// Arduino controlled timer socket
// (CC BY) 2011
// http://awooga.nl
 
// pull in libraries
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Metro.h>
 
 
// arduino pins constants
#define RELAY 2 // black wire connected to input on shield
#define RED   6 // green wire
#define GREEN 7 // white wire
 
// i2c pin A5 = white wire
// i2c pin A4 = green wire
 
// allow between 1 and 6 hours
#define MINIMUM_TIME 1
#define DEFAULT_TIME 6
#define MAXIMUM_TIME 6
 
 
const unsigned long MILLISECONDS=1;
const unsigned long SECONDS=(1000*MILLISECONDS);
const unsigned long MINUTES=(60*SECONDS);
const unsigned long HOURS=(60*MINUTES);
const unsigned long DAYS=(24*HOURS);
 
const unsigned long UNITS=HOURS;
 
 
// prgram states
#define IDLE         0
#define RED_BUTTON   1
#define GREEN_BUTTON 2
#define MENU         3
#define PAUSE        4
#define STOP_TIMER   5
#define CANCEL_TIMER 6
 
 
// global variables
byte events;
byte countdowntime;
boolean menu_running;
boolean timer_running;
 
boolean debug = false;
 
byte currentRed = LOW;
byte currentGreen = LOW;
byte previousRed = LOW;
byte previousGreen = LOW;
 
// set the LCD address to 0x27 for the 16x2 display
LiquidCrystal_I2C lcd(0x27, 16, 2);
 
// initiate Metro object
Metro relayMetro = Metro(0, true);
 
 
// arduino setup routine
void setup() {
 
  // set the arduino pins
  pinMode(RELAY, OUTPUT);
  pinMode(RED, INPUT);
  pinMode(GREEN, INPUT);  
 
  // initialise the lcd
  lcd.init();
  lcd.backlight();
 
  // activate debugging on the serial port
  if (debug) {
    Serial.begin(9600);
    Serial.println("Lets go!");
  }
 
  // initialise variables
  events = IDLE;
  countdowntime = DEFAULT_TIME;
  menu_running = false;
  timer_running = false;
  digitalWrite(RELAY, LOW);
}
 
 
// arduino loop routine
void loop() {
 
  switch (events) {
 
    case IDLE:
      events = Idling();
      break;
 
    case MENU:
      events = MainMenu();
      break;
 
    case RED_BUTTON:
      events = RedButton();
      break;
 
    case GREEN_BUTTON:
      events = GreenButton();
      break;
 
    case PAUSE:
      events = Pause();
      break;
 
    case STOP_TIMER:
      events = StopTimer();
      break;
 
    case CANCEL_TIMER:
      events = CancelTimer();
      break;
 
    default:
      events = IDLE;
      break;
  }
}
 
 
int MainMenu() {
 
  if (timer_running) {
    return IDLE;
  }
 
  if (menu_running) {
    return IDLE;
  }
 
  if (debug) { Serial.println("MainMenu()"); }
 
  lcd.clear();
  lcd.print("  Red: Set time");
  lcd.setCursor(0, 1);
  lcd.print("Green: Go (");
  lcd.print(countdowntime, DEC);
  if (countdowntime == 1) {
    lcd.print("hr)");
  }
  else {
    lcd.print("hrs)");
  }
 
  menu_running = true;
 
  return IDLE;
}
 
 
int Idling() {
 
  boolean do_red = false;
  boolean do_green = false;
 
  if (timer_running) {
    if (relayMetro.check()) {
      return STOP_TIMER;
    }
  }
 
  currentRed = digitalRead(RED);
  currentGreen = digitalRead(GREEN);
 
  if (currentRed != previousRed) {
    do_red = (currentRed == HIGH);
  }
  previousRed = currentRed;
 
  if (currentGreen != previousGreen) {
    do_green = (currentGreen == HIGH);
  }
  previousGreen = currentGreen;
 
  if ((do_red) && (!do_green)) {
    return RED_BUTTON;
  }
 
  if ((!do_red) && (do_green)) {
    return GREEN_BUTTON;
  }
 
  // all other button combinations are ignored
  return MENU;
}
 
 
int RedButton() {
  if (debug) { Serial.println("RedButton()"); }
 
  if (timer_running) {
    return CANCEL_TIMER;
  }
 
  if (++countdowntime > MAXIMUM_TIME) { countdowntime = MINIMUM_TIME; }
 
  lcd.clear();
  lcd.print("Time set to");
  lcd.setCursor(0, 1);
  lcd.print(countdowntime, DEC);
  if (countdowntime == 1) {
    lcd.print(" hour");
  }
  else {
    lcd.print(" hours");
  }
 
  menu_running = false;
 
  return PAUSE;
}
 
 
int GreenButton() {
  if (debug) { Serial.println("GreenButton()"); }
 
  if (timer_running) {
    return CANCEL_TIMER;
  }
 
  lcd.clear();
  lcd.print("Running timer");
  lcd.setCursor(0, 1);
  lcd.print("for ");
  lcd.print(countdowntime, DEC);
  if (countdowntime == 1) {
    lcd.print(" hour");
  }
  else {
    lcd.print(" hours");
  }
 
  unsigned long t = countdowntime * UNITS;
 
  timer_running = true;
  if (debug) {
    Serial.print("Setting metro for ");
    Serial.print(t);
    Serial.println(" seconds");
  }
  relayMetro.interval(t);
 
  digitalWrite(RELAY, HIGH);
 
  return IDLE;
}
 
 
int StopTimer() {
  if (debug) { Serial.println("StopTimer()"); }
 
  digitalWrite(RELAY, LOW);
 
  lcd.clear();
  lcd.print("Timer finished");
 
  timer_running = false;
  menu_running = false;
  relayMetro.reset();
 
  return PAUSE;
}
 
 
int CancelTimer() {
  if (debug) { Serial.println("CancelTimer()"); }
 
  digitalWrite(RELAY, LOW);
 
  lcd.clear();
  lcd.print("Timer stopped");
 
  timer_running = false;
  menu_running = false;
  relayMetro.reset();
 
  return PAUSE;
}
 
 
int Pause() {
  delay(1000);
  return IDLE;
}