/*
* 
* https://docs.arduino.cc/language-reference/
* https://docs.arduino.cc/built-in-examples/digital/BlinkWithoutDelay/
*
*
*/

// Include the library code:
#include <LiquidCrystal.h>

// Initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);
#define INDIALPIN 3
#define PULSEPIN 2
boolean inDialPinLastState;
boolean pulsPinLastState;
byte counter = 0;
byte holdOff = 0; // countdown


// constants won't change. Used here to set a pin number:
const int ledPin = LED_BUILTIN;  // the number of the LED pin

// Variables will change:
int ledState = LOW;  // ledState used to set the LED

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0;  // will store last time LED was updated

// constants won't change:
const long interval = 500;  // interval at which to blink (milliseconds)



void setup() {
  Serial.begin(115200);
  Serial.println("System started");
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // set the fixed text
  lcd.setCursor(0, 0);
  pinMode(INDIALPIN, INPUT_PULLUP);
  pinMode(PULSEPIN, INPUT_PULLUP);
  inDialPinLastState = digitalRead(INDIALPIN);
  pulsPinLastState = digitalRead(PULSEPIN);
}

/*
* The dial has two wires
* DIAL :  -----___________________________--------- 
* PULSE:  -------__---__---__---__---__------------
*
* The Telephone loops the line so get a time from PULSE 
* The user pick up the handset, 
* so the phone goes off goes OFF_HOOK
* As it dials set holdOff and decrement on a timer tick
* after the dialing has stopped holdOff gets to 1 , emit count.
* 
* DIAL    :  -----___________________________--------- 
* PULSE   :  -------__---__---__---__---__------------
* holdOff :  -------__________________________----------
*/

void loop() {

    // here is where you'd put code that needs to be running all the time.

  // check to see if it's time to blink the LED; that is, if the difference
  // between the current time and last time you blinked the LED is bigger than
  // the interval at which you want to blink the LED.
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
    } else {
      ledState = LOW;
    }

    // set the LED with the ledState of the variable:
    // digitalWrite(ledPin, ledState);
    if ( holdOff > 0 ){
      
      holdOff += -1;
      if ( holdOff == 1  ){
        Serial.println("timeout:");
        Serial.println(counter);
        //lcd.print("_");
        lcd.print(counter);

      }
    }  
  }



  boolean inDialPinState = digitalRead(INDIALPIN);
  boolean pulsPinState = digitalRead(PULSEPIN);
  if (inDialPinState != inDialPinLastState) {
    if (!inDialPinState) {
      Serial.println("Start of dial");
      counter = 0;
    } else {
      Serial.println("End of dial");
      Serial.print("Dialed Digit - ");
      Serial.println(counter);
      if (counter) {
        counter = counter % 10;
        //lcd.print(counter);
      }
    } //end if
    inDialPinLastState = inDialPinState;
  } //end if
  if (pulsPinLastState != pulsPinState) {
    holdOff = 3;
    if (!pulsPinLastState) {
      counter++;
    } // end if
    Serial.println("pulsPinState - " + String(pulsPinState));
    pulsPinLastState = pulsPinState;
  }
}