import { readdir } from 'fs/promises';
import { join } from 'path';
import Module from 'module';

// Lists of required and optional attributes of command modules
const required = ['data', 'execute'];
const optional = ['autocomplete', 'modalSubmit'];

/**
 * Recursively scans a directory for all files in it.
 * @param {string} dir
 * @returns {Promise<Array<string>>} Array of paths to the files within.
 */
export const getFiles = async (dir) => {
	const dirents = await readdir(dir, { withFileTypes: true });
	const files = await Promise.all(
		dirents.map((dirent) => {
			const res = join(dir, dirent.name);
			return dirent.isDirectory() ? getFiles(res) : res;
		})
	);
	return Array.prototype.concat(...files);
};

/**
 * Imports and checks a command from a path as a module.
 * @param {string} filePath
 * @returns {Promise<Module|0>}
 */
export const importAndCheck = async (filePath) => {
	if (!filePath.endsWith('.js') || filePath.endsWith('.example.js')) {
		// Skip this file
		return 0;
	}
	const command = await import(filePath);
	// Warn incomplete commands
	if (!required.every((name) => name in command)) {
		console.error(
			`[ERROR] The command at ${filePath} is missing a required "data" or "execute" property.`
		);
		return 0;
	}
	const properties = optional.filter((name) => !(name in command));
	if (properties.length > 0)
		properties.forEach((name) =>
			console.warn(
				`[WARNING] The command at ${filePath} is missing an optional "${name}" property.`
			)
		);
	// Add command to collection
	return command;
};