FontsamplerPlugin.php

<?php

/**
 * Class FontsamplerPlugin
 *
 * Main plugin class containing the frontend and backend routines
 * for rendering Fontsampler instances from shortcodes
 */
class FontsamplerPlugin {

	public $font_formats;
	public $settings_defaults;
	public $font_formats_legacy;
	public $default_features;
	public $admin_hide_legacy_formats;
	public $fontsampler_db_version;
	public $twig;

	// helper classes
	public $msg;
	public $db;
	public $helpers;
	public $notifications;
	private $forms;

	const FONTSAMPLER_OPTION_DB_VERSION = 'fontsampler_db_version';
	const FONTSAMPLER_OPTION_LAST_CHANGELOG = 'fontsampler_last_changelog'; // note, hardcoded also in FontsamplerHelpers.php:351 due to bug
	const FONTSAMPLER_OPTION_HIDE_LEGACY_FORMATS = 'fontsampler_hide_legacy_formats';

	function __construct( $wpdb, $twig ) {
		$this->wpdb = $wpdb;
		$this->twig = $twig;
	}

	function init() {
		
		// TODO combined default_features and boolean options as array of objects
		// with "isBoolean" attribute
		$this->default_features = array(
			'fontsize',
			'letterspacing',
			'lineheight',
			'sampletexts',
			'alignment',
			'invert',
			'multiline',
			'opentype',
			'locl',
			'fontpicker',
			'buy',
			'specimen',
		);
		// note: font_formats order matters: most preferred to least preferred
		// note: so far no feature detection and no fallbacks, so woff2 last until fixed
		$this->font_formats        = array( 'woff', 'ttf', 'eot');//, 'woff2' );
		$this->font_formats_legacy = array( 'eot', 'ttf' );

		$this->settings_defaults = array(
			/* translators: Default label for font size slider in the front end */
			'fontsize_label'           => __('Size', 'fontsampler'),
			'fontsize_min'             => '8',
			'fontsize_max'             => '96',
			'fontsize_initial'         => '14',
			'fontsize_unit'            => 'px',
			/* translators: Default label for letter spacing slider in the front end */
			'letterspacing_label'      => __('Letter spacing', 'fontsampler'),
			'letterspacing_min'        => '-5',
			'letterspacing_max'        => '5',
			'letterspacing_initial'    => '0',
			'letterspacing_unit'       => 'px',
			/* translators: Default label for the line height slider in the front end */
			'lineheight_label'         => __('Line height', 'fontsampler'),
			'lineheight_min'           => '70',
			'lineheight_max'           => '300',
			'lineheight_initial'       => '110',
			'lineheight_unit'          => '%',
			'alignment_initial'         => 'left',
			'sample_texts'              => "hamburgerfontstiv\nabcdefghijklmnopqrstuvwxyz\nABCDEFGHIJKLMNOPQRSTUVWXYZ\nThe quick brown fox jumps over the lazy cat",
			/* translators: Default selection in the sample text dropdown */
			"sample_texts_default_option" => __("Select a sample text", "fontsampler"),
			'locl_options'				=> null,
			/* translators: Default selection in the language (locl feature) dropdown */
			'locl_default_option'		=> __("Select language", "fontsampler"),
			'css_color_text'            => '#333333',
			'css_color_background'      => '#ffffff',
			'css_color_label'           => '#333333',
			'css_value_size_label'       	=> 'inherit',
			'css_value_fontfamily_label' 	=> 'inherit',
			'css_value_lineheight_label' 	=> 'normal',
			'css_color_button_background'	=> '#efefef',
			'css_color_button_background_inactive' => '#dfdfdf',
			'css_color_highlight'       => '#efefef',
			'css_color_highlight_hover' => '#dedede',
			'css_color_line'            => '#333333',
			'css_color_handle'          => '#333333',
			'css_value_column_gutter'   => '10px',
			'css_value_row_height'      => '30px',
			'css_value_row_gutter'      => '10px',
			'css_color_notdef'			=> '#dedede',
			'fontsize'                  => 1,
			'letterspacing'             => 1,
			'lineheight'                => 1,
			'sampletexts'               => 0,
			'locl'						=> 0,
			'alignment'                 => 0,
			'invert'                    => 0,
			'multiline'                 => 1,
			'opentype'                  => 0,
			'fontpicker'                => 0,
			'buy'                       => 0,
			'specimen'                  => 0,
			'notdef'					=> 0,
			/* translators: Default label for the buy button in the front end */
			'buy_label'                 => __('Buy', 'fontsampler'),
			'buy_image'                 => null,
			'buy_url'                   => null,
			'buy_type'                  => 'label',
			'buy_target'                => '_blank',
			/* translators: Default label for the specimen download button in the front end */
			'specimen_label'            => __('Specimen', 'fontsampler'),
			'specimen_image'            => null,
			'specimen_url'              => null,
			'specimen_type'             => 'label',
			'specimen_target'           => '_blank',
			'ui_columns'                => 3,
			'ui_order'                  => null,
			'is_ltr'                    => 1,
			'notdef'					=> 0, // by default do nothing on notdef glyph input
			'initial'                   => null // initial fontset_id
		);

		// instantiate all needed helper subclasses
		$this->msg     = new FontsamplerMessages();
		$this->helpers = new FontsamplerHelpers( $this );
		$this->db      = new FontsamplerDatabase( $this->wpdb, $this );
		$this->notifications = new FontsamplerNotifications( $this );

		// keep track of db versions and migrations via this
		// simply set this to the current PLUGIN VERSION number when bumping it
		// i.e. a database update always bumps the version number of the plugin as well
		$this->fontsampler_db_version = '0.4.0';
		$current_db_version           = get_option( self::FONTSAMPLER_OPTION_DB_VERSION );

		// if no previous db version has been registered assume new install and set
		// to current version
		if ( ! $current_db_version ) {
			add_option( self::FONTSAMPLER_OPTION_DB_VERSION, $this->fontsampler_db_version );
			$current_db_version = $this->fontsampler_db_version;
		}
		if ( version_compare( $current_db_version, $this->fontsampler_db_version ) < 0 ) {
			$this->db->migrate_db();
		}


		// check if to display legacy formats or not
		$option_legacy_formats = get_option( self::FONTSAMPLER_OPTION_HIDE_LEGACY_FORMATS );

		// set the option in the db, if it's unset; default to hiding the legacy formats
		if ( $option_legacy_formats === false ) {
			add_option( self::FONTSAMPLER_OPTION_HIDE_LEGACY_FORMATS, '1' );
			$this->admin_hide_legacy_formats = 1;
		} else {
			$this->admin_hide_legacy_formats = $option_legacy_formats;
		}

		// hoist some of those settings defaults to the twig engine, so some things
		// are available globally in all twig templates
		$this->helpers->extend_twig( $this->twig );
	}


	/*
	 * DIFFERENT HOOKS
	 */


	/*
	 * Register the [fontsampler id=XX] hook for use in pages and posts
	 */
	function fontsampler_shortcode( $atts ) {
		global $wp_styles;
		
		// on printing the shortcode enqueue the scripts to be output to the footer
		wp_enqueue_script('fontsampler-js');

		// when the shortcode was detected already in the header the styles should
		// be added already; if the styles are not enqueued (for example if called
		// via do_shortcode()) then add them now, regardless of them getting added
		// to the html body, which is less ideal
		if (!in_array('fontsampler-css', array_keys($wp_styles->registered))) {
            echo "shortcode called, but styles not present";
            $this->enqueue_styles();
		}

		// merge in possibly passed in attributes
		$attributes = shortcode_atts( array( 'id' => '0', 'fonts' => NULL, 'text' => NULL ), $atts );
		$id = intval($attributes['id']);

		// store any text that was passed in as part of the shortcode
		// this will overwrite the text defined in the settings of this fontsampler
		// or if only fonts are passed in as part of the shortcode the fontsampler
		// will used that text
		$attribute_text = $attributes['text'];

		// do nothing if missing id
		if ( 0 != $id ) {
			$set   = $this->db->get_set( $id );
			$css   = $this->helpers->get_custom_css( $set ); // returns false or link to generated custom css
			$fonts = $this->helpers->get_best_file_from_fonts( $this->db->get_fontset_for_set( intval( $attributes['id'] ) ) );

            var_dump($fonts);

			if ( false !== $css ) {
				wp_enqueue_style( 'fontsampler-interface-' . $id, $css, array(), false );
			}

			if ( false == $set || false == $fonts ) {
				if ( current_user_can( 'edit_posts' ) || current_user_can( 'edit_pages' ) ) {
					return '<div class="fontsampler-warning"><strong>The typesampler with ID ' . $attributes['id'] . ' can not be displayed because some files or the type sampler set are missing!</strong> <em>You are seeing this notice because you have rights to edit posts - regular users will see an empty spot here.</em></div>';
				} else {
					return '<!-- typesampler #' . $attributes['id'] . ' failed to render -->';
				}
			}

			// some of these get overwritten from defaults, but list them all here explicitly
			$options = array_merge( $set, $this->settings_defaults, $this->db->get_settings() );
			$initialFont = isset( $fonts[ $set['initial_font'] ] ) ? $fonts[ $set['initial_font'] ] : false;
			if ($initialFont) {
				$firstFont = array_filter($set['fonts'], function ($item) use ($set) {
					if ($item['id'] === $set['initial_font']) {
						return $item;
					}
				});
				$initialFontNameOverwrite = array_pop($firstFont)['name'];
			}

			$settings = $this->db->get_settings();
			$layout = new FontsamplerLayout();
			$blocks = $layout->stringToArray( $set['ui_order'], $set );

			// get the calculated initial values for data-font-size- etc, where the set overwrites options
			// where available
			$data_initial = array();
			foreach ($set as $key => $value) {
				$data_initial[$key] = $value;
				if ($value === null && $options[$key] !== null) {
					$data_initial[$key] = $options[$key];
				}
			}

			// create an array for fontnames to overwrite
			$fontNameOverwrites = [];
			foreach ($set['fonts'] as $font) {
				foreach ($this->font_formats as $format) {
					if (!empty($font[$format])) {
						$fileName = basename($font[$format]);
						$fontNameOverwrites[$fileName] = $font['name'];
					}
				}
			}

			// buffer output until return
			ob_start();

			?>
			<div class='fontsampler-wrapper on-loading'
			     data-fonts='<?php echo implode( ',', $fonts ); ?>'
				<?php if ( $initialFont ) : ?>
					data-initial-font='<?php echo $initialFont; ?>'
					data-initial-font-name-overwrite='<?php echo $initialFontNameOverwrite; ?>'
				<?php endif; ?>
				<?php if (!empty($fontNameOverwrites)): ?>
					data-overwrites='<?php echo json_encode($fontNameOverwrites); ?>'
				<?php endif; ?>
			>
			<?php

			// include, aka echo, template with replaced values from $replace above
			include( 'includes/interface.php' );

			echo '</div>';

			// return all that's been buffered
			return ob_get_clean();
		} 

		else if ( $attributes['fonts'] !== NULL ) {
			// you cannot pass in a json encoded string (because the square brackets would
			// be interpreted as the end of the shortcode), so the json encoded string is
			// EXPECTED to be a json encoded array, but missing the opening and ending
			// square brackets
			$fonts_passed_in = json_decode( "[" . $attributes['fonts'] . "]" );

			$fonts_passed_in = array_map(function ($item, $index) {
				$item = (array) $item;
				// the fake font id is needed for fontsampler internals,
				// but since these are not fonts exising in the DB the 
				// passed in array index will suffice as ID
				$item["id"] = $index;
				return $item;
			}, $fonts_passed_in, array_keys($fonts_passed_in));

			// retrieve an array with the must suitable webfont files
			$fonts = $this->helpers->get_best_file_from_fonts( $fonts_passed_in );

			// some of these get overwritten from defaults, but list them all here explicitly
			// $set   = $this->db->get_set( $id );
			$set = $this->db->get_settings();
			$set['id'] = 0;

			$options = array_merge( $set, $this->settings_defaults, $this->db->get_settings() );
			$settings = $this->db->get_settings();
			$layout = new FontsamplerLayout();
			$blocks = $layout->stringToArray( $set['ui_order'], $set );

			$initialFont = array_filter($fonts_passed_in, function ($item) {
				return isset($item['initial']) && $item['initial'] === true;
			});
			$initialFont = array_shift($initialFont) ;
			$initialFontNameOverwrite = $initialFont['name'];
			$initialFont = $this->helpers->get_best_file_from_fonts(array($initialFont));
			$initialFont = is_array($initialFont) ? array_shift($initialFont) : "";

			$data_initial = $settings;


			// create an array for fontnames to overwrite
			$fontNameOverwrites = [];
			foreach ($fonts_passed_in as $font) {
				foreach ($this->font_formats as $format) {
					if (!empty($font[$format])) {
						$fileName = basename($font[$format]);
						$fontNameOverwrites[$fileName] = $font['name'];
					}
				}
			}

			ob_start();
			?>

			<div class='fontsampler-wrapper on-loading'
			     data-fonts='<?php echo implode( ',', $fonts ); ?>'
				<?php if ( $initialFont ) : ?>
					data-initial-font='<?php echo $initialFont; ?>'
				<?php endif; ?>
				<?php if (!empty($fontNameOverwrites)): ?>
					data-overwrites='<?php echo json_encode($fontNameOverwrites); ?>'
					data-initial-font-name-overwrite='<?php echo $initialFontNameOverwrite; ?>'
				<?php endif; ?>
			>

			<?php

			// include, aka echo, template with replaced values from $replace above
			include( 'includes/interface.php' );

			echo '</div>';


			return ob_get_clean();
		}
	}

	/**
	 * To output the plugin styles only on pages that have the shortcode check
	 * in the 'wp' action hook if this page seems to have the shortcode and enqueue
	 * the styles if so
	 */
	function check_shortcodes_enqueue_styles() {
		global $post;
		if ( has_shortcode( $post->post_content, 'fontsampler') || apply_filters('fontsampler_enqueue_styles', false) ) {
            $this->enqueue_styles();
		}
	}

	/**
	 * The actual style enqueue
	 */
	function enqueue_styles() {
		wp_enqueue_style( 'fontsampler-css', $this->helpers->get_css_file() );
	}

	/*
	 * Register scripts and styles needed in the admin panel
	 */
	function fontsampler_admin_enqueues($hook) {

		// Load only on fontsampler plugin page hooks
		if ( preg_match("/fontsampler/i", $hook) === 0 ) {
                return;
        }

		wp_enqueue_script( 'fontsampler-clipboard', plugin_dir_url( __FILE__ ) . 'admin/js/clipboard.min.js');
		wp_enqueue_script( 'fontsampler-admin-main-js', plugin_dir_url( __FILE__ ) . 'admin/js/fontsampler-admin.js', array(
			'jquery',
			'wp-color-picker',
			'jquery-ui-sortable',
			'jquery-ui-accordion',
			'fontsampler-clipboard', // make clipboard a global requirement
		), false, true);

		wp_enqueue_style( 'wp-color-picker' );
		wp_enqueue_style( 'jquery-ui-accordion' );
		wp_enqueue_style( 'fontsampler-css-admin', $this->helpers->get_css_file() );
		wp_enqueue_style( 'fontsampler_admin_css', plugin_dir_url( __FILE__ ) . '/admin/css/fontsampler-admin.css', false, '1.0.0' );

		wp_enqueue_media();
	}


	/*
	 * Add the fontsampler admin menu to the sidebar
	 */
	function fontsampler_plugin_setup_menu() {

		$numNotifications = $this->notifications->get_notifications()['num_notifications'];
		$notifications = "";
		if ($numNotifications > 0) {
			$notifications = ' <span class="update-plugins count-' . $numNotifications . '">
				<span class="plugin-count">' . $numNotifications . '</span></span>';
		}

		add_menu_page( 'Fontsampler plugin page', 'Fontsampler' . $notifications, 
			'manage_options', 'fontsampler', array(
				$this,
				'fontsampler_admin_init',
			), 'dashicons-editor-paragraph' );

		add_submenu_page( 'fontsampler', 'New Fontsampler', 'New Fontsampler', 
			'manage_options', 'fontsampler-new', 
			array( $this, 'fontsampler_admin_init' )
		);

		add_submenu_page( 'fontsampler', 'Settings',  'Settings', 
			'manage_options', 'fontsampler-settings', 
			array( $this, 'fontsampler_admin_init' )
		);

		// replace default entry label for main Fontsampler menu entry 
		global $submenu;
		$submenu['fontsampler'][0][0] = "All Fontsamplers";
	}


	/**
	 * Register the text deomain for translations
	 */
	function fontsampler_load_text_domain() {
		load_plugin_textdomain( 'fontsampler', false, dirname( plugin_basename(__FILE__) ) . '/lang/' );
	}


	/*
	 * Expand allowed upload types to include font files
	 */
	function allow_font_upload_types( $existing_mimes = array() ) {
		$existing_mimes['woff']  = 'application/font-woff';
		$existing_mimes['woff2'] = 'application/font-woff2';
		$existing_mimes['eot']   = 'application/eot';
		$existing_mimes['ttf']   = 'application/ttf';

		return $existing_mimes;
	}


	/*
	 * Augment the plugin description links
	 */
	function add_action_links ( $links ) {
		$mylinks = array(
			'<a href="' . admin_url( 'admin.php?page=fontsampler' ) . '">Settings</a>',
		);
		return array_merge( $links, $mylinks );
	}


	/*
	 * React to the plugin being activated
	 */
	function fontsampler_activate() {
		$this->db->check_and_create_tables();
		$this->helpers->check_and_create_folders();
	}

	/*
	 * FLOW CONTROL
	 */

	/*
	 * Rendering the admin interface and dealing for form interactions
	 */
	function fontsampler_admin_init() {
		global $title;

		// if entering this hook from the submenu callbacks, load different subpages
		if ( $title === "Settings" ) {
			$_GET['subpage'] = "settings";
		}

		if ( $title === "New Fontsampler" ) {
			$_GET['subpage'] = "set_create";
		}

		echo '<section id="fontsampler-admin" class="';
		echo $this->admin_hide_legacy_formats
			? 'fontsampler-admin-hide-legacy-formats'
			: 'fontsampler-admin-show-legacy-formats';
		echo '">';

		$this->db->check_and_create_tables();

		// check upload folder is writable
		$dir    = wp_upload_dir();
		$upload = $dir['basedir'];
		if ( ! is_dir( $upload ) ) {
			echo '<p>Uploads folder does not exist! Make sure Wordpress has writing 
				permissions to create the uploads folder at: <em>' . $upload . '</em></p>';
		}


		// handle any kind of form processing and output any messages inside a notice, if there were any
		if ( 'POST' == $_SERVER['REQUEST_METHOD'] && isset( $_POST['action'] ) ) {
			$this->forms = new FontsamplerFormhandler( $this, $_POST, $_FILES );

			// buffer the output generated during form processing, then, if
			// not empty, print any output wrapped in a notice element
			ob_start( function ( $buffer ) {
				if ( ! empty( $buffer ) ) {
					return '<div class="notice">' . $buffer . '</div>';
				}
			} );

			$id = isset( $_POST['id'] ) && intval( $_POST['id'] ) > 0 ? intval( $_POST['id'] ) : null;
			switch ( $_POST['action'] ) {
				case 'edit_font':
					if ( ! isset( $id ) ) {
						$this->forms->handle_font_insert();
					} else {
						$this->forms->handle_font_edit( $id );
					}
					break;
				case 'delete_font':
					$this->forms->handle_font_delete( $id );
					break;
				case 'edit_set':
					if ( ! isset( $id ) ) {
						$this->forms->handle_set_insert();
					} else {
						$this->forms->handle_set_edit( $id );
					}
					break;
				case 'delete_set':
					$this->forms->handle_set_delete( $id );
					break;
				case 'edit_settings':
					$this->forms->handle_settings_edit();
					break;
				case 'reset_settings':
					if ($this->forms->handle_settings_reset()) {
					$this->msg->add_info( 'Settings successfully reset. You may have to refresh the page for the reset CSS to reload.' );
					}
					break;
				case 'fix_default_settings':
					if ($this->db->fix_settings_from_defaults()) {
						$this->msg->add_info( 'Settings successfully restored from defaults');
					}
					break;
				case 'hide_changelog':
					$this->helpers->hide_changelog();
					break;
				default:
					$this->msg->add_notice( 'Form submitted, but no matching action found for ' . $_POST['action'] );
					break;
			}
			ob_end_flush();
		}

		$subpage = isset( $_GET['subpage'] ) ? $_GET['subpage'] : '';
		switch ( $subpage ) {
			case 'set_create':
				$defaults = $this->db->get_default_settings();

				$set = $defaults;
				$set['use_defaults'] = 1;
				$set['alignment_initial'] = null;

				// generate all necessary info for the live layout preview
				$layout = new FontsamplerLayout();
				$str = $layout->sanitizeString($set['ui_order'], $set);
				$layout->stringToArray($str);
				$ui_order = !empty( $set['ui_order'] )
					? $layout->sanitizeString( $set['ui_order'], $set )
					: $layout->arrayToString( $layout->getDefaultBlocks(), $set );

				$blocks = array_merge( $layout->getDefaultBlocks(), $layout->stringToArray( $set['ui_order'], $set ) );

				echo $this->twig->render( 'set-edit.twig', array(
					'set' => $set,
					'defaults' => $defaults,
					'fonts'    => $this->db->get_fontfile_posts(),
					'ui_order'    => $ui_order,
					'blocks'      => $blocks
				));
				break;

			case 'set_edit':
				$defaults = $this->db->get_settings();
				$set = $this->db->get_set( intval( $_GET['id'] ) );

				// generate all necessary info for the live layout preview
				$layout = new FontsamplerLayout();
				$str = $layout->sanitizeString($set['ui_order'], $set);
				$layout->stringToArray($str);
				$ui_order = !empty( $set['ui_order'] )
					? $layout->sanitizeString( $set['ui_order'], $set )
					: $layout->arrayToString( $layout->getDefaultBlocks(), $set );

				$blocks = array_merge( $layout->getDefaultBlocks(), $layout->stringToArray( $set['ui_order'], $set ) );

				// grab all possible included fonts
				$fonts       = $this->db->get_fontfile_posts();
				$fonts_order = implode( ',', array_map( function ( $font ) {
					return $font['id'];
				}, $set['fonts'] ) );

				if ( empty($set) ){
					$this->msg->add_error('No set selected');
				}

				echo $this->twig->render( 'set-edit.twig', array(
					'set'         => $set,
					'defaults'    => $defaults,
					'fonts'       => $fonts,
					'fonts_order' => $fonts_order,
					'ui_order'    => $ui_order,
					'blocks'      => $blocks
				));
				break;

			case 'set_delete':
				$set = $this->db->get_set( intval( $_GET['id'] ) );
				echo $this->twig->render( 'set-delete.twig', array( 'set' => $set ));
				break;

			case 'fonts':
				$offset     = isset( $_GET['offset'] ) ? intval( $_GET['offset'] ) : 0;
				$num_rows   = isset( $_GET['num_rows'] ) ? intval( $_GET['num_rows'] ) : 10;
				$initials   = $this->db->get_fontsets_initials();
				$pagination = new FontsamplerPagination( $initials, $num_rows, false, $offset );

				echo $this->twig->render( 'fontsets.twig', array(
						'fonts'      => $this->db->get_fontsets( $offset, $num_rows ),
						'pagination' => $pagination->pages('?page=fontsampler&amp;subpage=fonts&amp;offset=###first###&amp;num_rows=###items###', sizeof( $initials )),
					)
				);
				break;

			case 'font_create':
				echo $this->twig->render( 'fontset-edit.twig' );
				break;

			case 'font_edit':
				echo $this->twig->render( 'fontset-edit.twig', array(
					'font' => $this->db->get_fontset( intval( $_GET['id'] ) )
				));
				break;

			case 'font_delete':
				$font = $this->db->get_fontset( intval( $_GET['id'] ) );
				echo $this->twig->render( 'fontset-delete.twig', array( 'font' => $font ) );
				break;

			case 'settings':
				// $this->helpers->check_is_writeable( plugin_dir_path( __FILE__ ) . 'css/fontsampler-css.css', true );
				$settings = $this->db->get_default_settings();

				// generate all necessary info for the live layout preview
				$layout = new FontsamplerLayout();
				$str = $layout->sanitizeString($settings['ui_order'], $settings);
				$layout->stringToArray($str);

				$ui_order = empty( $settings['ui_order'] )
					? $layout->arrayToString( $layout->getDefaultBlocks(), $settings )
					: $layout->sanitizeString( $settings['ui_order'], $settings );

				$blocks = array_merge( $layout->getDefaultBlocks(), $layout->stringToArray( $settings['ui_order'], $settings ) );

				echo $this->twig->render( 'settings.twig', array(
					'set' => $settings,
					'defaults' => $settings, // for the most part use 'set', but some sliders read the "default" value
					'ui_order'    => $ui_order,
					'blocks'      => $blocks
				));
				break;

			case 'settings_reset':
				echo $this->twig->render( 'settings-reset.twig' );
				break;

			case 'changelog':
				echo $this->twig->render( 'changelog.twig' );
				break;

			case 'about':
				echo $this->twig->render( 'about.twig' );
				break;

			case 'notifications':
				$notifications = $this->notifications->get_notifications();
				echo $this->twig->render( 'notifications.twig', array(
					'missing_files' => $notifications['fonts_missing_files'],
					'missing_fonts' => $notifications['sets_missing_fonts'],
					'missing_names' => $notifications['fonts_missing_name'],
					'missing_settings' => $notifications['settings_defaults'],
					'folder_permissions' => $notifications['folder_permissions']
				));
				break;

			default:
				$offset   = isset( $_GET['offset'] ) ? intval( $_GET['offset'] ) : 0;
				$num_rows = isset( $_GET['num_rows'] ) ? intval( $_GET['num_rows'] ) : 10;
				$initials = $this->db->get_samples_ids();
				$pagination = new FontsamplerPagination( $initials, $num_rows, true, $offset );

				$sets = $this->db->get_sets( $offset, $num_rows );

				echo $this->twig->render( 'sets.twig', array(
						'sets' => $sets,
						'pagination' => $pagination->pages('?page=fontsampler&amp;subpage=sets&amp;offset=###first###&amp;num_rows=###items###', sizeof($initials)),
					)
				);
				break;
		}

		echo '</section>';
	}


	/**
	 * Registered ajax action to get a mockup fontsampler in the admin interface
	 * for layout previewing
	 */
	function ajax_get_mock_fontsampler () {
		check_ajax_referer( 'ajax_get_mock_fontsampler', 'action', false );

		$layout = new FontsamplerLayout();

		$data = $_POST['data'];

		// data['ui_order'] contains a string with all the blocks transmitted
		// from the admin UI
		$fields = array_keys($layout->stringToArray($data['ui_order']));

		// fill all these with a simple "1", like they would be fetched from a
		// set in the db that has those fields enabled (or content in them signifiying
		// they should render)
		$fieldsFromUI = array_combine($fields, array_fill(0, sizeof($fields), 1));

		// emulate a set from the passed in mock data
		// if any field like "specimen" got not just passed in ui_order but as explicit
		// field with content, that overwrites the "1" array value
		$set = array_merge( $fieldsFromUI, $data, array(
			'multiline' => 0,
			'is_ltr' => 1
		));

		$font = plugin_dir_url( __FILE__ ) . 'admin/fonts/PTS55F-webfont.woff';
		$set['fonts'] = array('woff' => $font);

		// from this set create all blocks; pass in the generated set to make
		// sure all fields sync
		$blocks = $layout->stringToArray( $set['ui_order'], $set );
		$options = $this->db->get_settings();
		$settings = $options;

?>

			<div class='fontsampler-wrapper on-loading'
			     data-fonts='<?php echo $font; ?>'
				 data-initial-font='<?php echo $font; ?>'
			 >
				 <?php include( 'includes/interface.php' ); ?>
			</div>
				<?php
		die();
	}

}