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

#define RING_PIN 5
#define NUM_PIXELS 16

const int NUM_BTNS = 8;
const int NUM_LEDS = 4;

// Button pins
//const int TRACK1BUTTON = 13;
//const int TRACK2BUTTON = 12;
//const int TRACK3BUTTON = 11;
//const int TRACK4BUTTON = 10;
//const int MODEBUTTON = 9;
//const int CLEARBUTTON = 8;
//const int STOPBUTTON = 7;
//const int RECORDBUTTON = 6;
const int BTN_PINS[] = {
  13, 12, 11, 10, 9, 8, 7, 6
};
// LED pins
const int RED_LED_PINS[] = {22, 24, 26, 28};
const int GRN_LED_PINS[] = {23, 25, 27, 29};

bool isPlayback = false;
bool isRecord   = false;
int mode = 0;
int btnState[NUM_BTNS];
int oldBtnState[NUM_BTNS];

Adafruit_SSD1306 oled(128, 64, &Wire, -1);
Adafruit_NeoPixel ring(NUM_PIXELS, RING_PIN, NEO_GRB + NEO_KHZ800);

// function returns which button was pressed, or 0 if none
int checkButtons()  {
  int btnPressed = 0;

  for (int i = 0; i < NUM_BTNS; i++) {
    btnState[i] = digitalRead(BTN_PINS[i]); // check each button
    if (btnState[i] != oldBtnState[i])  {   // if it changed
      oldBtnState[i] = btnState[i];         // remember state for next time
      if (btnState[i] == 0)  {              // was just pressed
        btnPressed = i + 1;
      }
      delay(20);  // debounce
    }
  }
  return btnPressed;
}

void setup() {
  Serial.begin(115200);
  Wire.begin();
  ring.begin();
  for (int i = 0; i < NUM_PIXELS; i++) {
    ring.setPixelColor(i, ring.Color(0, 255, 0)); // Green
  }
  ring.show();
  //oled.setRotation(2);
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED NOT FOUND!");
    for (;;);
  }
  oled.setTextSize(1);
  oled.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
  for (int i = 0; i < NUM_LEDS; i++) {
    pinMode(RED_LED_PINS[i], OUTPUT);
    pinMode(GRN_LED_PINS[i], OUTPUT);
    digitalWrite(RED_LED_PINS[0], HIGH);
  }
  for (int i = 0; i < NUM_BTNS; i ++) {
    pinMode(BTN_PINS[i], INPUT_PULLUP);
  }
  oled.clearDisplay();
  oled.setTextSize(2);
  oled.setCursor(0, 0);
  oled.print("Mode: ");
  oled.display();
}

void loop() {
  int btnNumber = checkButtons();
  if (btnNumber)  {
    // if a button was pressed turn all the red LEDs off, green LEDs on
    for (int i = 0; i < NUM_LEDS; i++) {
      digitalWrite(RED_LED_PINS[i], LOW);
      digitalWrite(GRN_LED_PINS[i], LOW);
    }
    if (btnNumber == 1) {
      digitalWrite(RED_LED_PINS[0], HIGH);
      digitalWrite(GRN_LED_PINS[0], LOW);
    } else if (btnNumber == 2) {
      digitalWrite(RED_LED_PINS[1], HIGH);
      digitalWrite(GRN_LED_PINS[1], LOW);
    } else if (btnNumber == 3) {
      digitalWrite(RED_LED_PINS[2], HIGH);
      digitalWrite(GRN_LED_PINS[2], LOW);
    } else if (btnNumber == 4) {
      digitalWrite(RED_LED_PINS[3], HIGH);
      digitalWrite(GRN_LED_PINS[3], LOW);
    } else if (btnNumber == 5) {
      mode++;
      if (mode == 2) mode = 0;

      for (int i = 0; i < NUM_LEDS; i++) {
        digitalWrite(RED_LED_PINS[i], LOW);
        digitalWrite(GRN_LED_PINS[i], LOW);
      }
      //}
      //}

      if (mode == 0) {
        oled.setCursor(65, 0);
        oled.print("PB ");
        oled.display();
        //for (int i = 0; i < NUM_LEDS; i++) {
        //digitalWrite(GRN_LED_PINS[i], HIGH);
        //}
        for (int i = 0; i < NUM_PIXELS; i++) {
          ring.setPixelColor(i, ring.Color(0, 255, 0)); // Green
        }
        ring.show();
      }
      if (mode == 1)  {
        oled.setCursor(65, 0);
        oled.print("REC");
        oled.display();
        //for (int i = 0; i < NUM_LEDS; i++) {
        //digitalWrite(RED_LED_PINS[i], HIGH);
        //}
        for (int i = 0; i < NUM_PIXELS; i++) {
          ring.setPixelColor(i, ring.Color(255, 0, 0)); // Green
        }
        ring.show();
      }
    }
  }

}

/*
      for (int i = 0; i < NUM_LEDS; i++) {
        digitalWrite(GRN_LED_PINS[i], HIGH);
      }
*/