174-lab-javascript-greatest-movies-solution.js

/* eslint no-restricted-globals: 'off' */

// Iteration 1: All rates average - Get the average of all rates with 2 decimals

function calculateAverageMovieRate(movies) {
  if (!movies.length) {
    return 0;
  }
  const arrayOfRates = movies.map(value => {
    return value.rate;
  });
  const sumOfRates = arrayOfRates.reduce((sum, rate, index, original) => {
    return sum + rate;
  }, 0);
  return sumOfRates / movies.length;
  /*
  return movies.reduce((sum, movie) => sum + movie.rate / movies.length, 0);
  */
}

// Iteration 2: Drama movies - Get the average of Drama Movies

function calculateAverageDramaRate(movies) {
  const dramaMovies = movies.filter(movie => {
    /*
    if (movie.genre.indexOf('Drama') > -1) {
      return true;
    }
    */
    /*
    if (movie.genre.includes('Drama')) {
      return true;
    }
    */
    return movie.genre.includes('Drama');
  });
  // if (!dramaMovies.length) return 0;
  return calculateAverageMovieRate(dramaMovies);
}

// Iteration 3: Ordering by duration - Order by time duration, ascending (in growing order)

function orderByYear(movies) {
  const arrayCopy = [...movies];
  return arrayCopy.sort((a, b) => {
    if (a.year > b.year) {
      return 1;
    } else if (a.year < b.year) {
      return -1;
    } else {
      const firstMovieTitle = a.title.toLowerCase();
      const secondMovieTitle = b.title.toLowerCase();
      if (firstMovieTitle > secondMovieTitle) {
        return 1;
      } else if (firstMovieTitle < secondMovieTitle) {
        return -1;
      } else {
        return 0;
      }
    }
  });
}

// Iteration 4: Steven Spielberg. The best? - How many movies did STEVEN SPIELBERG direct

function countSpielbergDramaMovies(movies) {
  return movies.filter(movie => {
    return movie.genre.includes('Drama') && movie.director === 'Steven Spielberg';
  }).length;
}
// Iteration 5: Alphabetic Order - Order by title and print the first 20 titles

function orderAlphabetically(movies) {
  return movies
    .map(movie => movie.title)
    .sort((a, b) => {
      const firstMovieTitle = a.toLowerCase();
      const secondMovieTitle = b.toLowerCase();
      if (firstMovieTitle > secondMovieTitle) {
        return 1;
      } else if (firstMovieTitle < secondMovieTitle) {
        return -1;
      } else {
        return 0;
      }
    })
    .slice(0, 20);
}

// Iteration 6: Time Format - Turn duration of the movies from hours to minutes

function turnHoursToMinutes(movies) {
  return movies.map(movie => {
    const duration = movie.duration.split(' ');
    let minutes = 0;
    for (let time of duration) {
      if (time.includes('h')) {
        minutes += parseInt(time) * 60;
      } else {
        minutes += parseInt(time);
      }
    }
    return {
      ...movie,
      duration: minutes
    };
  });
}

// BONUS Iteration: Best yearly rate average - Best yearly rate average

function bestYearAvg(movies) {
  if (!movies.length) return null;
  const movieRatesByYear = movies.reduce((accumulator, movie) => {
    const { year, rate } = movie;
    if (!accumulator[year]) {
      accumulator[year] = [];
    }
    accumulator[year].push(rate);
    return accumulator;
  }, {});
  const bestYearRateCombo = Object.entries(movieRatesByYear)
    .map(item => {
      const year = item[0];
      const rateArray = item[1];
      const averageRate = rateArray.reduce((sum, value) => {
        return sum + value / rateArray.length;
      }, 0);
      return { year, averageRate };
    })
    .reduce((bestItem, item) => {
      if (typeof bestItem === 'undefined' || item.averageRate > bestItem.averageRate) {
        return item;
      } else {
        return bestItem;
      }
    });
  return `The best year was ${bestYearRateCombo.year} with an average rate of ${bestYearRateCombo.averageRate}`;
}

// Filipe's Solution
function bestYearAvg(someArray) {
  if (someArray.length === 0) {
    return null;
  } else {
    const moviesByYear = orderByYear(someArray);

    // control variables
    let lastCheckedYear = 0;
    let biggestAverage = 0;
    let bestYear = 0;

    for (i = 0; i < moviesByYear.length; i++) {
      if (moviesByYear[i].year > lastCheckedYear) {
        // Filter by the year we are at

        const justThisYearMovies = moviesByYear.filter(value => {
          if (value.year === moviesByYear[i].year) {
            return true;
          } else {
            return false;
          }
        });

        // calculate average of the year and save rate and year

        if (calculateAverageMovieRate(justThisYearMovies) > biggestAverage) {
          biggestAverage = calculateAverageMovieRate(justThisYearMovies);
          bestYear = moviesByYear[i].year;
        }
        lastCheckedYear = moviesByYear[i].year;
      }
    }
    return `The best year was ${bestYear} with an average rate of ${biggestAverage}`;
  }
}