#define lBtn 2
#define rBtn 3
#define lLed A2
#define rLed A3

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define spk 4

#define SCREEN_WIDTH        128 // OLED display width, in pixels
#define SCREEN_HEIGHT        64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

int x0, y0, x, y, r;
int xl0, yl0;
int xl, yl, w, h;
int dx, dy, dxl;
int startMidi[6] = {262, 294, 330, 349, 392, 0}; //C4, D4, E4, F4, G4(Do, Re, Mi, Fa, So)
int endMidi[6] = {392, 349, 330, 294, 262, 0}; //G4, F4, E4, D4, C4

void game_init() {
  display.clearDisplay();
  x=SCREEN_WIDTH/2; y=SCREEN_HEIGHT/2; r=3;
  dx = 2; dy = 1;
  display.fillCircle(x, y, r, WHITE);
  x0 = x; y0 = y;
  w = 24;
  h = 3;
  xl = SCREEN_WIDTH/2 - w/2;
  yl = SCREEN_HEIGHT - h - 5;
  display.fillRect(xl, yl, w, h, WHITE);
  xl0 = xl; yl0 = yl; dxl = 1;
  display.display();
  midi_play(startMidi);
}

void midi_play(int *midi) {
  for(int i=0; midi[i]!=0; i++) {
    tone(spk, midi[i], 100);
    delay(100);
  }
}


void setup() {
  // put your setup code here, to run once:
  pinMode(lBtn, INPUT_PULLUP);
  pinMode(rBtn, INPUT_PULLUP);
  pinMode(lLed, OUTPUT);
  pinMode(rLed, OUTPUT);
  digitalWrite(lLed, LOW);
  digitalWrite(rLed, LOW);
  pinMode(spk, OUTPUT);

  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    while(true);
  }
  game_init();

}

void loop() {
  // put your main code here, to run repeatedly:
  delay(30);
  if(digitalRead(lBtn)==LOW) {
    digitalWrite(lLed, HIGH);
    xl -= dxl;
    if(xl<0) xl = 0;
    display.fillRect(xl0, yl0, w, h, BLACK);
    display.fillRect(xl, yl, w, h, WHITE);
    xl0 = xl; yl0 = yl;
  }
  else 
    digitalWrite(lLed, LOW);
  if(digitalRead(rBtn)==LOW){
    digitalWrite(rLed, HIGH);
    xl += dxl;
    if(xl>SCREEN_WIDTH-w) xl = SCREEN_WIDTH - w;
    display.fillRect(xl0, yl0, w, h, BLACK);
    display.fillRect(xl, yl, w, h, WHITE);
    xl0 = xl; yl0 = yl;
  }
  else 
    digitalWrite(rLed, LOW);

  display.display();
}