<?php
/**
 * WordPress Administration Screen API.
 *
 * @package WordPress
 * @subpackage Administration
 */

/**
 * Get the column headers for a screen
 *
 * @since 2.7.0
 *
 * @param string|object $screen The screen you want the headers for
 * @return array Containing the headers in the format id => UI String
 */
function get_column_headers( $screen ) { // TODO: fold into WP_Screen?
	if ( is_string( $screen ) )
		$screen = convert_to_screen( $screen );

	global $_wp_column_headers;

	if ( !isset( $_wp_column_headers[ $screen->id ] ) ) {
		$_wp_column_headers[ $screen->id ] = apply_filters( 'manage_' . $screen->id . '_columns', array() );
	}

	return $_wp_column_headers[ $screen->id ];
}

/**
 * Get a list of hidden columns.
 *
 * @since 2.7.0
 *
 * @param string|object $screen The screen you want the hidden columns for
 * @return array
 */
function get_hidden_columns( $screen ) { // TODO: fold into WP_Screen
	if ( is_string( $screen ) )
		$screen = convert_to_screen( $screen );

	return (array) get_user_option( 'manage' . $screen->id . 'columnshidden' );
}

/**
 * Get Hidden Meta Boxes
 *
 * @since 2.7.0
 *
 * @param string|object $screen Screen identifier
 * @return array Hidden Meta Boxes
 */
function get_hidden_meta_boxes( $screen ) { // TODO: fold into WP_Screen
	if ( is_string( $screen ) )
		$screen = convert_to_screen( $screen );

	$hidden = get_user_option( "metaboxhidden_{$screen->id}" );

	// Hide slug boxes by default
	if ( !is_array( $hidden ) ) {
		if ( 'post' == $screen->base || 'page' == $screen->base )
			$hidden = array('slugdiv', 'trackbacksdiv', 'postcustom', 'postexcerpt', 'commentstatusdiv', 'commentsdiv', 'authordiv', 'revisionsdiv');
		else
			$hidden = array( 'slugdiv' );

		$hidden = apply_filters('default_hidden_meta_boxes', $hidden, $screen);
	}

	return $hidden;
}

/**
 * Convert a screen string to a screen object
 *
 * @since 3.0.0
 *
 * @param string $screen The name of the screen
 * @return object An object containing the safe screen name and id
 */
function convert_to_screen( $screen ) { // TODO: fold into WP_Screen?
	$screen = str_replace( array('.php', '-new', '-add', '-network', '-user' ), '', $screen);

	if ( is_network_admin() )
		$screen .= '-network';
	elseif ( is_user_admin() )
		$screen .= '-user';

	// why do we need this? $screen = (string) apply_filters( 'screen_meta_screen', $screen );
	$screen = (object) array('id' => $screen, 'base' => $screen);
	return $screen;
}

function screen_icon( $for = '' ) { // TODO: fold into WP_Screen?
	global $current_screen;

	if ( !isset($current_screen) )
		return;

	echo $current_screen->get_screen_icon( $for );
}

/**
 *  Get the current screen object
 *
 *  @since 3.1.0
 *
 * @return object Current screen object
 */
function get_current_screen() {
	global $current_screen;

	if ( !isset($current_screen) )
		return null;

	return $current_screen;
}

/**
 * Set the current screen object
 *
 * @since 3.0.0
 *
 * @uses $current_screen
 *
 * @param string $id Screen id, optional.
 */
function set_current_screen( $id = '' ) {
	global $current_screen;

	if ( !is_a( $current_screen, 'WP_Screen' ) )
		$current_screen = new WP_Screen( $id );

	// why do we need this? $current_screen = apply_filters('current_screen', $current_screen);
}

/**
 * A class representing the current admin screen.
 *
 * @since 3.3.0
 * @access public
 */
final class WP_Screen {
	/**
	 * Any action associated with the screen.  'add' for *-add.php and *-new.php screens.  Empty otherwise.
	 *
	 * @since 3.3.0
	 * @var string
	 * @access public
	 */
	public $action = '';

	/**
	 * The base type of the screen.  This is typically the same as $id but with any post types and taxonomies stripped.
	 * For example, for an $id of 'edit-post' the base is 'edit'.
	 *
	 * @since 3.3.0
	 * @var string
	 * @access public
	 */
	public $base;

	/**
	 * The unique ID of the screen.
	 *
	 * @since 3.3.0
	 * @var string
	 * @access public
	 */
	public $id;

	/**
	 * Whether the screen is in the network admin.
	 *
	 * @since 3.3.0
	 * @var bool
	 * @access public
	 */
	public $is_network;

	/**
	 * Whether the screen is in the user admin.
	 *
	 * @since 3.3.0
	 * @var bool
	 * @access public
	 */
	public $is_user;

	/**
	 * The base menu parent.
	 * This is derived from $parent_file by removing the query string and any .php extension.
	 * $parent_file values of 'edit.php?post_type=page' and 'edit.php?post_type=post' have a $parent_base of 'edit'.
	 *
	 * @since 3.3.0
	 * @var string
	 * @access public
	 */
	public $parent_base;

	/**
	 * The parent_file for the screen per the admin menu system.
	 * Some $parent_file values are 'edit.php?post_type=page', 'edit.php', and 'options-general.php'.
	 *
	 * @since 3.3.0
	 * @var string
	 * @access public
	 */
	public $parent_file;

	/**
	 * The post type associated with the screen, if any.
	 * The 'edit.php?post_type=page' screen has a post type of 'page'.
	 *
	 * @since 3.3.0
	 * @var string
	 * @access public
	 */
	public $post_type;

	/**
	 * The taxonomy associated with the screen, if any.
	 * The 'edit-tags.php?taxonomy=category' screen has a taxonomy of 'category'.
	 * @since 3.3.0
	 * @var string
	 * @access public
	 */
	public $taxonomy;

	/**
	 * The help tab data associated with the screen, if any.
	 *
	 * @since 3.3.0
	 * @var array
	 * @access private
	 */
	private $_help_tabs = array();

	/**
	 * The help sidebar data associated with the screen, if any.
	 *
	 * @since 3.3.0
	 * @var string
	 * @access private
	 */
	private $_help_sidebar = '';

	/**
	 * The screen options associated with the screen, if any.
	 *
	 * @since 3.3.0
	 * @var array
	 * @access private
	 */
	private $_options = array(
		'_context' => '',
		'_screen_settings' => ''
	);

	/**
	 * Show screen options if any.
	 *
	 * @since 3.3.0
	 * @var bool
	 * @access private
	 */
	private $_show_options = false;

	/**
	 * Constructor
	 *
	 * @since 3.3.0
	 *
	 * @param string $id A screen id.  If empty, the $hook_suffix global is used to derive the ID.
	 */
	public function __construct( $id = '' ) {
		global $hook_suffix, $typenow, $taxnow;

		$action = '';

		if ( empty( $id ) ) {
			$screen = $hook_suffix;
			$screen = str_replace('.php', '', $screen);

			if ( preg_match('/-add|-new$/', $screen) )
				$action = 'add';

			$screen = str_replace('-new', '', $screen);
			$screen = str_replace('-add', '', $screen);
			$this->id = $this->base = $screen;
		} else {
			$id = sanitize_key( $id );

			if ( false !== strpos($id, '-') ) {
				list( $id, $typenow ) = explode('-', $id, 2);

				if ( taxonomy_exists( $typenow ) ) {
					$id = 'edit-tags';
					$taxnow = $typenow;
					$typenow = '';
				}
			}
			$this->id = $this->base = $id;
		}

		$this->action = $action;

		// Map index to dashboard
		if ( 'index' == $this->base )
			$this->base = 'dashboard';

		if ( 'index' == $this->id )
			$this->id = 'dashboard';

		if ( 'edit' == $this->id ) {
			if ( empty($typenow) )
				$typenow = 'post';

			$this->id .= '-' . $typenow;
			$this->post_type = $typenow;
		} elseif ( 'post' == $this->id ) {
			if ( empty($typenow) )
				$typenow = 'post';

			$this->id = $typenow;
			$this->post_type = $typenow;
		} elseif ( 'edit-tags' == $this->id ) {
			if ( empty($taxnow) )
				$taxnow = 'post_tag';

			$this->id = 'edit-' . $taxnow;
			$this->taxonomy = $taxnow;
		}

		$this->is_network = is_network_admin();
		$this->is_user = is_user_admin();

		if ( $this->is_network ) {
			$this->base .= '-network';
			$this->id .= '-network';
		} elseif ( $this->is_user ) {
			$this->base .= '-user';
			$this->id .= '-user';
		}
	}

	/**
	 * Set the parent information for the screen.
	 * This is called in admin-header.php after the menu parent for the screen has been determined.
	 *
	 * @since 3.3.0
	 *
	 * @param string $parent_file The parent file of the screen.  Typically the $parent_file global.
	 */
	function set_parentage( $parent_file ) {
		$this->parent_file = $parent_file;
		$this->parent_base = preg_replace('/\?.*$/', '', $parent_file);
		$this->parent_base = str_replace('.php', '', $this->parent_base);
	}

	/**
	 * Adds an option for the screen.
	 * Use the 'add_screen_help_and_options' action to add screen options.
	 *
	 * @since 3.3.0
	 *
	 * @param string $option Option ID
	 * @param mixed $args Associative array of arguments particular to the default $option or the HTML string to be printed in the Screen Options tab.
	 */
	public function add_option( $option, $args = null ) {
		if ( is_array($args) && !empty($option) )
			$this->_options[ $option ] = $args;
		elseif ( is_string($option) )
			$this->_options['_screen_settings'] .= $option;
		else
			return false;

		$this->_show_options = true;
		return true;
	}
	
	/**
	 * Adds option context.
	 * Use the 'add_screen_help_and_options' action to add it. Will not be shown if there aren't any screen options.
	 *
	 * @since 3.3.0
	 *
	 * @param string $text
	 */
	public function add_option_context( $text ) {
		$this->_options['_context'] .= $text;
	}

	/**
	 * Add a help tab to the contextual help for the screen.
	 * Use the 'add_screen_help_and_options' action to add contextual help tabs.
	 *
	 * @since 3.3.0
	 *
	 * @param array $args
	 * - string   - title    - Title for the tab.
	 * - string   - id       - Tab ID.
	 * - string   - section  - Section title for the tab. Optional.
	 * - string   - content  - Help tab content in plain text or HTML. Optional.
	 * - callback - callback - A callback to generate the tab content. Optional.
	 *
	 */
	public function add_help_tab( $args ) {
		$defaults = array(
			'title'    => false,
			'id'       => false,
			'section'  => false,
			'content'  => '',
			'callback' => false
		);
		$args = wp_parse_args( $args, $defaults );

		// Ensure we have title and ID.
		if ( ! $args['title'] || ! $args['id'] )
			return false;

		$this->_help_tabs[] = $args;
		return true;
	}

	/**
	 * Add a sidebar to the contextual help for the screen.
	 * Use the 'add_screen_help_and_options' action to add a sidebar to the contextual help.
	 *
	 * @since 3.3.0
	 *
	 * @param string $content Sidebar content in plain text or HTML.
	 */
	public function add_help_sidebar( $content ) {
		if ( empty($this->_help_sidebar) ) // add only one
			$this->_help_sidebar = $content;
	}

	/**
	 * Render the screen's help section.
	 *
	 * This will trigger the deprecated filters for backwards compatibility.
	 *
	 * @since 3.3.0
	 */
	public function render_screen_meta() {
		global $_wp_contextual_help;

		// Intended for adding Help and Screen Options.
		do_action('add_screen_help_and_options', $this);

		// Call old contextual_help_list filter.
		if ( ! isset( $_wp_contextual_help ) )
			$_wp_contextual_help = array();

		// why are we filtering a global? $_wp_contextual_help = apply_filters( 'contextual_help_list', $_wp_contextual_help, $this );

		if ( isset( $_wp_contextual_help[ $this->id ] ) ) {
			// Call old contextual_help filter.
			// why are we filtering the same global second time??
			$contextual_help = apply_filters( 'contextual_help', $_wp_contextual_help[ $this->id ], $this->id, $this );

			$this->add_help_tab( array(
				'title'		=> __('Screen Info'),
				'id'		=> 'screen-info',
				'content'	=> $_wp_contextual_help[ $this->id ]
			) );
		}

		// Time to render!
		?>
		<div id="screen-meta" class='metabox-prefs'>
			<div id="contextual-help-wrap" class="hidden">
				<div class="contextual-help-tabs">
					<ul>
					<?php

					if ( $this->_show_options ) {
						$class = true;
						?>
						<li id="tab-link-screen-options" class="active">
							<a href="#tab-panel-screen-options">
								<?php _e('Screen Options'); ?>
							</a>
						</li>
						<?php
					}

					foreach ( $this->_help_tabs as $i => $tab ) {
						$id = esc_attr($tab['id']);
						$class = empty($class) && $i == 0 ? ' class="active"' : '';
						?>
						<li id="<?php echo "tab-link-$id"; ?>"<?php echo $class; ?>>
							<a href="<?php echo "#tab-panel-$id"; ?>">
								<?php echo esc_html( $tab['title'] ); ?>
							</a>
						</li>
					<?php } ?>
					</ul>
				</div>
				<?php

				if ( $this->_help_sidebar )
					echo '<div class="contextual-help-sidebar">' . $this->_help_sidebar . '</div>';

				?>
				<div class="contextual-help-tabs-wrap">
					<?php

					if ( $this->_show_options ) {
						$class2 = true;
						echo '<div id="tab-panel-screen-options" class="help-tab-content active">';

						if ( !empty($this->_options['_context']) )
							echo $this->_options['_context'];

						$this->render_screen_options();
						echo '</div>';
					}

					foreach ( $this->_help_tabs as $i => $tab ) {
						$class2 = empty($class2) && $i == 0 ? ' active' : '';
						?>

						<div id="<?php echo esc_attr( "tab-panel-{$tab['id']}" ); ?>" class="help-tab-content<?php echo $class2; ?>">
							<?php
							if ( $tab['section'] )
								echo '<h3>' . esc_html( $tab['section'] ) . '</h3>';

							// Print tab content.
							echo $tab['content'];

							// If it exists, fire tab callback.
							if ( ! empty( $tab['callback'] ) )
								call_user_func( $tab['callback'], $this );
							?>
						</div>
					<?php } ?>
				</div>
			</div>
		</div>
		<?php
	}

	/**
	 * Render the screen options tab.
	 *
	 * @since 3.3.0
	 */
	public function render_screen_options() {

		$screen_settings = $this->_options['_screen_settings'];

		// Default screen_settings for various screens.
		// TODO: should probably be set on these screens, not here.
		switch ( $this->id ) {
			case 'widgets':
				$screen_settings .= '<p><a id="access-on" href="widgets.php?widgets-access=on">' . __('Enable accessibility mode') . '</a><a id="access-off" href="widgets.php?widgets-access=off">' . __('Disable accessibility mode') . "</a></p>\n";
				break;
		}

		// TODO: deprecate
		$screen_settings = apply_filters( 'screen_settings', $screen_settings, $this );

		echo '<form id="adv-settings" action="" method="post">';

		$this->render_table_columns_prefs();
		$this->render_metabox_prefs();
		$this->render_screen_layout();
		$this->render_per_page_options();
		echo $screen_settings;

		wp_nonce_field( 'screen-options-nonce', 'screenoptionnonce', false );
		echo '</form>';

	}

	/**
	 * Render the option for hiding table columns on the page
	 *
	 * @since 3.3.0
	 */
	function render_table_columns_prefs() {
		$columns = get_column_headers( $this );

		if ( ! empty( $columns ) ) {
			$hidden = get_hidden_columns( $this );
			?>
			<h5><?php echo ( isset( $columns['_title'] ) ?  $columns['_title'] :  _x('Show on screen', 'Columns') ) ?></h5>
			<div class="metabox-prefs">
				<?php
				$special = array('_title', 'cb', 'comment', 'media', 'name', 'title', 'username', 'blogname');

				foreach ( $columns as $column => $title ) {
					// Can't hide these for they are special
					if ( in_array( $column, $special ) )
						continue;
					if ( empty( $title ) )
						continue;

					if ( 'comments' == $column )
						$title = __( 'Comments' );

					$id = "$column-hide";
					echo '<label for="' . $id . '">';
					echo '<input class="hide-column-tog" name="' . $id . '" type="checkbox" id="' . $id . '" value="' . $column . '"' . checked( !in_array($column, $hidden), true, false ) . ' />';
					echo "$title</label>\n";
				}
				?>
				<br class="clear" />
			</div>
		<?php }
	}

	/**
	 * Render the option for hiding metaboxes on the page
	 *
	 * @since 3.3.0
	 */
	function render_metabox_prefs() {
		global $wp_meta_boxes;

		if ( !empty( $wp_meta_boxes[ $this->id ] ) ) {
			$hidden = get_hidden_meta_boxes($this);
			?>
			<h5><?php _ex('Show on screen', 'Metaboxes') ?></h5>
			<div class="metabox-prefs">
				<?php

				foreach ( array_keys($wp_meta_boxes[$this->id]) as $context ) {
					foreach ( array_keys($wp_meta_boxes[$this->id][$context]) as $priority ) {
						foreach ( $wp_meta_boxes[$this->id][$context][$priority] as $box ) {
							if ( false == $box || ! $box['title'] )
								continue;
							// Submit box cannot be hidden
							if ( 'submitdiv' == $box['id'] || 'linksubmitdiv' == $box['id'] )
								continue;
							$box_id = $box['id'];
							echo '<label for="' . $box_id . '-hide">';
							echo '<input class="hide-postbox-tog" name="' . $box_id . '-hide" type="checkbox" id="' . $box_id . '-hide" value="' . $box_id . '"' . (! in_array($box_id, $hidden) ? ' checked="checked"' : '') . ' />';
							echo "{$box['title']}</label>\n";
						}
					}
				}

				?>
				<br class="clear" />
			</div>
			<?php
		}
	}

	/**
	 * Render the option for number of columns on the page
	 *
	 * @since 3.3.0
	 */
	function render_screen_layout() {
		global $screen_layout_columns;

		// Back compat for plugins using the filter instead of add_screen_option()
		// TODO: deprecate it
		$columns = apply_filters( 'screen_layout_columns', array(), $this->id, $this );

		if ( ! empty( $columns ) && isset( $columns[ $this->id ] ) )
			$this->add_option( 'layout_columns', array('max' => $columns[ $this->id ] ) );

		if ( ! isset( $this->_options['layout_columns'] ) ) {
			$screen_layout_columns = 0;
			return;
		}

		$screen_layout_columns = get_user_option("screen_layout_$this->id");
		$num = $this->_options['layout_columns']['max'];

		if ( ! $screen_layout_columns || 'auto' == $screen_layout_columns ) {
			if ( isset( $this->_options['layout_columns']['default'] ) )
				$screen_layout_columns = $this->_options['layout_columns']['default'];
		}

		?>
		<h5><?php _e('Screen Layout'); ?></h5>
		<div class='columns-prefs'><?php
			_e('Number of Columns:');
			for ( $i = 1; $i <= $num; ++$i ):
				?>
				<label>
					<input type='radio' name='screen_columns' value='<?php echo esc_attr( $i ); ?>'
						<?php checked( $screen_layout_columns, $i ); ?> />
					<?php echo esc_html( $i ); ?>
				</label>
				<?php
			endfor; ?>
		</div>
		<?php
	}

	/**
	 * Render the items per page option
	 *
	 * @since 3.3.0
	 */
	function render_per_page_options() {
		if ( empty( $this->_options['per_page'] ) )
			return;

		$per_page_label = $this->_options['per_page']['label'];

		if ( empty( $this->_options['per_page']['option'] ) ) {
			$option = str_replace( '-', '_', "{$this->id}_per_page" );
		} else {
			$option = $this->_options['per_page']['option'];
		}

		$per_page = (int) get_user_option( $option );
		if ( empty( $per_page ) || $per_page < 1 ) {
			if ( isset($this->_options['per_page']['default']) )
				$per_page = $this->_options['per_page']['default'];
			else
				$per_page = 20;
		}

		if ( 'edit_comments_per_page' == $option ) {
			$comment_status = isset( $_REQUEST['comment_status'] ) ? $_REQUEST['comment_status'] : 'all';
			$per_page = apply_filters( 'comments_per_page', $per_page, $comment_status );
		} elseif ( 'categories_per_page' == $option ) {
			$per_page = apply_filters( 'edit_categories_per_page', $per_page );
		} else {
			$per_page = apply_filters( $option, $per_page );
		}

		// Back compat
		if ( isset( $this->post_type ) )
			$per_page = apply_filters( 'edit_posts_per_page', $per_page, $this->post_type );

		?>
		<h5><?php _ex('Show on screen', 'Screen Options') ?></h5>
		<div class='screen-options'>
			<?php if ( !empty($per_page_label) ): ?>
				<input type='text' class='screen-per-page' name='wp_screen_options[value]'
					id='<?php echo esc_attr( $option ); ?>' maxlength='3'
					value='<?php echo esc_attr( $per_page ); ?>' />
				<label for='<?php echo esc_attr( $option ); ?>'>
					<?php echo esc_html( $per_page_label ); ?>
				</label>
			<?php endif;

			echo get_submit_button( __( 'Apply' ), 'button', 'screen-options-apply', false ); ?>
			<input type='hidden' name='wp_screen_options[option]' value='<?php echo esc_attr($option); ?>' />
		</div>
		<?php
	}
	
	function get_screen_icon( $for = '' ) {

		if ( !empty($for) && is_string($for) ) {
			$name = $for;
		} else {
			if ( !empty($this->parent_base) )
				$name = $this->parent_base;
			else
				$name = $this->base;
		}

		if ( 'edit' == $name && isset($this->post_type) && 'page' == $this->post_type )
			$name = 'edit-pages';

		$class = '';
		if ( !empty( $this->post_type ) )
			$class = ' ' . sanitize_html_class( 'icon32-posts-' . $this->post_type );

		return '<div id="icon-' . esc_attr( $name ) . '" class="icon32' . $class . '"><br /></div>';
	}
}