<?php
/**
 * modified PHP implementation of Matthias Mullie's convert path class
 * Convert paths relative from 1 file to another.
 *
 * E.g.
 *     ../../images/icon.jpg relative to /css/imports/icons.css
 * becomes
 *     ../images/icon.jpg relative to /css/minified.css
 *
 * @author Matthias Mullie <pathconverter@mullie.eu>
 * @copyright Copyright (c) 2015, Matthias Mullie. All rights reserved
 * @license MIT License
 */

namespace LiteSpeed\Lib\CSS_JS_MIN\PathConverter;

defined( 'WPINC' ) || exit;

interface ConverterInterface {

	/**
	 * Convert file paths.
	 *
	 * @param string $path The path to be converted
	 *
	 * @return string The new path
	 */
	public function convert( $path );
}

class Converter implements ConverterInterface {

	/**
	 * @var string
	 */
	protected $from;

	/**
	 * @var string
	 */
	protected $to;

	/**
	 * @param string $from The original base path (directory, not file!)
	 * @param string $to   The new base path (directory, not file!)
	 * @param string $root Root directory (defaults to `getcwd`)
	 */
	public function __construct( $from, $to, $root = '' ) {
		$shared = $this->shared( $from, $to );
		if ( $shared === '' ) {
			// when both paths have nothing in common, one of them is probably
			// absolute while the other is relative
			$root = $root ?: getcwd();
			$from = strpos( $from, $root ) === 0 ? $from : preg_replace( '/\/+/', '/', $root . '/' . $from );
			$to   = strpos( $to, $root ) === 0 ? $to : preg_replace( '/\/+/', '/', $root . '/' . $to );

			// or traveling the tree via `..`
			// attempt to resolve path, or assume it's fine if it doesn't exist
			$from = @realpath( $from ) ?: $from;
			$to   = @realpath( $to ) ?: $to;
		}

		$from = $this->dirname( $from );
		$to   = $this->dirname( $to );

		$from = $this->normalize( $from );
		$to   = $this->normalize( $to );

		$this->from = $from;
		$this->to   = $to;
	}

	/**
	 * Normalize path.
	 *
	 * @param string $path
	 *
	 * @return string
	 */
	protected function normalize( $path ) {
		// deal with different operating systems' directory structure
		$path = rtrim( str_replace( DIRECTORY_SEPARATOR, '/', $path ), '/' );

		// remove leading current directory.
		if ( substr( $path, 0, 2 ) === './' ) {
			$path = substr( $path, 2 );
		}

		// remove references to current directory in the path.
		$path = str_replace( '/./', '/', $path );

		/*
		 * Example:
		 *     /home/forkcms/frontend/cache/compiled_templates/../../core/layout/css/../images/img.gif
		 * to
		 *     /home/forkcms/frontend/core/layout/images/img.gif
		 */
		do {
			$path = preg_replace( '/[^\/]+(?<!\.\.)\/\.\.\//', '', $path, -1, $count );
		} while ( $count );

		return $path;
	}

	/**
	 * Figure out the shared path of 2 locations.
	 *
	 * Example:
	 *     /home/forkcms/frontend/core/layout/images/img.gif
	 * and
	 *     /home/forkcms/frontend/cache/minified_css
	 * share
	 *     /home/forkcms/frontend
	 *
	 * @param string $path1
	 * @param string $path2
	 *
	 * @return string
	 */
	protected function shared( $path1, $path2 ) {
		// $path could theoretically be empty (e.g. no path is given), in which
		// case it shouldn't expand to array(''), which would compare to one's
		// root /
		$path1 = $path1 ? explode( '/', $path1 ) : array();
		$path2 = $path2 ? explode( '/', $path2 ) : array();

		$shared = array();

		// compare paths & strip identical ancestors
		foreach ( $path1 as $i => $chunk ) {
			if ( isset( $path2[ $i ] ) && $path1[ $i ] == $path2[ $i ] ) {
				$shared[] = $chunk;
			} else {
				break;
			}
		}

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

	/**
	 * Convert paths relative from 1 file to another.
	 *
	 * E.g.
	 *     ../images/img.gif relative to /home/forkcms/frontend/core/layout/css
	 * should become:
	 *     ../../core/layout/images/img.gif relative to
	 *     /home/forkcms/frontend/cache/minified_css
	 *
	 * @param string $path The relative path that needs to be converted
	 *
	 * @return string The new relative path
	 */
	public function convert( $path ) {
		// quit early if conversion makes no sense
		if ( $this->from === $this->to ) {
			return $path;
		}

		$path = $this->normalize( $path );
		// if we're not dealing with a relative path, just return absolute
		if ( strpos( $path, '/' ) === 0 ) {
			return $path;
		}

		// normalize paths
		$path = $this->normalize( $this->from . '/' . $path );

		// strip shared ancestor paths
		$shared = $this->shared( $path, $this->to );
		$path   = mb_substr( $path, mb_strlen( $shared ) );
		$to     = mb_substr( $this->to, mb_strlen( $shared ) );

		// add .. for every directory that needs to be traversed to new path
		$to = str_repeat( '../', count( array_filter( explode( '/', $to ) ) ) );

		return $to . ltrim( $path, '/' );
	}

	/**
	 * Attempt to get the directory name from a path.
	 *
	 * @param string $path
	 *
	 * @return string
	 */
	protected function dirname( $path ) {
		if ( @is_file( $path ) ) {
			return dirname( $path );
		}

		if ( @is_dir( $path ) ) {
			return rtrim( $path, '/' );
		}

		// no known file/dir, start making assumptions

		// ends in / = dir
		if ( mb_substr( $path, -1 ) === '/' ) {
			return rtrim( $path, '/' );
		}

		// has a dot in the name, likely a file
		if ( preg_match( '/.*\..*$/', basename( $path ) ) !== 0 ) {
			return dirname( $path );
		}

		// you're on your own here!
		return $path;
	}
}

class NoConverter implements ConverterInterface {

	/**
	 * {@inheritdoc}
	 */
	public function convert( $path ) {
		return $path;
	}
}
