<?php

/***************************************************************************
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 ***************************************************************************/

/**
* Template Class based on the PHPbb template class from phpbb2 
* Modified it to support caching and use php5 conventions
* Scott Horne @ support@web-professor.net
*/

/**
 * Template class. By Nathan Codding of the phpBB group.
 * The interface was originally inspired by PHPLib templates,
 * and the template file formats are quite similar.
 *
 */

class Phpbb_Template {

	// variable that holds all the data we'll be substituting into
	// the compiled templates.
	// ...
	// This will end up being a multi-dimensional array like this:
	// $this->_tpldata[block.][iteration#][child.][iteration#][child2.][iteration#][variablename] == value
	// if it's a root-level variable, it'll be like this:
	// $this->_tpldata[.][0][varname] == value
	private $_tpldata = array();

	// Hash of filenames for each template handle.
	public $files = array();

	// Root template directory.
	public $root = "";

	// this will hash handle names to the compiled code for that handle.
	private $compiled_code = array();

	// This will hold the uncompiled code for that handle.
	private $uncompiled_code = array();

	// switch to decide if we are going to use the cache

	private $use_cache = false;
	private $cache_directory = '';

	/**
	 * Constructor. Simply sets the root dir.
	 *
	 */
	function __construct($root = "." , $use_cache = false, $cache_directory = '' )
	{

		if( $this->set_rootdir($root))
		{

		} else {
			throw new Exception('Unable to find template root directory: ' . $root );	
		}

		$this->use_cache = $use_cache;
		if( $this->use_cache )
		{
			if( $cache_directory )
			{
				$this->cache_directory = $cache_directory;
			} else {
				$this->cache_directory = $this->root . '/cache';
			}
		}
	}

	/**
	 * Destroys this template object. Should be called when you're done with it, in order
	 * to clear out the template data so you can load/parse a new template set.
	 */
	function __destruct()
	{
		$this->_tpldata = array();
	}

	/**
	 * Sets the template root directory for this Template object.
	 */
	public function set_rootdir($dir)
	{
		if (!is_dir($dir))
		{
			return false;
		}

		$this->root = $dir;
		return true;
	}


	/**
	 * Sets the template filenames for handles. $filename_array
	 * should be a hash of handle => filename pairs.
	 */

	public function set_filenames( array $filename_array)
	{

		reset($filename_array);

		foreach( $filename_array as $handle => $filename )
		{
			$this->files[$handle] = $this->make_filename($filename);
		}

		return true;
	}

	/**
	 * Load the file for the handle, compile the file,
	 * and run the compiled code. This will print out
	 * the results of executing the template.
	 */
	public function pparse($handle)
	{

		$code = '';

		if( $this->use_cache )
		{
			$code = $this->get_cached_code( $handle );
		} else {
			if (!$this->loadfile($handle))
			{
				throw new Exception("Template->pparse(): Couldn't load template file for handle $handle");
			}
			// actually compile the template now.
			if (!isset($this->compiled_code[$handle]) || empty($this->compiled_code[$handle]))
			{
				// Actually compile the code now.
				$this->compiled_code[$handle] = $this->compile($this->uncompiled_code[$handle]);
			}
			$code = $this->compiled_code[$handle];
		}
		eval( $code );
		return true;
	}

	public function get_html($handle)
	{
		if (!$this->loadfile($handle))
		{
			throw new Exception("Template->assign_var_from_handle(): Couldn't load template file for handle $handle");
		}

		// Compile it, with the "no echo statements" option on.
		$_str = "";
		$code = '';

		if( $this->use_cache )
		{
			$code = $this->get_cached_code( $handle, true, '_str');
		} else {
			$code = $this->compile($this->uncompiled_code[$handle], true, '_str');
		}

		// evaluate the variable assignment.
		eval($code);
		// assign the value of the generated variable to the given varname.
		return $_str;
	}


	/**
	 * Inserts the uncompiled code for $handle as the
	 * value of $varname in the root-level. This can be used
	 * to effectively include a template in the middle of another
	 * template.
	 * Note that all desired assignments to the variables in $handle should be done
	 * BEFORE calling this function.
	 */
	public function assign_var_from_handle($varname, $handle)
	{
		if (!$this->loadfile($handle))
		{
			throw new Exception("Template->assign_var_from_handle(): Couldn't load template file for handle $handle");
		}

		// Compile it, with the "no echo statements" option on.
		$_str = "";
		$code = '';

		if( $this->use_cache )
		{
			$code = $this->get_cached_code( $handle, true, '_str');
		} else {
			$code = $this->compile($this->uncompiled_code[$handle], true, '_str');
		}

		// evaluate the variable assignment.
		eval($code);
		// assign the value of the generated variable to the given varname.
		$this->assign_var($varname, $_str);

		return true;
	}

	/**
	 * Block-level variable assignment. Adds a new block iteration with the given
	 * variable assignments. Note that this should only be called once per block
	 * iteration.
	 */
	public function assign_block_vars($blockname, $vararray)
	{
		if (strstr($blockname, '.'))
		{
			// Nested block.
			$blocks = explode('.', $blockname);
			$blockcount = sizeof($blocks) - 1;
			$str = '$this->_tpldata';
			for ($i = 0; $i < $blockcount; $i++)
			{
				$str .= '[\'' . $blocks[$i] . '.\']';
				eval('$lastiteration = sizeof(' . $str . ') - 1;');
				$str .= '[' . $lastiteration . ']';
			}
			// Now we add the block that we're actually assigning to.
			// We're adding a new iteration to this block with the given
			// variable assignments.
			$str .= '[\'' . $blocks[$blockcount] . '.\'][] = $vararray;';

			// Now we evaluate this assignment we've built up.
			eval($str);
		}
		else
		{
			// Top-level block.
			// Add a new iteration to this block with the variable assignments
			// we were given.
			$this->_tpldata[$blockname . '.'][] = $vararray;
		}

		return true;
	}

	/**
	 * Root-level variable assignment. Adds to current assignments, overriding
	 * any existing variable assignment with the same name.
	 */
	public function assign_vars($vararray)
	{
		reset ($vararray);
		while (list($key, $val) = each($vararray))
		{
			$this->_tpldata['.'][0][$key] = $val;
		}

		return true;
	}

	/**
	 * Root-level variable assignment. Adds to current assignments, overriding
	 * any existing variable assignment with the same name.
	 */
	public function assign_var($varname, $varval)
	{
		$this->_tpldata['.'][0][$varname] = $varval;

		return true;
	}


	/**
	 * Generates a full path+filename for the given filename, which can either
	 * be an absolute name, or a name relative to the rootdir for this Template
	 * object.
	 */
	private	function make_filename($filename)
	{
		// check to see if its a remote template
		$from_http = 0;

		if( strtolower( substr( $filename, 0 ,4 )) == 'http' )
		{
			$from_http = 1;
		}

		if( $from_http )
		{
// we are loading the template over http so we don't check if the file is good or not
		} else {
			// Check if it's an absolute or relative path.
			if (substr($filename, 0, 1) != '/' )
			{
	// this allows loading of a template by url 	
		       		$filename = realpath($this->root . '/' . $filename);
			}

			if (!file_exists($filename))
			{
				throw new Exception("Template->make_filename(): Error - file $filename does not exist");
			}
		}

		return $filename;
	}


	/**
	 * If not already done, load the file for the given handle and populate
	 * the uncompiled_code[] hash with its code. Do not compile.
	 */
	private	function loadfile($handle)
	{
		// If the file for this handle is already loaded and compiled, do nothing.
		if (isset($this->uncompiled_code[$handle]) && !empty($this->uncompiled_code[$handle]))
		{
			return true;
		}

		// If we don't have a file assigned to this handle, throw new Exception.
		if (!isset($this->files[$handle]))
		{
			throw new Exception("Template->loadfile(): No file specified for handle $handle");
		}

		$filename = $this->files[$handle];

		$str = implode("", @file($filename));
		if (empty($str))
		{
			throw new Exception("Template->loadfile(): File $filename for handle $handle is empty");
		}

		$this->uncompiled_code[$handle] = $str;

		return true;
	}


	/**
	 * Compiles the given string of code, and returns
	 * the result in a string.
	 * If "do_not_echo" is true, the returned code will not be directly
	 * executable, but can be used as part of a variable assignment
	 * for use in assign_code_from_handle().
	 */
	public function compile($code, $do_not_echo = false, $retvar = '')
	{
		// replace \ with \\ and then ' with \'.
		$code = str_replace('\\', '\\\\', $code);
		$code = str_replace('\'', '\\\'', $code);

		// change template varrefs into PHP varrefs

		// This one will handle varrefs WITH namespaces
		$varrefs = array();
		preg_match_all('#\{(([a-z0-9\-_]+?\.)+?)([a-z0-9\-_]+?)\}#is', $code, $varrefs);
		$varcount = sizeof($varrefs[1]);
		for ($i = 0; $i < $varcount; $i++)
		{
			$namespace = $varrefs[1][$i];
			$varname = $varrefs[3][$i];
			$new = $this->generate_block_varref($namespace, $varname);

			$code = str_replace($varrefs[0][$i], $new, $code);
		}

		// This will handle the remaining root-level varrefs
		$code = preg_replace('#\{([a-z0-9\-_]*?)\}#is', '\' . ( ( isset($this->_tpldata[\'.\'][0][\'\1\']) ) ? $this->_tpldata[\'.\'][0][\'\1\'] : \'\' ) . \'', $code);

		// Break it up into lines.
		$code_lines = explode("\n", $code);

		$block_nesting_level = 0;
		$block_names = array();
		$block_names[0] = ".";

		// Second: prepend echo ', append ' . "\n"; to each line.
		$line_count = sizeof($code_lines);
		for ($i = 0; $i < $line_count; $i++)
		{
			$code_lines[$i] = chop($code_lines[$i]);
			if (preg_match('#<!-- BEGIN (.*?) -->#', $code_lines[$i], $m))
			{
				$n[0] = $m[0];
				$n[1] = $m[1];

				// Added: dougk_ff7-Keeps templates from bombing if begin is on the same line as end.. I think. :)
				if ( preg_match('#<!-- END (.*?) -->#', $code_lines[$i], $n) )
				{
					$block_nesting_level++;
					$block_names[$block_nesting_level] = $m[1];
					if ($block_nesting_level < 2)
					{
						// Block is not nested.
						$code_lines[$i] = '$_' . $n[1] . '_count = ( isset($this->_tpldata[\'' . $n[1] . '.\']) ) ?  sizeof($this->_tpldata[\'' . $n[1] . '.\']) : 0;';
						$code_lines[$i] .= "\n" . 'for ($_' . $n[1] . '_i = 0; $_' . $n[1] . '_i < $_' . $n[1] . '_count; $_' . $n[1] . '_i++)';
						$code_lines[$i] .= "\n" . '{';
					}
					else
					{
						// This block is nested.

						// Generate a namespace string for this block.
						$namespace = implode('.', $block_names);
						// strip leading period from root level..
						$namespace = substr($namespace, 2);
						// Get a reference to the data array for this block that depends on the
						// current indices of all parent blocks.
						$varref = $this->generate_block_data_ref($namespace, false);
						// Create the for loop code to iterate over this block.
						$code_lines[$i] = '$_' . $n[1] . '_count = ( isset(' . $varref . ') ) ? sizeof(' . $varref . ') : 0;';
						$code_lines[$i] .= "\n" . 'for ($_' . $n[1] . '_i = 0; $_' . $n[1] . '_i < $_' . $n[1] . '_count; $_' . $n[1] . '_i++)';
						$code_lines[$i] .= "\n" . '{';
					}

					// We have the end of a block.
					unset($block_names[$block_nesting_level]);
					$block_nesting_level--;
					$code_lines[$i] .= '} // END ' . $n[1];
					$m[0] = $n[0];
					$m[1] = $n[1];
				}
				else
				{
					// We have the start of a block.
					$block_nesting_level++;
					$block_names[$block_nesting_level] = $m[1];
					if ($block_nesting_level < 2)
					{
						// Block is not nested.
						$code_lines[$i] = '$_' . $m[1] . '_count = ( isset($this->_tpldata[\'' . $m[1] . '.\']) ) ? sizeof($this->_tpldata[\'' . $m[1] . '.\']) : 0;';
						$code_lines[$i] .= "\n" . 'for ($_' . $m[1] . '_i = 0; $_' . $m[1] . '_i < $_' . $m[1] . '_count; $_' . $m[1] . '_i++)';
						$code_lines[$i] .= "\n" . '{';
					}
					else
					{
						// This block is nested.

						// Generate a namespace string for this block.
						$namespace = implode('.', $block_names);
						// strip leading period from root level..
						$namespace = substr($namespace, 2);
						// Get a reference to the data array for this block that depends on the
						// current indices of all parent blocks.
						$varref = $this->generate_block_data_ref($namespace, false);
						// Create the for loop code to iterate over this block.
						$code_lines[$i] = '$_' . $m[1] . '_count = ( isset(' . $varref . ') ) ? sizeof(' . $varref . ') : 0;';
						$code_lines[$i] .= "\n" . 'for ($_' . $m[1] . '_i = 0; $_' . $m[1] . '_i < $_' . $m[1] . '_count; $_' . $m[1] . '_i++)';
						$code_lines[$i] .= "\n" . '{';
					}
				}
			}
			else if (preg_match('#<!-- END (.*?) -->#', $code_lines[$i], $m))
			{
				// We have the end of a block.
				unset($block_names[$block_nesting_level]);
				$block_nesting_level--;
				$code_lines[$i] = '} // END ' . $m[1];
			}
			else
			{
				// We have an ordinary line of code.
				if (!$do_not_echo)
				{
					$code_lines[$i] = 'echo \'' . $code_lines[$i] . '\' . "\\n";';
				}
				else
				{
					$code_lines[$i] = '$' . $retvar . '.= \'' . $code_lines[$i] . '\' . "\\n";'; 
				}
			}
		}

		// Bring it back into a single string of lines of code.
		$code = implode("\n", $code_lines);
		return $code	;

	}


	/**
	 * Generates a reference to the given variable inside the given (possibly nested)
	 * block namespace. This is a string of the form:
	 * ' . $this->_tpldata['parent'][$_parent_i]['$child1'][$_child1_i]['$child2'][$_child2_i]...['varname'] . '
	 * It's ready to be inserted into an "echo" line in one of the templates.
	 * NOTE: expects a trailing "." on the namespace.
	 */
	private	function generate_block_varref($namespace, $varname)
	{
		// Strip the trailing period.
		$namespace = substr($namespace, 0, strlen($namespace) - 1);

		// Get a reference to the data block for this namespace.
		$varref = $this->generate_block_data_ref($namespace, true);
		// Prepend the necessary code to stick this in an echo line.

		// Append the variable reference.
		$varref .= '[\'' . $varname . '\']';

		$varref = '\' . ( ( isset(' . $varref . ') ) ? ' . $varref . ' : \'\' ) . \'';

		return $varref;

	}


	/**
	 * Generates a reference to the array of data values for the given
	 * (possibly nested) block namespace. This is a string of the form:
	 * $this->_tpldata['parent'][$_parent_i]['$child1'][$_child1_i]['$child2'][$_child2_i]...['$childN']
	 *
	 * If $include_last_iterator is true, then [$_childN_i] will be appended to the form shown above.
	 * NOTE: does not expect a trailing "." on the blockname.
	 */
	private function generate_block_data_ref($blockname, $include_last_iterator)
	{
		// Get an array of the blocks involved.
		$blocks = explode(".", $blockname);
		$blockcount = sizeof($blocks) - 1;
		$varref = '$this->_tpldata';
		// Build up the string with everything but the last child.
		for ($i = 0; $i < $blockcount; $i++)
		{
			$varref .= '[\'' . $blocks[$i] . '.\'][$_' . $blocks[$i] . '_i]';
		}
		// Add the block reference for the last child.
		$varref .= '[\'' . $blocks[$blockcount] . '.\']';
		// Add the iterator for the last child if requried.
		if ($include_last_iterator)
		{
			$varref .= '[$_' . $blocks[$blockcount] . '_i]';
		}

		return $varref;
	}

/*
Checks to see if the cached version of the compiled code exists in the cache directory and if its up to date
if so it retrieves the cached version if not it attempts to create a cached version of the template and returns the code
*/
	private	function get_cached_code( $handle , $do_not_echo = false, $ret_var = '' )
	{

		$cache_file = $this->cache_directory . '/' . md5( $this->files[$handle] );

		$create_new_cache = 1; 
		if( $cache_present = file_exists( $cache_file ) )
		{
			$cache_stat = stat( $cache_file );
			$template_stat = stat( $this->files[$handle] );
			$create_new_cache = ( $cache_stat['mtime'] < $template_stat['mtime'] )?1:0 ;
		}

		$code = '';
		if( $create_new_cache )
		{
			if (!$this->loadfile($handle))
			{
				throw new Exception("Template->pparse(): Couldn't load template file for handle $handle");
			}
	
			// actually compile the template now.
			if (!isset($this->compiled_code[$handle]) || empty($this->compiled_code[$handle]))
			{
				// Actually compile the code now.
				$code = $this->compile($this->uncompiled_code[$handle], $do_not_echo, $ret_var );
				$this->compiled_code[$handle] = $code;
			}

			$fh = fopen( $cache_file, 'w' );
			fwrite( $fh, $code );
			fclose( $fh );

		} else {
			$fh = fopen( $cache_file, 'r' );
			$code = fread( $fh, filesize( $cache_file ));
			fclose( $fh );
		} 

		return 	$code;
	}
}

?>