tools.js

/****************************************************
* Tool.js is responsible for handling the functions *
* that are important to index.js (main app).        *
* Example: function to write (log) user messages    *
* to a file inside project.                         *
 ****************************************************/

const fs = require('fs');
const productsList = require('./products.json');

/********************
 * Global variables *
 ********************/
const botResponseTemplate = 'Bot says: ';
/** @type {Array}
This array is used to store the latest bot responses. It is used to help the bot
to continue the flow of conversation in case user asks for subscription price for example */
let arrLastListing = [];

module.exports = {
  /**
   * This function is responsible to handle the record (log) of user's message
   * @param  {string} userResponse receive the user input from form
   */
  recordNewMessage: function(arrGroupedResponses) {
    fs.open('./records/records.txt', 'w', (err, fd) => {
      if (err) throw err;
      fs.writeFile(fd, arrGroupedResponses.join("\n"), 'utf8', (err) => {
        fs.close(fd, (err) => {
          if (err) throw err;
        });
        if (err) throw err;
      });
    });
  },
  /**
   * This function is responsible to handle the user input message
   * @param  {string} userResponse receive the user input from form
   * @return {array or string} returns arrays in cases where user asks for a list or string if just single product
   */
  checkUserResponse: function(userResponse) {
    /** @type {Array} This variable is responsible to return array when the user asks for listing. Eg: brands */
    let arrFilteredProductsList = [];

    switch(true) {
      case userResponse === '':
        return botResponseTemplate + "Sorry, you should type something.";
        break;
      case userResponse.includes('list'):
        productsList.forEach(function(product) {
          arrFilteredProductsList.push(product.name);
        });
        return botResponseTemplate + "Here is the list of all of our products:<br><br>" + arrFilteredProductsList.join('<br>');
        break;
      case userResponse.includes('categories') || userResponse.includes('category'):
        productsList.forEach(function(product) {
          arrFilteredProductsList.push(product.category);
        });
        return botResponseTemplate + "Here is the list of all of our product's categories:<br><br>" + arrFilteredProductsList.join('<br>');
        break;
      case userResponse.includes('subscription price') || userResponse.includes('subscription') || userResponse.includes('price'):
        let arrPreviousListingProductsPrice = [];
        if (arrLastListing.length >= 1) {
          arrLastListing.forEach(product => arrPreviousListingProductsPrice.push("Product: " + product.name + " | Price: €" + product.subscriptionPrice));
          // The arrLastListing is cleaned every time after it's used, as it's used just to store last bot responses temporarily
          arrLastListing = [];
          return botResponseTemplate + "Here is the subscription price(s) for above product(s):<br><br>" + arrPreviousListingProductsPrice.join("<br>");
        } else {
          return botResponseTemplate + "For which product you want to know the subscription price? Remember: you could ask for brand, category or list also.";
        }
        break;
      default:
        /***********************************************************************************
         * This arrays are used as temporary to assign functions of filtering and finding. *
         ***********************************************************************************/
        var responseMatchedWithProductsBrands = productsList.filter(product => product.brand.toUpperCase().includes(userResponse.toUpperCase()));
        var responseMatchedWithProductsCategories = productsList.filter(product => product.category.toUpperCase().includes(userResponse.toUpperCase()));
        var responseMatchedWithSingleProduct = productsList.find(product => product.name.toUpperCase() === userResponse.toUpperCase());

        /****************************************************************************************************************
         * returns according to what user asked for. E.g a list of product's according to a specific brand or categorie *
         ****************************************************************************************************************/
        if (responseMatchedWithProductsBrands.length >= 1) {
          // The arrLastListing is cleaned every time after it's used, as it's used just to store last bot responses temporarily
          arrLastListing = [];
          responseMatchedWithProductsBrands.forEach(product => {
            arrFilteredProductsList.push(product.name);
            arrLastListing.push(product);
          });
          return botResponseTemplate + "Here is the product's brands that matched your criteria:<br><br>" + arrFilteredProductsList.join('<br>');
        } else if(responseMatchedWithProductsCategories.length >= 1) {
          // The arrLastListing is cleaned every time after it's used, as it's used just to store last bot responses temporarily
          arrLastListing = [];
          responseMatchedWithProductsCategories.forEach(product => {
            arrFilteredProductsList.push(product.name);
            arrLastListing.push(product);
          });
          return botResponseTemplate + "Here is the product's categories that matched your criteria:<br><br>" + arrFilteredProductsList.join('<br>');
        } else if(responseMatchedWithSingleProduct) {
          return botResponseTemplate + "The subscription price for " + responseMatchedWithSingleProduct.name + " is €" + responseMatchedWithSingleProduct.subscriptionPrice;
        } else {
          return botResponseTemplate + "Sorry, no products matched your criteria. Try something else.";
        }
    }
  }
};