<?php

// +----------------------------------------------------------------------+
// | Copyright 2013  Madpixels  (email : visualizer@madpixels.net)        |
// +----------------------------------------------------------------------+
// | This program is free software; you can redistribute it and/or modify |
// | it under the terms of the GNU General Public License, version 2, as  |
// | published by the Free Software Foundation.                           |
// |                                                                      |
// | This program is distributed in the hope that it will be useful,      |
// | but WITHOUT ANY WARRANTY; without even the implied warranty of       |
// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        |
// | GNU General Public License for more details.                         |
// |                                                                      |
// | You should have received a copy of the GNU General Public License    |
// | along with this program; if not, write to the Free Software          |
// | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,               |
// | MA 02110-1301 USA                                                    |
// +----------------------------------------------------------------------+
// | Author: Eugene Manuilov <eugene@manuilov.org>                        |
// +----------------------------------------------------------------------+
/**
 * Frontend module class.
 *
 * @category Visualizer
 * @package Module
 *
 * @since 1.0.0
 */
class Visualizer_Module_Frontend extends Visualizer_Module {

	const NAME = __CLASS__;

	/**
	 * The array of charts to render.
	 *
	 * @since 1.0.0
	 *
	 * @access private
	 * @var array
	 */
	private $_charts = array();

	/**
	 * Lazy render script.
	 *
	 * @access private
	 * @var bool
	 */
	private $lazy_render_script = true;

	/**
	 * Constructor.
	 *
	 * @since 1.0.0
	 * @uses add_filter() To add "do_shortcode" hook for "widget_text" and "term_description" filters.
	 *
	 * @access public
	 * @param Visualizer_Plugin $plugin The instance of the plugin.
	 */
	public function __construct( Visualizer_Plugin $plugin ) {
		parent::__construct( $plugin );

		$this->_addAction( 'wp_print_footer_scripts', 'printFooterScripts' );
		$this->_addAction( 'wp_enqueue_scripts', 'enqueueScripts' );
		$this->_addAction( 'load-index.php', 'enqueueScripts' );
		$this->_addAction( 'load-visualizer_page_visualizer-setup-wizard', 'enqueueScripts' );
		$this->_addAction( 'visualizer_enqueue_scripts', 'enqueueScripts' );
		$this->_addFilter( 'visualizer_get_language', 'getLanguage' );
		$this->_addShortcode( 'visualizer', 'renderChart' );

		// add do_shortocde hook for widget_text filter
		if ( ! has_filter( 'widget_text', 'do_shortcode' ) ) {
			add_filter( 'widget_text', 'do_shortcode' );
		}

		// add do_shortcode hook for term_description filter
		if ( ! has_filter( 'term_description', 'do_shortcode' ) ) {
			add_filter( 'term_description', 'do_shortcode' );
		}

		add_action( 'rest_api_init', array( $this, 'endpoint_register' ) );

		$this->_addFilter( 'script_loader_tag', 'script_loader_tag', null, 10, 3 );
	}

	/**
	 * Adds the async attribute to certain scripts.
	 */
	public function script_loader_tag( $tag, $handle, $src ) {
		if ( is_admin() ) {
			return $tag;
		}
		// Async scripts.
		$async_scripts = array( 'google-jsapi', 'chartjs', 'visualizer-datatables' );
		foreach ( $async_scripts as $async ) {
			if ( $async === $handle ) {
				$tag = str_replace( ' src', ' async src', $tag );
				break;
			}
		}

		// Async scripts.
		$scripts = array( 'dom-to-image' );
		foreach ( array( 'async', 'defer' ) as $attr ) {
			if ( wp_scripts()->get_data( $handle, $attr ) ) {
				break;
			}
			if ( in_array( $handle, $async_scripts, true ) || false === strpos( $handle, 'visualizer-' ) ) {
				break;
			}
			if ( ! preg_match( ":\s$attr(=|>|\s):", $tag ) ) {
				$tag = preg_replace( ':(?=></script>):', " $attr", $tag, 1 );
				if ( $this->lazy_render_script ) {
					$tag = str_replace( ' src', ' data-visualizer-script', $tag );
				}
			}
			// Only allow async or defer, not both.
			break;
		}
		return $tag;
	}

	/**
	 * Returns the language/locale.
	 */
	public function getLanguage( $dummy, $only_language ) {
		return $this->get_language();
	}


	/**
	 * Registers the endpoints
	 */
	public function endpoint_register() {
		register_rest_route(
			'visualizer/v' . VISUALIZER_REST_VERSION,
			'/action/(?P<chart>\d+)/(?P<type>.+)/',
			array(
				// POST is required for save/cancel, GET for all others
				'methods'  => array( 'POST', 'GET' ),
				'args'     => array(
					'chart' => array(
						'required' => true,
						'sanitize_callback' => function ( $param ) {
							return is_numeric( $param ) ? $param : null;
						},
					),
					'type' => array(
						'required' => true,
						'type' => 'string',
						'enum' => array_merge( array( 'save', 'cancel' ), array_keys( $this->get_actions() ) ),
					),
				),
				'permission_callback' => function ( WP_REST_Request $request ) {
					$chart_id   = filter_var( sanitize_text_field( $request->get_param( 'chart' ), FILTER_VALIDATE_INT ) );
					if ( ! empty( $chart_id ) && in_array( $request->get_param( 'type' ), array( 'save', 'cancel' ), true ) ) {
						// let save and cancel go without any check as past version of pro
						// did not send the X-WP-Nonce
						// we can change this at a later date.
						return true;
					}
					return ! empty( $chart_id ) && apply_filters( 'visualizer_pro_show_chart', true, $chart_id );
				},
				'callback' => array( $this, 'perform_action' ),
			)
		);
	}

	/**
	 * All possible actions and their labels
	 *
	 * @access private
	 */
	private function get_actions() {
		$actions = apply_filters(
			'visualizer_action_buttons',
			array(
				'print'     => array(
					'label' => esc_html__( 'Print', 'visualizer' ),
					'title' => esc_html__( 'Print Chart', 'visualizer' ),
				),
				'csv'       => array(
					'label' => esc_html__( 'CSV', 'visualizer' ),
					'title' => esc_html__( 'Download as a CSV', 'visualizer' ),
				),
				'xls'       => array(
					'label' => esc_html__( 'Excel', 'visualizer' ),
					'title' => esc_html__( 'Download as a spreadsheet', 'visualizer' ),
				),
				'copy'      => array(
					'label' => esc_html__( 'Copy', 'visualizer' ),
					'title' => esc_html__( 'Copy data', 'visualizer' ),
				),
				'image'      => array(
					'label' => esc_html__( 'Download', 'visualizer' ),
					'title' => esc_html__( 'Download as an image', 'visualizer' ),
				),
			)
		);

		// backward compatibility before label and title attributes were introduced.
		if ( isset( $actions['edit'] ) && is_string( $actions['edit'] ) ) {
			$actions['edit'] = array(
				'label' => esc_html__( 'Edit', 'visualizer' ),
				'title' => esc_html__( 'Edit data', 'visualizer' ),
			);
		}
		return $actions;
	}

	/**
	 * The print button
	 *
	 * @since 1.0.0
	 *
	 * @access public
	 */
	public function perform_action( WP_REST_Request $params ) {
		$chart_id   = filter_var( sanitize_text_field( $params['chart'] ), FILTER_VALIDATE_INT );
		$type       = sanitize_text_field( $params['type'] );
		$data       = null;

		if ( ! $chart_id ) {
			return new WP_REST_Response( array( 'error' => new WP_Error( __( 'Invalid chart ID', 'visualizer' ) ) ) );
		}

		if ( ! $type ) {
			return new WP_REST_Response( array( 'error' => new WP_Error( __( 'Invalid action', 'visualizer' ) ) ) );
		}

		switch ( $type ) {
			case 'print':
				$data   = $this->_getDataAs( $chart_id, 'print' );
				break;
			case 'csv':
				$data   = $this->_getDataAs( $chart_id, 'csv' );
				break;
			case 'xls':
				$data   = $this->_getDataAs( $chart_id, 'xls' );
				break;
			case 'image':
				$settings = get_post_meta( $chart_id, Visualizer_Plugin::CF_SETTINGS, true );
				$title       = 'visualizer#' . $chart_id;
				if ( ! empty( $settings['title'] ) ) {
					$title  = $settings['title'];
				}
				// for ChartJS, title is an array.
				if ( is_array( $title ) && isset( $title['text'] ) ) {
					$title = $title['text'];
				}
				if ( empty( $title ) ) {
					$title  = 'visualizer#' . $chart_id;
				}
				$data   = array( 'name' => $title );
				break;
			default:
				$data   = apply_filters( 'visualizer_action_data', $data, $chart_id, $type, $params, $this );
				break;
		}

		return new WP_REST_Response( array( 'data' => $data ) );
	}

	/**
	 * Registers scripts for charts rendering.
	 *
	 * @since 1.0.0
	 * @uses wp_register_script To register javascript file.
	 *
	 * @access public
	 */
	public function enqueueScripts() {
		wp_register_script( 'visualizer-customization', $this->get_user_customization_js(), array(), null, true );
		do_action( 'visualizer_pro_frontend_load_resources' );
	}

	/**
	 * Returns placeholder for chart according to visualizer shortcode attributes.
	 *
	 * @since 1.0.0
	 * @uses shortcode_atts() To parse income shortocdes.
	 * @uses apply_filters() To filter chart's data and series arrays.
	 * @uses get_post_meta() To fetch chart's meta information.
	 * @uses wp_enqueue_script() To enqueue charts render script.
	 * @uses wp_localize_script() To add chart data to the page inline script.
	 *
	 * @access public
	 * @param array $atts The array of shortcode attributes.
	 */
	public function renderChart( $atts ) {
		global $wp_version;
		$atts = shortcode_atts(
			array(
				// chart id
				'id'     => false,
				// chart class
				'class'  => false,
				// for lazy load
				// set 'yes' to use the default intersection limit (300px)
				// OR set a number (e.g. 700) to use 700px as the intersection limit
				'lazy' => apply_filters( 'visualizer_lazy_by_default', false, $atts['id'] ),
				// Use image chart
				'use_image' => 'no',
			),
			$atts
		);

		$atts['id']        = (int) $atts['id'];
		$atts['class']     = esc_attr( $atts['class'] );
		$atts['lazy']      = esc_attr( $atts['lazy'] );
		$atts['use_image'] = esc_attr( $atts['use_image'] );

		global $sitepress;
		if ( Visualizer_Module::is_pro() && ( function_exists( 'icl_get_languages' ) && $sitepress instanceof \SitePress ) ) {
			global $sitepress;
			$locale       = icl_get_current_language();
			$locale       = strtolower( str_replace( '_', '-', $locale ) );
			$trid         = $sitepress->get_element_trid( $atts['id'], 'post_' . Visualizer_Plugin::CPT_VISUALIZER );
			$translations = $sitepress->get_element_translations( $trid );
			if ( isset( $translations[ $locale ] ) && is_object( $translations[ $locale ] ) ) {
				$atts['id'] = $translations[ $locale ]->element_id;
			}
		}

		$chart_data = $this->getChartData( Visualizer_Plugin::CF_CHART_CACHE, $atts['id'] );
		// if empty chart does not exists, then return empty string.
		if ( ! $chart_data ) {
			return '';
		}

		$chart        = $chart_data['chart'];
		$type         = $chart_data['type'];
		$series       = $chart_data['series'];
		// do not show the chart?
		if ( ! apply_filters( 'visualizer_pro_show_chart', true, $atts['id'] ) ) {
			return '';
		}

		if ( ! is_admin() && ! empty( $chart_data['is_woocommerce_report'] ) ) {
			return '';
		}

		// in case revisions exist (skip D3 charts to avoid reverting AI data).
		$chart_library = get_post_meta( $chart->ID, Visualizer_Plugin::CF_CHART_LIBRARY, true );
		if ( 'd3' !== $chart_library ) {
			$revisions = $this->undoRevisions( $chart->ID, true );
			if ( true === $revisions ) {
				$chart = get_post( $chart->ID );
			}
		}

		$id = 'visualizer-' . $atts['id'];
		$defaultClass   = 'visualizer-front';
		$class = apply_filters( Visualizer_Plugin::FILTER_CHART_WRAPPER_CLASS, $atts['class'], $atts['id'] );

		$lazyClass = $atts['lazy'] === 'yes' || ctype_digit( $atts['lazy'] ) ? 'visualizer-lazy' : '';

		$class  = sprintf( '%s %s %s %s', $defaultClass, $class, 'visualizer-front-' . $atts['id'], $lazyClass );
		$attributes = array();
		if ( ! empty( $class ) ) {
			$attributes['class'] = trim( $class );
		}

		if ( ctype_digit( $atts['lazy'] ) ) {
			$attributes['data-lazy-limit'] = $atts['lazy'];
		}

		$attributes = apply_filters( 'visualizer_container_attributes', $attributes, $chart->ID );

		$chart = apply_filters( 'visualizer_schedule_refresh_chart', $chart, $chart->ID, false );

		// Get and update settings.
		$settings = $chart_data['settings'];
		$settings = ! empty( $settings ) ? $settings : array();
		if ( empty( $settings['height'] ) ) {
			$settings['height'] = '400';
		}

		// handle series filter hooks
		$series = apply_filters( Visualizer_Plugin::FILTER_GET_CHART_SERIES, $series, $chart->ID, $type );

		// handle settings filter hooks
		$settings = apply_filters( Visualizer_Plugin::FILTER_GET_CHART_SETTINGS, $settings, $chart->ID, $type );

		$lazy_load = isset( $settings['lazy_load_chart'] ) ? $settings['lazy_load_chart'] : false;
		$lazy_load = apply_filters( 'visualizer_lazy_load_chart', $lazy_load, $chart->ID );
		$container_class = 'visualizer-front-container';
		if ( ! $lazy_load ) {
			$this->lazy_render_script = false;
		} else {
			$container_class .= ' visualizer-lazy-render';
		}

		// handle data filter hooks
		$data   = self::get_chart_data( $chart, $type );

		$css        = '';
		$arguments  = $this->get_inline_custom_css( $id, $settings );
		if ( ! empty( $arguments ) ) {
			$css        = $arguments[0];
			$settings   = $arguments[1];
		}

		$library    = $this->load_chart_type( $chart->ID );

		$id         = $id . '-' . rand();

		$amp = Visualizer_Plugin::instance()->getModule( Visualizer_Module_AMP::NAME );
		if ( $amp && $amp->is_amp() ) {
			return '<div data-amp-auto-lightbox-disable id="' . $id . '"' . $this->getHtmlAttributes( $attributes ) . '>' . $amp->get_chart( $chart, $data, $series, $settings ) . '</div>';
		}

		if ( 'yes' === $atts['use_image'] ) {
			$chart_image = $chart_data['chart_image'];
			if ( $chart_image ) {
				return '<div id="' . $id . '"' . $this->getHtmlAttributes( $attributes ) . '>' . wp_get_attachment_image( $chart_image, 'full' ) . '</div>';
			}
		}
		// Unset chart image base64 string.
		if ( isset( $settings['chart-img'] ) ) {
			unset( $settings['chart-img'] );
		}

		$enable_controls = false;
		if ( isset( $settings['controls'] ) && ! empty( $settings['controls']['controlType'] ) ) {
			$column_index = $settings['controls']['filterColumnIndex'];
			$column_label = $settings['controls']['filterColumnLabel'];
			if ( 'false' !== $column_index || 'false' !== $column_label ) {
				$enable_controls = true;
			}
		}

		if ( ! $enable_controls ) {
			unset( $settings['controls'] );
		}

		// add chart to the array
		$chart_entry = array(
			'type'     => $type,
			'series'   => $series,
			'settings' => $settings,
			'data'     => $data,
			'library'  => $library,
		);

		// For D3 charts, include the stored code so the renderer can execute it.
		if ( 'd3' === $library ) {
			$chart_entry['code'] = get_post_meta( $chart->ID, Visualizer_Module_AIBuilder::CF_D3_CODE, true );
		}

		$this->_charts[ $id ] = $chart_entry;

		$actions_div            = '';
		$actions_visible        = apply_filters( 'visualizer_pro_add_actions', isset( $settings['actions'] ) ? $settings['actions'] : array(), $atts['id'] );
		if ( ! empty( $actions_visible ) ) {
			$actions            = $this->get_actions();
			$actions_div        = '<div class="visualizer-actions">';
			foreach ( $actions_visible as $action_type ) {
				$key            = $action_type;
				$mime           = '';
				if ( strpos( $action_type, ';' ) !== false ) {
					$array      = explode( ';', $action_type );
					$key        = $array[0];
					$mime       = end( $array );
				}
				$label          = $actions[ $key ]['label'];
				$title          = $actions[ $key ]['title'];
				$actions_div    .= sprintf( '<a href="#" class="visualizer-action visualizer-action-%s" data-visualizer-type="%s" data-visualizer-chart-id="%s" data-visualizer-container-id="%s" data-visualizer-mime="%s" title="%s"', $key, $key, $atts['id'], $id, $mime, $title );

				if ( 'copy' === $key ) {
					$copy           = $this->_getDataAs( $atts['id'], 'csv' );
					$actions_div    .= ' data-clipboard-text="' . esc_attr( $copy['csv'] ) . '"';
					wp_enqueue_script( 'clipboard' );
				}

				$actions_div    .= apply_filters( 'visualizer_action_attributes', '', $key, $atts['id'] );
				$actions_div    .= '>' . $label . '</a> &nbsp;';
			}

			$actions_div        .= '</div>';
		}

		$actions_div            .= $css;

		$_charts = array();
		$_charts_type = '';
		$count = 0;
		static $visualizer_localized = false;
		static $visualizer_charts = array();
		static $d3_localized = false;
		$facade_handle = 'visualizer-render-facade';
		foreach ( $this->_charts as $id => $array ) {
			$_charts = $this->_charts;
			$library = $array['library'];
			$_charts_type = $library;
			$facade_deps = apply_filters( 'visualizer_assets_render', array( 'jquery', 'visualizer-customization' ), true );
			if ( ! wp_script_is( $facade_handle, 'registered' ) ) {
				wp_register_script(
					$facade_handle,
					VISUALIZER_ABSURL . 'js/render-facade.js',
					$facade_deps,
					Visualizer_Plugin::VERSION,
					true
				);
				wp_enqueue_script( $facade_handle );
			} else {
				// Ensure newly discovered dependencies are attached to the facade.
				global $wp_scripts;
				if ( isset( $wp_scripts->registered[ $facade_handle ] ) ) {
					$wp_scripts->registered[ $facade_handle ]->deps = array_unique(
						array_merge( $wp_scripts->registered[ $facade_handle ]->deps, $facade_deps )
					);
				}
				foreach ( $facade_deps as $dep_handle ) {
					wp_enqueue_script( $dep_handle );
				}
			}

			// For D3 charts, also enqueue the dedicated renderer bundle.
			if ( 'd3' === $library ) {
				$d3_renderer_asset = VISUALIZER_ABSPATH . '/classes/Visualizer/D3Renderer/build/index.asset.php';
				if ( file_exists( $d3_renderer_asset ) && ! wp_script_is( 'visualizer-d3-renderer', 'registered' ) ) {
					/**
					 * Ignore missing build asset in source checkout.
					 *
					 * @phpstan-ignore-next-line
					 */
					$d3_asset = include $d3_renderer_asset;
					wp_register_script(
						'visualizer-d3-renderer',
						VISUALIZER_ABSURL . 'classes/Visualizer/D3Renderer/build/index.js',
						array_merge( $d3_asset['dependencies'], array( 'jquery' ) ),
						$d3_asset['version'],
						true
					);
					wp_enqueue_script( 'visualizer-d3-renderer' );
				}
				if ( ! $d3_localized ) {
					wp_localize_script(
						'visualizer-d3-renderer',
						'vizD3Renderer',
						array(
							'iframeJsUrl' => VISUALIZER_ABSURL . 'classes/Visualizer/D3Renderer/build/iframe.js',
						)
					);
					$d3_localized = true;
				}
			}

			if ( wp_script_is( $facade_handle ) && 0 === $count ) {
				if ( ! $visualizer_localized ) {
					$visualizer_charts = $this->_charts;
					wp_localize_script(
						$facade_handle,
						'visualizer',
						array(
							'charts'        => $this->_charts,
							'language'      => $this->get_language(),
							'map_api_key'   => get_option( 'visualizer-map-api-key' ),
							'rest_url'      => version_compare( $wp_version, '4.7.0', '>=' ) ? rest_url( 'visualizer/v' . VISUALIZER_REST_VERSION . '/action/#id#/#type#/' ) : '',
							'wp_nonce'      => wp_create_nonce( 'wp_rest' ),
							'i10n'          => array(
								'copied'        => __( 'The data has been copied to your clipboard. Hit Ctrl-V/Cmd-V in your spreadsheet editor to paste the data.', 'visualizer' ),
							),
							'page_type' => 'frontend',
							'is_front'  => true,
						)
					);
					$visualizer_localized = true;
				} else {
					$new_charts = array_diff_key( $this->_charts, $visualizer_charts );
					if ( ! empty( $new_charts ) ) {
						wp_add_inline_script(
							$facade_handle,
							'window.visualizer = window.visualizer || {};' .
							'window.visualizer.charts = Object.assign(window.visualizer.charts || {}, ' . wp_json_encode( $new_charts ) . ');',
							'before'
						);
						$visualizer_charts = array_merge( $visualizer_charts, $new_charts );
					}
				}
			}
			++$count;
		}
		$prefix = 'C' . 'h' . 'a' . 'rt';
		if ( $type === 'tabular' ) {
			$prefix = 'T' . 'a' . 'bl' . 'e';
		}
		if ( Visualizer_Module::is_pro() && $enable_controls ) {
			$actions_div .= '<div id="control_wrapper_' . $id . '"></div>';
		}
		// return placeholder div
		return '<div class="' . $container_class . '" id="chart_wrapper_' . $id . '">' . $actions_div . '<div id="' . $id . '"' . $this->getHtmlAttributes( $attributes ) . '></div>' . $this->addSchema( $chart->ID ) . '</div>';
	}

	/**
	 * Converts the array of attributes to a string of HTML attributes.
	 *
	 * @since ?
	 *
	 * @access private
	 */
	private function getHtmlAttributes( $attributes ) {
		$string = '';
		if ( ! $attributes ) {
			return $string;
		}

		foreach ( $attributes as $name => $value ) {
			$string .= sprintf( ' %s="%s"', esc_attr( $name ), esc_attr( $value ) );
		}
		return $string;
	}

	/**
	 * Adds the schema corresponding to the dataset.
	 *
	 * @since 3.3.2
	 *
	 * @access private
	 */
	private function addSchema( $id ) {
		// should we show informative errors as HTML comments?
		$show_errors = apply_filters( 'visualizer_schema_show_errors', true, $id );

		$settings = get_post_meta( $id, Visualizer_Plugin::CF_SETTINGS, true );
		$title = '';
		if ( isset( $settings['title'] ) && ! empty( $settings['title'] ) ) {
			$title  = $settings['title'];
			if ( is_array( $title ) ) {
				$title  = $settings['title']['text'];
			}
		}
		$title = apply_filters( 'visualizer_schema_name', $title, $id );
		if ( empty( $title ) ) {
			if ( $show_errors ) {
				return "<!-- Not showing structured data for chart $id because title is empty -->";
			}
			return '';
		}

		$desc = '';
		if ( isset( $settings['description'] ) && ! empty( $settings['description'] ) ) {
			$desc  = $settings['description'];
		}
		$desc = apply_filters( 'visualizer_schema_description', $desc, $id );
		if ( empty( $desc ) ) {
			if ( $show_errors ) {
				return "<!-- Not showing structured data for chart $id because description is empty -->";
			}
			return '';
		}

		// descriptions below 50 chars are not allowed.
		if ( strlen( $desc ) < 50 ) {
			if ( $show_errors ) {
				return "<!-- Not showing structured data for chart $id because description is shorter than 50 characters -->";
			}
			return '';
		}

		$license = '';
		if ( isset( $settings['license'] ) && ! empty( $settings['license'] ) ) {
			$license  = $settings['license'];
			if ( is_array( $license ) ) {
				$license  = $settings['license']['text'];
			}
		}
		$license = apply_filters( 'visualizer_schema_license', $license, $id );
		if ( empty( $license ) ) {
			if ( $show_errors ) {
				return "<!-- Not showing structured data for chart $id because license is empty -->";
			}
			return '';
		}

		$creator = '';
		if ( isset( $settings['creator'] ) && ! empty( $settings['creator'] ) ) {
			$creator  = $settings['creator'];
			if ( is_array( $creator ) ) {
				$creator  = $settings['creator']['text'];
			}
		}
		$creator = apply_filters( 'visualizer_schema_creator', $creator, $id );
		if ( empty( $creator ) ) {
			if ( $show_errors ) {
				return "<!-- Not showing structured data for chart $id because creator is empty -->";
			}
			return '';
		}

		$schema = apply_filters(
			'visualizer_schema',
			'{
			  "@context":"https://schema.org/",
			  "@type":"Dataset",
			  "name":"' . esc_html( $title ) . '",
			  "description":"' . esc_html( $desc ) . '",
			  "license": "' . esc_html( $license ) . '",
			  "creator": {
			  	"@type": "Person",
			  	"name": "' . esc_html( $creator ) . '"
			  }
			}',
			$id
		);

		if ( empty( $schema ) ) {
			return '';
		}

		return '<script type="application/ld+json">' . $schema . '</script>';
	}

	/**
	 * Get chart by ID.
	 *
	 * @param string $cache_key Cache key.
	 * @param int    $chart_id Chart ID.
	 * @return mixed
	 */
	private function getChartData( $cache_key = '', $chart_id = 0 ) {
		if ( ! $chart_id ) {
			return false;
		}
		// Create unique cache key of each chart.
		$cache_key .= '_' . $chart_id;
		// Get chart from cache.
		$chart = get_transient( $cache_key );
		if ( $chart ) {
			return $chart;
		}

		// Get chart by ID.
		$chart = get_post( $chart_id );
		if ( $chart && Visualizer_Plugin::CPT_VISUALIZER === $chart->post_type ) {
			$settings              = get_post_meta( $chart->ID, Visualizer_Plugin::CF_SETTINGS, true );
			$series                = get_post_meta( $chart->ID, Visualizer_Plugin::CF_SERIES, true );
			$is_woocommerce_report = get_post_meta( $chart->ID, Visualizer_Plugin::CF_IS_WOOCOMMERCE_SOURCE, true );

			if ( isset( $settings['series'] ) && ! ( count( $settings['series'] ) - count( $series ) > 1 ) ) {
				$diff_total_series = abs( count( $settings['series'] ) - count( $series ) );
				if ( $diff_total_series ) {
					foreach ( range( 1, $diff_total_series ) as $k => $diff_series ) {
						$settings['series'][] = end( $settings['series'] );
					}
				}
			}
			$chart_data = array(
				'chart'                 => $chart,
				'type'                  => get_post_meta( $chart->ID, Visualizer_Plugin::CF_CHART_TYPE, true ),
				'settings'              => $settings,
				'series'                => $series,
				'chart_image'           => get_post_meta( $chart->ID, Visualizer_Plugin::CF_CHART_IMAGE, true ),
				'is_woocommerce_report' => $is_woocommerce_report,
			);

			// Put the results in a transient. Expire after 12 hours.
			set_transient( $cache_key, $chart_data, apply_filters( Visualizer_Plugin::FILTER_HANDLE_CACHE_EXPIRATION_TIME, 12 * HOUR_IN_SECONDS ) );
			return $chart_data;
		}

		return false;
	}

	/**
	 * Print footer script.
	 */
	public function printFooterScripts() {
		if ( $this->lazy_render_script ) {
			?>
		<script type="text/javascript">
			var visualizerUserInteractionEvents = [
				"scroll",
				"mouseover",
				"keydown",
				"touchmove",
				"touchstart"
			];

			visualizerUserInteractionEvents.forEach(function(event) {
				window.addEventListener(event, visualizerTriggerScriptLoader, { passive: true });
			});

			function visualizerTriggerScriptLoader() {
				visualizerLoadScripts();
				visualizerUserInteractionEvents.forEach(function(event) {
					window.removeEventListener(event, visualizerTriggerScriptLoader, { passive: true });
				});
			}

			function visualizerLoadScripts() {
				document.querySelectorAll("script[data-visualizer-script]").forEach(function(elem) {
					jQuery.getScript( elem.getAttribute("data-visualizer-script") )
					.done( function( script, textStatus ) {
						elem.setAttribute("src", elem.getAttribute("data-visualizer-script"));
						elem.removeAttribute("data-visualizer-script");
						setTimeout( function() {
							visualizerRefreshChart();
						} );
					} );
				});
			}

			function visualizerRefreshChart() {
				jQuery( '.visualizer-front:not(.visualizer-chart-loaded)' ).resize();
				if ( jQuery( 'div.viz-facade-loaded:not(.visualizer-lazy):empty' ).length > 0 ) {
					visualizerUserInteractionEvents.forEach( function( event ) {
						window.addEventListener( event, function() {
							jQuery( '.visualizer-front:not(.visualizer-chart-loaded)' ).resize();
						}, { passive: true } );
					} );
				}
			}
		</script>
			<?php
		}
	}
}
