#include <Arduino.h>
#include <Keypad.h>
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
String val = "";
String win = "calc";
int menuPage = 1;
int maxPage = 6;
int piXS = 0;
String pi1 = "3.14159265358979";
String pi2 = "3238462643383279";
int befMenP;
bool MenuStart = false;
bool PiStart = false;
bool randomNumberGeneratorStart = false;
// number generator
int cursorY = 0;
String num1 = "";
String num2 = "";
bool countedNG = false;
// e dice
bool eDiceStart = false;
int diceNum;
// Settings
int settingsPage = 1;
String language = "Cesky";
bool settingsStart = false;
bool diagnosticsStart = false;
int maxSettingsPage = 2;

double evaluateExpression(String expression) {
  int len = expression.length();
  char operators[len];
  double operands[len];
  int op_index = 0;
  int num_index = 0;

  for (int i = 0; i < len; i++) {
    char c = expression.charAt(i);
    if (c == ' ')
      continue;

    if (isdigit(c)) {
      double num = 0;
      while (i < len && isdigit(expression.charAt(i))) {
        num = num * 10 + (expression.charAt(i) - '0');
        i++;
      }
      i--;
      operands[num_index++] = num;
    } else if (c == '(') {
      operators[op_index++] = c;
    } else if (c == ')') {
      while (op_index > 0 && operators[op_index - 1] != '(') {
        double b = operands[--num_index];
        double a = operands[--num_index];
        char op = operators[--op_index];
        if (op == '+') {
          operands[num_index++] = a + b;
        } else if (op == '-') {
          operands[num_index++] = a - b;
        } else if (op == '*') {
          operands[num_index++] = a * b;
        } else if (op == '/') {
          operands[num_index++] = a / b;
        }
      }
      op_index--; // remove '('
    } else {
      while (op_index > 0 && precedence(operators[op_index - 1]) >= precedence(c)) {
        double b = operands[--num_index];
        double a = operands[--num_index];
        char op = operators[--op_index];
        if (op == '+') {
          operands[num_index++] = a + b;
        } else if (op == '-') {
          operands[num_index++] = a - b;
        } else if (op == '*') {
          operands[num_index++] = a * b;
        } else if (op == '/') {
          operands[num_index++] = a / b;
        }
      }
      operators[op_index++] = c;
    }
  }

  while (op_index > 0) {
    double b = operands[--num_index];
    double a = operands[--num_index];
    char op = operators[--op_index];
    if (op == '+') {
      operands[num_index++] = a + b;
    } else if (op == '-') {
      operands[num_index++] = a - b;
    } else if (op == '*') {
      operands[num_index++] = a * b;
    } else if (op == '/') {
      operands[num_index++] = a / b;
    }
  }

  return operands[0];
}

int precedence(char op) {
  if (op == '+' || op == '-') {
    return 1;
  }
  if (op == '*' || op == '/') {
    return 2;
  }
  return 0;
}
const byte ROWS = 4; // počet řádků na klávesnici
const byte COLS = 4; // počet sloupců na klávesnici

// definice symbolů pro klávesy
char keys[ROWS][COLS] = {
  {'1','2','3','+'},
  {'4','5','6','-'},
  {'7','8','9','*'},
  {'D','0','=','/'}
};

// definice pinů pro sloupce a řádky
byte rowPins[ROWS] = {12, 11, 10, 9}; // připojené k pinům pro řádky
byte colPins[COLS] = {8, 7, 6, 5}; // připojené k pinům pro sloupce

// vytvoření instance objektu klávesnice
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

LiquidCrystal_I2C lcd(0x27, 16, 2);
bool clr;
void setup() {
  
  //Serial.begin(9600);
  //Serial.print("Started!");
 //Serial.println(evaluateExpression(val));
  lcd.init();
  lcd.backlight();
  if (language == "English") {
    lcd.setCursor(4,0);
    lcd.print("Welcome");
    lcd.setCursor(6,1);
    lcd.print("o_o");
  } else if (language == "Cesky") {
    lcd.setCursor(4,0);
    lcd.print("Vitejte");
    lcd.setCursor(6,1);
    lcd.print("o_o");
  }
  delay(2000);
  lcd.clear();
}

void loop() {
  char key = keypad.getKey();
  if(win == "calc") {
    if (key) {
      if (key == '=') {
        lcd.setCursor(0,1);
        lcd.print(evaluateExpression(val));
        if (val == "/00/") {
          win = "menu";
          lcd.clear();
        }
        val = "";
        clr = false;
      } else if (key == 'D') {
        val = "";
        lcd.clear();
        clr = true;
      } else {
        if (clr == false) {
          clr = true;
          lcd.clear();
        }
        val += key;
        lcd.setCursor(0,0);
        lcd.print(val);
        clr = false;
      }
    }
  }else if (win == "menu") { // MENU
    if (MenuStart == false) {
      lcd.clear();
      lcd.setCursor(0,0);
      if (language == "English") {
          lcd.print("Calculator");
          MenuStart = true;
        } else if (language == "Cesky") {
          lcd.print("Kalkulacka");
          MenuStart = true;
        } else if (language == "Bahasa Indonesia") {
          lcd.print("Kalkulator");
          MenuStart = true;
        }

      
    }
    befMenP = menuPage;
    if (key == '-') {
      menuPage++;
      if (maxPage+1 == menuPage) {
        menuPage = 1;
      }
      //delay(500);
    } else if (key == '+') {
      menuPage--;
      if (menuPage == 0) {
        menuPage = maxPage;
      }
      //delay(500);
    } else if (key == '=') {
      if (menuPage == 1) {
        win = "calc";
        lcd.clear();
        MenuStart = false;
      } else if (menuPage == 2) {
        win = "pi";
        lcd.clear();
        PiStart = false;
        MenuStart = false;
      } else if (menuPage == 3) {
        win = "randomNumberGenerator";
        lcd.clear();
        MenuStart = false;
        randomNumberGeneratorStart = false;
      } else if (menuPage == 4) {
        win = "eDice";
        lcd.clear();
        MenuStart = false;
        eDiceStart = false;
      } else if (menuPage == 5) {
        win = "diagnostics";
        lcd.clear();
        diagnosticsStart = false;
      } else if (menuPage == 6) {
        win = "settings";
        lcd.clear();
        settingsStart = false;
      }
    }
    /*
    Serial.println(befMenP);
    Serial.println(menuPage);
    Serial.println(key);

    */
    if (befMenP != menuPage) {
      if (menuPage == 1) {
        lcd.clear();
        if (language == "English") {
          lcd.print("Calculator");
          lcd.setCursor(0,0);
        } else if (language == "Cesky") {
          lcd.print("Kalkulacka");
          lcd.setCursor(0,0);
        } else if (language == "Bahasa Indonesia") {
          lcd.print("Kalkulator");
          lcd.setCursor(0,0);
        }
        
      } else if (menuPage == 2) {
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print("Pi");
      } else if (menuPage == 3) {
        lcd.clear();
        if (language == "English") {
          lcd.setCursor(0,0);
          lcd.print("Random number");
          lcd.setCursor(0,1);
          lcd.print("generator");
        } else if (language == "Cesky") {
          lcd.setCursor(0,0);
          lcd.print("Generator");
          lcd.setCursor(0,1);
          lcd.print("nahodnych cisel");
        } else if (language == "Bahasa Indonesia") {
          lcd.setCursor(0,0);
          lcd.print("Penghasil");
          lcd.setCursor(0,1);
          lcd.print("angla acak");
        }
        
      } else if (menuPage == 4) {
        lcd.clear();
        lcd.setCursor(0,0);
        if (language == "Cesky") {
          lcd.print("Hraci kostka");
        } else if (language == "English") {
          lcd.print("Dice");
        } else if (language == "Bahasa Indonesia") {
          lcd.print("Dadu");
        }
      } else if (menuPage == 5){
        lcd.clear();
        lcd.setCursor(0,0);
        if (language == "English") {
          lcd.print("Diagnostics");
        } else if (language == "Cesky") {
          lcd.print("Diagnostika");
        } else if (language == "Bahasa Indonesia") {
          lcd.print("Diagnostik");
        }
      } else if (menuPage == 6) {
        lcd.clear();
        lcd.setCursor(0,0);
        if (language == "English") {
          lcd.print("Settings");
        } else if (language == "Cesky") {
          lcd.print("Nastaveni");
        } else if (language == "Bahasa Indonesia") {
          lcd.print("Pengaturan");
        }
      }
    }
  } else if (win == "pi") {
    if (PiStart == false) {
      PiStart = true;
      lcd.setCursor(0,0);
      lcd.print(pi1);
      lcd.setCursor(0,1);
      lcd.print(pi2);
    }
    while (true) {
      char key = keypad.getKey();
      if (key == '/') {
        win = "menu";
        lcd.clear();
        menuPage = 1;
        lcd.clear();
        lcd.setCursor(0,0);
        if (language == "English") {
            lcd.print("Calculator");
            MenuStart = true;
          } else if (language == "Cesky") {
            lcd.print("Kalkulacka");
            MenuStart = true;
          } else if (language == "Bahasa Indonesia") {
            lcd.print("Kalkulator");
            MenuStart = true;
          }
        break;
      }
    }
    
  } else if (win == "randomNumberGenerator") {
    if (randomNumberGeneratorStart == false) {
      if (language == "English") {
        lcd.setCursor(0,0);
        lcd.print("FROM:");
        lcd.setCursor(0,1);
        lcd.print("TO:");
      } else if (language == "Cesky") {
        lcd.setCursor(0,0);
        lcd.print("OD:");
        lcd.setCursor(0,1);
        lcd.print("DO:");
      } else if (language == "Bahasa Indonesia") {
          lcd.setCursor(0,0);
          lcd.print("DARI:");
          lcd.setCursor(0,1);
          lcd.print("KE:");
      }
      randomNumberGeneratorStart = true;
    }
    while (true) {
      char key = keypad.getKey();
      if (key) {
        //Serial.println(key);
        if (key == '+') {
          cursorY = 0;
          //Serial.println(cursorY);
        } else if (key == '-') {
          cursorY = 1;
          //Serial.println(cursorY);
        } else if (key == '/') {
          win = "menu";
          menuPage = 1;
          lcd.clear();
          lcd.setCursor(0,0);
          if (language == "English") {
              lcd.print("Calculator");
              MenuStart = true;
            } else if (language == "Cesky") {
              lcd.print("Kalkulacka");
              MenuStart = true;
            } else if (language == "Bahasa Indonesia") {
              lcd.print("Kalkulator");
              MenuStart = true;
            }
          break;
        } else if (key == '=') {
          int out = random(num1.toInt(), num2.toInt()+1);
          num1 = out;
          num2 = "";
          countedNG = true;
        } else if (key != '*' and key != 'D' and countedNG == false) {
          if (cursorY == 0) {
            num1 += key;
            //Serial.println(num1);
          } else if (cursorY == 1) {
            num2 += key;
            //Serial.println(num2);
          }
        } else if (key = 'D'){
          if (cursorY == 0) {
            num1 = "";
          } else if (cursorY == 1) {
            num2 = "";
          } else {
            lcd.clear();
            lcd.setCursor(0,0);
            lcd.print("ERROR");
            lcd.setCursor(0,1);
            lcd.print("Restart device");
            while (true) {
              delay(1);
            }
          }

          if (countedNG == true) {
            num1 = "";
            num2 = "";
            countedNG = false;
            cursorY = 0;
            if (language == "English") {
              lcd.setCursor(0,0);
              lcd.print("FROM:");
              lcd.setCursor(0,1);
              lcd.print("TO:");
            } else if (language == "Cesky") {
              lcd.setCursor(0,0);
              lcd.print("OD:");
              lcd.setCursor(0,1);
              lcd.print("DO:");
            }  else if (language == "Bahasa Indonesia") {
              lcd.setCursor(0,0);
              lcd.print("DARI:");
              lcd.setCursor(0,1);
              lcd.print("KE:");
            }
          }
        } 
        lcd.clear();
        if (language == "English") {
          lcd.setCursor(0,0);
          lcd.print("FROM:");
          lcd.setCursor(5,0);
          lcd.print(num1);
          lcd.setCursor(0,1);
          lcd.print("TO:");
          lcd.setCursor(3,1);
          lcd.print(num2);
        } else if (language == "Cesky") {
          lcd.setCursor(0,0);
          lcd.print("OD:");
          lcd.setCursor(3,0);
          lcd.print(num1);
          lcd.setCursor(0,1);
          lcd.print("DO:");
          lcd.setCursor(3,1);
          lcd.print(num2);
        }  else if (language == "Bahasa Indonesia") {
          lcd.setCursor(0,0);
          lcd.print("DARI:");
          lcd.setCursor(5,0);
          lcd.print(num1);
          lcd.setCursor(0,1);
          lcd.print("KE:");
          lcd.setCursor(3,1);
          lcd.print(num1);
        }
      }
    }
  } else if (win == "eDice") {
    if (eDiceStart == false) {
      eDiceStart = true;
      lcd.setCursor(5,0);
      if (language == "English") {
        lcd.print("Dice");
        lcd.setCursor(6,1);
      } else if (language == "Cesky") {
        lcd.print("Kostka");
        lcd.setCursor(6,1);
      } else if (language == "Bahasa Indonesia") {
        lcd.print("Dadu");
        lcd.setCursor(6,1);
      }
      lcd.print("<0>");
    }
    while (true) {
      char key = keypad.getKey();
      if (key) {
        if (key == '=') {
          if (language == "English") {
            diceNum = random(1,7);
            lcd.clear();
            lcd.setCursor(5,0);
            lcd.print("Dice");
            lcd.setCursor(6,1);
            lcd.print("<");
            lcd.setCursor(7,1);
            lcd.print(diceNum);
            lcd.setCursor(8,1);
            lcd.print(">");
          } else if (language == "Cesky") {
            diceNum = random(1,7);
            lcd.clear();
            lcd.setCursor(5,0);
            lcd.print("Kostka");
            lcd.setCursor(6,1);
            lcd.print("<");
            lcd.setCursor(7,1);
            lcd.print(diceNum);
            lcd.setCursor(8,1);
            lcd.print(">");
          } else if (language == "Bahasa Indonesia") {
            diceNum = random(1,7);
            lcd.setCursor(5,0);
            lcd.print("Dadu");
            lcd.setCursor(6,1);
            lcd.print("<"+String(diceNum)+">");
          }
          
        } else if (key == '/') {
          win = "menu";
          menuPage = 1;
          lcd.clear();
          lcd.setCursor(0,0);
          if (language == "English") {
              lcd.print("Calculator");
              MenuStart = true;
            } else if (language == "Cesky") {
              lcd.print("Kalkulacka");
              MenuStart = true;
            } else if (language == "Bahasa Indonesia") {
              lcd.print("Kalkulator");
              MenuStart = true;
            }
          break;
        }
      }
    }
  } else if (win == "diagnostics") {
    if (diagnosticsStart == false) {
      diagnosticsStart = true;
      lcd.clear();
      lcd.setCursor(0,0);
      if (language == "English") {
        lcd.print("Does not work");
      } else if (language = "Cesky") {
        lcd.print("Nefunguje");
      } else if (language == "Bahasa Indonesia") {
        lcd.print("Ini tidak berhasil");
      }
    }
    while (true) {
      char key = keypad.getKey();
      if (key) {
        if (key == '/') {
          lcd.clear();
          win = "menu";
          menuPage = 1;
          lcd.clear();
          lcd.setCursor(0,0);
          if (language == "English") {
              lcd.print("Calculator");
              MenuStart = true;
            } else if (language == "Cesky") {
              lcd.print("Kalkulacka");
              MenuStart = true;
            } else if (language == "Bahasa Indonesia") {
              lcd.print("Kalkulator");
              MenuStart = true;
            }
          break;
        }
      }
    }
  } else if (win == "settings") {
    if (settingsStart == false) {
      settingsStart = true;
      lcd.clear();
    }
    while (true) {
      char key = keypad.getKey();
      if (settingsPage == 1) {  
        if (language == "English") {
          lcd.setCursor(0,0);
          lcd.print("Language:");
          lcd.setCursor(0,1);
          lcd.print(language);
        } else if (language == "Cesky") {
          lcd.setCursor(0,0);
          lcd.print("Jazyk:");
          lcd.setCursor(0,1);
          lcd.print(language);
        } else if (language == "Bahasa Indonesia") {
          lcd.setCursor(0,0);
          lcd.print("Bahasa:");
          lcd.setCursor(0,1);
          lcd.print(language);
        }
      } else if (settingsPage == 2) {
        if (language == "English") {
          lcd.setCursor(0,0);
          lcd.print("Stand-by mode");
          lcd.setCursor(0,1);
          lcd.print("Enter ->");
        } else if (language == "Cesky") {
          lcd.setCursor(0,0);
          lcd.print("Rezim spanku");
          lcd.setCursor(0,1);
          lcd.print("Zapnout ->");
        } else if (language == "Bahasa Indonesia") {
          lcd.setCursor(0,0);
          lcd.print("Modus siaga");
          lcd.setCursor(0,1);
          lcd.print("menyalakan ->");
        }
      }
      if (key) {
        if (key == '=') {
          lcd.clear();
          if (settingsPage == 1) {
            if (language == "English") {
              language = "Cesky";
            } else if (language == "Cesky") {
              language = "Bahasa Indonesia";
            } else if (language == "Bahasa Indonesia") {
              language = "English";
            }
          } else if (settingsPage == 2) {
            lcd.clear();
            lcd.noBacklight();
            key = '0';
            while (key != '=') {
              key = keypad.getKey();
            }
            if (key == '=') {
              win = "menu";
              menuPage = 1;
              lcd.backlight();
              lcd.clear();
              lcd.setCursor(0,0);
              if (language == "English") {
                  lcd.print("Calculator");
                  MenuStart = true;
                } else if (language == "Cesky") {
                  lcd.print("Kalkulacka");
                  MenuStart = true;
                } else if (language == "Bahasa Indonesia") {
                  lcd.print("Kalkulator");
                  MenuStart = true;
                }
              break;
            }
          }
        } else if (key == '/') {
          lcd.clear();
          win = "menu";
          menuPage = 1;
          lcd.setCursor(0,0);
          if (language == "English") {
              lcd.print("Calculator");
              MenuStart = true;
            } else if (language == "Cesky") {
              lcd.print("Kalkulacka");
              MenuStart = true;
            } else if (language == "Bahasa Indonesia") {
              lcd.print("Kalkulator");
              MenuStart = true;
            }
          break;
        } else if (key == '+') {
          settingsPage += 1;
          if (settingsPage == maxSettingsPage+1) {
            settingsPage = 1;
          }
          lcd.clear();
        } else if (key == '-') {
          settingsPage -= 1;
          if (settingsPage == 0) {
            settingsPage = maxSettingsPage;
          }
          lcd.clear();
        }
      }
    }
  }
}

void BINtoDEC(String num) {
  String bin = num; // Binární hodnota jako řetězec
  int dec = strtol(num.c_str(), NULL, 2); // Převod na desítkovou hodnotu
  return dec;
}

void DECtoBIN(int num) {
  int dec = num; // Desítková hodnota
  String bin = String(num, BIN); // Převod na binární hodnotu
  return bin;
}

void blueScreen(String id) {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print(":-(         E" + id);
  lcd.setCursor(0,1);
  lcd.print("Restart device");
  while (true) {
    delay(1);
  }
}