#include <Adafruit_NeoPixel.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// --- Hardware Setup ---
#define PIN_DATA      3
#define MATRIX_WIDTH  16
#define MATRIX_HEIGHT 16
#define NUM_PIXELS    (MATRIX_WIDTH * MATRIX_HEIGHT)

#define LCD_ADDRESS   0x27  // Change if needed (e.g., 0x3F)
#define LCD_COLUMNS   20
#define LCD_ROWS      4

Adafruit_NeoPixel pixels(NUM_PIXELS, PIN_DATA, NEO_GRB + NEO_KHZ800);
LiquidCrystal_I2C lcd(LCD_ADDRESS, LCD_COLUMNS, LCD_ROWS);

// --- Timing ---
#define CHASE_INTERVAL   50
#define RAINBOW_INTERVAL 10
#define SWITCH_INTERVAL  20000

unsigned long lastFrameTime = 0;
unsigned long lastSwitchTime = 0;

// --- Animation State ---
enum Animation { CHASE, RAINBOW, SPARKLE, WIPE, BREATH };
Animation currentAnim = CHASE;
const int NUM_ANIMATIONS = 5;

// --- Setup ---
void setup() {
  Serial.begin(9600);
  lcd.begin(20, 4);
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("NeoPixel Matrix Ready");

  pixels.begin();
  pixels.setBrightness(50);
  pixels.clear();
  pixels.show();
}

// --- Main Loop ---
void loop() {
  if (millis() - lastSwitchTime > SWITCH_INTERVAL) {
    lastSwitchTime = millis();
    switchAnimation();
  }

  switch (currentAnim) {
    case CHASE:    updateChase(); break;
    case RAINBOW:  updateRainbow(); break;
    case SPARKLE:  updateSparkle(); break;
    case WIPE:     updateWipe(); break;
    case BREATH:   updateBreath(); break;
  }
}

// --- Animation Switching ---
void switchAnimation() {
  currentAnim = static_cast<Animation>((currentAnim + 1) % NUM_ANIMATIONS);
  String name = getAnimName(currentAnim);

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Animation:");
  lcd.setCursor(0, 1);
  lcd.print(name);

  Serial.println("Switched to: " + name);
}

// --- Animation Names ---
String getAnimName(Animation a) {
  switch (a) {
    case CHASE:   return "CHASE";
    case RAINBOW: return "RAINBOW";
    case SPARKLE: return "SPARKLE";
    case WIPE:    return "WIPE";
    case BREATH:  return "BREATHING";
    default:      return "CODE BY ARVIND";
  }
}

// --- Pixel Index Helper ---
uint16_t getPixelIndex(int x, int y) {
  if (y % 2 == 0) return y * MATRIX_WIDTH + x;
  else return y * MATRIX_WIDTH + (MATRIX_WIDTH - 1 - x);
}

// --- Color Wheel ---
uint32_t Wheel(byte pos) {
  pos = 255 - pos;
  if (pos < 85) return pixels.Color(255 - pos * 3, 0, pos * 3);
  if (pos < 170) {
    pos -= 85;
    return pixels.Color(0, pos * 3, 255 - pos * 3);
  }
  pos -= 170;
  return pixels.Color(pos * 3, 255 - pos * 3, 0);
}

// --- Animations ---
void updateChase() {
  static int x = 0, y = 0;
  if (millis() - lastFrameTime > CHASE_INTERVAL) {
    lastFrameTime = millis();
    pixels.setPixelColor(getPixelIndex(x, y), 0);
    x++;
    if (x >= MATRIX_WIDTH) {
      x = 0;
      y = (y + 1) % MATRIX_HEIGHT;
    }
    pixels.setPixelColor(getPixelIndex(x, y), pixels.Color(255, 0, 0));
    pixels.show();
  }
}

void updateRainbow() {
  static uint16_t j = 0;
  if (millis() - lastFrameTime > RAINBOW_INTERVAL) {
    lastFrameTime = millis();
    for (uint16_t i = 0; i < NUM_PIXELS; i++) {
      pixels.setPixelColor(i, Wheel((i * 256 / NUM_PIXELS + j) & 255));
    }
    pixels.show();
    j++;
  }
}

void updateSparkle() {
  static unsigned long lastSparkle = 0;
  if (millis() - lastSparkle > 100) {
    lastSparkle = millis();
    int index = random(NUM_PIXELS);
    pixels.setPixelColor(index, pixels.Color(255, 255, 255));
    pixels.show();
    delay(30);
    pixels.setPixelColor(index, 0);
    pixels.show();
  }
}

void updateWipe() {
  static int row = 0;
  if (millis() - lastFrameTime > 100) {
    lastFrameTime = millis();
    for (int x = 0; x < MATRIX_WIDTH; x++) {
      pixels.setPixelColor(getPixelIndex(x, row), pixels.Color(0, 255, 0));
    }
    pixels.show();
    row++;
    if (row >= MATRIX_HEIGHT) {
      row = 0;
      pixels.clear();
    }
  }
}

void updateBreath() {
  static int brightness = 0;
  static int delta = 5;
  if (millis() - lastFrameTime > 30) {
    lastFrameTime = millis();
    brightness += delta;
    if (brightness >= 255 || brightness <= 0) delta = -delta;
    pixels.setBrightness(brightness);
    for (int i = 0; i < NUM_PIXELS; i++) {
      pixels.setPixelColor(i, pixels.Color(0, 0, 255));
    }
    pixels.show();
  }
}