#include <Adafruit_NeoPixel.h>

#define BUTTON_PIN  1      // button pin (other leg -> GND)
#define LED_PIN     2      // NeoPixel data pin
#define NUMPIXELS   2      // two LEDs chained

Adafruit_NeoPixel pixels(NUMPIXELS, LED_PIN, NEO_GRB + NEO_KHZ800);

// Morse timing
#define WPM 10
const unsigned long UNIT_MS = 1200UL / WPM;
const unsigned long DOT_DASH_THRESH_MS = (unsigned long)(2.5 * UNIT_MS);
const unsigned long LETTER_GAP_MS      = (unsigned long)(3.5 * UNIT_MS);
const unsigned long WORD_GAP_MS        = (unsigned long)(7.0 * UNIT_MS);
const unsigned long DEBOUNCE_MS        = 25;

bool lastLevel = HIGH;
unsigned long lastEdgeMs = 0;
unsigned long pressStartMs = 0;
unsigned long lastReleaseMs = 0;
String currentMorse;

struct MorseEntry { const char* code; char ch; };
const MorseEntry table[] PROGMEM = {
  {".-", 'A'}, {"-...", 'B'}, {"-.-.", 'C'}, {"-..", 'D'}, {".", 'E'},
  {"..-.", 'F'}, {"--.", 'G'}, {"....", 'H'}, {"..", 'I'}, {".---", 'J'},
  {"-.-", 'K'}, {".-..", 'L'}, {"--", 'M'}, {"-.", 'N'}, {"---", 'O'},
  {".--.", 'P'}, {"--.-", 'Q'}, {".-.", 'R'}, {"...", 'S'}, {"-", 'T'},
  {"..-", 'U'}, {"...-", 'V'}, {".--", 'W'}, {"-..-", 'X'}, {"-.--", 'Y'},
  {"--..", 'Z'},
  {"-----",'0'}, {".----",'1'}, {"..---",'2'}, {"...--",'3'}, {"....-",'4'},
  {".....",'5'}, {"-....",'6'}, {"--...",'7'}, {"---..",'8'}, {"----.",'9'},
};

char decode(const String& code) {
  for (auto &e : table) if (code == e.code) return e.ch;
  return '?';
}

void flashDot() {
  pixels.clear();
  pixels.setPixelColor(0, pixels.Color(0, 0, 255)); // blue for dot
  pixels.show();
  delay(UNIT_MS);
  pixels.clear(); pixels.show();
}

void flashDash() {
  pixels.clear();
  pixels.setPixelColor(0, pixels.Color(255, 0, 0)); // both red
  pixels.setPixelColor(1, pixels.Color(255, 0, 0));
  pixels.show();
  delay(3 * UNIT_MS);
  pixels.clear(); pixels.show();
}

void endLetter() {
  if (currentMorse.isEmpty()) return;
  Serial.print(decode(currentMorse));
  currentMorse = "";
}

void setup() {
  Serial.begin(115200);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pixels.begin();
  pixels.clear(); pixels.show();
  Serial.println("Morse ready: short=dot, long=dash, LED feedback enabled");
}

void loop() {
  unsigned long now = millis();
  int level = digitalRead(BUTTON_PIN);

  if (level != lastLevel && (now - lastEdgeMs) > DEBOUNCE_MS) {
    lastEdgeMs = now;

    if (level == LOW) {
      pressStartMs = now;
    } else {
      unsigned long dur = now - pressStartMs;
      lastReleaseMs = now;

      if (dur < DOT_DASH_THRESH_MS) {
        Serial.print('.');
        currentMorse += '.';
        flashDot();
      } else {
        Serial.print('-');
        currentMorse += '-';
        flashDash();
      }
    }
    lastLevel = level;
  }

  if (lastLevel == HIGH && lastReleaseMs != 0) {
    unsigned long idle = now - lastReleaseMs;
    if (idle >= LETTER_GAP_MS && currentMorse.length() > 0) {
      endLetter();
      lastReleaseMs = now;
    }
    if (idle >= WORD_GAP_MS) {
      Serial.print(' ');
      lastReleaseMs = now;
    }
  }
}