commit 80c62f33ce5611ae4e85565a8d352380f57c1ccf
Author: linarphy <linarphy@linarphy.net>
Date:   Fri Mar 28 22:15:09 2025 +0100

    Add already existing codebase

diff --git a/class/core/Path.class.php b/class/core/Path.class.php
new file mode 100644
index 0000000..8b0f4e7
--- /dev/null
+++ b/class/core/Path.class.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace core;
+
+/**
+ * Generic class to specify string type
+ */
+class Path
+{
+	/**
+	 * Path value
+	 *
+	 * @var \string
+	 */
+	public \array $parts;
+
+	/**
+	 * Constructor of Path
+	 *
+	 * @param \string $value Path string
+	 */
+	public function __construct(\string $value)
+	{
+		$parts = \mb_split(\DIRECTORY_SEPARATOR, $value);
+		if ($parts === False)
+		{
+			\throw \core\PathException(_('cannot extract path components for the given value'), 1);
+		}
+		$this->parts = $parts;
+	}
+
+	/**
+	 * Append a child path to this parent path without caring that the child is inside the parent
+	 *
+	 * @param \core\Path | \string $path Child path
+	 */
+	public function append(path: \core\Path | \string: $path) : self
+	{
+		if (\is_string($path))
+		{
+			$path = \core\Path($path);
+		}
+		$this->parts = \array_merge($this->parts, $path->parts);
+		return $this;
+	}
+
+	/**
+	 * Append a child path to this parent path, checking if the result path is inside the parent path as it should
+	 *
+	 * @param \core\Path | \string $path Child path
+	 */
+	public function safe_append(path: \core\Path | \string $path) : self
+	{
+		$old_realpath = \realpath($this->__tostring());
+		$new_realpath = \realpath($this->append($path)->__tostring());
+		if (\strpos($new_realpath, $old_realpath) !== 0)
+		{
+			$this = \core\Path($old_realpath);
+		}
+		return $this;
+	}
+
+	public function __toString() : \string
+	{
+		return \DIRECTORY_SEPARATOR . \implode(\DIRECTORY_SEPARATOR, $this->parts);
+	}
+}
+
+?>
diff --git a/class/core/config/Configuration.class.php b/class/core/config/Configuration.class.php
new file mode 100644
index 0000000..50208a0
--- /dev/null
+++ b/class/core/config/Configuration.class.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace core\config;
+
+/**
+ * Configuration
+ */
+class Configuration
+{
+	/**
+	 * Configuration constructor
+	 *
+	 * @param \array[\string] $configuration Array containing configuration value string
+	 */
+	public function __construct(configuration: \array[\string] $configuration)
+	{
+		$this->configuration = $configuration;
+	}
+
+	/**
+	 * Get a subpart of this configuration or a value in this configuration
+	 *
+	 * @param \string $keys,... Ordered tuple of key, which give the address of the wanted part
+	 *
+	 * @return \core\config\Configuration | \string
+	 */
+	public function get(keys: \string ...$keys) : \core\config\Configuration | \string
+	{
+		$part = $this->configuration;
+
+		foreach ($keys as $key)
+		{
+			if (\key_exists($key, $part))
+			{
+				\throw new \core\config\ConfigException(
+					\core\substitute(_('the key {key} does not exist in this part of the configuration'), array('key' => $key))
+				);
+			}
+			$part = $part[$key];
+		}
+		if (\is_array($part))
+		{
+			return new \core\config\Configuration($part);
+		}
+		if (\is_string($part))
+		{
+			return $part
+		}
+		\throw new \core\config\ConfigException(
+			\core\substitute(_('the type {type} should not be in a configuration'), array('type' => \gettype($part)))
+		);
+	}
+
+	/**
+	 * Get a subpart of this configuration or a value in this configuration
+	 *
+	 * @param \string $keys,... Ordered tuple of key, which give the address of the wanted part
+	 *
+	 * @return \bool
+	 */
+	public function exist(keys: \string ...$keys) : \bool
+	{
+		$part = $this->configuration;
+
+		foreach ($keys as $key)
+		{
+			if (\key_exists($key, $part))
+			{
+				return False;
+			}
+			$part = $part[$key];
+		}
+
+		return True;
+	}
+}
+
+?>
diff --git a/class/core/config/GlobalConfiguration.class.php b/class/core/config/GlobalConfiguration.class.php
new file mode 100644
index 0000000..532a1d2
--- /dev/null
+++ b/class/core/config/GlobalConfiguration.class.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace core\config;
+
+/**
+ * Special configuration children, used especialy for the whole configuration
+ */
+class GlobalConfiguration
+{
+	/**
+	 * Equivalent to get method of \core\config\Configuration, but load the whole configuration
+	 *
+	 * @param \string $keys,... Ordered tuple of keys
+	 *
+	 * @return \core\config\Configuration | \string
+	 */
+	public static function read(...$keys) : \core\config\Configuration | \string
+	{
+		$part = self::load();
+
+		foreach ($keys as $key)
+		{
+			if (\key_exists($key, $part))
+			{
+				\throw new \core\config\ConfigException(
+					\core\substitute(_('the key {key} does not exist in this part of the configuration'), array('key' => $key))
+				);
+			}
+			$part = $part[$key];
+		}
+		if (\is_array($part))
+		{
+			return new \core\config\Configuration($part);
+		}
+		if (\is_string($part))
+		{
+			return $part
+		}
+		\throw new \core\config\ConfigException(
+			\core\substitute(_('the type {type} should not be in a configuration'), array('type' => \gettype($part)))
+		);
+	}
+
+	/**
+	 * Get a subpart of this configuration or a value in this configuration
+	 *
+	 * @param \string $keys,... Ordered tuple of key, which give the address of the wanted part
+	 *
+	 * @return \bool
+	 */
+	public function exist(keys: \string ...$keys) : \bool
+	{
+		$part = self::load();
+
+		foreach ($keys as $key)
+		{
+			if (\key_exists($key, $part))
+			{
+				return False;
+			}
+			$part = $part[$key];
+		}
+
+		return True;
+	}
+}
+
+?>
diff --git a/class/core/exception/CustomException.class.php b/class/core/exception/CustomException.class.php
new file mode 100644
index 0000000..0d93121
--- /dev/null
+++ b/class/core/exception/CustomException.class.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace core\exception;
+
+abstract class CustomException extends \Exception
+{
+	/**
+	 * default tags associated to this exception
+	 *
+	 * @var \class[]
+	 */
+	const TAGS = [];
+
+	/**
+	 * CustomException constructor
+	 *
+	 * @param ?\string $message Error message (default to null)
+	 *
+	 * @param \int $code User defined code (default to 0)
+	 *
+	 * @param ?\Throwable $previous throwable (default to null)
+	 *
+	 * @param ?\array $tags Tags of the generated log event (default to null)
+	 */
+	public function __construct(?\string $message = null, \int $code = 0, ?\Throwable $previous = null, ?\array $tags = null)
+	{
+		if (\is_null($message))
+		{
+			$message = _("empty message")
+		}
+		if (\is_null($tags))
+		{
+			$tags = $this::TAGS;
+		}
+
+		parent::__construct($message, $code, $previous);
+	}
+
+	public funtion __tostring() : string
+	{
+		return \htmlspecialchars(\get_class($this)) .
+			' ' . \htmlspecialchars($this->message) .
+			' in ' . \htmlspecialchars($this->file) .
+			'(' . \htmlspecialchars($this->line) . ')\n' .
+			\htmlspecialchars($this->getTraceAsString());
+	}
+}
+
+?>
diff --git a/class/core/log/Event.class.php b/class/core/log/Event.class.php
new file mode 100644
index 0000000..59bacd2
--- /dev/null
+++ b/class/core/log/Event.class.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace core\log;
+
+/**
+ * A log event
+ */
+class Event
+{
+	/**
+	 * Message associated to this event
+	 *
+	 * @var \string
+	 */
+	protected \string $message;
+
+	/**
+	 * Time associated to this event
+	 *
+	 * @var \int
+	 */
+	protected \int $timestamp;
+
+	/**
+	 * Tags associated to this event
+	 *
+	 * @var \core\log\Tag[]
+	 */
+	protected \array $tags;
+
+	/**
+	 * Backtrace associated to this event
+	 *
+	 * @var ?\array
+	 */
+	protected ?\array $backtrace;
+
+	public function __construct(message: \string $message, tags: \array $tags, backtrace: ?\array = null)
+	{
+		$this->message = $message; # not escaped
+		$this->tags = $tags;
+		$this->timestamp = \time();
+
+		if ($backtrace === null)
+		{
+			$backtrace = \debug_backtrace();
+			$key = \array_search(__FUNCTION__, \array_column($backtrace, 'function'),); # NOTE: manual search, can change with time
+			$backtrace = $backtrace[$key];
+		}
+		$this->backtrace = $backtrace;
+	}
+
+	/**
+	 * Display this event for logging
+	 *
+	 * This can be changed from configuration.
+	 * The EOL (end of line sequence) is automatically added at the end.
+	 */
+	public function display() : \string
+	{
+		$configuration = \core\config\GlobalConfiguration::read('class', 'core', 'log');
+		$format = '[{tags}] - {date}: {message} in {file} at line {line}'; # NOTE: hard-coded fallback
+		$date_format = 'Y-m-d H:i:s'; # NOTE: hard-coded fallback
+		if ($configuration->exist('format'))
+		{
+			$format = $configuration->get('format');
+		}
+		if ($configuration->exist('date-format'))
+		{
+			$date_format = $configuration->get('date-format');
+		}
+		return \core\substitute(
+			$format,
+			array(
+				'date'    => \date($date_format),
+				'file'    => $this->backtrace['file'],
+				'line'    => $this->backtrace['line'],
+				'message' => $this->message,
+				'tags'    => $this->tags,
+			),
+		) . \PHP_EOL;
+	}
+}
+
+?>
diff --git a/class/core/log/Logger.class.php b/class/core/log/Logger.class.php
new file mode 100644
index 0000000..505bd1e
--- /dev/null
+++ b/class/core/log/Logger.class.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace core\log;
+
+/**
+ * Manage server logs
+ */
+class Logger
+{
+
+	/**
+	 * Array of streams used by this logger
+	 *
+	 * @var \core\log\Stream[]
+	 */
+	protected \array $streams;
+
+	/**
+	 * Constructor of Logger
+	 *
+	 * @param \core\path\Path $path Path to the folder where logs manaded by this object are stored
+	 */
+	public function __construct()
+	{
+		$this->streams = \array();
+	}
+
+	/**
+	 * Add a stream to manage
+	 *
+	 * @param \core\log\Tag $tag Tag of the stream to manage
+	 *
+	 * @throws \core\log\StreamException
+	 *
+	 * @return \core\log\Stream
+	 */
+	protected function add_stream(\core\log\Tag $tag) : \core\log\Stream
+	{
+		if (!$this->stream_exist(tag: $tag))
+		{
+			$this->streams[$tag] = \core\log\StreamFactory::build(tag: $tag); # NOTE: can throw \core\log\StreamException too
+			return $this->streams[$tag];
+		}
+		\throw new \core\log\StreamException(_('the stream already exist, cannot add it', 1));
+	}
+
+	/**
+	 * Check if stream associated to the tag already exist
+	 *
+	 * @param ?\core\log\Tag $tag Tag associated to a stream
+	 *
+	 * @param ?\core\log\Stream $stream Stream to search for
+	 *
+	 * @throws \core\log\LogException
+	 *
+	 * @return bool
+	 */
+	protected function stream_exist(tag: ?\core\log\Tag $tag = null, stream: ?\core\log\Stream $stream = null) : bool
+	{
+		if (\is_null($stream))
+		{
+			if (\is_null($tag))
+			{
+				\throw new \core\log\LogException(_("tag and stream arguments cannot be null at the same time"), 1);
+			}
+
+			if (\in_array($tag, \array_keys($this->streams)))
+			{
+				return True;
+			}
+			return False;
+		}
+		if (\is_null($tag))
+		{
+			if (\in_array($stream, $this->streams))
+			{
+				return True
+			}
+			return False
+		}
+		# this will never be reached
+	}
+}
+
+?>
diff --git a/class/core/log/Stream.class.php b/class/core/log/Stream.class.php
new file mode 100644
index 0000000..c3d8bee
--- /dev/null
+++ b/class/core/log/Stream.class.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace core\log;
+
+/**
+ * Interface to manage streaming system
+ */
+interface Stream
+{
+	/**
+	 * Dispatcher configuration
+	 *
+	 * @var \core\config\Configuration
+	 */
+	protected \core\config\Configuration $configuration;
+
+	/**
+	 * Tag associated to the stream
+	 *
+	 * @var \core\log\Tag
+	 */
+	protected \core\log\Tag $tag;
+
+	/**
+	 * Stream constructor
+	 *
+	 * @param \core\config\Configuration $config Dispatcher configuration
+	 *
+	 * @throws \core\config\ConfigException
+	 */
+	public function __construct(config: \core\config\Configuration $configuration, tag: \core\log\Tag $tag);
+
+	/**
+	 * Push an event to the stream
+	 *
+	 * @param \core\log\Event $event Event to push
+	 *
+	 * @throws \core\log\StreamException
+	 *
+	 * @return \core\log\Event Event pushed
+	 */
+	public function push(event: \core\log\Event $event) : \core\log\Event;
+
+	/**
+	 * Connect to an existing stream running outside of PHP
+	 *
+	 * @param \core\log\StreamSettings $settings Settings to connect to the stream
+	 *
+	 * @throws \core\log\StreamException
+	 */
+	public function connect();
+
+	/**
+	 * Close the connection to an existing stream running outside of PHP
+	 *
+	 * @throws \core\log\StreamException
+	 */
+	public function close();
+}
+
+?>
diff --git a/class/core/log/StreamException.class.php b/class/core/log/StreamException.class.php
new file mode 100644
index 0000000..03e782b
--- /dev/null
+++ b/class/core/log/StreamException.class.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace core\log;
+
+/**
+ * Exception on stream processing
+ */
+class StreamException extends \core\exception\CustomException
+{
+	/**
+	 * default tags associated to this exception
+	 *
+	 * @var \class[]
+	 */
+	const TAGS = [
+		\core\log\tag\Error,
+		\core\log\tag\Logging,
+	]
+}
+
+?>
diff --git a/class/core/log/StreamFactory.class.php b/class/core/log/StreamFactory.class.php
new file mode 100644
index 0000000..09f8de9
--- /dev/null
+++ b/class/core/log/StreamFactory.class.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace core\log;
+
+/**
+ * Stream factory, to create stream with ease
+ */
+class StreamFactory
+{
+	/**
+	 * Available client NOTE: to update for "vanilla" client
+	 *
+	 * @var \string[]
+	 */
+	const AVAILABLE_CLIENTS = [
+		'\\core\\log\\client\\MQTT',
+	];
+
+  /**
+   * @throws \core\config\ConfigException
+   * @throws \core\log\StreamException
+   */
+	public static function build(tag: \core\log\Tag $tag) : \core\log\Stream
+	{
+		$configuration = \core\config\Configuration(array(
+			'tags'   => array(),
+			'client' => array('name' => '\\core\\log\\client\\File'),
+		));
+		if (\core\config\GlobalConfiguration::exist('class', 'core', 'log'))
+		{
+			$configuration = \core\config\GlobalConfiguration::read('class' 'core', 'log');
+		}
+		if (!\in_array($tag->__tostring(), $configuration.get('tags')))
+		{
+			\throw new \core\log\StreamException(_('this stream should not be created as the admin does not want to listen to it', 1)); # WARNING: this should only be seen at [DEBUG] level
+		}
+
+		$client = '\\core\\log\\client\\File'; # NOTE: hard-coded fallback
+		if ($configuration->exist('client', 'name'))
+		{
+
+			if (\mb_split('\\', $configuration->get('client', 'name'))[0] !== 'plugins') # WARNING: any plugin can add a client, but then the name should start with "plugins" (and then "\\foo\\Bar)"
+			{
+				if (!\in_array($configuration->get('client', 'name'), self::AVAILABLE_CLIENTS))
+				{
+					\throw new \core\log\StreamException(_('unknown client in configuration', 2));
+				}
+				$client = $configuration.get('client', 'name');
+			}
+			else
+			{
+				$client = $configuration.get('client', 'name');
+			}
+		}
+
+		$stream = new $client($configuration.get('client', 'settings'), $tag);
+	}
+}
+
+?>
diff --git a/class/core/log/Tag.class.php b/class/core/log/Tag.class.php
new file mode 100644
index 0000000..ced010f
--- /dev/null
+++ b/class/core/log/Tag.class.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace core\log;
+
+/**
+ * Base class for logging tag
+ */
+class Tag
+{
+	/**
+	 * Name of the tag
+	 *
+	 * @var \string
+	 */
+	protected \string $name;
+
+	/**
+	 * Constructor of Tag
+	 *
+	 * @param \string $name Name of the tag
+	 */
+	public function __construct(\string $name)
+	{
+		if (\str_contains($name, '..')) 
+		{
+			\throw \core\log\LogException(_('tag name cannot contains .. as it could be used to write outside the main log directory', 2))
+		}
+		else
+		{
+			$this->name = $name;
+		}
+	}
+
+	/**
+	 * Generate safe id for general purpose (only [A-Z][a-Z]-_ chars)
+	 *
+	 * Replace whitespace character and non base latin character to "_".
+	 * Keep [A-Z][a-z]- chars as it is
+	 */
+	public function generate_id() : \string
+	{
+		return \preg_replace(
+			'/[^a-zA-Z-]/gm',
+			'_',
+			\mb_convert_encoding(
+				$this->__tostring(),
+				'ASCII',
+				'UTF-8',
+			),
+		);
+	}
+
+	public function __toString() : \string
+	{
+		return $this->name;
+	}
+}
+
+?>
diff --git a/class/core/log/client/MQTT.class.php b/class/core/log/client/MQTT.class.php
new file mode 100644
index 0000000..bce25c7
--- /dev/null
+++ b/class/core/log/client/MQTT.class.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace core\log\client;
+
+/**
+ * MQTT stream
+ */
+class MQTT implements \core\log\Stream
+{
+	/**
+	 * Client object from php-mqtt
+	 *
+	 * @var \PhpMqtt\Client\MqttClient
+	 */
+	protected \PhpMqtt\Client\MqttClient $client;
+
+	/**
+	 * Connection settings from php-mqtt
+	 *
+	 * @var \PhpMqtt\Client\ConnectionSettings
+	 */
+	protected \PhpMqtt\Client\ConnectionSettings $connection_settings;
+
+	/**
+	 * @throws \core\config\ConfigException
+	 */
+	public function __construct(config: \core\config\Configuration $configuration, tag: \core\log\Tag $tag)
+	{
+		$this->configuration = $configuration;
+		$this->tag = $tag;
+
+		$client_id = 'php-mqtt-client';
+		if ($this->configuration.exist('client_id'))
+		{
+			$client_id = $this->configuration.get('client_id'); # TODO: Check if we need to sanitize
+		}
+
+		$this->client = new \PhpMqtt\Client\MqttClient($this->configuration('hostname'), $this->configuration.get('port'), $client_id, \PhpMqtt\Client\MqttClient::MQTT_3_1, null);
+
+		$this->connection_settings = new \PhpMqtt\Client\ConnectionSettings;
+		if ($this->configuration.exist('auth', 'username'))
+		{
+			$this->connection_settings->setUsername($this->configuration.get('auth', 'username'));
+		}
+		if ($this->configuration.exist('auth', 'password'))
+		{
+			$this->connection_settings->setPassword($this->configuration.get('auth', 'password'));
+		}
+	}
+
+	public function push(event: \core\log\Event $event) : \core\log\Event
+	{
+		$this->client->connect($this->connection_settings, True);
+		$this->client->publish($tag->generate_id(), $event->display(), \PhpMqtt\Client\MqttClient::QO5_EXACTLY_ONCE);
+		$this->client->loop(True, True);
+		$this->client->disconnect()
+	}
+}
+
+?>
diff --git a/class/core/log/client/file.class.php b/class/core/log/client/file.class.php
new file mode 100644
index 0000000..e68e0b9
--- /dev/null
+++ b/class/core/log/client/file.class.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace core\log\client;
+
+/**
+ * Store stream in files
+ */
+class File
+{
+	/**
+	 * File where event are stored
+	 *
+	 * @var \resource
+	 */
+	protected \resource $file;
+
+	/**
+	 * @throws \core\config\ConfigException
+	 * @throws \core\log\LogException
+	 */
+	public function __construct(config: \core\config\Configuration $configuration, tag: \core\log\Tag $tag)
+	{
+		$this->configuration = $configuration;
+		$this->tag = $tag;
+
+		$path = $configuration.get('path'); # WARNING: must be absolute path
+		$path->safe_append($tag->generate_id());
+
+		$this->file = \fopen($path->__tostring(), 'a');
+
+		if (!$this->file)
+		{
+			\throw new \core\log\LogException(_('cannot open log file'), 1);
+		}
+	}
+
+	public funtion push(event: \core\log\Event $event) : \core\log\Event
+	{
+		if (!\flock($this->file, \LOCK_EX))
+		{
+			\throw new \core\log\LogException(_('cannot guarantee that the file is not already being edited'));
+		}
+		\fwrite($this->file, $event->display());
+		\flock($this->file, LOCK_UN);
+	}
+}
+
+?>
diff --git a/class/core/log/client/redis.class.php b/class/core/log/client/redis.class.php
new file mode 100644
index 0000000..addd2af
--- /dev/null
+++ b/class/core/log/client/redis.class.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace core\log\client;
+
+/**
+ * Redis stream (only https://github.com/phpredis/phpredis for now)
+ */
+class Redis
+{
+	/**
+	 * Client object for redis
+	 *
+	 * @var \Redis
+	 */
+	protected \Redis $client;
+
+	/**
+	 * @throws \core\config\ConfigException
+	 */
+	public function __construct(config: \core\config\Configuration $configuration, tag: \core\log\Tag $tag)
+	{
+		$this->configuration = $configuration;
+		$this->tag = $tag;
+		$config = array(
+			'host' => $this->configuration.get('hostname'),
+			'port' => $this->configuration.get('port'), // -1 if socket
+		);
+		if ($this->configuration.exist('auth'))
+		{
+			$config['auth'] = array();
+			if ($this->configuration.exist('auth', 'username'))
+			{
+				$config['auth'][] = $this->configuration.get('auth', 'username');
+			}
+			$config['auth'][] = $this->configuration.get('auth', 'password');
+		}
+		$this->client = new \Redis($config);
+	}
+
+	public function push(event: \core\log\Event $event) : \core\log\Event
+	{
+		$this->client->rpush($tag->generate_id(), $event->display());
+	}
+}
+
+?>
diff --git a/func/core/utils.class.php b/func/core/utils.class.php
new file mode 100644
index 0000000..020c690
--- /dev/null
+++ b/func/core/utils.class.php
@@ -0,0 +1,152 @@
+<?php
+
+namespace core;
+
+/**
+ * convert nearly anything to a string (not protected for html, use html_special_chars)
+ *
+ * @param \mixed $var Variable to convert
+ *
+ * @return \string string conversion result
+ */
+function display(\mixed $var) : \string
+{
+	if (\is_string($var))
+	{
+		return $var;
+	}
+	if (\is_bool($var))
+	{
+		return ($var ? 'True' : 'False');
+	}
+	if (\is_int($var) || \is_float($var))
+	{
+		return (string) $var;
+	}
+	if (\is_null($var))
+	{
+		return 'null';
+	}
+	if (\is_resource($var))
+	{
+		return \get_resource_type($var);
+	}
+	if (\is_array($var))
+	{
+		$ret = 'array (';
+		foreach ($var as $key => $el)
+		{
+			$ret .= ' ' . \core\display($key) . ' => ' . \core\display($el);
+		}
+		return $ret . ' )';
+	}
+	if (\is_object($var))
+	{
+		if (!\method_exists($var, '__toString'))
+		{
+			return \get_class($var) . ' : ' . \core\display(\core\table($var, 3)); // NOTE: arbitrary hard-coded recursion value
+		}
+		else
+		{
+			return $var->__toString();
+		}
+	}
+	if (\is_callable($var))
+	{
+		if ($var instanceOf \Closure)
+		{
+			return 'a closure';
+		}
+		return 'unknown callable';
+	}
+	if (\is_iterable($var))
+	{
+		return 'iterable';
+	}
+	return 'cannot convert the variable that should be here to a string';
+}
+
+/**
+ * substitution helper
+ *
+ * substitute {element} with element for each element in token
+ * Not safe to display without sanitization on a webpage
+ *
+ * @param \string $content
+ *
+ * @param \array $tokens
+ *
+ * @return \string
+ */
+function substitute(\string $content, \array $tokens) : \string
+{
+	$parts = \preg_split('/({(?:\\}|[^\\}])+})/Um', $content, -1, \PREG_SPLIT_DELIM_CAPTURE);
+
+	if (\count($tokens) > 0)
+	{
+		foreach ($tokens as $name => $value)
+		{
+			if (\in_array('{' . $name . '}', $parts))
+			{
+				foreach (\array_keys($parts, '{' . $name . '}') as $key)
+				{
+					$parts[$key] = \core\display($value);
+				}
+			}
+		}
+	}
+
+	return \implode($parts);
+}
+
+/**
+ * convert any object into a table
+ *
+ * @param \object $object Object to convert
+ *
+ * @param \int $depth Depth of the recursion if there is an object. -1 for infinite, 0 for no recursion.
+ *                    Default to 0.
+ *
+ * @return \array
+ */
+function table(\object $object, \int $depth = 0) : \array
+{
+	if (\in_array(\core\Base::class, \class_uses($object)))
+	{
+		return $object->table();
+	}
+
+	$attributes = [];
+
+	if ($depth < -1)
+	{
+		throw new \Exception('Depth cannot be below -1');
+	}
+
+	foreach (\array_keys(\get_class_vars(\get_class($object))) as $attribute)
+	{
+		if (\is_object($object->$attribute))
+		{
+			if ($depth === 0)
+			{
+				$attributes[$attribute] = $object->$attribute;
+			}
+			else if ($depth > 0)
+			{
+				$attributes[$attribute] = \core\table($object->$attribute, $depth - 1);
+			}
+			else // depth === -1
+			{
+				$attributes[$attribute] = \core\table($object->$attribute, $depth);
+			}
+		}
+		else
+		{
+			$attributes[$attribute] = $object->$attribute;
+		}
+	}
+
+	return $attributes;
+}
+
+?>