JavaScript

Promises

const searchMovie = (movieName, callback) => {
  setTimeout(() => {
    console.log(`Searching for the movie: ${movieName}`);
    const movie = {
      title: movieName,
      availableSeats: 5
    };
    callback(null, movie);
  }, 1000);
};

const checkSeatAvailability = (movie, callback) => {
  setTimeout(() => {
    console.log(`Checking seat availability for "${movie.title}"`);
    if (movie.availableSeats > 0) {
      callback(null, movie);
    } else {
      callback("No seats available for this movie.");
    }
  }, 1000);
};

const reserveSeats = (movie, callback) => {
  setTimeout(() => {
    console.log(`Reserving seats for "${movie.title}"`);
    movie.reservedSeats = 2;
    movie.availableSeats -= 2;
    callback(null, movie);
  }, 1000);
};

const confirmBooking = (movie, callback) => {
  setTimeout(() => {
    console.log(
      `Booking confirmed for the movie: "${movie.title}". Enjoy your show!`
    );
    callback(null);
  }, 1000);
};

searchMovie("Inception", (err, movie) => {
  if (err) return console.error(err);
  checkSeatAvailability(movie, (err, availableMovie) => {
    if (err) return console.error(err);
    reserveSeats(availableMovie, (err, reservedMovie) => {
      if (err) return console.error(err);
      confirmBooking(reservedMovie, (err) => {
        if (err) return console.error(err);
        console.log("Cinema booking process completed!");
      });
    });
  });
});

const searchMovie = (movieName) => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log(`Searching for the movie: ${movieName}`);
      const movie = {
        title: movieName,
        availableSeats: 5
      };
      if (movie) {
        resolve(movie);
      } else {
        reject("Movie not found.");
      }
    }, 1000);
  });
};

const checkSeatAvailability = (movie) => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      console.log(`Checking seat availability for "${movie.title}"`);
      if (movie.availableSeats > 0) {
        resolve(movie);
      } else {
        reject("No seats available for this movie.");
      }
    }, 1000);
  });
};

const reserveSeats = (movie) => {
  return new Promise((resolve) => {
    setTimeout(() => {
      console.log(`Reserving seats for "${movie.title}"`);
      movie.reservedSeats = 2;
      movie.availableSeats -= 2;
      resolve(movie);
    }, 1000);
  });
};

const confirmBooking = (movie) => {
  return new Promise((resolve) => {
    setTimeout(() => {
      console.log(
        `Booking confirmed for the movie: "${movie.title}". Enjoy your show!`
      );
      resolve();
    }, 1000);
  });
};

searchMovie("Inception")
  .then((movie) => checkSeatAvailability(movie))
  .then((availableMovie) => reserveSeats(availableMovie))
  .then((reservedMovie) => confirmBooking(reservedMovie))
  .then(() => {
    console.log("Cinema booking process completed!");
  })
  .catch((error) => {
    console.error(error);
  });