crawler/discuss

const Crawler = require('crawler');
const $ = require('cheerio');
const debug = require('debug')('amazonScraper:crawler');


/**
 * Método que retorna a uri para o scraper
 * @param {String} asin 
 */
const URI = (asin) => `https://www.amazon.com/gp/video/detail/${asin}`;

/**
 * Classe Scraper
 * 
 * Classe com os métodos scrapMovieById e scrapShowById
 * que procura filmes ou séries pelo ASIN e retorna os dados
 * do filme ou série informados
 */
class Scraper {
        /**
     * Realiza o scrap da página
     * @param {String} asin 
     */
    scrapMovieById(asin) {
        const self = this;
        return new Promise(function(resolve, reject) {
            const crawler = new Crawler({
                rateLimit: 500,
                retries: 3,
            });
            let movie;
            crawler.direct({
                uri: URI(asin),
                callback: function(error, res) {
                    if (error) {
                        reject(error);
                    }
                    const $ = res.$;
                    movie = self.parseMovieData($);
                    movie.program.asin = asin;
                    debug('Movie dentro do Crawler:scrapById: %O', movie);
                    resolve(movie);
                }
            });
        });
    };

    parseMovieData($) {
        const description = $('div[data-automation-id="synopsis"]').text();
        const releaseYear = $('span[data-automation-id="release-year-badge"]').text();
        const genres = $('dt[data-automation-id="meta-info-genres"]').next().children('a')
            .map(function() {
                return $.trim($(this).text());
            });
        const title = $('h1[data-automation-id="title"]').text();
        const images = $('div.av-fallback-packshot > img')
            .map(function() {
                return $.trim($(this).attr("src"));
            });
        const keywords = $('meta[name="keywords"]').attr("content");
        const cast = $( 'th:contains("Starring"), th:contains("Supporting actors")' ).next().text().split(',')
        const duration = parseInt($('div.av-badges > span').eq(2).text().split(' ')[0]);
        const movie = {
            program: {
                description,
                releaseYear,
                genres,
                title,
                images,
                keywords,
                cast,
                duration,
            },
        };
        debug('Movie em crawler:parsevideodata: %O', movie);
        return movie;
    };
}

module.exports = Scraper;