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TankTrouble Development Library

Shared library for TankTrouble userscript development

Ce script ne devrait pas être installé directement. C'est une librairie créée pour d'autres scripts. Elle doit être inclus avec la commande // @require https://update.greasyfork.org/scripts/482092/1309109/TankTrouble%20Development%20Library.js 

// ==UserScript==
// @name        TankTrouble Development Library
// @author      commander
// @namespace   https://github.com/asger-finding/tanktrouble-userscripts
// @version     1.0.0-beta.1
// @license     GPL-3.0
// @description Shared library for TankTrouble userscript development
// @match       *://*.tanktrouble.com/*
// @grant       none
// @run-at      document-start
// @noframes
// ==/UserScript==

// eslint-disable-next-line no-unused-vars
class Loader {

	/**
	 * Pass a function to a hook with the correct context
	 * @param context Function context (e.g `window`)
	 * @param funcName Function identifier in the context
	 * @param handler Hook to call before the original
	 * @param attributes Optionally additional descriptors
	 */
	static interceptFunction(context, funcName, handler, attributes) {
		const original = Reflect.get(context, funcName);
		if (typeof original !== 'function') throw new Error('Item passed is not typeof function');

		Reflect.defineProperty(context, funcName, {
			/**
			 * Call the handler with the original function bound to its context
			 * and supply with the arguments list
			 * @param args Arguments passed from outside
			 * @returns Original function return value
			 */
			value: (...args) => handler(original.bind(context), ...args),
			...attributes
		});
	}

	/**
	 * Fires when the `main()` function is done on TankTrouble.
	 * @returns Promise that resolves when Content.init() finishes
	 */
	static whenContentInitialized() {
		if (GM.info.script.runAt !== 'document-start') return Loader.#createGameProxy();
		return whenContentLoaded().then(() => Loader.#createGameProxy());
	}

	/**
	 * Fires when the document is readyState `interactive` or `complete`
	 * @returns Promise that resolves upon content loaded
	 */
	static whenContentLoaded() {
		return new Promise(resolve => {
			if (document.readyState === 'interactive' || document.readyState === 'complete') resolve();
			else document.addEventListener('DOMContentLoaded', () => resolve());
		});
	}

	/**
	 * Apply a hook to the Content.init function which resolves when the promise ends
	 * @returns Promise when Content.init has finished
	 * @private
	 */
	static #createGameProxy() {
		const functionString = Function.prototype.toString.call(Content.init);
		const isAlreadyHooked = /hooked-by-userscript/u.test(functionString);

		return new Promise(resolve => {
			if (isAlreadyHooked) {
				const eventListener = document.addEventListener('content-initialized', () => {
					document.removeEventListener('content-initialized', eventListener);
					resolve();
				});
			} else {
				const event = new Event('content-initialized');

				const { init } = Content;
				Reflect.defineProperty(Content, 'init', {
					/**
					 * Intercept the Content.init function, add a stamp, dispatch the custom event and resolve
					 * @param args Arguments passed from outside
					 * @returns Original function return value
					 */
					value: (...args) => {
						// Hack that will add the string to
						// the return of toString so we can
						// lookup if it's already hooked
						// eslint-disable-next-line no-void
						void 'hooked-by-userscript';

						const result = init(...args);

						document.dispatchEvent(event);
						resolve();
						return result;
					},
					configurable: true
				});
			}
		});
	}

}