#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 20 , 4); 

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0;  // will store last time LED was updated
unsigned long currentMillis = 0;


// constants won't change:
const long interval = 1000;  // interval at which to blink (milliseconds)

const int buttonEscPin = 3;  // the number of the pushbutton pin
const int buttonEnterPin = 2;  // the number of the pushbutton pin
const byte ledPin = 13;

int escFlag = 0;
int enterFlag = 0;
int startProgramFlag = 0;
int stepSoudeFlag = 0;

int runFlag = 0;

// Here a structure to describe a valve
struct kValve {
  char name;     //enum to describe which valve
  bool isOpen;   // if valve is realy open or not
  bool toBeOpen; // if valvle has to be opened by a script
};

struct kProgram {
  char name;       // name/type, such as "keg washing" or "fermentor washing"
  bool isRunning;  // flag set to "true" if programm in progress
  bool toBeRan;    // flag set to "true" if program is selected and has to be ran
};

struct kStep {
  char name;       // the name/type of step, such as "caustic washing"
  char nature;     // name of product in it, such as "caustic"
  int  duration;  // duration of this step
  int  start;
};

struct kValve vanneIn {'A', false, false};
struct kValve vanneOut {'B', false, false};

bool vanneInFlag = false;
bool vanneOutFlag = false;
bool vanneSoudeInFlag = false;
bool vanneSoudeOutFlag = false;

enum programme {
  programme1,
  programme2,
  programme3  
};

// the following variables are unsigned longs because the time, measured in
// milliseconds, will quickly become a bigger number than can be stored in an int.
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50; 

void setup()
{
  runFlag = 1;
  lcd.init();
  Serial.begin(9600);
  lcd.begin(20, 4);
  pinMode(ledPin, OUTPUT);
  pinMode(buttonEscPin, INPUT_PULLUP);
  pinMode(buttonEnterPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(buttonEscPin), myEsc, FALLING);
  attachInterrupt(digitalPinToInterrupt(buttonEnterPin), myEnter, FALLING);
}

int myTimer(int previous, int interval) {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;
    return 1;
  }
  return 0;
}

void displayTime(int time){
  lcd.setCursor(0, 0);
  lcd.print("     ");
  lcd.setCursor(0, 0);
  lcd.print(time / 1000);
}

void  displayFlag(){
  lcd.setCursor(0, 0);
  lcd.print("     ");
  lcd.setCursor(0, 0);
  if (escFlag) {
    lcd.print("ESC");
    escFlag = 0;
  }
  if (enterFlag) {
    lcd.print("ENTER");
    enterFlag = 0;
  }
}

void myEsc(){
  escFlag = 1;
}

void myEnter(){
  enterFlag = 1;
}

void runProgram() {
  // par exemple :
  // on ouvre les vannes de soude et on place le circuit correctement
  // on pompe 1min
  // on arrete la pompe
  // on ferme la vanne de soude et on ferme la boucle du circuit
  // on fait tourner 1min
  // on stop la pompe
  // on ouvre la vanne de retour de soude, et on rouvre le circuit correctement
  // on fait tourner 1min
  // on arrete la pompe

  // ici test : on affiche un timer pendant 5 secondes puis on sort
  if (myTimer(previousMillis, 5000)) {
    Serial.print("run");
    if (myTimer(previousMillis, interval)) {
      // if the LED is off turn it on and vice-versa:
      displayTime(currentMillis);
    } 
    else {
      displayError();      
    }
  }
  else {
    runFlag = 0;
  }
}

void displayError() {
  lcd.setCursor(0, 0);
  lcd.print("error");
}

void displayMenu() {
  lcd.setCursor(0, 0);
  lcd.print("Menu");
}

void loop() {
  currentMillis = millis();

  // Check state :
  // on regarde si RUN est setté
  // soit RUN a une valeur et on est dans un programme
  // soit RUN est a 0 et on affiche le menu
  if(runFlag){
    runProgram();
  }
  else
  {
    displayMenu();
  }

  // if (digitalRead(buttonDownPin)) {
  //   downFlag = 1;
  //   displayFlag();
  // }
  // if (digitalRead(buttonUpPin)) {
  //   upFlag = 1;
  //   displayFlag();
  // }

  if (escFlag || enterFlag) {
    displayFlag();
  }
}