/*
 * Very simple menu on an OLED display (with 8 lines of text).
 * Displays menu items from the array menu. Max. number of items is 7.
 * 
 * This sketch uses the library "U8g2", "Bounce2" and uses 3 buttons (up/down/select).
 * 
 */

#include <U8g2lib.h>
#include <Bounce2.h>


byte button_pins[] = {7, 8, 6}; // button pins, 4,5 = up/down, 6 = select (10 heb ik bijgezet voor exit te maken)
#define NUMBUTTONS sizeof(button_pins)
Bounce * buttons = new Bounce[NUMBUTTONS];
U8X8_SSD1306_128X64_NONAME_HW_I2C display(U8X8_PIN_NONE);



#define MENU_SIZE 6 // schrijf hier hoeveel menu thema's.


char *menu[MENU_SIZE] = { "SAVE", "PRESET", "MIDI CC", "MIDI CHANNEL", "MIDI MONITOR", "EXIT" }; // schrijf hier de namen.



int cursor=0;



void setup() {
  Serial.begin(9600);

  // Make input & enable pull-up resistors on switch pins

  
  for (int i=0; i<NUMBUTTONS; i++) {
    buttons[i].attach( button_pins[i], INPUT_PULLUP); // setup the bounce instance for the current button
    buttons[i].interval(25); // interval in ms
  }
  
  display.begin();
  display.setPowerSave(0);
  display.setFont(u8x8_font_pxplusibmcgathin_f);

  showMenu();
}

void loop() {
  // process button press:
  for (int i = 0; i<NUMBUTTONS; i++) {
    buttons[i].update(); // Update the Bounce instance
    if ( buttons[i].fell() ) { // If it fell
      if (i==2) { // select
         display.clearLine(7);
         display.setCursor(0,7);
         display.print(">>");
         display.print(menu[cursor]);
         executeChoice(cursor);
      }
      else {
        // erase previous cursor:
        display.setCursor(0,cursor);
        display.print(' ');
        if (i==0) { // up
          cursor++;
          if (cursor>(MENU_SIZE-1)) cursor=0;
        }
        else { // down
          cursor--;
          if (cursor<0) cursor=(MENU_SIZE-1);
        }
        // show cursor at new line:
        display.setCursor(0,cursor);
        display.print('>');
      }
    } // end if button fell...
  } // end for-loop of button check
}

/**
 * Clear display and show the menu.
 */
void showMenu() {
  cursor=0;
  display.clearDisplay();
  // show menu items:
  for (int i = 0; i<MENU_SIZE; i++) {
    display.drawString(2,i,menu[i]);

    
  }
  display.setCursor(0,0);
  display.print('>'); 
}

/**
 * Execute the task which matches the chosen menu item.
 */
void executeChoice(int choice) {
  switch(choice) {
      case 0 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 1 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 2 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 3 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 4 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      case 5 :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
      default :
                Serial.print("Execute choice "); Serial.print(choice); Serial.print(" - "); Serial.println(menu[choice]);
                break;
  }
  
}