<?php

/**
 * Operation
 *
 * @package Less
 * @subpackage tree
 */
class Less_Tree_Operation extends Less_Tree {

	public $op;
	public $operands;
	public $isSpaced;
	public $type = 'Operation';

	/**
	 * @param string $op
	 */
	public function __construct( $op, $operands, $isSpaced = false ) {
		$this->op = trim( $op );
		$this->operands = $operands;
		$this->isSpaced = $isSpaced;
	}

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

	public function compile( $env ) {
		$a = $this->operands[0]->compile( $env );
		$b = $this->operands[1]->compile( $env );

		if ( Less_Environment::isMathOn() ) {

			if ( $a instanceof Less_Tree_Dimension && $b instanceof Less_Tree_Color ) {
				$a = $a->toColor();

			} elseif ( $b instanceof Less_Tree_Dimension && $a instanceof Less_Tree_Color ) {
				$b = $b->toColor();

			}

			if ( !method_exists( $a, 'operate' ) ) {
				throw new Less_Exception_Compiler( "Operation on an invalid type" );
			}

			return $a->operate( $this->op, $b );
		}

		return new Less_Tree_Operation( $this->op, array( $a, $b ), $this->isSpaced );
	}

	/**
	 * @see Less_Tree::genCSS
	 */
	public function genCSS( $output ) {
		$this->operands[0]->genCSS( $output );
		if ( $this->isSpaced ) {
			$output->add( " " );
		}
		$output->add( $this->op );
		if ( $this->isSpaced ) {
			$output->add( ' ' );
		}
		$this->operands[1]->genCSS( $output );
	}

}