//#include <Wire.h> //Importer la library Wire
//#include "rgb_lcd.h" //Importer la library rgb_lcd
//rgb_lcd lcd; //Crée l'ecran
 
#include <LiquidCrystal_I2C.h> //Importer la library LCD_I2C
LiquidCrystal_I2C lcd(0x27,16,2);  //Définir l'adress et la taille de l'ecran

int p1[] = {0, 0};
int p2[] = {0, 0};
float pM[] = {0, 0};

int int_step = 0;

const int colorR = 255;
const int colorG = 255;
const int colorB = 255;

String point_list[] = {"x1", "y1", "x2", "y2"};

void setup() {
  Serial.begin(9600);
  Serial.println("fdp");
  // set up the LCD's number of columns and rows:
  //lcd.begin(16, 2); //Définir la taille de l'ecran
  //lcd.setRGB(colorR, colorG, colorB); //Définir la couleur de l'ecran

  lcd.init(); //Initialiser l'ecran
  lcd.backlight(); //Allumer le backlight
}

void loop() {
  if (Serial.available()) {
    String inputString = ""; // Create an empty string to store the input
    while (Serial.available()) {
      char inChar = Serial.read();
      if (inChar == '\n') { // Check for newline character to indicate end of input
        break;
      }
      inputString += inChar; // Append the character to the string
    }

    if (inputString.length() > 0) {
      if (int_step < 2) {
        p1[int_step%2] = inputString.toInt();
      }
      if (int_step < 4) {
        p2[int_step%2] = inputString.toInt();
      }
      
      lcd.clear();
      lcd.setCursor(7, 0);
      lcd.print("OK");
      delay(500);
      lcd.clear();
      int_step++;

      if (int_step > 4) {
        int_step = 0;
      }
    }
  }

  if (int_step < 4) {
    lcd.setCursor(0, 0);
    String pos = point_list[int_step];
    lcd.print(pos);
    lcd.print(" ?");
  }
  if (int_step == 4) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("p1 ");
    lcd.print(p1[0]);
    lcd.print(",");
    lcd.print(p1[1]);
    
    lcd.print(" p2 ");
    lcd.print(p2[0]);
    lcd.print(",");
    lcd.print(p2[1]);

    pM[0] = (p1[0]+p2[0])/2.0;
    pM[1] = (p1[1]+p2[1])/2.0;

    lcd.setCursor(0, 1);
    lcd.print("M = (");
    lcd.print(pM[0]);
    lcd.print(", ");
    lcd.print(pM[1]);
    lcd.print(")");
    
    delay(500);
    lcd.clear();
  }
}