<?php

    if(!defined('IRB_TPL_PHP'))
        define('IRB_TPL_PHP', true);

/**    
 * IRBTemplate - PHP templating engine   
 * NOTE: Requires PHP version 5 or later     
 * Info: http://irbis-school.com      
 * @author IT studio IRBIS-team    
 * @copyright © 2014 IRBIS-team    
 * @version 0.1    
 * @license http://www.opensource.org/licenses/rpl1.5.txt    
 */   
   
class IRB_Template  
{  

/**     
*   PABLIC PROPERTIES  
*/ 

/**     
* Path to the directory templates   
* @access public  
* @var string     
*/   
    private $tpl_dir     = IRB_DIR_TEMPLATE;     

/**     
* The template type   
* @access public  
* @var string     
*/       
    public  $tpl_php    = IRB_TPL_PHP; 
 
/**     
* Sets the file extension template   
* @access public  
* @var string     
*/       
    public  $tpl_ext     = 'tpl';  
 
/**      
* The left-delimiter to specify the variable tags  
* @access public   
* @var string      
*/         
    public $left_delim   = '{';   
/**      
* The right-delimiter to specify the variable tags  
* @access public   
* @var string      
*/     
    public $right_delim  = '}';    

/**      
* Includes automatic provisioning template variables  
* @access public   
* @var bolean     
*/       
    public  $inialize    = true; 
    
/**      
* Debug mode  
* @access public   
* @var bolean     
*/       
    public  $debug       = IRB_CONFIG_DEBUG;     

/**     
* The name of the exception class 
* You can enable trigger_error 
* @access public  
* @var string    
*/      
    public  $exception   = 'trigger_error';   
    

/**      
*    PROTECTED PROPERTIES  
*/  

/**     
* Template content 
* @access protected  
* @var string    
*/   
    protected $_tpl      = '';  

/**     
* Data variables 
* @access protected  
* @var array   
*/  
    protected $_data     = array();   

/**     
* Installed blocks 
* @access protected  
* @var array   
*/  
    protected $_blocks   = array();  

/**     
* Parsed blocks 
* @access protected  
* @var array   
*/  
    protected $_parsed   = array();  

/**     
* Call stack 
* @access protected  
* @var array   
*/  
    protected $_stack    = array();    

/**     
* Errors 
* @access protected  
* @var array   
*/  
    protected $_errors   = array();  

/**     
* Sets a message header error 
* @access protected  
* @var bolean   
*/    
    protected $_errhead  = true;   

/**     
* Result of work 
* @access protected  
* @var string   
*/  
    protected $_total    = '';   
    
/**     
* Сlass name
* @access protected  
* @var string   
*/  
    protected $_class    = __CLASS__;  

    
/**    
*    PABLIC METHODS  
*/      
   

/**
* Constructor.
* @param string $tpl_name      The name of the template
* @param string $block_parent  The name of the parent block
*/
    public function __construct($tpl_name, $block_parent = '')
    {
        $this->_path = $this->tpl_dir . $tpl_name .'.'. $this->tpl_ext;
        $this->start_delim = $this->left_delim . $this->left_delim;
        $this->end_delim   = $this->right_delim . $this->right_delim;

        if(!$this->_tpl = @file_get_contents($this->_path))
            $this->_debug('File does not exist or empty');

        if(!empty($block_parent))
        {
            $parent_out = $this-> tpl_php ? '<?=$'. $block_parent .'; ?>'
                                          : $this->left_delim . $block_parent . $this->right_delim;

            $this->_tpl = preg_replace('~<!--//\s+('. preg_quote($block_parent, '~')
                                      .')\s*#*.*?\s+\-\->.*?\\1\s+?end\s*#*.*?\s+?\-\->~uis',
                                       $parent_out,
                                       $this->_tpl
                                       );

            if($this->debug && false === strpos($this->_tpl, $parent_out))
                $this->_debug('parent block ['. $block_parent .'] does not exist or incorrect syntax');
        }

        $this->_initiate();
    }
/**
* Assign a variable.
*
* @example Simplest case:
* @example $tpl->assign('name', 'value');
* @example <?php $name ?> in template
*
* @example Array assign:
* @example $tpl->assign(array('name' => 'value', 'name2' => 'value2'));
* @example <?php $name ?>  <?php $name2 ?>  in template
*
* @access public
* @param string/array $data
* @param string/array $value
* @return object
*/
    public function assign($data, $value = '')
    {
        if(is_array($data))
        {
            $this->_data = array_merge($this->_data, $data);
            $this->_stack[]['assign'] = $data;
        }
        else
        {
            $this->_data[$data] = $value;
            $this->_stack[]['assign'] = array($data => $value);
        }

        if(!$this->tpl_php)
            $this->_normalise($this->_data);

        return $this;
    }

/**
* Assign a variable to the processing of html.
* @access public
* @param string/array $data
* @param string/array $value
* @return object
*/
    public function assignHtml($data, $value = '')
    {
        if(is_array($data))
        {
            $this->_data = array_merge($this->_data, $this->_htmlChars($data));
            $this->_stack[]['assign'] = $this->_htmlChars($data);
        }
        else
        {
            $this->_data[$data] = $this->_htmlChars($value);
            $this->_stack[]['assign'] = array($data => $this->_htmlChars($value));
        }

        if(!$this->tpl_php)
            $this->_normalise($this->_data);

        return $this;
    }

/**
* Sets the block in the template.
*
* @example $tpl->setBlock('content');
* @example render <!--// content -->...<!--// content end -->
*
* @access public
* @param string $block_name
* @return object
*/
    public function setBlock($block_name)
    {
        $block_tag  = $this->start_delim . $block_name . $this->end_delim;
        $this->_stack[]['setBlock'] = $block_name;
        $block = '';

        if(isset($this->_blocks[$block_tag]))
        {
            $block = $this->_execute($this->_blocks[$block_tag]);
            $block = $this->_parse($block);
        }
        else
            $this->_errors[$block_name] = true;

        @$this->_parsed[$block_tag] .= $block;
        return $this;
    }

/**
* Clears the contents of the block
*
* @example $tpl->clearBlock('row');
* @example clears the contents of the block "row"
*
* @access public
* @param string $block_name
* @return object
*/
    public function clearBlock($block_name)
    {
        $block_tag  = $this->start_delim . $block_name . $this->end_delim;
        $this->_stack[]['clearBlock'] = $block_name;

        if(isset($this->_blocks[$block_tag]))
            $this->_parsed[$block_tag] = '';
        else
            $this->_errors[$block_name] = true;

        return $this;
    }

/**
* Parse the template
* @access public
* @return string
*/
    public function parseTpl()
    {
        return $this->_parseTpl();
    }

/**
* Rendering the template
* @access public
* @return void
*/
    public function display()
    {
        if(empty($this->_total))
            $this->_total = $this->parseTpl();

        echo $this->_total;
    }

/**
* Extends the template
* @access public
* @param string $tpl
* @param string $block
* @return object
*/
    public function extendsTpl($tpl, $block)
    {
        $child = $this->_parseChild();
        $parent_tpl = new $this->_class($tpl, $block);
        $parent_tpl->assign($block, $child);

        foreach($this->_stack as $stack)
        {
            $method = key($stack);
            $parent_tpl->$method($stack[$method]);
        }

        $this->_total  = $parent_tpl->_parseChild();
        $this->_checkblock($this->_errors, $parent_tpl->_errors);
        return $this;
    }

/**
*   PROTECTED METHODS
*/

/**
* Parses the child template
* @access protected
* @return string
*/
    protected function _parseChild()
    {
        return $this->_parseTpl(false);
    }

/**
* Parses the template
* @access protected
* $param bolean $check
* @return string
*/
    protected function _parseTpl($check = true)
    {
        $this->_tpl   = $this->_parse($this->_tpl);
        $this->_tpl   = $this->_clear($this->_tpl);
        $this->_total = $this->_execute($this->_tpl);

        if($check)
            $this->_checkblock($this->_errors);

        return $this->_total;
    }

/**
* Collects in the array contents of all nested blocks
* @access protected
* $param string $block
* @return string
*/
    protected function _parse($block)
    {
        $block = $this->_replace($block);

        if(!empty($this->_parsed))
        {
            $tags = array_keys($this->_parsed);

            foreach($this->_parsed as $name => $cont)
            {
                foreach($tags as $tag)
                {
                    $this->_parsed[$name] = str_replace($tag,
                                                        $this->_parsed[$tag],
                                                        $this->_parsed[$name]
                                                        );
                }
            }

            $block = str_replace($tags, $this->_parsed, $block);
        }

        return $block;
    }

/**
* Executes php code in the template with the given parameters
* @access protected
* $param string $block
* @return string
*/
    protected function _execute($block = '')
    {
        if(!$this->tpl_php)
            return $this->_parsing($block);

        $block = $this->_includesPhp($block);
        $block = str_ireplace('<?xml', '<xml', $block);

        extract($this->_data);
        ob_start();
            eval('?>'.$block);
        $block = ob_get_clean();

        $block = stripslashes($block);
        $block = str_ireplace('<xml', '<?xml', $block);

        return $block;
    }

/**
* Replacing instruction "include" to contents of the include file
* @param string $block
* @access protected
* @return string
*/
    protected function _includesPhp($block)
    {
        $pattern = '~(<?[ph=][^\?>]*?)include[\s\'"]+(.*?)\..+?[\'"]+(;*)~uis';
        preg_match_all($pattern, $block, $include);

        if(!empty($include[2]))
        {
            foreach($include[2] as $file)
            {
                $md5   = md5($file);
                $cont  = $this->_includes($file, $md5);
                $block = preg_replace($pattern, '$1 echo "'. addslashes($cont) .'"$3', $block);
            }
        }

        return $block;
    }

/**
* Connection files in the template
* @param array $matсh
* @access protected
* @return string
*/
    protected function _includesPsd($match)
    {
        $md5  = md5($match[1]);
        $this->_data[$md5] = $this->_includes($match[1], $md5);

        return $this->left_delim . $md5 . $this->right_delim;
    }

/**
* Parse of external template
* @param string $file
* @param string $md5
* @access protected
* @return string
*/
    protected function _includes($file, $md5)
    {
        $inc = new $this->_class($file);

        if($this->debug)
        {
            $search = array($this->start_delim, $this->end_delim);
            $replace = array('');

            foreach($inc->_blocks as $tag => $val)
            {
                $bname = str_replace($search, $replace, $tag);
                unset($this->_errors[$bname]);
            }
        }

        foreach($this->_stack as $stack)
        {
            $method = key($stack);
            $inc->$method($stack[$method]);
        }

        return $inc->_parseChild();
    }

/**
* Replaces the pseudo variables to values
* @access protected
* $param string $block
* @return string
*/
    protected function _parsing($block = '')
    {
        $names  = array_keys($this->_data);
        $valyes = array_values($this->_data);

        $block  = preg_replace_callback('~'. preg_quote($this->left_delim, '~')
                                           .'FILE ([a-z0-9\._]+?)'
                                           . preg_quote($this->right_delim, '~')
                                           .'~uis',
                                           array($this, '_includesPsd'),
                                           $block);

        $tags   = preg_replace('~([a-z0-9\._]+)~uis',
                              $this->left_delim .'$1'. $this->right_delim,
                              $names
                              );

        $block = str_replace($tags, $valyes, $block);
        return  preg_replace('~<\?[^x].*?\?>~uis', '', $block);
    }

/**
* Processing variables for output stream
* @param array $data
* @access protected
* @return mix
*/
    protected function _htmlChars($data)
    {
        if(is_array($data))
            $data = array_map(array($this, '_htmlChars'), $data);
        else
            $data = htmlspecialchars($data);

        return $data;
    }

/**
* Normalization of names array
* @param array $data
* @access protected
* @return void
*/
    protected function _normalise($data, $html = false)
    {
        foreach($data as $name => $value)
        {
            if(is_array($value))
            {
                foreach($value as $key => $val)
                {
                    if($html)
                        $val = htmlspecialchars($val);

                    $names[$name .'.'. $key]  = $val;
                }
            }
            else
                $names[$name] = htmlspecialchars($value);
        }

        $this->_data = $names;
    }

/**
* Initialization of variables and sampling blocks
* @access protected
* @return void
*/
    protected function _initiate()
    {
        if($this->inialize && $this->tpl_php)
        {
            preg_match_all('~\$([a-z0-9_]+)~ui', $this->_tpl, $vars);

            if(!empty($vars[1]))
            {
                foreach($vars[1] as $var)
                {
                    $this->_data[$var] = '';
                }
            }
        }

        $this->_tpl = preg_replace('~(<!--//\s+[^#]+)#*.*?(\s+-->)~ui',
                                   '$1$2$3',
                                   $this->_tpl
                                   );

        preg_match_all('~<!--//\s+([^\s]+?)\s+-->~uis', $this->_tpl, $blocks);
        $this->_prepare($blocks[1]);
    }

/**
* Recursive extract the contents of nested blocks
* @access protected
* $param array $blocks
* @return void
*/
    protected function _prepare($blocks)
    {
        if(is_array($blocks))
        {
            foreach($blocks as $block_name)
            {
                preg_match('~<!--//\s*'. preg_quote($block_name, '~')
                          .'\s+-->+[\r\n]*(.*?)[\r\n]*<!--//\s*?'. preg_quote($block_name, '~')
                          .'\s+end\s+-->~uis',
                           $this->_tpl,
                           $blocks_array
                           );

                if(!empty($blocks_array[1]))
                {
                    preg_match_all('~<!--//\s+([^\s]+?)\s+-->~uis',
                                   $blocks_array[1],
                                   $blocks_recursion
                                   );

                    if(!empty($blocks_recursion[1]))
                    {
                        foreach($blocks_recursion[1] as $blocks)
                        {
                            $this->_prepare($blocks);
                        }
                    }

                    $tag = $this->start_delim . $block_name . $this->end_delim;
                    $this->_blocks[$tag] = $this->_replace($blocks_array[1]);
                }
            }
        }
    }

/**
* Replaces the block on the token
* @access protected
* $param string $tpl
* @return void
*/
    protected function _replace($tpl)
    {
        return preg_replace('~<!--//\s+([^\s]+?)\s+-->\n*.*?\\1\s+end\s*-->~uis',
                            $this->start_delim .'$1'. $this->end_delim,
                            $tpl
                            );
    }

/**
* Replaces the block on the token
* @access protected
* $param string $tpl
* @return void
*/
    protected function _clear($tpl)
    {
        return preg_replace('~'. preg_quote($this->start_delim, '~')
                               .'.*?'
                               . preg_quote($this->end_delim, '~')
                               .'~uis',
                            '',
                            $tpl
                            );
    }

/**
* Checks for the presence of blocks in the template
* @access protected
* $param array $error_blocks
* $param array/bollean $parent_blocks
* @return bolean/void
*/
    protected function _checkblock($error_blocks, $parent_blocks = false)
    {
        if(!$this->debug || empty($error_blocks))
            return false;

        if(is_array($parent_blocks))
            $error = array_intersect_key($error_blocks, $parent_blocks);
        else
            $error = $error_blocks;

        if(!empty($error))
        {
            foreach($error as $bname => $v)
            {
                $this->_debug('block ['. $bname .'] does not exist or incorrect syntax');
            }
        }
    }

/**
* Sets the way of displaying errors
* @access protected
* $param string $mess
* @return void
*/
    protected function _debug($mess)
    {
        if($this->debug)
        {
            $mess = '<strong>Template error:</strong> <br>'. $mess
                  . '<strong> in: </strong> '. $this->_path;

            if($this->exception === 'trigger_error')
            {
                trigger_error($mess, E_USER_WARNING);
            }
            elseif(!empty($this->exception))
            {
                throw new $this->exception($mess, E_USER_WARNING);
            }
            else
            {
                echo $this->_errhead ? '<div style="color:red; padding:5px; background:#FECBCC">'
                                       . 'Template error:</div>' : '';

                echo '<div style="color:black; padding:0 0 5px 5px; background:#FECBCC">'
                     . $mess
                     .'</div>';

                $this->_errhead = false;
            }
        }
    }
}