/* Smart Bin Project 2025
   Name: GUO CHAO
   Class: DEEC1
   Date: 20 JUL 2025
   
*/

#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>
#include <LiquidCrystal_I2C.h>  // Include LCD library

// LCD Configuration (I2C address typically 0x27 or 0x3F)
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Set the LCD address and dimensions

const char* ssid = "Wokwi-GUEST";
const char* password = "";
 
const char* hostname = "broker.hivemq.com";
 
WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "esp32Client_9951651U";
int PORTNUM = 1883;

// Bin status variables
String binStatus = "Initializing...";
int lastAdcValue = 0;
 
void setup_wifi() {
  WiFi.begin(ssid, password);
  while(WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
    lcd.setCursor(0, 0);
    lcd.print("Connecting WiFi");
    lcd.setCursor(0, 1);
    lcd.print("SSID: Wokwi-GUEST");
  }
  
  Serial.println();
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("Given IP by the router to ESP32 is ");
  Serial.println(WiFi.localIP());
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("WiFi Connected");
  lcd.setCursor(0, 1);
  lcd.print("IP: ");
  lcd.print(WiFi.localIP());
  delay(2000);
}
 
void callback(String topic, byte* tpayLoad, unsigned int length) {
  String payload;
 
  for (int i = 0; i < length; i++) {
    payload += (char)tpayLoad[i];
  }
 
  // Handle your topics and payload here
  if (topic == "GUO/9951651U/GreenLED") {
    if (payload == "On") {
      digitalWrite(18, LOW);
      lcd.setCursor(0, 1);
      lcd.print("Green LED ON    ");
    }
    else if (payload == "Off") {
      digitalWrite(18, HIGH);
      lcd.setCursor(0, 1);
      lcd.print("Green LED OFF   ");
    }
  }
  else if (topic == "GUO/9951651U/YellowLED") {
    if (payload == "On") {
      digitalWrite(19, LOW);
      lcd.setCursor(0, 1);
      lcd.print("Yellow LED ON   ");
    }
    else if (payload == "Off") {
      digitalWrite(19, HIGH);
      lcd.setCursor(0, 1);
      lcd.print("Yellow LED OFF  ");
    }
  }
  else if (topic == "GUO/9951651U/RedLED") {
    if (payload == "On") {
      digitalWrite(23, LOW);
      lcd.setCursor(0, 1);
      lcd.print("Red LED ON      ");
    }
    else if (payload == "Off") {
      digitalWrite(23, HIGH);
      lcd.setCursor(0, 1);
      lcd.print("Red LED OFF     ");
    }
  }
  
  // Update LCD with MQTT command info
  lcd.setCursor(0, 0);
  lcd.print("MQTT Cmd: ");
  lcd.print(topic.substring(0, 6));
  delay(1000);
  updateLCDStatus(); // Return to normal display
}
 
void MQTTSubscribe() {
  client.subscribe("GUO/9951651U/GreenLED");  
  client.subscribe("GUO/9951651U/YellowLED");
  client.subscribe("GUO/9951651U/RedLED");
}
 
void setup_MQTT() {
  client.setServer(hostname, PORTNUM);
  client.setCallback(callback);
}
 
void connectMQTT() {
  while(!client.connected()) {
    Serial.println("Connecting to MQTT ...");
    lcd.clear();
    lcd.print("Connecting MQTT");
    
    if (client.connect(espClientName)) {
      Serial.println("Connected");
      lcd.setCursor(0, 1);
      lcd.print("MQTT Connected");
      delay(1000);
      MQTTSubscribe();
    }
    else {
      Serial.print("Failed with state ");
      Serial.print(client.state());
      lcd.setCursor(0, 1);
      lcd.print("Failed: ");
      lcd.print(client.state());
      delay(2000);
    }
  }
}

void updateLCDStatus() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Bin Status:");
  
  lcd.setCursor(0, 1);
  lcd.print(binStatus);
  
  lcd.setCursor(13, 1);
  lcd.print(lastAdcValue);
}
 
void setup() {
  Serial.begin(9600);
  
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Smart Bin System");
  lcd.setCursor(0, 1);
  lcd.print("Initializing...");
  delay(2000);
 
  setup_wifi();
  setup_MQTT();
 
  pinMode(18, OUTPUT); // Green LED
  pinMode(19, OUTPUT); // Yellow LED
  pinMode(23, OUTPUT); // Red LED
  pinMode(25, INPUT);  // Button
}
 
void loop() {
  if (!client.connected()) {
    connectMQTT();
  }
  client.loop();
 
  int adcRes = analogRead(A5);
  Serial.print("Analog Value: ");
  Serial.println(adcRes);
  lastAdcValue = adcRes;
  
  // Publish ADC value
  char payload[10];
  snprintf(payload, sizeof(payload), "%d", adcRes);
  client.publish("GUO/9951651U/ADC", payload);
 
  if (adcRes >= 0 && adcRes <= 1000) {
    digitalWrite(18, LOW);
    digitalWrite(19, HIGH);
    digitalWrite(23, HIGH);
    binStatus = "Empty/Low    ";
    Serial.println("Green LED ON: Easy/Little-Trash");
  }
  else if (adcRes > 1000 && adcRes <= 3000) {
    digitalWrite(18, HIGH);
    digitalWrite(19, LOW);
    digitalWrite(23, HIGH);
    binStatus = "Half Full    ";
    Serial.println("Yellow LED ON: Alert/AlmostFull-Trash");
  }
  else if (adcRes > 3000 && adcRes <= 4095) {
    if (digitalRead(25) == 0) {
      digitalWrite(23, HIGH);
      binStatus = "Reset Mode   ";
      Serial.println("Red LED OFF: RESET");
    }
    else {
      digitalWrite(23, LOW);
      digitalWrite(18, HIGH);
      digitalWrite(19, HIGH);
      binStatus = "FULL! Clean! ";
      Serial.println("Red LED ON: Danger/Full-Trash");
    }
  }
  else {
    digitalWrite(18, LOW);
    digitalWrite(19, LOW);
    digitalWrite(23, HIGH);
    binStatus = "Error        ";
  }
  
  updateLCDStatus();
  delay(2000);
}