// ==== HTMAA Touch + OLED Mini Game: Paddle Ball ====

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

// ---------- OLED ----------
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
// I2C  0x3C 0x3D
#define OLED_ADDR 0x3C

// ---------- Touch (SAMD21 FreeTouch) ----------
#define N_TOUCH 6
// 6touchpin 2~7
uint8_t touch_pins[N_TOUCH] = {2, 3, 4, 5, 6, 7};
// button
enum { BTN_LEFT=1, BTN_RIGHT=0, BTN_START=2, BTN_PAUSE=3, BTN_RESET=4, BTN_SPEED=5 };
#define THRESHOLD 500

Adafruit_FreeTouch* touch_devices[N_TOUCH];
int  touch_values[N_TOUCH]     = {0,0,0,0,0,0};
bool pin_now[N_TOUCH]          = {false,false,false,false,false,false};
bool pin_past[N_TOUCH]         = {false,false,false,false,false,false};

// ----------  LED ----------
#define PIN_LED 13   // Fab/SAMD21  13=PA15 15

// ---------- Game ----------
enum GameState { MENU, PLAYING, PAUSED, GAMEOVER };
GameState state = MENU;

int score = 0;
int bestScore = 0;


int paddleW = 20;
int paddleH = 3;
int paddleY = SCREEN_HEIGHT - 4;   
int paddleX = (SCREEN_WIDTH - paddleW)/2;
int paddleSpeed = 3;


float ballX = SCREEN_WIDTH/2;
float ballY = SCREEN_HEIGHT/2;
float ballDX = 1.5;
float ballDY = -1.5;
int   ballR  = 2;

// 0=1=2=
int difficulty = 1;

void setDifficulty(int d){
  difficulty = constrain(d, 0, 2);
  float v = (difficulty==0)? 1.2 : (difficulty==1? 1.6 : 2.2);
  ballDX = (ballDX<0?-v:+v);
  ballDY = (ballDY<0?-v:+v);
  paddleW = (difficulty==2)? 16 : (difficulty==1? 20 : 26);
  paddleSpeed = (difficulty==2)? 4 : (difficulty==1? 3 : 2);
}

void resetBallPaddle(){
  paddleX = (SCREEN_WIDTH - paddleW)/2;
  ballX = SCREEN_WIDTH/2;
  ballY = SCREEN_HEIGHT/2;
  
  float v = (difficulty==0)? 1.2 : (difficulty==1? 1.6 : 2.2);
  ballDX = v * (random(0,2)==0 ? -1 : +1);
  ballDY = -v;
}

void updateTouch(){
  Ptc *ptc = (Ptc *)PTC;
  for(int i=0;i<N_TOUCH;i++){
    touch_devices[i]->begin();
    touch_values[i] = touch_devices[i]->measure();

    // PTC
    ptc->CTRLA.bit.ENABLE = 0;
    ptc->CTRLA.bit.SWRESET = 1;

    pin_past[i] = pin_now[i];
    pin_now[i]  = (touch_values[i] > THRESHOLD);
  }
}

bool pressed(int b){  
  return (pin_now[b] && !pin_past[b]);
}
bool held(int b){     // touch
  return pin_now[b];
}

void drawHUD(){
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.print("Score:");
  display.print(score);
  display.setCursor(72,0);
  display.print("Best:");
  display.print(bestScore);
}

void drawMenu(){
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(12,10);
  display.println("Paddle Ball (6-touch)");

  display.setCursor(0,24);
  display.println("Q1: LEFT   Q0: RIGHT");
  display.setCursor(0,34);
  display.println("Q2: START  Q3: PAUSE");
  display.setCursor(0,44);
  display.println("Q4: RESET  Q5: SPEED");
  display.setCursor(0,54);
  display.print("Difficulty: ");
  display.println(difficulty==0?"SLOW":(difficulty==1?"NORM":"FAST"));

  display.display();
}

void drawGame(){
  display.clearDisplay();
  drawHUD();

  
  display.fillCircle((int)ballX, (int)ballY, ballR, SSD1306_WHITE);
  
  display.fillRect(paddleX, paddleY, paddleW, paddleH, SSD1306_WHITE);

  display.display();
}

void drawPaused(){
  drawGame();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(40, 28);
  display.println("PAUSED");
  display.display();
}

void drawGameOver(){
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(28, 14);
  display.println("GAME OVER");

  display.setCursor(18, 30);
  display.print("Score: "); display.println(score);
  display.setCursor(18, 40);
  display.print("Best:  "); display.println(bestScore);

  display.setCursor(0, 54);
  display.println("Q2:Start  Q4:Reset  Q5:Speed");
  display.display();
}

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

  // OLED
  Wire.begin(); // SAMD21  SDA=D4, SCL=D5
  if(!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)){
    while(1){ delay(10); }
  }
  display.clearDisplay();
  display.display();

  // Touch init
  for(int i=0;i<N_TOUCH;i++){
    touch_devices[i] = new Adafruit_FreeTouch(touch_pins[i],
                        OVERSAMPLE_1, RESISTOR_100K, FREQ_MODE_NONE);
  }

  pinMode(PIN_LED, OUTPUT);
  setDifficulty(1);
  resetBallPaddle();
  drawMenu();
}

void loop(){
  updateTouch();

  
  if(pressed(BTN_SPEED)){
    setDifficulty((difficulty+1)%3);
    if(state==MENU) drawMenu();
  }
  if(pressed(BTN_RESET)){
    score = 0;
    resetBallPaddle();
    state = MENU;
    drawMenu();
  }

  switch(state){
    case MENU:
      if(pressed(BTN_START)){
        score = 0;
        resetBallPaddle();
        state = PLAYING;
      }
      break;

    case PAUSED:
      if(pressed(BTN_PAUSE)) state = PLAYING;
      break;

    case GAMEOVER:
      if(pressed(BTN_START)){
        score = 0;
        resetBallPaddle();
        state = PLAYING;
      }
      break;

    case PLAYING:
    default:
      // /
      if(held(BTN_LEFT))  paddleX -= paddleSpeed;
      if(held(BTN_RIGHT)) paddleX += paddleSpeed;
      paddleX = constrain(paddleX, 0, SCREEN_WIDTH - paddleW);

      
      if(pressed(BTN_PAUSE)){ state = PAUSED; break; }

      
      ballX += ballDX;
      ballY += ballDY;

      
      if(ballX - ballR <= 0){ ballX = ballR; ballDX = -ballDX; }
      if(ballX + ballR >= SCREEN_WIDTH){ ballX = SCREEN_WIDTH - ballR; ballDX = -ballDX; }
      if(ballY - ballR <= 10){ ballY = 10 + ballR; ballDY = -ballDY; } // HUD

      // AABB +
      if( (ballY + ballR >= paddleY) &&
          (ballX >= paddleX) && (ballX <= paddleX + paddleW) &&
          (ballDY > 0) ){
        ballY = paddleY - ballR;
        ballDY = -ballDY;

        
        float hitPos = (ballX - paddleX) / (float)paddleW; // 0..1
        float offset = (hitPos - 0.5f) * 1.2f;             // -0.6..+0.6
        ballDX += offset;
        
        float maxv = (difficulty==2)? 2.8 : (difficulty==1? 2.2 : 1.8);
        if(ballDX >  maxv) ballDX =  maxv;
        if(ballDX < -maxv) ballDX = -maxv;

        score++;
        if(score > bestScore) bestScore = score;
        digitalWrite(PIN_LED, HIGH);  
      }else{
        digitalWrite(PIN_LED, LOW);
      }

      // Game Over
      if(ballY - ballR > SCREEN_HEIGHT){
        state = GAMEOVER;
      }

      break;
  }

  
  if(state==MENU){
    
  }else if(state==PAUSED){
    drawPaused();
  }else if(state==GAMEOVER){
    drawGameOver();
  }else{ // PLAYING
    drawGame();
  }

  // serialdebug
  // for(int i=0;i<N_TOUCH;i++){ Serial.print(touch_values[i]); Serial.print(' '); }
  // Serial.println();

  delay(16); // ~60 FPS
}