google-book-shell/src/commands/CommandBuilder.js

Search books on Google Books

const vorpal = require('vorpal')();
const opn = require('opn');
const inquirer = require('inquirer-question');
const ora = require('ora');
const chalk = require('chalk');
const d = require('debug')('CommandBuilder');


const BookSearchService = require('../services/BookSearchService');
const Writer = require('../Writer');


class CommandBuilder {
  constructor() {
    this.bookSearchService = new BookSearchService();
    this.writer = new Writer();
  }


  validateBookNumber(number) {
    if (number == undefined) return true;

    // make sure that a user has entered a numeric value.
    if (!Number.isInteger(number)) {
      return "Enter a number for <number> argument!";
    }
    // remind user to search for a book first
    else if (this.books.length === 0) {
      return "Search for a book first...";
    }
    // check that number falls between the searched book count
    else if (0 >= parseInt(number) || parseInt(number) > this.books.length) {
      return `Enter a number between 1 and ${this.books.length}`;
    }

    return true;
  }

  async getAmazonBookURLByISBN(isbn) {
    const books = await this.bookSearchService.getAmazonBookAsync(isbn);
    d("getAmazonBookURLByISBN.books", books);
    return books[0].DetailPageURL[0];
  }

  async buildAsync() {
    // "search" command
    vorpal
      .command('search <book>', 'search for a book in Google Books')
      .alias('s')
      .action(async (args, callback) => {
        this.books = await this.bookSearchService.getGoogleBooks(args.book);
        this.writer.printBooks(this.books);

        callback();
      });

    // "open" in browser command
    vorpal
      .command('open <number>', 'open # in searched book list')
      // Populate 1-N https://stackoverflow.com/a/34388474/4035
      // .autocomplete(Array(10).fill().map((e,i) => (i + 1).toString()))
      .alias('o')
      // Get Amazon Book link.
      .option('-a, --amazon', 'open Amazon link')
      // If you are uncomfortable with Affiliate links, strip it out
      .option('-s, --strip-amazon-affiliate', 'strip affiliate query parameter')
      // later on add options to open preview, info links.
      .validate(args => this.validateBookNumber(args.number))
      .action(async (args, callback) => {
        const bookIndex = args.number - 1;
        const book = this.books[bookIndex];
        let bookURL = book.volumeInfo.previewLink;
        d("args", args);

        if (args.options.amazon) {
          const spinner = ora(chalk.red('Fetching data from Amazon Product Advertising API...')).start();

          try {
            const isbns = book.volumeInfo.industryIdentifiers;
            // isbn[0] = ISBN 10, while isbn[1] contains ISBN 13
            const isbn = isbns && isbns[0] ? isbns[0].identifier : "";
            bookURL = await this.getAmazonBookURLByISBN(isbn);

            spinner.stop();

            // Remove Amazon affiliate link if user choose to do so.
            if (args.options["strip-amazon-affiliate"]) {
              bookURL = bookURL.split('?')[0];
            }
          } catch (ex) {
            spinner.fail('Error while fetching Amazon URL from Product Advertising API...');
          } finally {
            spinner.clear();
          }
        }

        d("finally bookURL", bookURL);
        opn(bookURL);

        callback();
      });

    // "view" (description) command
    vorpal
      .command('view [number]', 'view detailed description of the book')
      .alias('v')
      .validate(args => this.validateBookNumber(args.number))
      .action(async (args, callback) => {
        if (args.number) {
          this.writer.viewBookDescription(this.books[args.number - 1]);
        } else {
          vorpal.hide();

          // build choices
          let choices = {};
          this.books.forEach((book, i) => {
            let number = (i + 1).toString().padStart(2, '0');
            const choice = `${number}: ${book.volumeInfo.title}`;
            choices[choice] = i;
          });

          inquirer.prompt({
            type: 'list',
            message: 'Select a book to view the detail',
            choices: choices
          }).then((result) => {
            // console.log(result); //=> 1 or 2
            this.writer.viewBookDescription(this.books[result]);
            vorpal.show();
          });
        }


        callback();
      });

    // "print" searched books
    vorpal
      .command("print", "print searched books")
      .alias('p')
      .action((args, callback) => {
        this.writer.printBooks(this.books);

        callback();
      });

    return vorpal;
  }
}

module.exports = CommandBuilder;