#include "U8glib.h"

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST); // Fast I2C / TWI
// U8GLIB_SSD1306_128X64 u8g(13, 11, 8, 9, 10); // SPI connection
// for SPI connection, use this wiring:
// GND > GND
// VCC > 5V
// SCL > 13
// SDA > 11
// RES > 10
// DC > 9
// CS > 8



// all the arrays below are generated from images using image2cpp website
// scroll down to see the actual code


// 'item_sel_outline', 128x21px
const unsigned char bitmap_item_sel_outline [] PROGMEM = {
  0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 
  0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 
  0x3f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 
  0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0
};



// ------------------ end generated bitmaps from image2cpp ---------------------------------



const int NUM_ITEMS = 2; // number of items in the list and also the number of screenshots and screenshots with QR codes (other screens)
const int MAX_ITEM_LENGTH = 25; // maximum characters for the item name
const int maxDrehzahl =6000;
const int lehrlauf =1000;

char menu_items [NUM_ITEMS] [MAX_ITEM_LENGTH] = {  // array with item names
  { "feste Drehzahl" }, 
  { "Zyklus" }
 };

#define BUTTON_UP_PIN 12 // pin for UP button 
#define BUTTON_SELECT_PIN 8 // pin for SELECT button
#define BUTTON_DOWN_PIN 4 // pin for DOWN button

int button_up_clicked = 0; // only perform action when button is clicked, and wait until another press
int button_select_clicked = 0; // same as above
int button_down_clicked = 0; // same as above

int item_selected = 0; // which item in the menu is selected

int item_sel_previous; // previous item - used in the menu screen to draw the item before the selected one
int item_sel_next; // next item - used in the menu screen to draw next item after the selected one

int current_screen = 0;   // 0 = menu, 1 = RPM, 2 = time , 3 = controlling

int drehzahl = 1000;
int zykluszeitInSekunden = 0;


void setup() {
  u8g.setColorIndex(1);  // set the color to white

  // define pins for buttons
  // INPUT_PULLUP means the button is HIGH when not pressed, and LOW when pressed
  // since it´s connected between some pin and GND
  pinMode(BUTTON_UP_PIN, INPUT_PULLUP); // up button
  pinMode(BUTTON_SELECT_PIN, INPUT_PULLUP); // select button
  pinMode(BUTTON_DOWN_PIN, INPUT_PULLUP); // down button
  
}


void loop() {


  if (current_screen == 0) { // MENU SCREEN

      // up and down buttons only work for the menu screen
      if ((digitalRead(BUTTON_UP_PIN) == LOW) && (button_up_clicked == 0)) { // up button clicked - jump to previous menu item
        item_selected = item_selected - 1; // select previous item
        button_up_clicked = 1; // set button to clicked to only perform the action once
        if (item_selected < 0) { // if first item was selected, jump to last item
          item_selected = NUM_ITEMS-1;
        }
      }
      else if ((digitalRead(BUTTON_DOWN_PIN) == LOW) && (button_down_clicked == 0)) { // down button clicked - jump to next menu item
        item_selected = item_selected + 1; // select next item
        button_down_clicked = 1; // set button to clicked to only perform the action once
        if (item_selected >= NUM_ITEMS) { // last item was selected, jump to first menu item
          item_selected = 0;
          }
      } 

      if ((digitalRead(BUTTON_UP_PIN) == HIGH) && (button_up_clicked == 1)) { // unclick 
        button_up_clicked = 0;
      }
      if ((digitalRead(BUTTON_DOWN_PIN) == HIGH) && (button_down_clicked == 1)) { // unclick
        button_down_clicked = 0;
      }

  }



   if (current_screen == 1) { // MENU SCREEN
  // up and down buttons only work for the menu screen
      if ((digitalRead(BUTTON_UP_PIN) == LOW) && (button_up_clicked == 0)) { // up button clicked - jump to previous menu item
        if (drehzahl < maxDrehzahl){
            drehzahl = drehzahl + 500; // select previous item
        }else(drehzahl = lehrlauf);
      
        button_up_clicked = 1; // set button to clicked to only perform the action once
       
      }
      else if ((digitalRead(BUTTON_DOWN_PIN) == LOW) && (button_down_clicked == 0)) { // down button clicked - jump to next menu item
        if (drehzahl > lehrlauf){
          drehzahl = drehzahl - 500;
        }else (drehzahl = lehrlauf);
        button_down_clicked = 1; // set button to clicked to only perform the action once
        
      } 

      if ((digitalRead(BUTTON_UP_PIN) == HIGH) && (button_up_clicked == 1)) { // unclick 
        button_up_clicked = 0;
      }
      if ((digitalRead(BUTTON_DOWN_PIN) == HIGH) && (button_down_clicked == 1)) { // unclick
        button_down_clicked = 0;
      }

   }

if (current_screen == 2) { // MENU SCREEN
  // up and down buttons only work for the menu screen
      if ((digitalRead(BUTTON_UP_PIN) == LOW) && (button_up_clicked == 0)) { // up button clicked - jump to previous menu item
            zykluszeitInSekunden = zykluszeitInSekunden + 1; // select previous item    
        button_up_clicked = 1; // set button to clicked to only perform the action once
       
      }
      else if ((digitalRead(BUTTON_DOWN_PIN) == LOW) && (button_down_clicked == 0)) { // down button clicked - jump to next menu item
        if (zykluszeitInSekunden > 0){
          zykluszeitInSekunden = zykluszeitInSekunden - 1;
        }else (zykluszeitInSekunden = 0);
        button_down_clicked = 1; // set button to clicked to only perform the action once
        
      } 

      if ((digitalRead(BUTTON_UP_PIN) == HIGH) && (button_up_clicked == 1)) { // unclick 
        button_up_clicked = 0;
      }
      if ((digitalRead(BUTTON_DOWN_PIN) == HIGH) && (button_down_clicked == 1)) { // unclick
        button_down_clicked = 0;
      }

   }


  if ((digitalRead(BUTTON_SELECT_PIN) == LOW) && (button_select_clicked == 0)) { // select button clicked, jump between screens
     button_select_clicked = 1; // set button to clicked to only perform the action once
     if (current_screen == 0) {
      current_screen = 1;} // menu items screen --> RPM screen
     else if ((current_screen == 1) && (item_selected==1)) {current_screen = 2;} // RPM screen --> time screen
      else if ((current_screen == 2) || ((item_selected==0) &&  (current_screen == 1)) ){current_screen = 3;}
     else {current_screen = 0;// time screen --> menu items screen
     drehzahl = lehrlauf;
    zykluszeitInSekunden = 0;
     } 
  }
  if ((digitalRead(BUTTON_SELECT_PIN) == HIGH) && (button_select_clicked == 1)) { // unclick 
    button_select_clicked = 0;
  }

  // set correct values for the previous and next items
  item_sel_previous = item_selected - 1;
  if (item_sel_previous < 0) {item_sel_previous = NUM_ITEMS - 1;} // previous item would be below first = make it the last
  item_sel_next = item_selected + 1;  
  if (item_sel_next >= NUM_ITEMS) {item_sel_next = 0;} // next item would be after last = make it the first


  u8g.firstPage(); // required for page drawing mode for u8g library
  do {

    if (current_screen == 0) { // MENU SCREEN

      // selected item background
      u8g.drawBitmapP(0, 0, 128/8, 21, bitmap_item_sel_outline);

      // draw selected item as icon + label in bold font
      u8g.setFont(u8g_font_7x14B);    
      u8g.drawStr(13, 16, menu_items[item_selected]);     

      // draw next item as icon + label
      u8g.setFont(u8g_font_7x14);     
      u8g.drawStr(13, 16+22, menu_items[item_sel_next]); 
  
      // draw scrollbar handle
      u8g.drawBox(125, 64/NUM_ITEMS * item_selected, 3, 64/NUM_ITEMS);                

    } 
    else if (current_screen == 1) { // SCREENSHOTS SCREEN
        u8g.setFont(u8g_font_7x14B);
        u8g.drawStr(15, 15, menu_items[item_selected]);
        u8g.drawStr(5, 35, "Drehzahl:");
        u8g.setPrintPos(5,50);
        u8g.print(drehzahl, DEC);
    }else if ((current_screen == 2) && (item_selected == 1)) { // SCREENSHOTS SCREEN
        u8g.setFont(u8g_font_7x14B);
        u8g.drawStr(15, 15, menu_items[item_selected]);
        u8g.drawStr(5, 35, "Zeit in s");
        u8g.setPrintPos(5,50);
        u8g.print(zykluszeitInSekunden, DEC);
    }else if ((current_screen == 3)) { // SCREENSHOTS SCREEN
        u8g.setFont(u8g_font_7x14B);
        u8g.drawStr(5, 35, "Regelt");
        
    }

  } while ( u8g.nextPage() ); // required for page drawing mode with u8g library


}