#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <SPI.h>
#include <MFRC522.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

const int SS_PIN = 4;
const int RST_PIN = 5;
const int LOCK = 16;

// WIFI
const char* ssid = "Edelweiss";
const char* password = "homesweethome";
const char* mqtt_server = "192.168.0.212";

bool lockState = false;

MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance
WiFiClient espClient;
PubSubClient client(espClient);

String getString(byte* payload, unsigned int length) {
  String tmp = "";
  for (int i = 0; i < length; i++)  tmp += (char)payload[i];
  return tmp;
}

void setup_lock() {
  pinMode(LOCK, OUTPUT);
}

void setup_wifi() {
  Serial.println("Connecting");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  randomSeed(micros());
}

void setup_rfid() {
  SPI.begin();      // Initiate  SPI bus
  mfrc522.PCD_Init();   // Initiate MFRC522
}


void findNewCards() {
  if ( ! mfrc522.PICC_IsNewCardPresent() || ! mfrc522.PICC_ReadCardSerial()) return;
  delay(2000);
}

String getRFIDUID() {

  findNewCards();

  Serial.print("UID tag :");
  String content = "";
  char message_buff[100] = "";

  for (byte i = 0; i < mfrc522.uid.size; i++){
    content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? "0" : ""));
    content.concat(String(mfrc522.uid.uidByte[i], HEX));
  }

  content.toUpperCase();
  content.toCharArray(message_buff, content.length() + 1);
  client.publish("cardUID", message_buff);

  return message_buff;
}


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

  Serial.println("Dit is de payload van de callback");
  Serial.println(getString(payload, length));

  if (getString(payload, length) == "true") {
    digitalWrite(LOCK, HIGH);
    Serial.println("Slot open");
  }

  if (getString(payload, length) == "false") {
    digitalWrite(LOCK, LOW);
    Serial.println("Slot dicht");
  }
}

void reconnect() {

  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.println("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str())) {
      client.subscribe("acces");
    }
    else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}


void setup() {
  Serial.begin(115200);
  setup_wifi();
  setup_rfid();
  setup_lock();

  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {
  if (!client.connected()) reconnect();
  client.loop();

  delay(500);
  getRFIDUID();

}