#include <LiquidCrystal.h>

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 53, en = 51, d4 = 49, d5 = 47, d6 = 45, d7 = 43;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

int red = 13;       // the red LED for Salad.
int green = 12;     // the green LED for fish.
int yellow = 11;    // the ywllow LED for Escalope.
int white = 10;     // the white LED for emergency case.


int customerButton = 8;   // push button to indicate new customer
int waiterButton = 7;     // push button to to accept to serve a customer
int fishButton = 6;       // push button to indicate the customer wants fish meal
int escalopeButton = 5;   // push button to indicate the customer wants Escalope meal
int saladButton = 4;      // push button to indicate the customer wants salad meal
int chefButton = 3;       // push button to indicate the chef has started to prepare that customer’s order
int emergencyButton = 2;  // push button to indicate emergency case

int potentiometer = A0;   // potentiometer to choose the weight of fish meal

int normalCase = 1;       // variable to indicate the normal case
int emergencyCase = 2;    // variable to indicate the emergency case
int status;               // variable to indicate the current status

int counter = 0;          // variable to store customer’s number
int waitingNumber = 0;    // variable to store a waiting number


int customerOrder = 0;    // variable to store the customer order
int fish = 8000;          // will be with the chef for 8 seconds
int Escalope = 6000;      // will be with the chef for 6 seconds
int salad = 4000;         // will be with the chef for 4 seconds
int chefBreak = 3000;     // 3 second break between every 2 customer

int emergencyTime = 0;    // will be with the chef for home delivery order

int fishWeight = 0;       // variable to store the weight of fish meal
int weight250g = 3;       // variable to indicate the weight of fish is 250 g
int weight500g = 2;       // variable to indicate the weight of fish is 500 g
int weight750g = 1;       // variable to indicate the weight of fish is 750 g

int breakCounter = 0;     // variable to store the customer counter according to chef break
int none = 0;             // variable to indicate none status


int normalState = 1;      // variable to indicate normal status
int emergencyState = 2;   // variable to indicate the emergency status
int breakTime = 3;        // variable to indicate the break time


int holdState = 4;        // variable to indicate the hold status
int mode;                 // varible to store current mode

unsigned long elapsedTime;        // variable to store the elapsed time of current mode before emergency
int previousMode;                 // variable to store the previous mode before the emergency

unsigned long previousMillis = 0; // variable to store the previous time in millis
unsigned long currentMillis;      // vraiable to store the current time in millis

bool waitConfirmation = false;    // variable to indicate the chef confiramation incase of emergency 


int PWM_Value = 0;                // variable to set the duty cycle of PWM
int randCustomer = 0;             // variable to store the customer random value 
bool newOrder = false;            // variable to indicate the new order

bool buttonFlag = false;          // store the customer button state

void setup() {
  // put your setup code here, to run once:
  pinMode(green, OUTPUT);                     // set the digital pin as output
  pinMode(red, OUTPUT);                       // set the digital pin as output
  pinMode(white, OUTPUT);                     // set the digital pin as output
  pinMode(yellow, OUTPUT);                    // set the digital pin as output
  pinMode(customerButton, INPUT_PULLUP);      // set the digital pin as input
  pinMode(waiterButton, INPUT_PULLUP);        // set the digital pin as input
  pinMode(fishButton, INPUT_PULLUP);          // set the digital pin as input
  pinMode(escalopeButton, INPUT_PULLUP);      // set the digital pin as input
  pinMode(saladButton, INPUT_PULLUP);         // set the digital pin as input
  pinMode(chefButton, INPUT_PULLUP);          // set the digital pin as input
  pinMode(emergencyButton, INPUT_PULLUP);     // set the digital pin as input
  // attach external interrupt to digital pin
  attachInterrupt(digitalPinToInterrupt(emergencyButton), emergency, FALLING);
  lcd.begin(16, 2);                           // initialize LCD
  Serial.begin(9600);                         // initialize serial
  Serial3.begin(9600);                        // initialize serial
  Serial.println("Start the system");         // serial monitor
  Serial3.println("Start the system");
  delay(1000);
  status = normalCase;
  lcd.clear();                                // clear LCD
  waitConfirmation = false; 
   mode = none;      
}

void loop() 
{
  // put your main code here, to run repeatedly:
  if (digitalRead(customerButton) == LOW && buttonFlag == false) {
    waitingNumber++;            // increment customer’s number
    lcd.clear();                // clear LCD
    lcd.setCursor(0, 0);        // set the LCD position
    lcd.print("C #: ");         // display text on LCD
    lcd.setCursor(6, 0);        // set the LCD position
    lcd.print(waitingNumber);   // display text on LCD
    lcd.setCursor(8, 0);        // set the LCD position
    lcd.print(" welcome");      // set the LCD position
    lcd.setCursor(0, 1);        // set the LCD position
    lcd.print("let's Order");   // display text on LCD
    buttonFlag = true;
    delay(1000);
  }
  else{
    buttonFlag = false;
  }
  if (digitalRead(waiterButton) == LOW) // check the waiter button
  {  
    if (mode == none) {
       if (counter < waitingNumber) // check there are waiting customers 
       {      
        counter++;                  // increment the counter
        breakCounter++;             // increment the break counter 
        newOrder = true;
        delay(500);
      } else {
        lcd.clear();                // clear LCD
        lcd.setCursor(0, 0);        // set the LCD position
        lcd.print("no customer");   // display text on LCD
        lcd.setCursor(0, 1);        // set the LCD position
        lcd.print("are waiting");   // display text on LCD
        delay(2000);
        lcd.clear();                // clear LCD
        return;
      }                             // check the customer status should be none
      if (breakCounter > 3 && mode != breakTime) // check the break status
      {   
        breakCounter = 0;             // reset the break counter 
        mode = breakTime;             // change the mode of the system to break
        previousMillis = millis();    // store the previous time 
      } else {
        mode = normalState;           // change the current mode  to normal 
        previousMillis = millis();    // store the previous time 
        }     
     
    } else {
      lcd.clear();                   // clear LCD
      lcd.setCursor(0, 0);           // set the LCD position on row 0 column 1
      lcd.print("chef ");            // display text on LCD
      lcd.setCursor(0, 1);           // set the LCD position on row 1 column 1
      lcd.print("still busy");       // display text on LCD
      delay(2000);
      lcd.clear();                   // clear LCD
    }
  }
  if (mode == normalState) {
    if(newOrder == true)
    {
      lcd.clear();               // clear LCD
      lcd.setCursor(0, 0);       // set the LCD position
      lcd.print("customer's #"); // display text on LCD
      lcd.print(counter);        // display text on LCD
      lcd.print("   ");          // display text on LCD
      lcd.setCursor(0, 1);       // set the LCD position
      lcd.print("ordering");     // display text on LCD
      while(digitalRead(fishButton) && digitalRead(escalopeButton) && digitalRead(saladButton));   
      if(digitalRead(fishButton) == LOW)
      {
        customerOrder = fish;
        lcd.clear();               // clear LCD
        lcd.setCursor(0, 0);       // set the LCD position
        lcd.print("fish is selected");  // display text on LCD
        lcd.setCursor(0, 1);       // set the LCD position 
        int potValue = analogRead(potentiometer);
        if(potValue < 300){
          fishWeight = weight750g;
          lcd.print("weight 750 g ");  // display text on LCD
        }
        else if(potValue >= 300 && potValue < 800){
          fishWeight = weight500g;
          lcd.print("weight 500 g ");  // display text on LCD
        }
        else{
          fishWeight = weight250g;
          lcd.print("weight 250 g");  // display text on LCD
        }
        
        
        
        newOrder = false;     

      }

      if(digitalRead(escalopeButton) == LOW)
      {
        customerOrder = Escalope;
        lcd.clear();                // clear LCD
        lcd.setCursor(0, 0);        // set the LCD position
        lcd.print("Escalope is");   // display text on LCD
        lcd.setCursor(0, 1);        // set the LCD position
        lcd.print("selected");      // display text on LCD    
        newOrder = false;

      }

      if(digitalRead(saladButton) == LOW)
      {
        customerOrder = salad;
        lcd.clear();                // clear LCD
        lcd.setCursor(0, 0);        // set the LCD position
        lcd.print("salad is");      // display text on LCD
        lcd.setCursor(0, 1);        // set the LCD position
        lcd.print("selected");      // display text on LCD      
        newOrder = false;

      }
      while(digitalRead(chefButton) == HIGH); // check the chef button


      previousMillis = millis();    // store the previous time 
    }
    lcd.clear();
    lcd.setCursor(0, 0);          // set the LCD position 
    lcd.print("#");               // display text on LCD
    lcd.print(counter);           // display text on LCD
    lcd.setCursor(5, 0);          // set the LCD position 
    lcd.print("meal being   ");   // display text on LCD
    lcd.setCursor(0, 1);          // set the LCD position 
    lcd.print("prepared-");       // display text on LCD

    currentMillis = millis();     // update the value of the current time
    int sec = (currentMillis - previousMillis) / 1000;    // calculate the time in sec
    char buffer[8];
    sprintf(buffer, "%d sec  ", sec);     // convert the time to string array 
    lcd.setCursor(11, 1);                 // set the LCD position
    lcd.print(buffer);                    // display text on LCD
    if(customerOrder == fish)
      digitalWrite(green, HIGH);          // turn on the green LED
    if(customerOrder == Escalope)
      digitalWrite(yellow, HIGH);         // turn on the yellow LED
    if(customerOrder == salad)
      digitalWrite(red, HIGH);            // turn on the red LED
    if ((currentMillis - previousMillis) > customerOrder)  // check the minimum interval of the break time is completed
    {
      delay(500);
      mode = none;                    // change the system mode to none
      customerOrder = none;
  
      lcd.clear();                    // clear LCD
      lcd.setCursor(0, 0);            // set the LCD position
      lcd.print("customer's #");      // display text on LCD
      lcd.print(counter);             // display text on LCD
      lcd.print("   ");               // display text on LCD
      lcd.setCursor(0, 1);            // set the LCD position
      lcd.print("being served");      // display text on LCD
      digitalWrite(red, LOW);         // turn off the red LED
      digitalWrite(yellow, LOW);      // turn off the yellow LED
      digitalWrite(green, LOW);       // turn off the green LED
      delay(2000);
      lcd.clear();                    // clear LCD
    }
    delay(200);
  }

  else if (mode == breakTime) {
    lcd.setCursor(0, 0);          // set the LCD position
    lcd.print("break time    ");  // display text on LCD
    lcd.setCursor(0, 1);          // set the LCD position
    lcd.print("        ");        // display text on LCD
    currentMillis = millis();     // update the value of the current time
    int sec = (currentMillis - previousMillis) / 1000;
    char buffer[8];
    sprintf(buffer, "(%d sec)  ", sec);
    lcd.setCursor(8, 1);          // set the LCD position
    lcd.print(buffer);            // display text on LCD
      digitalWrite(red, LOW);     // turn off the red LED
      digitalWrite(yellow, LOW);  // turn off the yellow LED
      digitalWrite(green, LOW);   // turn off the green LED
    if ((currentMillis - previousMillis) > chefBreak)  // check the minimum interval of the break time is completed
    {
      delay(500);
      mode = normalState;
      previousMillis = millis();
    }
  } 
  else if (mode == emergencyState) {

    if(randCustomer == fish)
    {
    lcd.setCursor(0, 0);          // set the LCD position
    lcd.print("home delivery");   // display text on LCD
    lcd.setCursor(0, 1);          // set the LCD position
    lcd.print("fish meal     ");     // display text on LCD
    emergencyTime = randCustomer;
    randCustomer = 0;
    delay(2000);
    }
    else if(randCustomer == Escalope)
    {
    lcd.setCursor(0, 0);          // set the LCD position
    lcd.print("home delivery");   // display text on LCD
    lcd.setCursor(0, 1);          // set the LCD position
    lcd.print("Escalope meal  "); // display text on LCD
    emergencyTime = randCustomer;
    randCustomer = 0;
    delay(2000);
    }
    else if(randCustomer == salad)
    {
    lcd.setCursor(0, 0);          // set the LCD position
    lcd.print("home delivery");   // display text on LCD
    lcd.setCursor(0, 1);          // set the LCD position
    lcd.print("salad         "); // display text on LCD
    emergencyTime = randCustomer;
    randCustomer = 0;
    delay(2000);
    }
    lcd.setCursor(0, 0);          // set the LCD position
    lcd.print("customer's #");    // display text on LCD
    lcd.print(counter);           // display text on LCD
    lcd.print("   ");             // display text on LCD
    lcd.setCursor(0, 1);          // set the LCD position
    lcd.print("on hold         ");// display text on LCD
    currentMillis = millis();     // update the value of the current time
    int sec = (currentMillis - previousMillis) / 1000;      // calculate the time in sec
    PWM_Value = sec * 10;
    char buffer[8];
    sprintf(buffer, "(%d sec)  ", sec);                     // convert the time to string array 
    lcd.setCursor(8, 1);                                    // set the LCD position on row 1 column 9
    lcd.print(buffer);                                      // display text on LCD
    digitalWrite(red,LOW);                                  // turn off red LED
    digitalWrite(yellow,LOW);                               // turn off yellow LED
    digitalWrite(green,LOW);                                // turn off green LED
    analogWrite(white, PWM_Value);                          // turn on white LED with PWM
    if ((currentMillis - previousMillis) > emergencyTime)   // check the minimum interval of the emergency time is completed
    {
      delay(500);
      analogWrite(white, 0);                            // turn off white LED
      mode = previousMode;                              // change the current mode to the previous mode
      previousMillis = millis() - elapsedTime;          // update the prevoius time 
    }
  } 
  else if (mode == none && waitingNumber == 0) {
    lcd.setCursor(0, 0);                // set the LCD position
    lcd.print("Welcome           ");   // display text on LCD
    lcd.setCursor(0, 1);                // set the LCD position
    lcd.print("Let's Order     ");   // display text on LCD
  }
  else if (mode == none && waitingNumber != 0) {
    lcd.setCursor(0, 0);                // set the LCD position
    lcd.print("Welcome            ");      // display text on LCD
    lcd.setCursor(0, 1);                // set the LCD position
    lcd.print("Let's Order       ");   // display text on LCD
  }


    if(waitConfirmation == true)        // check the emergency 
    {

    Serial3.println(" An emergency case has arrived; press (y) to begin it."); // inform the doctor with the coming emergency case
    waitConfirmation = false;           // set the emergency confirmation
    }



  if(Serial.available())                // check serial monitor in Arduino IDE
  {
    char x = Serial.read();             // read serial data from chef 
    if((x == 'y' || x == 'Y') && waitConfirmation == false) // check 'y' is received and emergency case is true
    {
    PWM_Value = 0;  
     
    int ran = random(0, 3);
    if (ran == 0)                       // generate random number (0,1 or 2)
      randCustomer = fish;              // fish is selceted
    else if (ran == 1)
      randCustomer = Escalope;          // Escalope is selected
    else if (ran == 2)
      randCustomer = salad;             // salad is selected
    delay(100);
    if (mode != 0)                    // check the current mode is none
    {   
      elapsedTime = millis() - previousMillis;  // store the elapsed time
      previousMode = mode;                      // store the previous mode
    }
    else
    {
      previousMode = none;    // clear the previous mode
      elapsedTime = 0;        // clear the elapsed time
    }
    mode = emergencyState;        // change the system mode to emergency
    previousMillis = millis();    // store the previous time 
    }
  }

}

  void emergency() {
    waitConfirmation = true; 
  }