//**************************************************
//      for ATtiny402 Practice Keyer with Sleep + Buffer
//
//      Pin1 Vcc  Pin2 Dit  Pin3 Dah  Pin4 Led
// 	Pin5 Piezo       Pin7 Button  Pin8 Gnd
//         XRQTechLab  2025.8.8
//     Speed 10~30 WPM  up by Button
//**************************************************

#include <EEPROM.h>
#include <avr/sleep.h>
#include <avr/interrupt.h>

#define DIT_PIN 0
#define DAH_PIN 1
#define LED_PIN 2
#define PIEZO_PIN 3
#define BUTTON_PIN 4

int wpm = 10;
int ditLength;
int dahLength;
bool ditPressed = false;
bool dahPressed = false;
bool squeezeMode = false;
bool lastWasDit = false;

volatile bool wakeUpFlag = false;
unsigned long lastInputTime = 0;

// バッファ機能追加
char paddleBuffer = 0;
bool sending = false;

void setup() {
  pinMode(DIT_PIN, INPUT_PULLUP);
  pinMode(DAH_PIN, INPUT_PULLUP);
  pinMode(LED_PIN, OUTPUT);
  pinMode(PIEZO_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  attachInterrupt(digitalPinToInterrupt(DIT_PIN), wakeISR, FALLING);
  attachInterrupt(digitalPinToInterrupt(DAH_PIN), wakeISR, FALLING);
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), wakeISR, FALLING);

  wpm = EEPROM.read(0);
  if (wpm < 10 || wpm > 30) {
    wpm = 10;
  }

  updateSpeed();
  playOpeningMessage();
  lastInputTime = millis();
}

void loop() {
  if (millis() - lastInputTime > 60000) {
    goToSleep();
  }

  if (digitalRead(BUTTON_PIN) == LOW) {
    delay(50);
    if (digitalRead(BUTTON_PIN) == LOW) {
      wpm++;
      if (wpm > 30) {
        wpm = 10;
      }
      EEPROM.write(0, wpm);
      updateSpeed();
      playSpeedSignal();
      lastInputTime = millis();
    }
  }

  // 入力処理（送出中ならバッファに記録）
  if (!sending) {
    if (paddleBuffer) {
      if (paddleBuffer == '.') sendDit();
      else if (paddleBuffer == '-') sendDah();
      paddleBuffer = 0;
    } else {
      if (digitalRead(DIT_PIN) == LOW) {
        ditPressed = true;
        lastInputTime = millis();
      }
      if (digitalRead(DAH_PIN) == LOW) {
        dahPressed = true;
        lastInputTime = millis();
      }

      if (ditPressed && dahPressed) {
        squeezeMode = true;
      }

      if (squeezeMode) {
        sendSqueeze();
        squeezeMode = false;
      } else {
        if (ditPressed) sendDit();
        if (dahPressed) sendDah();
      }
    }
  } else {
    // 送出中の入力を記録
    if (digitalRead(DIT_PIN) == LOW) {
      paddleBuffer = '.';
    } else if (digitalRead(DAH_PIN) == LOW) {
      paddleBuffer = '-';
    }
  }
}

void goToSleep() {
  digitalWrite(LED_PIN, LOW);
  sleep_enable();
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
  sleep_cpu();
  sleep_disable();
  wakeUpFlag = false;
  lastInputTime = millis();
}

void wakeISR() {
  wakeUpFlag = true;
}

void updateSpeed() {
  ditLength = 1200 / wpm;
  dahLength = ditLength * 3;
}

void sendDit() {
  sending = true;
  digitalWrite(LED_PIN, HIGH);
  tone(PIEZO_PIN, 800);
  delay(ditLength);
  digitalWrite(LED_PIN, LOW);
  noTone(PIEZO_PIN);
  delay(ditLength);
  ditPressed = false;
  lastWasDit = true;
  sending = false;
}

void sendDah() {
  sending = true;
  digitalWrite(LED_PIN, HIGH);
  tone(PIEZO_PIN, 800);
  delay(dahLength);
  digitalWrite(LED_PIN, LOW);
  noTone(PIEZO_PIN);
  delay(ditLength);
  dahPressed = false;
  lastWasDit = false;
  sending = false;
}

void sendSqueeze() {
  while (digitalRead(DIT_PIN) == LOW && digitalRead(DAH_PIN) == LOW) {
    if (lastWasDit) {
      sendDah();
    } else {
      sendDit();
    }
  }
}

void playSpeedSignal() {
  for (int i = 0; i < 3; i++) {
    tone(PIEZO_PIN, 800);
    delay(ditLength);
    noTone(PIEZO_PIN);
    delay(ditLength);
  }
}

void playOpeningMessage() {
  tone(PIEZO_PIN, 800);
  delay(ditLength);
  noTone(PIEZO_PIN);
  delay(ditLength);
  tone(PIEZO_PIN, 800);
  delay(dahLength);
  noTone(PIEZO_PIN);
  delay(ditLength);
  tone(PIEZO_PIN, 800);
  delay(ditLength);
  noTone(PIEZO_PIN);
  delay(ditLength);
}