`@std/cli`: Support multiple spinners at the same time about deno_std HOT 9 OPEN

import { Spinner } from "@std/cli";

/**
 * @implements {Spinner}
 * @extends {Spinner}
 * @example
 * const loader = new Loader({
 * 	color: "blue",
 * 	message: "Loading..."
 * });
 *
 * loader.start(); // "Loading..."
 *
 * await new Promise((resolve) => setTimeout(resolve, 1000));
 *
 * loader.setBlock("block1", "a"); // "1 | a"
 *
 * await new Promise((resolve) => setTimeout(resolve, 1000));
 *
 * loader.setBlock("block1", "b"); // "2 | b"
 * loader.setBlock("block2", "c"); // "3 | b | c"
 *
 * await new Promise((resolve) => setTimeout(resolve, 1000));
 *
 * loader.removeBlock("block1"); // "4 | c"
 *
 * await new Promise((resolve) => setTimeout(resolve, 1000));
 *
 * loader.stop();
 */
const Loader = class extends Spinner {

	/**
	 * @type {Map<unknown, string>}
	 */
	#blocks = new Map();

	/**
	 * @type {Map<unknown, number>}
	 */
	#maximumLengths = new Map();

	/**
	 * @type {number}
	 */
	#messageCount = 0;

	/**
	 * @type {unknown[]}
	 */
	#order = [];

	/**
	 * Updates the message.
	 *
	 * @example
	 * this.#updateMessage();
	 */
	#updateMessage = () => {
		this.message = [
			this.#messageCount,
			...this.#order
				.filter((blockId) => this.#blocks.has(blockId))
				.map((blockId, index) => {
					const blockValue = this.#blocks.get(blockId);

					return (
						index === 0
							? blockValue
							: blockValue.padStart(this.#maximumLengths.get(blockId))
					);
				})

		]
			.join(" | ");
	};

	/**
	 *
	 * @param {unknown} id - The id of the block.
	 * @example
	 * const loader = new Loader({
	 * 	color: "blue",
	 * 	message: "Loading..."
	 * });
	 *
	 * loader.start();
	 *
	 * loader.setBlock("block1", "value1");
	 *
	 * loader.removeBlock("block1");
	 *
	 * loader.stop();
	 */
	removeBlock = (id) => {
		this.#blocks.delete(id);

		this.#messageCount += 1;

		if (this.#messageCount % 1 === 0) {
			this.#updateMessage();
		}
	};

	/**
	 * Set the value of a block.
	 *
	 * @param {unknown} id - The id of the block.
	 * @param {string|number|boolean} value - The value of the block.
	 * @example
	 * const loader = new Loader({
	 * 	color: "blue",
	 * 	message: "Loading..."
	 * });
	 *
	 * loader.start();
	 *
	 * loader.setBlock("block1", "value1");
	 *
	 * loader.stop();
	 */
	setBlock = (id, value) => {
		const valueString = String(value);

		this.#maximumLengths.set(id, Math.max(
			this.#maximumLengths.get(id) ?? 0,
			valueString.length
		));

		this.#blocks.set(id, valueString);

		if (!this.#order.includes(id)) {
			this.#order.push(id);
		}

		this.#messageCount += 1;

		this.#updateMessage();
	};

};

export default Loader;