const int LED_PIN = 16;
const int RELAY_PIN = 4;   // 继电器引脚, GPIO/0, GPIO/1(TX), GPIO/2(LED), GPIO/3(RX)
const int BUTTON_PIN = 5;  // 物理按钮引脚
bool relayState = false;   // 设备初始状态

unsigned long lastMillis = 0;
unsigned long lastInterruptTime = 0;
unsigned long longPressTime = 1000;
unsigned long debounceTime = 110;

void IRAM_ATTR buttonPressHandler();
void IRAM_ATTR buttonReleaseHandler();

/**
* Interrupt Service Routine (ISR)
*
* 按下按键, 引脚从高电平变为低电平(FALLING)
*/
void IRAM_ATTR buttonPressHandler() {
  detachInterrupt(digitalPinToInterrupt(BUTTON_PIN));

  unsigned long interruptTime = millis();
  unsigned long timeDiff;

  timeDiff = interruptTime - lastInterruptTime;

  // If interrupts come faster than 100ms, assume it's a bounce and ignore
  if (timeDiff > debounceTime) {
    lastInterruptTime = interruptTime;
  }

  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), buttonReleaseHandler, RISING);
}

/**
* Interrupt Service Routine (ISR)
*
* 松开按键, 引脚从低电平变为高电平(RISING)
*/
void IRAM_ATTR buttonReleaseHandler() {
  detachInterrupt(digitalPinToInterrupt(BUTTON_PIN));

  unsigned long interruptTime = millis();
  unsigned long timeDiff;

  timeDiff = interruptTime - lastInterruptTime;

  // 小于100ms, 判断为抖动, 忽略
  if (timeDiff > debounceTime) {
    // 长按
    if ( timeDiff >= longPressTime ) {
      digitalWrite(LED_PIN, !digitalRead(LED_PIN));
    }
    // 短按
    else {
      switchRelay(false);
      //digitalWrite(RELAY_PIN, !digitalRead(RELAY_PIN));
    }

    lastInterruptTime = interruptTime;
  }

  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), buttonPressHandler, FALLING);
}

/**
* 切换继电器状态
*/
void switchRelay(bool publish) {
  relayState = !relayState;
  digitalWrite(RELAY_PIN, relayState);
}

void setup() {
  Serial.begin(9600);
  //Serial.setDebugOutput(false);
  delay(100);  // Wait for serial port

  pinMode(LED_PIN, OUTPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);  // 设置物理按键引脚
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), buttonPressHandler, FALLING);  // 设置中断
  digitalWrite(RELAY_PIN, relayState);

  Serial.println("Beginning...");

}

void loop() {
  delay(100);
  Serial.println(relayState);

}