// Library
#include <ESP32Servo.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include "HX711.h"
#include "ArduinoJson.h"
#include <HTTPClient.h>

// Variables
Servo servoFood;
Servo servoDoor;
HX711 scale;

const int LOADCELL_DOUT_PIN = 21;
const int LOADCELL_SCK_PIN = 19;
int servoFoodPin = 13;
int servoDoorPin = 12;
int buzzerPin = 33;
const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* mqttServer = "broker.hivemq.com"; 
int port = 1883;
WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

// Test food amount
int food = 0;

// Internet connection
void wifiConnect() {
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected!");
}

void mqttConnect() {
  while(!mqttClient.connected()) {
    Serial.println("Attemping MQTT connection...");
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    if(mqttClient.connect(clientId.c_str())) {
      Serial.print("Connected!");

      //***Subscribe all topic you need***
      mqttClient.subscribe("21127345/DoAnCuoiKiInput");
    }
    else {
      Serial.println("Try again in 5 seconds");
      delay(5000);
    }
  }
}

//MQTT Receiver
void callback(char* topic, byte* message, unsigned int length) {
  Serial.println(topic);
  String strMsg;
  for(int i=0; i<length; i++) {
    strMsg += (char)message[i];
  }
  Serial.println(strMsg);
  int num = 0;

  //***Code here to process the received package**
  // Json code is from: https://www.youtube.com/watch?v=iuHxPQB6Rx4 (Applying for version 5)
  // Upgrading to version 6 is seen in this link: https://arduinojson.org/v6/doc/upgrade/

  StaticJsonDocument<300> doc;
  auto error = deserializeJson(doc, strMsg);
  // Give errors when there is parsing error
  if (error) {
    Serial.print(F("deserializeJson() failed with code "));
    Serial.println(error.c_str());
    return;
  }
  // Take data from input JSON
  int phanAn = doc["PhanAn"];
  Serial.println(phanAn);
  bool batLoa = doc["BatLoa"];

  // Check if there is still food
  if (food <= 0) {
    return;
  }

  // Feeding servo
  for (int i = 0; i < phanAn; i++) {
    if (checkServoFood()) {
      food = scale.get_units() / 2100 * 5000; // Dòng này là dùng để cập nhật lại lượng thức ăn
      remainFoodNotif();
    }
    else {
      return;
    }
  }

  // Servo for door
  if (phanAn) {
    if (!servoDoorWork()) {
      return;
    }

    // Buzzer
    if (batLoa) {
      buzzerWork();
    }
  }

}

void setup() {
  Serial.begin(9600);

  configTime(7 * 3600, 0, "pool.ntp.org");

  // Internet setup
  Serial.print("Connecting to WiFi");
  wifiConnect();
  mqttClient.setServer(mqttServer, port);
  mqttClient.setCallback(callback);
  mqttClient.setKeepAlive( 90 );

  // Servo setup
  servoDoor.attach(servoDoorPin);
  servoFood.attach(servoFoodPin);
  servoFood.write(0);
  servoDoor.write(180);

  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
}

void loop() {
  // Internet
  if(!mqttClient.connected()) {
    mqttConnect();
  }
  mqttClient.loop();

  // Update food
  food = scale.get_units() / 2100 * 5000;
  remainFoodNotif();
  delay(3000);
}

// Functions
/* Servo quay phần đồ ăn
- Đầu tiên hàm sẽ kiểm tra xem servo đang ở góc nhiêu độ
- Nếu là 180 độ thì quay về 0, còn nếu là 0 thì quay 180
- Sau khi quay, kiểm tra xem liệu quay đủ chưa, chưa đủ thì báo kẹt*/
bool checkServoFood() {
  if (servoFood.read() > 175) {
    servoFood.write(0);
    delay(2000);
    
    // Kiểm tra kẹt
    if (servoFood.read() > 5 || servoFood.read() < -5) {
      mqttClient.publish("21127345/MachineAlert", "Servo quay phần đồ ăn bị kẹt");
      return 0;
    }
  }

  else { 
    servoFood.write(180); 
    delay(2000);

    // Kiểm tra kẹt
    if (servoFood.read() > 185 || servoFood.read() < 175) {
      mqttClient.publish("21127345/MachineAlert", "Servo quay phần đồ ăn bị kẹt");
      return 0;
    }
  }
  mqttClient.publish("21127345/MachineAlert", "");
  return 1;
}

bool servoDoorWork() {
  servoDoor.write(90);
  delay(5000);

  // Kiểm tra kẹt
  if (servoDoor.read() < 120) {
    servoDoor.write(180);
    delay(2000);
    if (servoDoor.read() < 175) {
      mqttClient.publish("21127345/MachineAlert", "Servo cửa đóng chưa chặt");
      return 0;
    }
  }

  else {
    mqttClient.publish("21127345/MachineAlert", "Servo cửa bị kẹt");
    return 0;
  }

  return 1;
}

void buzzerWork() {
  for (int i = 0; i < 5; i++) {
    tone(buzzerPin, 262, 1000);
  }
  noTone(buzzerPin);
}

void remainFoodNotif() {
  char buffer[10];
  sprintf(buffer, "%s", String(food));
  mqttClient.publish("21127345/FoodNotif", buffer);

  if (food < 100) {
    mqttClient.publish("21127345/FoodAlert", "Vui lòng nạp thêm thức ăn vào máy");
    
    HTTPClient http;
    String event = "send_emer_food";
    String apiKey = "bSK-eSTNQ1pneR465knJhu"; // Thay YOUR_API_KEY_HERE bằng API Key của bạn

    String url = "https://maker.ifttt.com/trigger/" + event + "/with/key/" + apiKey;
    url += "?value1=" + String(food);

    http.begin(url);
    int httpResponseCode = http.POST("");  // Gửi POST request mà không cần dữ liệu
    http.end();
  }

  else if (food < 1000) {
    mqttClient.publish("21127345/FoodAlert", "Sắp hết thức ăn");
  }

  else {
    mqttClient.publish("21127345/FoodAlert", "");
  }
}