<?php
/**
 * This file is part of RSS-Bridge, a PHP project capable of generating RSS and
 * Atom feeds for websites that don't have one.
 *
 * For the full license information, please view the UNLICENSE file distributed
 * with this source code.
 *
 * @package	Core
 * @license	http://unlicense.org/ UNLICENSE
 * @link	https://github.com/rss-bridge/rss-bridge
 */

class FormatFactory
{
	private $folder;
	private $formatNames;

	public function __construct(string $folder = PATH_LIB_FORMATS)
	{
		$this->folder = $folder;

		// create format names
		foreach(scandir($this->folder) as $file) {
			if(preg_match('/^([^.]+)Format\.php$/U', $file, $m)) {
				$this->formatNames[] = $m[1];
			}
		}
	}

	/**
	 * @throws \InvalidArgumentException
	 * @param string $name The name of the format e.g. "Atom", "Mrss" or "Json"
	 */
	public function create(string $name): FormatInterface
	{
		if (! preg_match('/^[a-zA-Z0-9-]*$/', $name)) {
			throw new \InvalidArgumentException('Format name invalid!');
		}
		$name = $this->sanitizeFormatName($name);
		if ($name === null) {
			throw new \InvalidArgumentException('Unknown format given!');
		}
		$className = '\\' . $name . 'Format';
		return new $className;
	}

	public function getFormatNames(): array
	{
		return $this->formatNames;
	}

	protected function sanitizeFormatName(string $name) {
		$name = ucfirst(strtolower($name));

		// Trim trailing '.php' if exists
		if (preg_match('/(.+)(?:\.php)/', $name, $matches)) {
			$name = $matches[1];
		}

		// Trim trailing 'Format' if exists
		if (preg_match('/(.+)(?:Format)/i', $name, $matches)) {
			$name = $matches[1];
		}
		if (in_array($name, $this->formatNames)) {
			return $name;
		}
		return null;
	}
}