import fs from 'node:fs';

// Some existing files and directories can be safely ignored when checking if a directory is a valid project directory.
// https://github.com/facebook/create-react-app/blob/d960b9e38c062584ff6cfb1a70e1512509a966e7/packages/create-react-app/createReactApp.js#L907-L934
const VALID_PROJECT_DIRECTORY_SAFE_LIST = [
	'.DS_Store',
	'.git',
	'.gitkeep',
	'.gitattributes',
	'.gitignore',
	'.gitlab-ci.yml',
	'.hg',
	'.hgcheck',
	'.hgignore',
	'.idea',
	'.npmignore',
	'.travis.yml',
	'.yarn',
	'.yarnrc.yml',
	'docs',
	'LICENSE',
	'mkdocs.yml',
	'Thumbs.db',
	/\.iml$/,
	/^npm-debug\.log/,
	/^yarn-debug\.log/,
	/^yarn-error\.log/,
];

export function isEmpty(dirPath: string) {
	if (!fs.existsSync(dirPath)) {
		return true;
	}

	const conflicts = fs.readdirSync(dirPath).filter((content) => {
		return !VALID_PROJECT_DIRECTORY_SAFE_LIST.some((safeContent) => {
			return typeof safeContent === 'string' ? content === safeContent : safeContent.test(content);
		});
	});

	return conflicts.length === 0;
}

export function isValidName(projectName: string) {
	return /^(?:@[a-z\d\-*~][a-z\d\-*._~]*\/)?[a-z\d\-~][a-z\d\-._~]*$/.test(projectName);
}

export function toValidName(projectName: string) {
	if (isValidName(projectName)) return projectName;

	return projectName
		.trim()
		.toLowerCase()
		.replace(/\s+/g, '-')
		.replace(/^[._]/, '')
		.replace(/[^a-z\d\-~]+/g, '-')
		.replace(/^-+/, '')
		.replace(/-+$/, '');
}