<?php

/**

 * WP_Theme Class

 *

 * @package WordPress

 * @subpackage Theme

 */

final class WP_Theme implements ArrayAccess {

	/**

	 * Headers for style.css files.

	 *

	 * @static

	 * @access private

	 * @var array

	 */

	private static $file_headers = array(

		'Name'        => 'Theme Name',

		'ThemeURI'    => 'Theme URI',

		'Description' => 'Description',

		'Author'      => 'Author',

		'AuthorURI'   => 'Author URI',

		'Version'     => 'Version',

		'Template'    => 'Template',

		'Status'      => 'Status',

		'Tags'        => 'Tags',

		'TextDomain'  => 'Text Domain',

		'DomainPath'  => 'Domain Path',

	);

	/**

	 * Default themes.

	 *

	 * @static

	 * @access private

	 * @var array

	 */

	private static $default_themes = array(

		'classic'      => 'WordPress Classic',

		'default'      => 'WordPress Default',

		'twentyten'    => 'Twenty Ten',

		'twentyeleven' => 'Twenty Eleven',

		'twentytwelve' => 'Twenty Twelve',

	);

	/**

	 * Absolute path to the theme root, usually wp-content/themes

	 *

	 * @access private

	 * @var string

	 */

	private $theme_root;

	/**

	 * Header data from the theme's style.css file.

	 *

	 * @access private

	 * @var array

	 */

	private $headers = array();

	/**

	 * Header data from the theme's style.css file after being sanitized.

	 *

	 * @access private

	 * @var array

	 */

	private $headers_sanitized;

	/**

	 * Header name from the theme's style.css after being translated.

	 *

	 * Cached due to sorting functions running over the translated name.

	 */

	private $name_translated;

	/**

	 * Errors encountered when initializing the theme.

	 *

	 * @access private

	 * @var WP_Error

	 */

	private $errors;

	/**

	 * The directory name of the theme's files, inside the theme root.

	 *

	 * In the case of a child theme, this is directory name of the the child theme.

	 * Otherwise, 'stylesheet' is the same as 'template'.

	 *

	 * @access private

	 * @var string

	 */

	private $stylesheet;

	/**

	 * The directory name of the theme's files, inside the theme root.

	 *

	 * In the case of a child theme, this is the directory name of the parent theme.

	 * Otherwise, 'template' is the same as 'stylesheet'.

	 *

	 * @access private

	 * @var string

	 */

	private $template;

	/**

	 * A reference to the parent theme, in the case of a child theme.

	 *

	 * @access private

	 * @var WP_Theme

	 */

	private $parent;

	/**

	 * URL to the theme root, usually an absolute URL to wp-content/themes

	 *

	 * @access private

	 * var string

	 */

	private $theme_root_uri;

	/**

	 * Flag for whether the theme's textdomain is loaded.

	 *

	 * @access private

	 * @var bool

	 */

	private $textdomain_loaded;

	/**

	 * Stores an md5 hash of the theme root, to function as the cache key.

	 *

	 * @access private

	 * @var string

	 */

	private $cache_hash;

	/**

	 * Flag for whether the themes cache bucket should be persistently cached.

	 *

	 * Default is false. Can be set with the wp_cache_themes_persistently filter.

	 *

	 * @access private

	 * @var bool

	 */

	private static $persistently_cache;

	/**

	 * Expiration time for the themes cache bucket.

	 *

	 * By default the bucket is not cached, so this value is useless.

	 *

	 * @access private

	 * @var bool

	 */

	private static $cache_expiration = 1800;

	/**

	 * Constructor for WP_Theme.

	 *

	 * @param string $theme_dir Directory of the theme within the theme_root.

	 * @param string $theme_root Theme root.

	 * @param WP_Error|null $_child If this theme is a parent theme, the child may be passed for validation purposes.

	 */

	public function __construct( $theme_dir, $theme_root, $_child = null ) {

		global $wp_theme_directories;

		// Initialize caching on first run.

		if ( ! isset( self::$persistently_cache ) ) {

			self::$persistently_cache = apply_filters( 'wp_cache_themes_persistently', false, 'WP_Theme' );

			if ( self::$persistently_cache ) {

				wp_cache_add_global_groups( 'themes' );

				if ( is_int( self::$persistently_cache ) )

					self::$cache_expiration = self::$persistently_cache;

			} else {

				wp_cache_add_non_persistent_groups( 'themes' );

			}

		}

		$this->theme_root = $theme_root;

		$this->stylesheet = $theme_dir;

		// Correct a situation where the theme is 'some-directory/some-theme' but 'some-directory' was passed in as part of the theme root instead.

		if ( ! in_array( $theme_root, (array) $wp_theme_directories ) && in_array( dirname( $theme_root ), (array) $wp_theme_directories ) ) {

			$this->stylesheet = basename( $this->theme_root ) . '/' . $this->stylesheet;

			$this->theme_root = dirname( $theme_root );

		}

		$this->cache_hash = md5( $this->theme_root . '/' . $this->stylesheet );

		$theme_file = $this->stylesheet . '/style.css';

		$cache = $this->cache_get( 'theme' );

		if ( is_array( $cache ) ) {

			foreach ( array( 'errors', 'headers', 'template' ) as $key ) {

				if ( isset( $cache[ $key ] ) )

					$this->$key = $cache[ $key ];

			}

			if ( $this->errors )

				return;

			if ( isset( $cache['theme_root_template'] ) )

				$theme_root_template = $cache['theme_root_template'];

		} elseif ( ! file_exists( $this->theme_root . '/' . $theme_file ) ) {

			$this->headers['Name'] = $this->stylesheet;

			if ( ! file_exists( $this->theme_root . '/' . $this->stylesheet ) )

				$this->errors = new WP_Error( 'theme_not_found', __( 'The theme directory does not exist.' ) );

			else

				$this->errors = new WP_Error( 'theme_no_stylesheet', __( 'Stylesheet is missing.' ) );

			$this->template = $this->stylesheet;

			$this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) );

			if ( ! file_exists( $this->theme_root ) ) // Don't cache this one.

				$this->errors->add( 'theme_root_missing', __( 'ERROR: The themes directory is either empty or doesn’t exist. Please check your installation.' ) );

			return;

		} elseif ( ! is_readable( $this->theme_root . '/' . $theme_file ) ) {

			$this->headers['Name'] = $this->stylesheet;

			$this->errors = new WP_Error( 'theme_stylesheet_not_readable', __( 'Stylesheet is not readable.' ) );

			$this->template = $this->stylesheet;

			$this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) );

			return;

		} else {

			$this->headers = get_file_data( $this->theme_root . '/' . $theme_file, self::$file_headers, 'theme' );

			// Default themes always trump their pretenders.

			// Properly identify default themes that are inside a directory within wp-content/themes.

			if ( $default_theme_slug = array_search( $this->headers['Name'], self::$default_themes ) ) {

				if ( basename( $this->stylesheet ) != $default_theme_slug )

					$this->headers['Name'] .= '/' . $this->stylesheet;

			}

		}

		// (If template is set from cache [and there are no errors], we know it's good.)

		if ( ! $this->template && ! ( $this->template = $this->headers['Template'] ) ) {

			$this->template = $this->stylesheet;

			if ( ! file_exists( $this->theme_root . '/' . $this->stylesheet . '/index.php' ) ) {

				$this->errors = new WP_Error( 'theme_no_index', __( 'Template is missing.' ) );

				$this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) );

				return;

			}

		}

		// If we got our data from cache, we can assume that 'template' is pointing to the right place.

		if ( ! is_array( $cache ) && $this->template != $this->stylesheet && ! file_exists( $this->theme_root . '/' . $this->template . '/index.php' ) ) {

			// If we're in a directory of themes inside /themes, look for the parent nearby.

			// wp-content/themes/directory-of-themes/*

			$parent_dir = dirname( $this->stylesheet );

			if ( '.' != $parent_dir && file_exists( $this->theme_root . '/' . $parent_dir . '/' . $this->template . '/index.php' ) ) {

				$this->template = $parent_dir . '/' . $this->template;

			} elseif ( ( $directories = search_theme_directories() ) && isset( $directories[ $this->template ] ) ) {

				// Look for the template in the search_theme_directories() results, in case it is in another theme root.

				// We don't look into directories of themes, just the theme root.

				$theme_root_template = $directories[ $this->template ]['theme_root'];

			} else {

				// Parent theme is missing.

				$this->errors = new WP_Error( 'theme_no_parent', sprintf( __( 'The parent theme is missing. Please install the "%s" parent theme.' ), $this->template ) );

				$this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) );

				$this->parent = new WP_Theme( $this->template, $this->theme_root, $this );

				return;

			}

		}

		// Set the parent, if we're a child theme.

		if ( $this->template != $this->stylesheet ) {

			// If we are a parent, then there is a problem. Only two generations allowed! Cancel things out.

			if ( is_a( $_child, 'WP_Theme' ) && $_child->template == $this->stylesheet ) {

				$_child->parent = null;

				$_child->errors = new WP_Error( 'theme_parent_invalid', sprintf( __( 'The "%s" theme is not a valid parent theme.' ), $_child->template ) );

				$_child->cache_add( 'theme', array( 'headers' => $_child->headers, 'errors' => $_child->errors, 'stylesheet' => $_child->stylesheet, 'template' => $_child->template ) );

				// The two themes actually reference each other with the Template header.

				if ( $_child->stylesheet == $this->template ) {

					$this->errors = new WP_Error( 'theme_parent_invalid', sprintf( __( 'The "%s" theme is not a valid parent theme.' ), $this->template ) );

					$this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) );

				}

				return;

			}

			// Set the parent. Pass the current instance so we can do the crazy checks above and assess errors.

			$this->parent = new WP_Theme( $this->template, isset( $theme_root_template ) ? $theme_root_template : $this->theme_root, $this );

		}

		// We're good. If we didn't retrieve from cache, set it.

		if ( ! is_array( $cache ) ) {

			$cache = array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template );

			// If the parent theme is in another root, we'll want to cache this. Avoids an entire branch of filesystem calls above.

			if ( isset( $theme_root_template ) )

				$cache['theme_root_template'] = $theme_root_template;

			$this->cache_add( 'theme', $cache );

		}

	}

	/**

	 * When converting the object to a string, the theme name is returned.

	 *

	 * @return string Theme name, ready for display (translated)

	 */

	public function __toString() {

		return (string) $this->display('Name');

	}

	/**

	 * __isset() magic method for properties formerly returned by current_theme_info()

	 */

	public function __isset( $offset ) {

		static $properties = array(

			'name', 'title', 'version', 'parent_theme', 'template_dir', 'stylesheet_dir', 'template', 'stylesheet',

			'screenshot', 'description', 'author', 'tags', 'theme_root', 'theme_root_uri',

		);

		return in_array( $offset, $properties );

	}

	/**

	 * __get() magic method for properties formerly returned by current_theme_info()

	 */

	public function __get( $offset ) {

		switch ( $offset ) {

			case 'name' :

			case 'title' :

				return $this->get('Name');

			case 'version' :

				return $this->get('Version');

			case 'parent_theme' :

				return $this->parent() ? $this->parent()->get('Name') : '';

			case 'template_dir' :

				return $this->get_template_directory();

			case 'stylesheet_dir' :

				return $this->get_stylesheet_directory();

			case 'template' :

				return $this->get_template();

			case 'stylesheet' :

				return $this->get_stylesheet();

			case 'screenshot' :

				return $this->get_screenshot( 'relative' );

			// 'author' and 'description' did not previously return translated data.

			case 'description' :

				return $this->display('Description');

			case 'author' :

				return $this->display('Author');

			case 'tags' :

				return $this->get( 'Tags' );

			case 'theme_root' :

				return $this->get_theme_root();

			case 'theme_root_uri' :

				return $this->get_theme_root_uri();

			// For cases where the array was converted to an object.

			default :

				return $this->offsetGet( $offset );

		}

	}

	/**

	 * Method to implement ArrayAccess for keys formerly returned by get_themes()

	 */

	public function offsetSet( $offset, $value ) {}

	/**

	 * Method to implement ArrayAccess for keys formerly returned by get_themes()

	 */

	public function offsetUnset( $offset ) {}

	/**

	 * Method to implement ArrayAccess for keys formerly returned by get_themes()

	 */

	public function offsetExists( $offset ) {

		static $keys = array(

			'Name', 'Version', 'Status', 'Title', 'Author', 'Author Name', 'Author URI', 'Description',

			'Template', 'Stylesheet', 'Template Files', 'Stylesheet Files', 'Template Dir', 'Stylesheet Dir',

			 'Screenshot', 'Tags', 'Theme Root', 'Theme Root URI', 'Parent Theme',

		);

		return in_array( $offset, $keys );

	}

	/**

	 * Method to implement ArrayAccess for keys formerly returned by get_themes().

	 *

	 * Author, Author Name, Author URI, and Description did not previously return

	 * translated data. We are doing so now as it is safe to do. However, as

	 * Name and Title could have been used as the key for get_themes(), both remain

	 * untranslated for back compatibility. This means that ['Name'] is not ideal,

	 * and care should be taken to use $theme->display('Name') to get a properly

	 * translated header.

	 */

	public function offsetGet( $offset ) {

		switch ( $offset ) {

			case 'Name' :

			case 'Title' :

				// See note above about using translated data. get() is not ideal.

				// It is only for backwards compatibility. Use display().

				return $this->get('Name');

			case 'Author' :

				return $this->display( 'Author');

			case 'Author Name' :

				return $this->display( 'Author', false);

			case 'Author URI' :

				return $this->display('AuthorURI');

			case 'Description' :

				return $this->display( 'Description');

			case 'Version' :

			case 'Status' :

				return $this->get( $offset );

			case 'Template' :

				return $this->get_template();

			case 'Stylesheet' :

				return $this->get_stylesheet();

			case 'Template Files' :

				return $this->get_files( 'php', 1, true );

			case 'Stylesheet Files' :

				return $this->get_files( 'css', 0, false );

			case 'Template Dir' :

				return $this->get_template_directory();