/*
NEW SKETCH

  8x8 WS2812B LED Matrix - Scrolling Text "0 WORLD" with Start/Stop Switch
  Hardware: Seeed XIAO ESP32C3
  Data Pin: GPIO2
  Switch Pin: GPIO3 (connect switch between GPIO3 and GND)
*/

#include <Adafruit_NeoPixel.h>

#define DATA_PIN     2
#define SWITCH_PIN   3      // GPIO3 — connect switch between GPIO3 and GND
#define NUM_LEDS     64
#define BRIGHTNESS   20
#define SCROLL_DELAY 80     // ms between scroll steps

Adafruit_NeoPixel strip(NUM_LEDS, DATA_PIN, NEO_GRB + NEO_KHZ800);

// Text color
#define TEXT_R 255
#define TEXT_G 255
#define TEXT_B 255

// 5x7 Font
const uint8_t font5x7[][5] = {
  { 0b1111111, 0b0001000, 0b0001000, 0b1111111, 0b0000000 }, // H
  { 0b1111111, 0b1001001, 0b1001001, 0b1000001, 0b0000000 }, // E
  { 0b1111111, 0b1000000, 0b1000000, 0b1000000, 0b0000000 }, // L
  { 0b1111111, 0b1000000, 0b1000000, 0b1000000, 0b0000000 }, // L
  { 0b0111110, 0b1000001, 0b1000001, 0b0111110, 0b0000000 }, // O
  { 0b0000000, 0b0000000, 0b0000000, 0b0000000, 0b0000000 }, // (space)
  { 0b1111111, 0b0100000, 0b0010000, 0b0100000, 0b1111111 }, // W
  { 0b0111110, 0b1000001, 0b1000001, 0b0111110, 0b0000000 }, // O
  { 0b1111111, 0b0001001, 0b0011001, 0b1100110, 0b0000000 }, // R
  { 0b1111111, 0b1000000, 0b1000000, 0b1000000, 0b0000000 }, // L
  { 0b1111111, 0b1000001, 0b1000001, 0b0111110, 0b0000000 }, // D
};

const int NUM_CHARS  = 11;
const int TOTAL_COLS = NUM_CHARS * 6;

uint8_t scrollBuf[7][NUM_CHARS * 6];

// --- State ---
bool animRunning  = false;   // is animation playing?
int  scrollOffset = -8;      // current scroll position

// --- Debounce ---
bool     lastSwitchState    = HIGH;
bool     switchState        = HIGH;
unsigned long lastDebounceTime = 0;
#define DEBOUNCE_DELAY 50

void buildScrollBuffer() {
  for (int c = 0; c < NUM_CHARS; c++) {
    for (int col = 0; col < 5; col++) {
      uint8_t colData = font5x7[c][col];
      for (int row = 0; row < 7; row++) {
        scrollBuf[row][c * 6 + col] = (colData >> row) & 1;
      }
    }
    for (int row = 0; row < 7; row++) {
      scrollBuf[row][c * 6 + 5] = 0;
    }
  }
}

void displayFrame(int offset) {
  strip.clear();
  for (int col = 0; col < 8; col++) {
    int srcCol = offset + col;
    for (int row = 0; row < 7; row++) {
      uint8_t lit = 0;
      if (srcCol >= 0 && srcCol < TOTAL_COLS) {
        lit = scrollBuf[row][srcCol];
      }
      if (lit) {
        int ledIndex;
        if (col % 2 == 0) {
          ledIndex = col * 8 + row;
        } else {
          ledIndex = col * 8 + (7 - row);
        }
        strip.setPixelColor(ledIndex, strip.Color(TEXT_R, TEXT_G, TEXT_B));
      }
    }
  }
  strip.show();
}

// Read switch with debounce — returns true on a LOW transition (button press)
bool switchPressed() {
  bool reading = digitalRead(SWITCH_PIN);

  if (reading != lastSwitchState) {
    lastDebounceTime = millis();
  }
  lastSwitchState = reading;

  if ((millis() - lastDebounceTime) > DEBOUNCE_DELAY) {
    if (reading != switchState) {
      switchState = reading;
      if (switchState == LOW) {  // Active LOW — pressed
        return true;
      }
    }
  }
  return false;
}

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

  pinMode(SWITCH_PIN, INPUT_PULLUP);  // Internal pull-up; switch connects GPIO3 → GND

  strip.begin();
  strip.setBrightness(BRIGHTNESS);
  strip.clear();
  strip.show();

  buildScrollBuffer();
  Serial.println("Ready. Press switch to start/stop.");
}

void loop() {
  // Always check the switch, even mid-scroll
  if (switchPressed()) {
    animRunning = !animRunning;
    Serial.println(animRunning ? "▶ Started" : "⏹ Stopped");

    if (!animRunning) {
      // Clear display immediately on stop
      strip.clear();
      strip.show();
      scrollOffset = -8;  // Reset position for next start
    }
  }

  if (animRunning) {
    displayFrame(scrollOffset);
    scrollOffset++;

    // Reset after full scroll
    if (scrollOffset >= TOTAL_COLS) {
      scrollOffset = -8;
    }

    // Non-blocking delay — still checks switch during scroll pause
    unsigned long start = millis();
    while (millis() - start < SCROLL_DELAY) {
      if (switchPressed()) {
        animRunning = false;
        strip.clear();
        strip.show();
        scrollOffset = -8;
        Serial.println("⏹ Stopped");
        break;
      }
    }
  }
}