@meese-os/server/src/package.js

meeseOS Server

/**
 * OS.js - JavaScript Cloud/Web Desktop Platform
 *
 * Copyright (c) 2011-Present, Anders Evenrud <andersevenrud@gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author  Anders Evenrud <andersevenrud@gmail.com>
 * @licence Simplified BSD License
 */

const path = require("path");
const chokidar = require("chokidar");

/**
 * TODO: typedef
 * @typedef {Object} PackageMetadata
 */

/**
 * Package Options
 * @typedef {Object} PackageOptions
 * @property {String} filename
 * @property {PackageMetadata} metadata
 */

/**
 * MeeseOS Package Abstraction
 */
class Package {
	/**
	 * Create new instance.
	 * @param {Core} core MeeseOS Core instance reference
	 * @param {PackageOptions} [options={}] Instance options
	 */
	constructor(core, options = {}) {
		/**
		 * @type {Core}
		 */
		this.core = core;

		this.script = options.metadata.server
			? path.resolve(path.dirname(options.filename), options.metadata.server)
			: null;

		/**
		 * @type {String}
		 */
		this.filename = options.filename;

		/**
		 * @type {PackageMetadata}
		 */
		this.metadata = options.metadata;

		this.handler = null;

		this.watcher = null;
	}

	/**
	 * Destroys instance.
	 */
	async destroy() {
		this.action("destroy");

		if (this.watcher) {
			await this.watcher.close();
			this.watcher = null;
		}
	}

	/**
	 * Run method on package script.
	 * @param {String} method Method name
	 * @param {*} [...args] Pass arguments
	 * @returns {Boolean}
	 */
	action(method, ...args) {
		try {
			if (this.handler && typeof this.handler[method] === "function") {
				this.handler[method](...args);

				return true;
			}
		} catch (e) {
			this.core.logger.warn(e);
		}

		return false;
	}

	/**
	 * Validates this package.
	 * @param {PackageMetadata[]} manifest Global manifest
	 * @returns {Boolean}
	 */
	validate(manifest) {
		return (
			this.script &&
			this.metadata &&
			Boolean(manifest.find((iter) => iter.name === this.metadata.name))
		);
	}

	/**
	 * Initializes this package.
	 * @returns {Promise<undefined>}
	 */
	init() {
		const mod = require(this.script);
		const handler = typeof mod.default === "function" ? mod.default : mod;

		this.handler = handler(this.core, this);

		if (typeof this.handler.init === "function") {
			return this.handler.init();
		}

		return Promise.resolve();
	}

	/**
	 * Starts server scripts.
	 * @returns {Promise<undefined>}
	 */
	start() {
		return this.action("start");
	}

	/**
	 * Creates a watch in package dist.
	 * @param {Function} cb Callback function on watch changes
	 * @returns {String} Watched path
	 */
	watch(cb) {
		const pub = this.core.config("public");
		const dist = path.join(pub, "apps", this.metadata.name);

		this.watcher = chokidar.watch(dist);
		this.watcher.on("change", () => cb(this.metadata));

		return dist;
	}

	/**
	 * Resolve an URL for resource.
	 * @param {String} path Input path
	 * @returns {String}
	 */
	resource(path) {
		if (path.charAt(0) !== "/") {
			path = `/${path}`;
		}

		return `/apps/${this.metadata.name}${path}`;
	}
}

module.exports = Package;