<?php

/**
 * Environment
 *
 * @package Less
 * @subpackage environment
 */
class Less_Environment {

	// public $paths = array();              // option - unmodified - paths to search for imports on
	//public static $files = array();		// list of files that have been imported, used for import-once
	//public $rootpath;						// option - rootpath to append to URL's
	//public static $strictImports = null;	// option -
	//public $insecure;						// option - whether to allow imports from insecure ssl hosts
	//public $processImports;				// option - whether to process imports. if false then imports will not be imported
	//public $javascriptEnabled;			// option - whether JavaScript is enabled. if undefined, defaults to true
	//public $useFileCache;					// browser only - whether to use the per file session cache
	public $currentFileInfo;				// information about the current file - for error reporting and importing and making urls relative etc.

	public $importMultiple = false; 		// whether we are currently importing multiple copies

	/**
	 * @var array
	 */
	public $frames = array();

	/**
	 * @var array
	 */
	public $mediaBlocks = array();

	/**
	 * @var array
	 */
	public $mediaPath = array();

	public static $parensStack = 0;

	public static $tabLevel = 0;

	public static $lastRule = false;

	public static $_outputMap;

	public static $mixin_stack = 0;

	/**
	 * @var array
	 */
	public $functions = array();

	public function Init() {
		self::$parensStack = 0;
		self::$tabLevel = 0;
		self::$lastRule = false;
		self::$mixin_stack = 0;

		if ( Less_Parser::$options['compress'] ) {

			Less_Environment::$_outputMap = array(
				','	=> ',',
				': ' => ':',
				''  => '',
				' ' => ' ',
				':' => ' :',
				'+' => '+',
				'~' => '~',
				'>' => '>',
				'|' => '|',
				'^' => '^',
				'^^' => '^^'
			);

		} else {

			Less_Environment::$_outputMap = array(
				','	=> ', ',
				': ' => ': ',
				''  => '',
				' ' => ' ',
				':' => ' :',
				'+' => ' + ',
				'~' => ' ~ ',
				'>' => ' > ',
				'|' => '|',
				'^' => ' ^ ',
				'^^' => ' ^^ '
			);

		}
	}

	public function copyEvalEnv( $frames = array() ) {
		$new_env = new Less_Environment();
		$new_env->frames = $frames;
		return $new_env;
	}

	public static function isMathOn() {
		return !Less_Parser::$options['strictMath'] || Less_Environment::$parensStack;
	}

	public static function isPathRelative( $path ) {
		return !preg_match( '/^(?:[a-z-]+:|\/)/', $path );
	}

	/**
	 * Canonicalize a path by resolving references to '/./', '/../'
	 * Does not remove leading "../"
	 * @param string path or url
	 * @return string Canonicalized path
	 *
	 */
	public static function normalizePath( $path ) {
		$segments = explode( '/', $path );
		$segments = array_reverse( $segments );

		$path = array();
		$path_len = 0;

		while ( $segments ) {
			$segment = array_pop( $segments );
			switch ( $segment ) {

				case '.':
				break;

				case '..':
					if ( !$path_len || ( $path[$path_len - 1] === '..' ) ) {
						$path[] = $segment;
						$path_len++;
					} else {
						array_pop( $path );
						$path_len--;
					}
				break;

				default:
					$path[] = $segment;
					$path_len++;
				break;
			}
		}

		return implode( '/', $path );
	}

	public function unshiftFrame( $frame ) {
		array_unshift( $this->frames, $frame );
	}

	public function shiftFrame() {
		return array_shift( $this->frames );
	}

}