<?php

namespace core\log;

/**
 * Stream factory, to create stream with ease
 */
class StreamFactory
{
	/**
	 * Available client NOTE: to update for "vanilla" client
	 *
	 * @var \array[\string]
	 */
	const array AVAILABLE_CLIENTS = array(
		'MQTT',
		'Redis',
		'File',
	);

	/**
	 * Check if the tag is in the allow list of tags
	 *
	 * @param \core\log\Tag $tag Tag to search for
	 * @param \array[\core\log\Tag] $allow_list Allow list of tags
	 *
	 * @return bool
	 */
	public static function search_tag(\core\log\Tag $tag, \core\log\TagsType $allow_list) : bool
	{
		$found = False;
		foreach ($allow_list as $accepted_tag) # NOTE: time depends on the number of tags (not constant time), but we don't care
		{
			if ($tag->__tostring() === $accepted_tag->__tostring())
			{
				$found = True;
				break;
			}
		}
		return $found;
	}

	/**
	 * Instanciate client from name, with tag as an argument
	 *
	 * @param string $client_name Name of the client
	 * @param \core\log\Tag $tag Tag associated to the client
	 *
	 * @throws \core\log\StreamException
	 *
	 * @return \core\log\Client
	 */
	public static function create_client(string $client_name, \core\log\Tag $tag) : \core\log\Stream
	{
		$client = null;

		$client_name = \ucwords($client_name);
		$client_name = \str_replace(' ', '', $client_name);

		$vanilla = '\\core\\log\\clients\\' . $client_name;

		if (\in_array($client_name, self::AVAILABLE_CLIENTS))
		{
			return new $vanilla($tag);
		}
		$plugin = \core\plugin\PluginManager::fetch_class($client_name);

		if (!\is_null($plugin) && \class_exists($plugin))
		{
			return new $plugin($tag);
		}

		throw new \core\log\StreamException(\core\substitute(
			_('unknown client {client} in configuration', 1),
			array('client' => $client_name),
		), 1);
	}

	/**
	 * Build the wanted tag to use for future logging purpose
	 *
	 * @throws \core\config\ConfigException
	 * @throws \core\log\StreamException
	 *
	 * @return \core\log\Stream | null If the tag should not be built, return null
	 */
	public static function build(\core\log\Tag $tag) : \core\log\Stream | null
	{
		$hardcoded_configuration = new \core\config\class\core\LogConfiguration(array(
			'tags'   => new \core\log\TagsType(array()),
			'client' => array('name' => 'File'),
		));
		$client_name = $hardcoded_configuration->get('client', 'name');
		$tags = $hardcoded_configuration->get('tags');

		if (\core\config\GlobalConfiguration::exists('class', 'core', 'log')) # set over hard-coded fallback
		{
			$configuration = \core\config\GlobalConfiguration::read('class', 'core', 'log');

			if ($configuration->exists('client', 'name'))
			{
				$client_name = $configuration->get('client', 'name');
			}
			if ($configuration->exists('tags'))
			{
				$tags = $configuration->get('tags');
			}
		}

		if (!self::search_tag($tag, $tags))
		{
			return null; # NOTE: the tag should not be created because the admin does not ask to log it
		}

		return self::create_client($client_name, $tag);
	}
}

?>