<?php
namespace W3TC;

class Cdn_Util {
	/**
	 * Check whether $engine is correct CDN engine
	 *
	 * @param string  $engine
	 * @return boolean
	 */
	static public function is_engine( $engine ) {
		return in_array( $engine, array(
				'akamai',
				'att',
				'azure',
				'cf',
				'cloudfront_fsd',
				'cf2',
				'cotendo',
				'edgecast',
				'maxcdn_fsd',
				'ftp',
				'google_drive',
				'highwinds',
				'maxcdn',
				'mirror',
				'netdna',
				'rscf',
				'rackspace_cdn',
				's3',
				's3_compatible',
			) );
	}

	/**
	 * Returns true if CDN engine is mirror
	 *
	 * @param string  $engine
	 * @return bool
	 */
	static public function is_engine_mirror( $engine ) {
		return in_array( $engine, array(
				'mirror', 'netdna', 'maxcdn', 'cotendo', 'cf2', 'akamai',
				'edgecast', 'att', 'highwinds', 'rackspace_cdn' ) );
	}

	/**
	 * Returns true if CDN engine is mirror
	 *
	 * @param string  $engine
	 * @return bool
	 */
	static public function is_engine_fsd( $engine ) {
		return in_array( $engine, array(
				'cloudfront_fsd',
				'maxcdn_fsd'
			) );
	}

	static public function is_engine_push( $engine ) {
		return !self::is_engine_mirror( $engine ) && !self::is_engine_fsd( $engine );
	}

	/**
	 * Returns true if CDN has purge all support
	 *
	 * @param unknown $engine
	 * @return bool
	 */
	static public function can_purge_all( $engine ) {
		return in_array( $engine, array(
				'att',
				'cotendo',
				'edgecast',
				'maxcdn_fsd',
				'highwinds',
				'maxcdn',
				'netdna',
			) );
	}

	/**
	 * Returns true if CDN engine is supporting purge
	 *
	 * @param string  $engine
	 * @return bool
	 */
	static public function can_purge( $engine ) {
		return in_array( $engine, array(
				'akamai',
				'att',
				'azure',
				'cf',
				'cf2',
				'cloudfront_fsd',
				'cotendo',
				'edgecast',
				'maxcdn_fsd',
				'ftp',
				'highwinds',
				'maxcdn',
				'netdna',
				'rscf',
				's3',
				's3_compatible',
			) );
	}

	/**
	 * Returns true if CDN supports realtime purge. That is purging on post changes, comments etc.
	 *
	 * @param unknown $engine
	 * @return bool
	 */
	static public function supports_realtime_purge( $engine ) {
		return !in_array( $engine, array( 'cf2' ) );
	}

	/**
	 * Search files
	 *
	 * @param string  $search_dir
	 * @param string  $base_dir
	 * @param string  $mask
	 * @param boolean $recursive
	 * @return array
	 */
	static function search_files( $search_dir, $base_dir, $mask = '*.*', $recursive = true ) {
		static $stack = array();
		$files = array();
		$ignore = array(
			'.svn',
			'.git',
			'.DS_Store',
			'CVS',
			'Thumbs.db',
			'desktop.ini'
		);

		$dir = @opendir( $search_dir );

		if ( $dir ) {
			while ( ( $entry = @readdir( $dir ) ) !== false ) {
				if ( $entry != '.' && $entry != '..' && !in_array( $entry, $ignore ) ) {
					$path = $search_dir . '/' . $entry;

					if ( @is_dir( $path ) && $recursive ) {
						array_push( $stack, $entry );
						$files = array_merge( $files, self::search_files(
								$path, $base_dir, $mask, $recursive ) );
						array_pop( $stack );
					} else {
						$regexp = '~^(' . self::get_regexp_by_mask( $mask ) . ')$~i';

						if ( preg_match( $regexp, $entry ) ) {
							$tmp = $base_dir != '' ? $base_dir . '/' : '';
							$tmp .= ( $p = implode( '/', $stack ) ) != '' ? $p . '/' : '';
							$files[] = $tmp . $entry;
						}
					}
				}
			}

			@closedir( $dir );
		}

		return $files;
	}

	/**
	 * Returns regexp by mask
	 *
	 * @param string  $mask
	 * @return string
	 */
	static function get_regexp_by_mask( $mask ) {
		$mask = trim( $mask );
		$mask = Util_Environment::preg_quote( $mask );

		$mask = str_replace( array(
				'\*',
				'\?',
				';'
			), array(
				'@ASTERISK@',
				'@QUESTION@',
				'|'
			), $mask );

		$regexp = str_replace( array(
				'@ASTERISK@',
				'@QUESTION@'
			), array(
				'[^\\?\\*:\\|\'"<>]*',
				'[^\\?\\*:\\|\'"<>]'
			), $mask );

		return $regexp;
	}

	static function replace_folder_placeholders( $file ) {
		static $content_dir, $plugin_dir, $upload_dir;
		if ( empty( $content_dir ) ) {
			$content_dir = str_replace( Util_Environment::document_root(), '', WP_CONTENT_DIR );
			$content_dir = substr( $content_dir, strlen( Util_Environment::site_url_uri() ) );
			$content_dir = trim( $content_dir, '/' );
			if ( defined( 'WP_PLUGIN_DIR' ) ) {
				$plugin_dir = str_replace( Util_Environment::document_root(), '', WP_PLUGIN_DIR );
				$plugin_dir = trim( $plugin_dir, '/' );
			} else {
				$plugin_dir = str_replace( Util_Environment::document_root(), '', WP_CONTENT_DIR . '/plugins' );
				$plugin_dir = trim( $plugin_dir, '/' );
			}
			$upload_dir = Util_Environment::wp_upload_dir();
			$upload_dir = str_replace( Util_Environment::document_root(), '', $upload_dir['basedir'] );
			$upload_dir = trim( $upload_dir, '/' );
		}
		$file = str_replace( '{wp_content_dir}', $content_dir, $file );
		$file = str_replace( '{plugins_dir}', $plugin_dir, $file );
		$file = str_replace( '{uploads_dir}', $upload_dir, $file );

		return $file;
	}
}