오브젝트 2과 연습

index.ts

class MovieTheaters {
  private _name: string;
  private _theaters: Set<Theater> = new Set();
  private _screenings: Set<Screening> = new Set();

  constructor(name: string) {
    this._name = name;
  }

  public createTheater(theater: Theater) {
    this._theaters.add(theater);
  }

  public createScreening(screening: Screening) {
    this._screenings.add(screening);
  }

  get name(): string {
    return this._name;
  }
  get theaters(): Theater[] {
    return Array.from(this._theaters);
  }
  get screenings(): Screening[] {
    return Array.from(this._screenings);
  }
}

class Theater {
  private _name: string;
  private _seats: number;

  constructor(name: string, seats: number) {
    this._name = name;
    this._seats = seats;
  }

  get name(): string {
    return this._name;
  }

  get seats(): number {
    return this._seats;
  }

  public allocateSeats(audienceCount: number) {
    if (this._seats - audienceCount > 0)
      this._seats = this._seats - audienceCount;
    else throw new Error("남은 좌석이 없습니다.");
  }
}

class Screening {
  private _theater: Theater;
  private _movie: Movie;
  private _whenScreened: string;
  private _fee: number;
  private _discountPolicy: DiscountPolicy;

  constructor(
    theater: Theater,
    movie: Movie,
    whenScreened: string,
    fee: number,
    discountPolicy: DiscountPolicy
  ) {
    this._theater = theater;
    this._movie = movie;
    this._whenScreened = whenScreened;
    this._fee = fee;
    this._discountPolicy = discountPolicy;
  }

  get theater(): Theater {
    return this._theater;
  }

  get fee(): number {
    return this._fee;
  }

  get movie(): Movie {
    return this._movie;
  }

  get whenScreened(): string {
    return this._whenScreened;
  }

  public createReservation(customer: Customer, audienceCount: number) {
    this._theater.allocateSeats(audienceCount);
    const fee = this.fee - this._discountPolicy.calculateDiscountAmount(this);
    return new Reservation(customer, this, fee, audienceCount);
  }
}

class Movie {
  private _name: string;
  constructor(name: string) {
    this._name = name;
  }

  get name() {
    return this._name;
  }
}

class Customer {
  private _name: string;
  constructor(name: string) {
    this._name = name;
  }

  public reserve(screening: Screening, audienceCount: number) {
    return screening.createReservation(this, audienceCount);
  }

  get name() {
    return this._name;
  }
}

abstract class DiscountPolicy {
  private _conditions: DiscountCondition[] = new Array<DiscountCondition>();
  constructor(...args: DiscountCondition[]) {
    this._conditions = args;
  }
  public calculateDiscountAmount(screening: Screening) {
    for (const each of this._conditions) {
      if (each.isSatisfiedBy()) {
        return this.getDiscountAmount(screening);
      }
    }
    return 0;
  }
  protected abstract getDiscountAmount(screening: Screening): number;
}

interface DiscountCondition {
  isSatisfiedBy(): boolean;
}

class PercentDiscountPolicy extends DiscountPolicy {
  private _percent: number;
  constructor(percent: number, ...args: DiscountCondition[]) {
    super(...args);
    this._percent = percent;
  }
  protected getDiscountAmount(screening: Screening): number {
    return screening.fee * this._percent;
  }
}

class SequenceDiscountCondition implements DiscountCondition {
  private _theater: Theater;
  private _sequence: number;

  constructor(theater: Theater, sequence: number) {
    this._theater = theater;
    this._sequence = sequence;
  }

  public isSatisfiedBy(): boolean {
    return this._theater.seats === this._sequence;
  }
}

class Reservation {
  private _customer: Customer;
  private _screening: Screening;
  private _fee: number;
  private _audienceCount: number;
  constructor(
    customer: Customer,
    screening: Screening,
    fee: number,
    audienceCount: number
  ) {
    this._customer = customer;
    this._screening = screening;
    this._fee = fee;
    this._audienceCount = audienceCount;
  }

  get information() {
    return {
      customerName: this._customer.name,
      movieName: this._screening.movie.name,
      whenScreened: this._screening.whenScreened,
      totalFee: this._fee * this._audienceCount,
    };
  }
}

function main() {
  const movieTheaters = new MovieTheaters("CGV 강남");
  const movie = new Movie("어벤져스");
  const theater = new Theater("상영관 1", 120);

  movieTheaters.createTheater(theater);

  const selectedTheater = movieTheaters.theaters[0];

  movieTheaters.createScreening(
    new Screening(
      selectedTheater,
      movie,
      "2020-11-11 13:00:00",
      12000,
      new PercentDiscountPolicy(
        0.11,
        new SequenceDiscountCondition(selectedTheater, 1)
      )
    )
  );

  movieTheaters.createScreening(
    new Screening(
      selectedTheater,
      movie,
      "2020-11-11 13:00:00",
      12000,
      new PercentDiscountPolicy(
        0.11,
        new SequenceDiscountCondition(selectedTheater, 1)
      )
    )
  );

  movieTheaters.createScreening(
    new Screening(
      selectedTheater,
      movie,
      "2020-11-11 16:00:00",
      12000,
      new PercentDiscountPolicy(
        0.11,
        new SequenceDiscountCondition(selectedTheater, 1)
      )
    )
  );

  movieTheaters.createScreening(
    new Screening(
      selectedTheater,
      movie,
      "2020-11-11 19:00:00",
      12000,
      new PercentDiscountPolicy(
        0.11,
        new SequenceDiscountCondition(selectedTheater, 1)
      )
    )
  );

  const customer = new Customer("김윤섭");
  const selectedScreening = movieTheaters.screenings[0];
  const reservation = customer.reserve(selectedScreening, 2);
  console.log(reservation.information);
}

main();