JalanTech-Alarm-Clock-Assignment

main.js

// @Author - Harshvardhan Joshi ([email protected])
// Objective:
//    Using object-oriented programming, please implement command line program to implement an
//    alarm clock
//    An alarm clock has following features:
//        1. It displays the current time
//        2. A user can create any number of alarms by specifying the alarm time and day of the week and
//        time when the alarm should alert
//        3. A user can snooze an alarm maximum of 3 times at an interval of 5 minutes each.
//        4. A user can delete an alarm

const kDefaultSnoozeTime = 5;
const kMaxSnoozeCount = 3;
const kMinsInHours = 60;

const weekdays = [
  "Sunday",
  "Monday",
  "Tuesday",
  "Wednesday",
  "Thursday",
  "Friday",
  "Saturday"
];

// Base class to show current time
class Clock {
  showTime() {
    console.log(new Date());
  }
}

// Alarm Data Model to hold & process alarm related data
class Alarm {
  constructor(time, day) {
    this.timeInEpochMilliseconds = time;
    this.dayOfTheWeek = day;
    this.snoozeCount = 0;
  }

  isSameAs(hours, minutes, dayOfTheWeek) {
    var alarmDate = new Date(this.timeInEpochMilliseconds);

    var alarmHour = alarmDate.getHours();
    var alarmMins = alarmDate.getMinutes();

    return (
      hours === alarmHour &&
      minutes === alarmMins &&
      dayOfTheWeek === this.dayOfTheWeek
    );
  }

  display() {
    var alarmDate = new Date(this.timeInEpochMilliseconds);

    var alarmHour = alarmDate.getHours();
    var alarmMins = alarmDate.getMinutes();

    var alarmDateString = `${alarmDate.getFullYear()}-${
      alarmDate.getMonth() + 1
    }-${alarmDate.getDate() + 1}`;
    var alarmTime = `${alarmHour}:${alarmMins}`;
    var weekDay = this.dayOfTheWeek;
    console.info(`\n${alarmDateString}(${weekDay}) - ${alarmTime}`);
  }

  snooze() {
    if (this.snoozeCount === kMaxSnoozeCount) {
      console.log("Cannot snooze further");
    } else {
      this.snoozeCount++;

      var alarmTime = new Date(this.timeInEpochMilliseconds);
      var minutes = alarmTime.getMinutes();
      var hours = alarmTime.getHours();
      minutes += kDefaultSnoozeTime;

      // Adjust Hours & minutes
      if (minutes >= kMinsInHours) {
        hours++;
        minutes -= kMinsInHours;
      }

      // Update alarm time
      var newTime = new Date(alarmTime);
      newTime.setMinutes(minutes);
      newTime.setHours(hours);

      console.log(`Snoozed, Next time to alarm: ${newTime.toUTCString()}`);
      this.timeInEpochMilliseconds = newTime.getTime();
    }
  }
}

// Derived Class from Clock to show time as well as hold Alarms
// This class allows user to interact with the alarms, by allowing to add, delete & display them
class AlarmClock extends Clock {
  constructor() {
    super();
    this.alarms = [];
  }

  displayAll() {
    console.info(
      `\n\n============  ALARMS  (${this.alarms.length})  ============\n============ Sorted By Date ============\n\n`
    );

    var allAlarms = [...this.alarms];
    allAlarms.sort(
      (a, b) => a.timeInEpochMilliseconds > b.timeInEpochMilliseconds
    );
    allAlarms.forEach((alarm) => {
      alarm.display();
    });
    console.info("\n\n================================\n\n");
  }

  validateNewAlarmTime(hours, minutes, currentDate) {
    var currentHour = currentDate.getHours();
    var currentMinutes = currentDate.getMinutes();

    if (currentHour > hours || currentMinutes > minutes) {
      return "Can't set alarm in past time";
    }
    return null;
  }

  add(hours, minutes, dayOfTheWeek) {
    var newAlarmDate = new Date();

    var currentDay = newAlarmDate.getDay();
    var alarmDay = weekdays.indexOf(dayOfTheWeek);

    var difference = alarmDay - currentDay;

    // Check if the day is different
    if (difference !== 0) {
      if (difference < 0) {
        difference = (difference + 7) % 7;
      }
    } else {
      // Check if the time is different for same day
      var error = this.validateNewAlarmTime(hours, minutes, newAlarmDate);
      if (error) {
        console.error(error);
        console.log("Updating the date by a week to create new alarm");
        difference = 7;
      }
    }

    newAlarmDate.setDate(newAlarmDate.getDate() + difference);
    newAlarmDate.setHours(hours);
    newAlarmDate.setMinutes(minutes);

    var alarmTimeInEpochMilliseconds = newAlarmDate.getTime();
    var newAlarm = new Alarm(alarmTimeInEpochMilliseconds, dayOfTheWeek);
    this.alarms.push(newAlarm);
    console.info(`Added new alarm => ${dayOfTheWeek} - ${hours}:${minutes}`);
  }

  deleteAlarm(hours, minutes, dayOfTheWeek) {
    var remainingAlarm = this.alarms.filter((alarm) => {
      return !alarm.isSameAs(hours, minutes, dayOfTheWeek);
    });

    if (this.alarms.length !== remainingAlarm.length) {
      console.info(`Alarm Deleted => ${dayOfTheWeek} - ${hours}:${minutes}`);
      this.alarms = remainingAlarm;
    } else {
      console.info("No matching alarm found");
    }
  }
}

console.log(`\n\n============  DEMO START ============\n\n`);

const alarmClock = new AlarmClock();
alarmClock.showTime();
alarmClock.add(6, 45, "Monday");
alarmClock.add(7, 0, "Monday");
alarmClock.add(7, 15, "Monday");
alarmClock.add(7, 30, "Monday");

alarmClock.add(15, 30, "Wednesday");

// Set alarm for Everyday in the week
weekdays.forEach((day) => {
  alarmClock.add(8, 0, day);
});

alarmClock.displayAll();

alarmClock.deleteAlarm(8, 0, "Sunday");
alarmClock.deleteAlarm(6, 45, "Monday");
alarmClock.deleteAlarm(7, 0, "Monday");
alarmClock.deleteAlarm(15, 30, "Wednesday");
alarmClock.displayAll();

alarmClock.add(8, 30, "Monday");
alarmClock.displayAll();

console.log(`\n\n============  DEMO END ============\n\n`);