<?php

/**
 * Expression
 *
 * @package Less
 * @subpackage tree
 */
class Less_Tree_Expression extends Less_Tree{

	public $value = array();
	public $parens = false;
	public $parensInOp = false;
	public $type = 'Expression';

	public function __construct( $value, $parens = null ){
		$this->value = $value;
		$this->parens = $parens;
	}

	function accept( $visitor ){
		$this->value = $visitor->visitArray( $this->value );
	}

	public function compile($env) {

		$doubleParen = false;

		if( $this->parens && !$this->parensInOp ){
			Less_Environment::$parensStack++;
		}

		$returnValue = null;
		if( $this->value ){

			$count = count($this->value);

			if( $count > 1 ){

				$ret = array();
				foreach($this->value as $e){
					$ret[] = $e->compile($env);
				}
				$returnValue = new Less_Tree_Expression($ret);

			}else{

				if( ($this->value[0] instanceof Less_Tree_Expression) && $this->value[0]->parens && !$this->value[0]->parensInOp ){
					$doubleParen = true;
				}

				$returnValue = $this->value[0]->compile($env);
			}

		} else {
			$returnValue = $this;
		}

		if( $this->parens ){
			if( !$this->parensInOp ){
				Less_Environment::$parensStack--;

			}elseif( !Less_Environment::isMathOn() && !$doubleParen ){
				$returnValue = new Less_Tree_Paren($returnValue);

			}
		}
		return $returnValue;
	}

    /**
     * @see Less_Tree::genCSS
     */
	function genCSS( $output ){
		$val_len = count($this->value);
		for( $i = 0; $i < $val_len; $i++ ){
			$this->value[$i]->genCSS( $output );
			if( $i + 1 < $val_len ){
				$output->add( ' ' );
			}
		}
	}

	function throwAwayComments() {

		if( is_array($this->value) ){
			$new_value = array();
			foreach($this->value as $v){
				if( $v instanceof Less_Tree_Comment ){
					continue;
				}
				$new_value[] = $v;
			}
			$this->value = $new_value;
		}
	}
}
