#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SH110X.h>


/* Uncomment the initialize the I2C address , uncomment only one, If you get a totally blank screen try the other*/
#define i2c_Address 0x3d //initialize with the I2C addr 0x3C Typically eBay OLED's
//#define i2c_Address 0x3d //initialize with the I2C addr 0x3D Typically Adafruit OLED's

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1   //   QT-PY / XIAO
Adafruit_SH1106G display = Adafruit_SH1106G(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define BUTTON_ONE_PIN 4 // pin for UP button 
#define BUTTON_TWO_PIN 2 // pin for SELECT button
//#define BUTTON_DOWN_PIN 13

//Constants
//const int button_one = 4;
//const int button_two = 2;
unsigned long DELAY_TIME = 15000;
unsigned long delayStart = 0;

bool delayRunning = false;
bool ledOn = false;

int button_one_clicked = 0; 
int button_two_clicked = 0;
int current_screen = 0;

void setup();
void screenA();
void screenB();
void screenC();
void screenOff();
void screenOn();
void loop() ;


void setup() {

  // put your setup code here, to run once:
  Serial.begin(115200);

  delay(250); // wait for the OLED to power up
  display.begin(i2c_Address, true); // Address 0x3C default
 //display.setContrast (0); // dim display
   
  display.display();
  delay(2000);

  // Clear the buffer
  display.clearDisplay();

  Wire.begin();

    pinMode(BUTTON_ONE_PIN, INPUT_PULLUP);
    pinMode(BUTTON_TWO_PIN, INPUT_PULLUP);

   //screenA();

  ledOn = false;
  // start delay
  delayStart = millis();
  delayRunning = false;

}

void screenA(){
    //display.clearDisplay();  
    display.setTextColor(SH110X_WHITE);
    display.setTextSize(1);
    display.setCursor(30,32);
    display.print("Screen A On");
    display.display();
    delay(1);
    display.clearDisplay();
    }  

void screenB(){  
    //display.clearDisplay();
    display.setTextColor(SH110X_WHITE);
    display.setTextSize(1);
    display.setCursor(30,32);
    display.print("Screen B On");
    display.display();
    //delay(5000);
    display.clearDisplay();
    }

void screenC(){  
    //display.clearDisplay();
    display.setTextColor(SH110X_WHITE);
    display.setTextSize(1);
    display.setCursor(30,32);
    display.print("Screen C On");
    display.display();
    //delay(5000);
    display.clearDisplay();
    }

void screenOff(){
  Wire.beginTransmission(0x3d);
  Wire.write((uint8_t)0x80);
  Wire.write((uint8_t)0xAE);
  Wire.endTransmission();
  Serial.print("Screen Off");
    }  

void screenOn(){
   Wire.beginTransmission(0x3d);
   Wire.write((uint8_t)0x80);
   Wire.write((uint8_t)0xAF);
   Wire.endTransmission();
   Serial.print("Screen On");
    } 

void loop() {

    int button_one_state = digitalRead(BUTTON_ONE_PIN);
    int button_two_state = digitalRead(BUTTON_TWO_PIN);
  
    //print out the value of the pushbutton
   Serial.print("Button_One_State = ");
   Serial.println(button_one_state);
   Serial.print("Button_Two_State = ");
   Serial.println(button_two_state);

   if (delayRunning && ((millis() - delayStart) >= DELAY_TIME)) {
       delayStart += DELAY_TIME; // this prevents drift in the delays
       screenOff();
   }
   if ((digitalRead(BUTTON_ONE_PIN) == LOW) && (button_one_clicked == 0)){
      button_one_clicked = 1;
      if (current_screen == 0) {current_screen = 1;}
      else if (current_screen == 1) {current_screen = 2;}
      else {current_screen = 0;}
      Serial.println(current_screen);
      }
   if ((digitalRead(BUTTON_ONE_PIN) == HIGH) && (button_one_clicked == 1)){
    button_one_clicked = 0;
   } 
   if (current_screen == 0){
       screenA();
   }  
   else if (current_screen == 1){
      screenB();
   }
   else if (current_screen == 2){
      screenC();
   }

   if (button_two_state == LOW) {
      screenOn();
      ledOn = false;
      // start delay
      delayStart = millis();
      delayRunning = false;
   }

      
}