leanwebclub/structure-and-scale/seven-seas-service-worker/treasure.js

(function () {
	'use strict';

	class TreasureChest {

		#bronze;
		#silver;
		#gold;
		#loot;

		/**
		 * Create the constructor object
		 * @param {Object} options User settings
		 */
		constructor (options = {}) {

			// Merge options into defaults
			let {bronze, silver, gold, loot} = Object.assign({
				bronze: 0,
				silver: 0,
				gold: 0,
				loot: `You have {{gold}} gold, {{silver}} silver, and {{bronze}} bronze.`
			}, options);

			// Set instance properties
			this.#bronze = bronze;
			this.#silver = silver;
			this.#gold = gold;
			this.#loot = loot;

		}

		/**
		 * Randomly shuffle an array
		 * https://stackoverflow.com/a/2450976/1293256
		 * @param  {Array} array The array to shuffle
		 * @return {Array}       The shuffled array
		 */
		static #shuffle (array) {

			let currentIndex = array.length;
			let temporaryValue, randomIndex;

			// While there remain elements to shuffle...
			while (0 !== currentIndex) {
				// Pick a remaining element...
				randomIndex = Math.floor(Math.random() * currentIndex);
				currentIndex -= 1;

				// And swap it with the current element.
				temporaryValue = array[currentIndex];
				array[currentIndex] = array[randomIndex];
				array[randomIndex] = temporaryValue;
			}

			return array;

		}

		/**
		 * Emit a custom event
		 * @param  {String} type   The event type
		 * @param  {*}      detail Any details to pass along with the event
		 */
		#emit (type, detail) {

			// Create a new event
			let event = new CustomEvent(type, {
				bubbles: true,
				cancelable: true,
				detail: detail
			});

			// Dispatch the event
			return document.dispatchEvent(event);

		}

		/**
		 * Add bronze to the treasure chest
		 * @param {Number} n The amount to add
		 */
		addBronze (n) {
			this.#bronze += n;
			this.#emit('treasure:bronze', this);
			return this;
		}

		/**
		 * Add silver to the treasure chest
		 * @param {Number} n The amount to add
		 */
		addSilver (n) {
			this.#silver += n;
			this.#emit('treasure:silver', this);
			return this;
		}

		/**
		 * Add gold to the treasure chest
		 * @param {Number} n The amount to add
		 */
		addGold (n) {
			this.#gold += n;
			this.#emit('treasure:gold', this);
			return this;
		}

		/**
		 * Get the total amount of loot as a string
		 * @return {String} The total amount of loot
		 */
		getLoot () {
			return this.#loot.replace('{{gold}}', this.#gold).replace('{{silver}}', this.#silver).replace('{{bronze}}', this.#bronze);
		}

		/**
		 * Get the amount of bronze
		 * @return {Number} The amount
		 */
		getBronze () {
			return this.#bronze;
		}

		/**
		 * Get the amount of silver
		 * @return {Number} The amount
		 */
		getSilver () {
			return this.#silver;
		}

		/**
		 * Get the amount of gold
		 * @return {Number} The amount
		 */
		getGold () {
			return this.#gold;
		}

		/**
		 * Generate random treasure
		 * @return {Object} The amount and type of loot found
		 */
		static random () {

			// Amount and type
			let amount = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50];
			let type = ['bronze', 'silver', 'gold'];

			// Randomize the amounts
			this.#shuffle(amount);
			this.#shuffle(type);

			// Return the random loot
			return {
				amount: amount[0],
				type: type[0]
			};

		}

	}

	//
	// Functions
	//

	// Hold the treasure instance
	let treasure;

	/**
	 * Create new treasure instance
	 * @return {Constructor} A new TreasureChest instance
	 */
	function createTreasure () {

		// Get any saved loot from localStorage
		let savedLoot = JSON.parse(localStorage.getItem('ss-treasure'));

		// Create new Treasure Chest instance
		treasure = new TreasureChest(savedLoot);

	}

	/**
	 * Display the amount of loot in the UI
	 */
	function showLoot () {
		let loot = document.querySelector('#loot');
		if (!loot) return;
		loot.textContent = treasure.getLoot();
	}

	/**
	 * Save loot to localStorage and update the UI
	 * @param  {Event} event The event object
	 */
	function saveLoot (event) {

		// Create the treasure object
		let treasure = {
			gold: event.detail.getGold(),
			silver: event.detail.getSilver(),
			bronze: event.detail.getBronze()
		};

		// Save it to localStorage
		localStorage.setItem('ss-treasure', JSON.stringify(treasure));

		// Update the UI
		showLoot(event.detail);

	}

	/**
	 * Handle treasure submit events
	 * @param  {Event} event The event object
	 */
	function submitHandler (event) {

		// Get the coin type
		// Only run on [data-treasure] forms
		let coin = event.target.getAttribute('data-treasure');
		if (!coin) return;

		// Stop the form from reloading the page
		event.preventDefault();

		// Get coin value
		let val = parseFloat(event.target.querySelector('[type="number"]').value);
		if (!val) return;

		// Add the correct loot
		if (coin === 'gold') {
			treasure.addGold(val);
		} else if (coin === 'silver') {
			treasure.addSilver(val);
		} else if (coin === 'bronze') {
			treasure.addBronze(val);
		}

	}

	/**
	 * Listen for loot events
	 * @param  {Constructor} treasure The TreasureChest object
	 */
	function lootListeners () {
		document.addEventListener('submit', submitHandler);
		document.addEventListener('treasure:gold', saveLoot);
		document.addEventListener('treasure:silver', saveLoot);
		document.addEventListener('treasure:bronze', saveLoot);
	}

	createTreasure();
	showLoot();
	lootListeners();

})();