<?php

/**
 * Tree
 *
 * @package Less
 * @subpackage tree
 */
class Less_Tree {

	public $cache_string;

	public function toCSS() {
		$output = new Less_Output();
		$this->genCSS( $output );
		return $output->toString();
	}


	/**
	 * Generate CSS by adding it to the output object
	 *
	 * @param Less_Output $output The output
	 * @return void
	 */
	public function genCSS( $output ) {}


	/**
	 * @param Less_Tree_Ruleset[] $rules
	 */
	public static function outputRuleset( $output, $rules ) {

		$ruleCnt = count( $rules );
		Less_Environment::$tabLevel++;

		// Compressed
		if ( Less_Parser::$options['compress'] ) {
			$output->add( '{' );
			for ( $i = 0; $i < $ruleCnt; $i++ ) {
				$rules[ $i ]->genCSS( $output );
			}

			$output->add( '}' );
			Less_Environment::$tabLevel--;
			return;
		}

		// Non-compressed
		$tabSetStr  = "\n" . str_repeat( Less_Parser::$options['indentation'], Less_Environment::$tabLevel - 1 );
		$tabRuleStr = $tabSetStr . Less_Parser::$options['indentation'];

		$output->add( ' {' );
		for ( $i = 0; $i < $ruleCnt; $i++ ) {
			$output->add( $tabRuleStr );
			$rules[ $i ]->genCSS( $output );
		}
		Less_Environment::$tabLevel--;
		$output->add( $tabSetStr . '}' );

	}

	public function accept( $visitor ) {}


	public static function ReferencedArray( $rules ) {
		foreach ( $rules as $rule ) {
			if ( method_exists( $rule, 'markReferenced' ) ) {
				$rule->markReferenced();
			}
		}
	}


	/**
	 * Requires php 5.3+
	 */
	public static function __set_state( $args ) {

		$class = get_called_class();
		$obj   = new $class( null, null, null, null );
		foreach ( $args as $key => $val ) {
			$obj->$key = $val;
		}
		return $obj;
	}

}
