Serial.print("Connecting to ");
    Serial.println(ssid);

    //loop while we wait for connection
    while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
    }

    //print out some more debug once connected
    Serial.println("");
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());
  }

  //make sure we are connected to WIFI before attemping to reconnect to MQTT
  if(WiFi.status() == WL_CONNECTED){
  // Loop until we're reconnected to the MQTT server
    while (!client.connected()) {
      Serial.print("Attempting MQTT connection...");

      // Generate client name based on MAC address and last 8 bits of microsecond counter
      String clientName;
      clientName += "esp8266-";
      uint8_t mac[6];
      WiFi.macAddress(mac);
      clientName += macToStr(mac);

      //if connected, subscribe to the topic(s) we want to be notified about
      //EJ: Delete "mqtt_username", and "mqtt_password" here if you are not using any
      if (client.connect((char*) clientName.c_str(),mqtt_username, mqtt_password)) {  //EJ: Update accordingly with your MQTT account
        Serial.print("\tMQTT Connected");
        client.subscribe(MQTT_LIGHT_COMMAND_TOPIC);
        //EJ: Do not forget to replicate the above line if you will have more than the above number of relay switches
      }

      //otherwise print failed for debugging
      else{Serial.println("\tFailed."); abort();}
    }
  }
}

//generate unique name from MAC addr
String macToStr(const uint8_t* mac){
  String result;
  for (int i = 0; i < 6; ++i) {
    result += String(mac[i], 16);

    if (i < 5){
      result += ':';
    }
  }
  return result;
}