#include "U8g2lib.h"
// #include "LetterAnalog.h"
#define SCL_PIN 22
#define SDA_PIN 21
#define BUTTON_UP_PIN 5
#define BUTTON_DOWN_PIN 4
#define BUTTON_SELECT_PIN 15
#define BUTTON_ANALOG 2

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE, SCL_PIN, SDA_PIN);


int button_up_clicked = 0; 
int button_select_clicked = 0; 
int button_down_clicked = 0; 

int selected = 0;
String letter_selected = "";
int letter_selected_length=0;
static const int TOTAL_MENU = 27;
const char *options[TOTAL_MENU] = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","_"};
void setup() {
  pinMode(BUTTON_UP_PIN, INPUT_PULLUP); 
  pinMode(BUTTON_DOWN_PIN, INPUT_PULLUP); 
  pinMode(BUTTON_SELECT_PIN, INPUT_PULLUP); 
  u8g2.begin();
  Serial.begin(115200);
}

void lett_analog(int an) {

  if (an == 0) { //0
      selected = 0;
  }
  else if (an>4077 ){ //
     selected = 26;
  }
  else {
      selected = an/151;
  }
}

void loop() {
  int Val = analogRead(BUTTON_ANALOG);
  Serial.println(selected);
  lett_analog(Val);

  u8g2.clearBuffer();
  u8g2.setFont(u8g2_font_6x13B_tf);
      for (int i = 0; i < TOTAL_MENU; i++) {
            if (i == selected) {
              u8g2.setFontMode(0);
              u8g2.setDrawColor(0);
            } else if (i != selected) {
              u8g2.setFontMode(1);
              u8g2.setDrawColor(1);
            }
            if (i <9) {
                int sel = (i*12)+4;
                u8g2.setCursor((sel), 36);
            }
            else if (i >8 && i <18) { 
                int sel = ((i-9)*12)+4;
                u8g2.setCursor((sel), 48);
            }
            else if (i >17 && i <27) {
                int sel = ((i-18)*12)+4;
                u8g2.setCursor((sel), 60);
            }
              
              u8g2.print(options[i]);
                
                // Serial.println(i);
                 
                
                // u8g2.print(letter_selected);
              // Serial.println(sel);
      }
      if ((digitalRead(BUTTON_SELECT_PIN) == LOW) && (button_select_clicked == 0)) {  
        for (int l = 0; l < TOTAL_MENU; l++) {
          letter_selected=letter_selected + options[l];
          Serial.println(letter_selected);
          letter_selected_length++;;
        }
        button_select_clicked = 1;
        
        }
      u8g2.setFontMode(1);
      u8g2.setDrawColor(1);
      u8g2.setCursor(4, 18);
  u8g2.sendBuffer();

  // start Unclick
  if ((digitalRead(BUTTON_UP_PIN) == HIGH) && (button_up_clicked == 1)) {  
                  button_up_clicked = 0;
                }
  if ((digitalRead(BUTTON_DOWN_PIN) == HIGH) && (button_down_clicked == 1)) { 
    button_down_clicked = 0;
  }
  if ((digitalRead(BUTTON_SELECT_PIN) == HIGH) && (button_select_clicked == 1)) {  
    button_select_clicked = 0;
  }
  // end Unclick

  if ((digitalRead(BUTTON_DOWN_PIN) == LOW) && (button_down_clicked == 0)) {
    button_down_clicked = 1;  
    selected = selected + 1;
    // Serial.println(selected);
    delay(200);
  };
  if ((digitalRead(BUTTON_UP_PIN) == LOW) && (button_up_clicked == 0)) {
    button_up_clicked = 1;  
    selected = selected - 1;
    // Serial.println(selected);
    delay(200);
  };
  
  
}