#define DEBUG(x) x
//#define DEBUG(x)

// units ms
#define UNLOCK_DURATION 10000

// arduino pin assignments
#define PTT 8
#define AUDIO_OUT 9
#define LED 13

#define TONE_DETECT 2
#define D1 4
#define D2 5
#define D3 6
#define D4 7

byte tone_detected = 0;
char dtmf_key[] = { 
  'D', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '*', '#', 'A', 'B', 'C' };

void dtmf_isr() {
  tone_detected = 1;
}

// Setup
void setup() {
  pinMode(PTT, OUTPUT);
  digitalWrite(PTT, HIGH);
  
  pinMode(LED, OUTPUT);
  pinMode(TONE_DETECT, INPUT);
  pinMode(D1, INPUT);
  pinMode(D2, INPUT);
  pinMode(D3, INPUT);
  pinMode(D4, INPUT);
  
  attachInterrupt(0, dtmf_isr, RISING);

  Serial.begin(9600);
  Serial.print("\r\nZL4DM 439.150 Repeater Controller\r\n\r\n");

}

void loop() {
  static byte dtmf;
  static byte unlocked = 0;
  static unsigned long relock_time = 0;
  static byte password_count = 0;
  static byte password_length = 3;
  static byte password[] = { 
    0x1, 0x4, 0x7   };

//  if (!tone_detected)
//    return; 

  if (tone_detected) {
    tone_detected = 0;
    dtmf = PIND >> 4;
    Serial.print("Tone: ");
    Serial.println(dtmf_key[dtmf]);
  
    if (!unlocked && (dtmf == password[password_count])) {
      DEBUG(Serial.println(" password hit!"));
      if (++password_count == password_length) {
        DEBUG(Serial.println("unlocked!"));
        unlocked = 1;
        relock_time = millis() + UNLOCK_DURATION;
        play_tone(700, 100);
        return;
      }
    } else {
      password_count = 0;
    }

    if(unlocked) {
      play_tone(dtmf * 100 + 200, 600);
      relock_time = millis() + UNLOCK_DURATION;
      return;
    }
  }

  if (unlocked && (relock_time < millis())) {
    DEBUG(Serial.println(" *locked*"));
    unlocked = 0;
    password_count = 0;
  }

}


void play_tone(int freq, int dur) {
  delay(1400);
  digitalWrite(LED, HIGH);
  digitalWrite(PTT, LOW);
  delay(300);
  tone(AUDIO_OUT, freq);
  delay(dur);
  noTone(AUDIO_OUT);
  delay(300);
  digitalWrite(PTT, HIGH);
  digitalWrite(LED, LOW);
  
  tone_detected = 0;
}