#include <ButtonDebounce.h>
#include <LiquidCrystal_I2C.h>
//For Documentation for the Libraries:
/*
  LiquicCrystal_I2C = https://github.com/fdebrabander/Arduino-LiquidCrystal-I2C-library
  ButtonDebounce    = https://github.com/maykon/ButtonDebounce
*/

//For Defining Input Pins
#define e_stop_pin  8
#define auto_pin    9
#define manual_pin  10

//For Degining Output Pins
#define red_led     7
#define green_led   6
#define yellow_led  5

//Initialization for the ButtonDebounce Library
ButtonDebounce e_stop       (e_stop_pin, 50);
ButtonDebounce auto_mode    (auto_pin, 50);
ButtonDebounce manual_mode  (manual_pin, 50);

//for storing last states of the button/switches used
bool last_e_stop_state, last_auto_state, last_manual_state;

// Set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2); 

//For Millis() prerequisite
unsigned long currentMillis;
unsigned long lastCurrentMillis;
unsigned long conveyorTimeRun = 3000;   //Equivalent to 3 seconds
unsigned long conveyorTimeStop = 1000;
unsigned long injectingTimeRun = 3000;
unsigned long injectingTimeRetract = 3000;

//For processes state
/*
  Stat:
  ConvRun   --Conveyor Run
  ConvStop  --Conveyor Stop
  Inject    --Syringe Inject
  Retract   --Syringe Retract
*/
String runningStat = "ConvRun";   //Default value


void setup() 
  {
    Serial.begin(9600);
    lcd.begin(16, 2);

    //For Outputs
    pinMode(red_led, OUTPUT);
    pinMode(green_led, OUTPUT);
    pinMode(yellow_led, OUTPUT);

    //Setting up what the current state of the btns
    last_e_stop_state = !e_stop.state();
    last_auto_state   = !auto_mode.state();
    last_manual_state = !manual_mode.state();
  }

void loop() 
  {
    output();   //for outputs function
    display();    //for display function

    //Necessary to put these to void loop
    //as required by the ButtonDebounce Library
    e_stop.update();
    auto_mode.update();
    manual_mode.update();
  }

void output()
  {
    if (e_stop.state() == LOW)
      {
        if (auto_mode.state() == LOW)
          {
              //Sets the Green Condition On
              digitalWrite(red_led, LOW);
              digitalWrite(green_led, HIGH);
              digitalWrite(yellow_led, LOW);

            //Insert auto mode process here
            //avoid using delay(), use millis() instead
            //example process:
              /*
              1. 3 seconds conveyor run
              2. 1 seconds conveyor stop
              3. 3 seconds injecting
              4. 3 seconds retraction
              */
            //ConvRun
            if (runningStat == "ConvRun")
              {
                //time starts
                currentMillis = millis();
                //Serial.println("im here!");

                //For Serial Monitor
                Serial.println("Conveyor Run!");

                //For LCD Display
                lcd.setCursor(0,1);
                lcd.print("Conveyor Running");

                //Insert your output commands here

                if (currentMillis - lastCurrentMillis >= conveyorTimeRun)
                  {
                    //makes the currentMillis as the lastCurrentMillis
                    lastCurrentMillis = currentMillis;
                    
                    //moves the next status to ConvStop
                    runningStat = "ConvStop";
                  }
              }
            //ConvStop
            else if (runningStat == "ConvStop")
              {
                //time starts
                currentMillis = millis();

                //For Serial Monitor
                Serial.println("Conveyor Stop!");

                //For LCD Display
                lcd.setCursor(0,1);
                lcd.print(" Conveyor  Stop ");

                //Insert your output commands here

                if (currentMillis - lastCurrentMillis >= conveyorTimeStop)
                  {
                    //makes the currentMillis as the lastCurrentMillis
                    lastCurrentMillis = currentMillis;
                    
                    //moves the next status to Inject
                    runningStat = "Inject";
                  }
              }
            //Inject
            else if (runningStat == "Inject")
              {
                //time starts
                currentMillis = millis();

                //For Serial Monitor
                Serial.println("Spice Injecting");

                //For LCD Display
                lcd.setCursor(0,1);
                lcd.print("Spice  Injecting");

                //Insert your output commands here

                if (currentMillis - lastCurrentMillis >= injectingTimeRun)
                  {
                    //makes the currentMillis as the lastCurrentMillis
                    lastCurrentMillis = currentMillis;
                    
                    //moves the next status to Retract
                    runningStat = "Retract";
                  }
              }
            //Retract
            else if (runningStat == "Retract")
              {
                //time starts
                currentMillis = millis();

                //For Serial Monitor
                Serial.println("Syringe Retracting");

                //For LCD Display
                lcd.setCursor(0,1);
                lcd.print("Syringe  Retract");

                //Insert your output commands here

                if (currentMillis - lastCurrentMillis >= injectingTimeRetract)
                  {
                    //makes the currentMillis as the lastCurrentMillis
                    lastCurrentMillis = currentMillis;
                    
                    //moves the next status to ConvRun
                    runningStat = "ConvRun";
                  }
              }
          }
        
        //Manual Mode
        //Insert your desired manual mode process here
        else if (manual_mode.state() == LOW)
          {
            //Insert similar process to manual control like
            /*
              1. Button/Switch for Conveyor Run
              2. Button for Injection Process
              3. Button for Retraction Process
            */
          }
        
        //No Mode is selected
        else if (auto_mode.state() == HIGH || manual_mode.state() == HIGH)
          {
            //Sets the Yellow Condition On
            digitalWrite(red_led, LOW);
            digitalWrite(green_led, LOW);
            digitalWrite(yellow_led, HIGH);

            //Resets Back all the timers and Millis
            runningStat = "ConvRun";            //Default runningStat Value
            lastCurrentMillis = currentMillis;  //Stores the current millis as last millis
          }
      }
      
      //If emergency stop
      else if (e_stop.state() == HIGH)
        {
          //Sets the Green Condition On
          digitalWrite(red_led, HIGH);
          digitalWrite(green_led, LOW);
          digitalWrite(yellow_led, LOW);
        }
    
  }

void display()
  {
    if (last_e_stop_state != e_stop.state())
      {
        if (e_stop.state() == HIGH)
          {
            //For Serial Communication
            Serial.println("Emergency Stop!");

            //For LCD Display
            lcd.setCursor(0,0);
            lcd.print(">> EMERGENCY  <<");
            lcd.setCursor(0,1);
            lcd.print(">>   STOP!!   <<");
          }
        else if (e_stop.state() == LOW && auto_mode.state() == HIGH && manual_mode.state() == HIGH)
          {
            //Sets the Green Condition On
            digitalWrite(red_led, LOW);
            digitalWrite(green_led, LOW);
            digitalWrite(yellow_led, HIGH);

            //For Serial Communication
            Serial.println("Automated Meat Spice Injector");

            //For LCD Display
            lcd.setCursor(0,0);
            lcd.print("Automated Meat  ");
            lcd.setCursor(0,1);
            lcd.print("  Spice Injector");

          }

        //stores the current read state of the btn as last state
        last_e_stop_state = e_stop.state();
      }
    
    else if (last_auto_state != auto_mode.state())
      {
        //Auto Mode
        if (e_stop.state() == LOW && manual_mode.state() == HIGH)
          {
            if (auto_mode.state() == LOW)
              {
                //For Serial Communication
                Serial.println(">> Auto Mode <<");

                //For LCD Display
                lcd.clear();
                lcd.setCursor(0,0);
                lcd.print(">> AUTO  MODE <<");
              }
            else if (auto_mode.state() == HIGH) 
              {
                //For Serial Communication
                Serial.println(">> Select Mode <<");

                //For LCD Display
                lcd.setCursor(0,0);
                lcd.print("Automated Meat  ");
                lcd.setCursor(0,1);
                lcd.print("  Spice Injector");
              }
          }
        
        //stores the current read state of the btn as last state
        last_auto_state = auto_mode.state();
      }

    else if (last_manual_state != manual_mode.state())
      {
        //Manual Mode
        if (e_stop.state() == LOW && auto_mode.state() == HIGH)
          {
            if (manual_mode.state() == LOW)
              {
                //For Serial Communication
                Serial.println(">> Manual Mode <<");
                
                //For LCD Display
                lcd.clear();
                lcd.setCursor(0,0);
                lcd.print("> MANUAL  MODE <");
              }
            else if (manual_mode.state() == HIGH) 
              {
                //For Serial Communication
                Serial.println(">> Select Mode <<");
                
                //For LCD Display
                lcd.setCursor(0,0);
                lcd.print("Automated Meat  ");
                lcd.setCursor(0,1);
                lcd.print("  Spice Injector");
              }
          }
        
        //stores the current read state of the btn as last state
        last_manual_state = manual_mode.state();
      }
  }