#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <RTClib.h>
#include <IRremote.hpp>

// OLED
#define OLED_SDA 21
#define OLED_SCL 22
Adafruit_SSD1306 display(128, 64, &Wire, -1);

// RTC
TwoWire RTCWire = TwoWire(1);
RTC_DS1307 rtc;

// IR
#define IR_PIN 14

// Joystick
#define JOY_X 34   // HORZ
#define JOY_Y 35   // VERT

// 7-seg segmenty
int segA = 23;
int segB = 19;
int segC = 18;
int segD = 5;
int segE = 4;
int segF = 2;
int segG = 15;

// Digity
int dig1 = 33;
int dig2 = 32;

// Snake premenné
struct Segment {
  int x;
  int y;
};
Segment snake[100];
int snakeLength = 1;
int foodX = 20;
int foodY = 20;
int score = 0;
bool gameRunning = false;

// Farba hada (simulácia veľkosťou bloku)
int snakeBlockSize = 4;

// Tabuľka číslic (CA logika: LOW = svieti)
byte digits[10][7] = {
  {LOW, LOW, LOW, LOW, LOW, LOW, HIGH},   // 0
  {HIGH, LOW, LOW, HIGH, HIGH, HIGH, HIGH}, // 1
  {LOW, LOW, HIGH, LOW, LOW, HIGH, LOW},  // 2
  {LOW, LOW, LOW, LOW, HIGH, HIGH, LOW},  // 3
  {HIGH, LOW, LOW, HIGH, HIGH, LOW, LOW}, // 4
  {LOW, HIGH, LOW, LOW, HIGH, LOW, LOW},  // 5
  {LOW, HIGH, LOW, LOW, LOW, LOW, LOW},   // 6
  {LOW, LOW, LOW, HIGH, HIGH, HIGH, HIGH}, // 7
  {LOW, LOW, LOW, LOW, LOW, LOW, LOW},    // 8
  {LOW, LOW, LOW, LOW, HIGH, LOW, LOW}    // 9
};

void setup() {
  Serial.begin(115200);

  Wire.begin(OLED_SDA, OLED_SCL);
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED error!");
    while(1);
  }

  // RTC init na druhej zbernici
  RTCWire.begin(25, 26); // SDA=25, SCL=26
  if (!rtc.begin(&RTCWire)) {
    Serial.println("RTC error!");
    while(1);
  }
  if (!rtc.isrunning()) {
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  // IR init
  IrReceiver.begin(IR_PIN, ENABLE_LED_FEEDBACK);
  Serial.println("IR prijimac pripraveny");

  // Joystick
  pinMode(JOY_X, INPUT);
  pinMode(JOY_Y, INPUT);

  // 7-seg init
  int segments[] = {segA, segB, segC, segD, segE, segF, segG};
  for (int i = 0; i < 7; i++) {
    pinMode(segments[i], OUTPUT);
    digitalWrite(segments[i], HIGH);
  }
  pinMode(dig1, OUTPUT);
  pinMode(dig2, OUTPUT);
  digitalWrite(dig1, HIGH);
  digitalWrite(dig2, HIGH);

  // Uvítacie okno
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10, 20);
  display.println("HADIK");
  display.setTextSize(1);
  display.setCursor(20, 50);
  display.println("Stlac 1 na ovladaci");
  display.display();

  snake[0].x = 64;
  snake[0].y = 32;
}

void loop() {
  // IR ovladac – start/stop/farba
  if (IrReceiver.decode()) {
    uint32_t code = IrReceiver.decodedIRData.decodedRawData;
    Serial.println(code, HEX);

    if (code == 0xCF30FF00) { // "1" start
      gameRunning = true;
      score = 0;
      snakeLength = 1;
      snake[0].x = 64;
      snake[0].y = 32;
      foodX = random(10, 118);
      foodY = random(10, 54);
    }
    if (code == 0xE718FF00) { // "2" toggle pause/resume
      gameRunning = !gameRunning;
      if (!gameRunning) {
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(SSD1306_WHITE);
        display.setCursor(20, 25);
        display.println("PAUZA");
        display.display();
      }
    }
    if (code == 0x857AFF00) { // "3" zmena farby
      if (snakeBlockSize == 4) snakeBlockSize = 6;
      else snakeBlockSize = 4;
    }

    IrReceiver.resume();
  }

  if (gameRunning) {
    playSnake();
  }
}

// Funkcia hry Snake
void playSnake() {
  int xVal = analogRead(JOY_X);
  int yVal = analogRead(JOY_Y);

  if (xVal > 3000) snake[0].x += 2; // doprava
  else if (xVal < 1000) snake[0].x -= 2; // doľava
  if (yVal < 1000) snake[0].y -= 2; // hore
  else if (yVal > 3000) snake[0].y += 2; // dole

  // posun tela vždy
  for (int i = snakeLength - 1; i > 0; i--) {
    snake[i].x = snake[i-1].x;
    snake[i].y = snake[i-1].y;
  }

  // kolízia s jedlom
  if (abs(snake[0].x - foodX) < 4 && abs(snake[0].y - foodY) < 4) {
    score++;
    if (snakeLength < 100) snakeLength++;
    foodX = random(10, 118);
    foodY = random(10, 54);
  }

  // OLED vykreslenie
  display.clearDisplay();

  // vykreslenie hada podľa veľkosti bloku
  for (int i = 0; i < snakeLength; i++) {
    display.fillRect(snake[i].x, snake[i].y, snakeBlockSize, snakeBlockSize, SSD1306_WHITE);
  }

  // jedlo
  display.fillCircle(foodX, foodY, 2, SSD1306_WHITE);

  // čas z RTC
  DateTime now = rtc.now();
  display.setTextSize(1);
  display.setCursor(80, 0);
  display.printf("%02d:%02d:%02d", now.hour(), now.minute(), now.second());

  display.display();

  // skóre na 7-seg
  showNumber(score);
}

// 7-seg funkcie
void showNumber(int num) {
  int tens = num / 10;
  int ones = num % 10;

  digitalWrite(dig1, LOW);
  digitalWrite(dig2, HIGH);
  setSegments(tens);
  delay(2);

  digitalWrite(dig1, HIGH);
  digitalWrite(dig2, LOW);
  setSegments(ones);
  delay(2);
}

void setSegments(int digit) {
  int segments[] = {segA, segB, segC, segD, segE, segF, segG};
  for (int i = 0; i < 7; i++) {
    digitalWrite(segments[i], digits[digit][i]);
  }
}