#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>
#include <Keypad.h>
#include "HX711.h"
#include <EEPROM.h>


LiquidCrystal_I2C lcd1(0x27, 16, 2); 
LiquidCrystal_I2C lcd2(0x3F, 16, 2); 


const int LOADCELL_DOUT_PIN = A3;
const int LOADCELL_SCK_PIN = A4;
HX711 scale;


const byte ROWS = 4; 
const byte COLS = 4; 
char keys[ROWS][COLS] = {
  {'1','2','3','A'}, 
  {'4','5','6','B'},
  {'7','8','9','C'}, 
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {22, 23, 24, 25}; 
byte colPins[COLS] = {26, 27, 28, 29}; 
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);


struct User {
  char id[14];
  char name[16];
  int score;
};

const int MAX_USERS = 10; 
User users[MAX_USERS] = {
  {"6801062611332", "Kitisak", 0},
  {"6801062611197", "Nawat", 0},
  {"6801062610344", "Nutnicha", 0}
};
int totalUsers = 3; 
int currentUserIndex = 2;

const int EEPROM_MAGIC_NUMBER = 123; 


String inputID = ""; 
bool isLoggedIn = false;


const int trig1 = 2, echo1 = 3; 
const int trig2 = 4, echo2 = 5; 

const int metalSensorPin = A0; 
const int lightSensorPin = A2;  


Servo servoDiverter;
Servo servoMetal;   
Servo servoNonMetal; 

void setup() {
  Serial.begin(115200);
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  
  pinMode(trig1, OUTPUT); pinMode(echo1, INPUT);
  pinMode(trig2, OUTPUT); pinMode(echo2, INPUT);
  
  
  servoDiverter.attach(9); 
  servoMetal.attach(10); 
  servoNonMetal.attach(11); 
  
  
  servoDiverter.write(90); 
  servoMetal.write(90); 
  servoNonMetal.write(90);
  
  lcd1.init(); lcd1.backlight();
  lcd2.init(); lcd2.backlight();
  
  loadEEPROM(); 
  showIdleDisplay();
}

void loadEEPROM() {
  int magic;
  EEPROM.get(0, magic); 
  
  if (magic != EEPROM_MAGIC_NUMBER) {
    EEPROM.put(0, EEPROM_MAGIC_NUMBER);
    EEPROM.put(sizeof(int), totalUsers);
    for (int i = 0; i < totalUsers; i++) {
      EEPROM.put(sizeof(int)*2 + (i * sizeof(User)), users[i]);
    }
  } else {
    EEPROM.get(sizeof(int), totalUsers);
    for (int i = 0; i < totalUsers; i++) {
      EEPROM.get(sizeof(int)*2 + (i * sizeof(User)), users[i]);
    }
  }
}

void saveScoreToEEPROM() {
  EEPROM.put(sizeof(int)*2 + (currentUserIndex * sizeof(User)), users[currentUserIndex]);
}

void saveNewUserToEEPROM() {
  EEPROM.put(sizeof(int), totalUsers);
  EEPROM.put(sizeof(int)*2 + (currentUserIndex * sizeof(User)), users[currentUserIndex]);
}


void showIdleDisplay() {
  lcd1.clear();
  lcd1.setCursor(0, 0); lcd1.print("SMART BIN SYSTEM");
  lcd1.setCursor(0, 1); lcd1.print("Please Login...");
}

void updateUserDisplay() {
  lcd1.clear();
  lcd1.setCursor(0, 0); lcd1.print("User: " + String(users[currentUserIndex].name));
  lcd1.setCursor(0, 1); lcd1.print("Score: " + String(users[currentUserIndex].score)); 
}

void loop() {
  char key = keypad.getKey();

  if (!isLoggedIn) {
    
    lcd2.setCursor(0, 0); lcd2.print("Enter Student ID");
    lcd2.setCursor(0, 1); lcd2.print("ID:" + inputID + "    ");

    if (key) {
      if (key >= '0' && key <= '9') {
        if (inputID.length() < 13) inputID += key;
      } 
      else if (key == '*') {
        inputID = ""; lcd2.clear();
      } 
      else if (key == '#') {
        if (inputID.length() == 13) checkLogin(inputID);
        else {
          lcd2.clear(); lcd2.print("ID must be 13!");
          delay(1000); lcd2.clear();
        }
      }
    }
  } 
  else {
    
    if (key == 'C') { 
      isLoggedIn = false; inputID = "";
      showIdleDisplay();
      lcd2.clear(); lcd2.print("Logged Out");
      delay(1500); lcd2.clear();
      return;
    }
    else if (key == 'A') { 
      users[currentUserIndex].score = 0;
      saveScoreToEEPROM(); 
      updateUserDisplay(); 
      lcd2.clear(); lcd2.print("Score Reset!");
      delay(1500); lcd2.clear();
    }

    handleSortingProcess();
  }
}

void checkLogin(String id) {
  int foundIndex = -1;
  for (int i = 0; i < totalUsers; i++) {
    if (String(users[i].id) == id) { foundIndex = i; break; }
  }

  lcd2.clear();
  if (foundIndex != -1) {
    isLoggedIn = true;
    currentUserIndex = foundIndex;
    updateUserDisplay();
    lcd2.print("Login Success!");
    delay(1500); lcd2.clear();
  } 
  else {
    lcd2.print("ID Not Found!");
    lcd2.setCursor(0, 1); lcd2.print("#: Register New");
    
    unsigned long start = millis();
    bool confirmed = false;
    while(millis() - start < 5000) {
      char k = keypad.getKey();
      if (k == '#') { confirmed = true; break; }
      if (k == '*') break;
    }

    if (confirmed && totalUsers < MAX_USERS) {
      id.toCharArray(users[totalUsers].id, 14);
      String tempName = "User_" + id.substring(9);
      tempName.toCharArray(users[totalUsers].name, 16);
      users[totalUsers].score = 0;
      
      currentUserIndex = totalUsers;
      totalUsers++;
      isLoggedIn = true;
      
      saveNewUserToEEPROM(); 
      updateUserDisplay();
      lcd2.clear(); lcd2.print("Registered!");
    } else {
      inputID = ""; lcd2.clear();
    }
    delay(1500);
  }
}

void handleSortingProcess() {
  long binLevel = getDistance(trig2, echo2);
  if (binLevel < 5 && binLevel > 0) { 
    lcd2.setCursor(0, 0); lcd2.print("BIN IS FULL!    ");
    return; 
  }

  lcd2.setCursor(0, 0); lcd2.print("Ready to sort...");
  lcd2.setCursor(0, 1); lcd2.print("Insert Item ->"); 

  long dropDist = getDistance(trig1, echo1);
  if (dropDist > 0 && dropDist <= 10) {
    lcd2.clear(); lcd2.print("Processing...");
    delay(1000);

    
    int metalVal = analogRead(metalSensorPin); 
    int lightVal = analogRead(lightSensorPin); 
    float weight = scale.get_units(1); 
    int wFactor = map(constrain(weight, 0, 1000), 0, 1000, 1, 10);

    String type = ""; int pts = 0;

    
    
    
    if (metalVal > 100) { 
    
      servoDiverter.write(45); 
      delay(1000);

      
      if (metalVal > 700) {
        type = "Iron/Steel"; pts = 10 + wFactor;
        servoMetal.write(180); 
      } else if (metalVal > 400) {
        type = "Aluminum"; pts = 8 + wFactor;
        servoMetal.write(90);  
      } else {
        type = "Copper/Brass"; pts = 15 + wFactor; 
        servoMetal.write(0);   
      }
      
      delay(2000);
      servoMetal.write(90); 
      
    } else { 
      
      servoDiverter.write(135); 
      delay(1000);

      
      if (lightVal > 700) { 
        
        if(wFactor > 5) { 
          type = "Clear Bottle"; pts = 5; 
          servoNonMetal.write(0); 
        } else { 
          type = "Plastic"; pts = 3; 
          servoNonMetal.write(60); 
        }
      } else { 
        
        if(wFactor > 4) { 
          type = "Paper"; pts = 2; 
          servoNonMetal.write(120); 
        } else { 
          type = "Bio/Wood"; pts = 1; 
          servoNonMetal.write(180); 
        }
      }
      
      delay(2000);
      servoNonMetal.write(90); 
    }

    
    delay(500);
    servoDiverter.write(90); 

     
    users[currentUserIndex].score += pts;
    saveScoreToEEPROM();  
    updateUserDisplay();  
    
   
    lcd2.clear();
    lcd2.print(type);
    lcd2.setCursor(0, 1); lcd2.print("Point: +" + String(pts));
    delay(3000); lcd2.clear();
  }
}

long getDistance(int trig, int echo) {
  digitalWrite(trig, LOW); delayMicroseconds(2);
  digitalWrite(trig, HIGH); delayMicroseconds(10);
  digitalWrite(trig, LOW);
  return pulseIn(echo, HIGH) * 0.034 / 2;
}