<?php
/**
*
* @package phpBB3
* @copyright (c) 2013 phpBB Group
* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
*
*/

/**
* @ignore
*/
if (!defined('IN_PHPBB'))
{
	exit;
}

/**
* Twig Template class.
* @package phpBB3
*/
class phpbb_template_twig implements phpbb_template
{
	/**
	* Template context.
	* Stores template data used during template rendering.
	* @var phpbb_template_context
	*/
	protected $context;

	/**
	* Path of the cache directory for the template
	*
	* Cannot be changed during runtime.
	*
	* @var string
	*/
	private $cachepath = '';

	/**
	* phpBB root path
	* @var string
	*/
	protected $phpbb_root_path;

	/**
	* adm relative path
	* @var string
	*/
	protected $adm_relative_path;

	/**
	* PHP file extension
	* @var string
	*/
	protected $php_ext;

	/**
	* phpBB config instance
	* @var phpbb_config
	*/
	protected $config;

	/**
	* Current user
	* @var phpbb_user
	*/
	protected $user;

	/**
	* Extension manager.
	*
	* @var phpbb_extension_manager
	*/
	protected $extension_manager;

	/**
	* Name of the style that the template being compiled and/or rendered
	* belongs to, and its parents, in inheritance tree order.
	*
	* Used to invoke style-specific template events.
	*
	* @var array
	*/
	protected $style_names;

	/**
	* Twig Environment
	*
	* @var Twig_Environment
	*/
	protected $twig;

	/**
	* Array of filenames assigned to set_filenames
	*
	* @var array
	*/
	protected $filenames = array();

	/**
	* Constructor.
	*
	* @param string $phpbb_root_path phpBB root path
	* @param string $php_ext php extension (typically 'php')
	* @param phpbb_config $config
	* @param phpbb_user $user
	* @param phpbb_template_context $context template context
	* @param phpbb_extension_manager $extension_manager extension manager, if null then template events will not be invoked
	* @param string $adm_relative_path relative path to adm directory
	*/
	public function __construct($phpbb_root_path, $php_ext, $config, $user, phpbb_template_context $context, phpbb_extension_manager $extension_manager = null, $adm_relative_path = null)
	{
		$this->phpbb_root_path = $phpbb_root_path;
		$this->adm_relative_path = $adm_relative_path;
		$this->php_ext = $php_ext;
		$this->config = $config;
		$this->user = $user;
		$this->context = $context;
		$this->extension_manager = $extension_manager;

		$this->cachepath = $phpbb_root_path . 'cache/twig/';

		// Initiate the loader, __main__ namespace paths will be setup later in set_style_names()
		$loader = new Twig_Loader_Filesystem('');

		$this->twig = new phpbb_template_twig_environment(
			$this->config,
			($this->extension_manager) ? $this->extension_manager->all_enabled() : array(),
			$this->phpbb_root_path,
			$loader,
			array(
				'cache'			=> (defined('IN_INSTALL')) ? false : $this->cachepath,
				'debug'			=> defined('DEBUG'),
				'auto_reload'	=> (bool) $this->config['load_tplcompile'],
				'autoescape'	=> false,
			)
		);

		$this->twig->addExtension(
			new phpbb_template_twig_extension(
				$this->context,
				$this->user
			)
		);

		$lexer = new phpbb_template_twig_lexer($this->twig);

		$this->twig->setLexer($lexer);
	}

	/**
	* Clear the cache
	*
	* @return phpbb_template
	*/
	public function clear_cache()
	{
		if (is_dir($this->cachepath))
		{
			$this->twig->clearCacheFiles();
		}

		return $this;
	}

	/**
	* Sets the template filenames for handles.
	*
	* @param array $filename_array Should be a hash of handle => filename pairs.
	* @return phpbb_template $this
	*/
	public function set_filenames(array $filename_array)
	{
		$this->filenames = array_merge($this->filenames, $filename_array);

		return $this;
	}

	/**
	* Sets the style names/paths corresponding to style hierarchy being compiled
	* and/or rendered.
	*
	* @param array $style_names List of style names in inheritance tree order
	* @param array $style_paths List of style paths in inheritance tree order
	* @param bool $is_core True if the style names are the "core" styles for this page load
	* 	Core means the main phpBB template files
	* @return phpbb_template $this
	*/
	public function set_style_names(array $style_names, array $style_paths, $is_core = false)
	{
		$this->style_names = $style_names;

		// Set as __main__ namespace
		$this->twig->getLoader()->setPaths($style_paths);

		// Core style namespace from phpbb_style::set_style()
		if ($is_core)
		{
			$this->twig->getLoader()->setPaths($style_paths, 'core');
		}

		// Add admin namespace
		if (is_dir($this->phpbb_root_path . $this->adm_relative_path . 'style/'))
		{
			$this->twig->getLoader()->setPaths($this->phpbb_root_path . $this->adm_relative_path . 'style/', 'admin');
		}

		// Add all namespaces for all extensions
		if ($this->extension_manager instanceof phpbb_extension_manager)
		{
			$style_names[] = 'all';

			foreach ($this->extension_manager->all_enabled() as $ext_namespace => $ext_path)
			{
				// namespaces cannot contain /
				$namespace = str_replace('/', '_', $ext_namespace);
				$paths = array();

				foreach ($style_names as $style_name)
				{
					$ext_style_path = $ext_path . 'styles/' . $style_name . '/template';

					if (is_dir($ext_style_path))
					{
						$paths[] = $ext_style_path;
					}
				}

				$this->twig->getLoader()->setPaths($paths, $namespace);
			}
		}

		return $this;
	}

	/**
	* Clears all variables and blocks assigned to this template.
	*
	* @return phpbb_template $this
	*/
	public function destroy()
	{
		$this->context = array();

		return $this;
	}

	/**
	* Reset/empty complete block
	*
	* @param string $blockname Name of block to destroy
	* @return phpbb_template $this
	*/
	public function destroy_block_vars($blockname)
	{
		$this->context->destroy_block_vars($blockname);

		return $this;
	}

	/**
	* Display a template for provided handle.
	*
	* The template will be loaded and compiled, if necessary, first.
	*
	* This function calls hooks.
	*
	* @param string $handle Handle to display
	* @return phpbb_template $this
	*/
	public function display($handle)
	{
		$result = $this->call_hook($handle, __FUNCTION__);
		if ($result !== false)
		{
			return $result[0];
		}

		$this->twig->display($this->get_filename_from_handle($handle), $this->get_template_vars());

		return $this;
	}

	/**
	* Calls hook if any is defined.
	*
	* @param string $handle Template handle being displayed.
	* @param string $method Method name of the caller.
	*/
	protected function call_hook($handle, $method)
	{
		global $phpbb_hook;

		if (!empty($phpbb_hook) && $phpbb_hook->call_hook(array(__CLASS__, $method), $handle, $this))
		{
			if ($phpbb_hook->hook_return(array(__CLASS__, $method)))
			{
				$result = $phpbb_hook->hook_return_result(array(__CLASS__, $method));
				return array($result);
			}
		}

		return false;
	}

	/**
	* Display the handle and assign the output to a template variable
	* or return the compiled result.
	*
	* @param string $handle Handle to operate on
	* @param string $template_var Template variable to assign compiled handle to
	* @param bool $return_content If true return compiled handle, otherwise assign to $template_var
	* @return phpbb_template|string if $return_content is true return string of the compiled handle, otherwise return $this
	*/
	public function assign_display($handle, $template_var = '', $return_content = true)
	{
		if ($return_content)
		{
			return $this->twig->render($this->get_filename_from_handle($handle), $this->get_template_vars());
		}

		$this->assign_var($template_var, $this->twig->render($this->get_filename_from_handle($handle, $this->get_template_vars())));

		return $this;
	}

	/**
	* Assign key variable pairs from an array
	*
	* @param array $vararray A hash of variable name => value pairs
	* @return phpbb_template $this
	*/
	public function assign_vars(array $vararray)
	{
		foreach ($vararray as $key => $val)
		{
			$this->assign_var($key, $val);
		}

		return $this;
	}

	/**
	* Assign a single scalar value to a single key.
	*
	* Value can be a string, an integer or a boolean.
	*
	* @param string $varname Variable name
	* @param string $varval Value to assign to variable
	* @return phpbb_template $this
	*/
	public function assign_var($varname, $varval)
	{
		$this->context->assign_var($varname, $varval);

		return $this;
	}

	/**
	* Append text to the string value stored in a key.
	*
	* Text is appended using the string concatenation operator (.).
	*
	* @param string $varname Variable name
	* @param string $varval Value to append to variable
	* @return phpbb_template $this
	*/
	public function append_var($varname, $varval)
	{
		$this->context->append_var($varname, $varval);

		return $this;
	}

	/**
	* Assign key variable pairs from an array to a specified block
	* @param string $blockname Name of block to assign $vararray to
	* @param array $vararray A hash of variable name => value pairs
	* @return phpbb_template $this
	*/
	public function assign_block_vars($blockname, array $vararray)
	{
		$this->context->assign_block_vars($blockname, $vararray);

		return $this;
	}

	/**
	* Change already assigned key variable pair (one-dimensional - single loop entry)
	*
	* An example of how to use this function:
	* {@example alter_block_array.php}
	*
	* @param	string	$blockname	the blockname, for example 'loop'
	* @param	array	$vararray	the var array to insert/add or merge
	* @param	mixed	$key		Key to search for
	*
	* array: KEY => VALUE [the key/value pair to search for within the loop to determine the correct position]
	*
	* int: Position [the position to change or insert at directly given]
	*
	* If key is false the position is set to 0
	* If key is true the position is set to the last entry
	*
	* @param	string	$mode		Mode to execute (valid modes are 'insert' and 'change')
	*
	*	If insert, the vararray is inserted at the given position (position counting from zero).
	*	If change, the current block gets merged with the vararray (resulting in new key/value pairs be added and existing keys be replaced by the new value).
	*
	* Since counting begins by zero, inserting at the last position will result in this array: array(vararray, last positioned array)
	* and inserting at position 1 will result in this array: array(first positioned array, vararray, following vars)
	*
	* @return bool false on error, true on success
	*/
	public function alter_block_array($blockname, array $vararray, $key = false, $mode = 'insert')
	{
		return $this->context->alter_block_array($blockname, $vararray, $key, $mode);
	}

	/**
	* Get template vars in a format Twig will use (from the context)
	*
	* @return array
	*/
	public function get_template_vars()
	{
		$context_vars = $this->context->get_data_ref();

		$vars = array_merge(
			$context_vars['.'][0], // To get normal vars
			$context_vars, // To get loops
			array(
				'definition'	=> new phpbb_template_twig_definition(),
				'user'			=> $this->user,
			)
		);

		// cleanup
		unset($vars['.']);

		return $vars;
	}

	/**
	* Get a filename from the handle
	*
	* @param string $handle
	* @return string
	*/
	protected function get_filename_from_handle($handle)
	{
		return (isset($this->filenames[$handle])) ? $this->filenames[$handle] : $handle;
	}

	/**
	* Get path to template for handle (required for BBCode parser)
	*
	* @return string
	*/
	public function get_source_file_for_handle($handle)
	{
		return $this->twig->getLoader()->getCacheKey($this->get_filename_from_handle($handle));
	}
}