hotel-booking

hotel-booking.js

class Hotel {
  constructor(numRooms) {
    this.totalRooms = numRooms;
    this.reservations = {};
  }

  book(startDay, endDay) {
    let checkIn = this._keyify(startDay);
    // do we have any reservations at this date
    if (this.reservations[checkIn] && this.reservations[checkIn].length) {
      // grab an available room from end of array
      const bookedRoom = this.reservations[checkIn].pop();
      this._removeRoomFromFutureAvailability(startDay, endDay, bookedRoom);
      return `You're booked at room ${bookedRoom}`;
    } else if (this.reservations[checkIn] && this.reservations[checkIn].length === 0) {
      // the array was empty, no available rooms
      return 'Hotel is fully booked on desired check-in day';
    } else {
      this.reservations[checkIn] = this._setAllRoomsAvailable();
      const bookedRoom = this.reservations[checkIn].pop();
      this._removeRoomFromFutureAvailability(startDay, endDay, bookedRoom);
      return `You're booked at room ${bookedRoom}`;
    }
  }

  _removeRoomFromFutureAvailability(startDay, endDay, bookedRoom) {
    // increment by 1 until we reach the end day
    // removing the room from availability
    const checkIn = this._keyify(startDay);
    const checkOut = this._keyify(endDay);
    
    for (let i=checkIn+1; i<=checkOut; i++) {
      i = i+''; // small hack: converting from number to string so key can be found
      if (this.reservations[i] && this.reservations[i].length) {
        // remove the room from availability
        this.reservations[i] = this.reservations[i].filter(room => room !== bookedRoom);
      } else {
        // don't have this key yet, add it, but don't include this room as available   
        this.reservations[i] = this._setAllRoomsAvailable(bookedRoom);
      }
    }
  }

  _setAllRoomsAvailable(blockedRoom=null) {
    const availableRooms = [];
    for (let i=1; i<=this.totalRooms; i++) {
      if (blockedRoom === i) continue;
      availableRooms.push(i);
    }
    return availableRooms;
  }

  _keyify(strDate) {
    const numArray = strDate.split('-').map(strNum => Number(strNum));
    return numArray[2] + numArray[0] + numArray[1];
  }
}

// create a new hotel with 3 total rooms
const hotel = new Hotel(3);

// make a booking - should be able to book at this date 3 times before you reach capacity
console.log(hotel.book('9-10-2019', '9-12-2019'));
console.log(hotel.book('9-10-2019', '9-12-2019'));
console.log(hotel.book('9-10-2019', '9-12-2019'));
console.log(hotel.book('9-10-2019', '9-12-2019'));

console.log(hotel.book('9-13-2019', '9-14-2019'));