<?php

if (!defined('ABSPATH')) {
    die('No direct access.');
}

/**
 * Generic Slider super class. Extended by library specific classes.
 */
class MetaImageSlide extends MetaSlide
{
    /**
     * Slide type
     *
     * @var string
     */
    public $identifier = 'image';

    /**
     * Register slide type
     */
    public function __construct()
    {
        parent::__construct();
        add_filter('metaslider_get_image_slide', array($this, 'get_slide' ), 10, 2);
        add_filter('metaslider_html_purifier_config', array($this, 'html_purifier_config'));
        add_action('metaslider_save_image_slide', array($this, 'save_slide' ), 5, 3);
        add_action('wp_ajax_create_image_slide', array($this, 'ajax_create_image_slides'));
        add_action('wp_ajax_resize_image_slide', array($this, 'ajax_resize_slide'));
        add_action('wp_ajax_duplicate_slide', array( $this, 'ajax_duplicate_slide' ));
    }

    /**
     * Creates one or more slide.
     * Currently this is used via an ajax call, but plans to keep this only called
     * by PHP methods, such as in an import situation.
     *
     * @param int   $slideshow_id The id of the slider
     * @param array $data         The data information for the new slide
     *
     * @return array | WP_error The status message and if success, an array of slide ids
     */
    public function create_slides($slideshow_id, $data)
    {
        $errors = array();
        $slides = array();
        foreach ($data as $slide_data) {
            // TODO check type and create slides based on that type
            // $method = 'create_' . $slide['type'] . '_slide';
            // $this->slider->add_slide($this->{$method}());
            $result = $this->add_slide($slideshow_id, $slide_data);
            if (is_wp_error($result)) {
                array_push($errors, $result);
            } else {
                array_push($slides, $result);
            }
        }

        // We don't bail on an error, so we need to send back a list of errors, if any
        if (count($errors)) {
            $error_response = new WP_Error('create_failed', 'We experienced some errors while adding slides.', array('status' => 409));
            foreach ($errors as $message) {
                $error_response->add('create_failed', $message, array('status' => 409));
            }
            return $error_response;
        }

        return $slides;
    }

    /**
     * Adds a single slide.
     * TODO refactor and put this in a Slider class
     *
     * @param int   $slideshow_id The id of the slider
     * @param array $data         The data information for the new slide
     *
     * @return array | WP_Error The slide_id and html content
     */
    public function add_slide($slideshow_id, $data)
    {

        // For now this only handles images, so check it's an image
        if (!wp_attachment_is_image($data['id'])) {
            // TODO this is the old way to handle errors
            // Remove this later and handle errors using data returns
            //echo '<tr><td colspan="2">ID: ' . esc_html($data['id']) . ' "' . esc_html(get_the_title($data['id'])) . '" - ' . esc_html__("Failed to add slide. Slide is not an image.", 'ml-slider') . "</td></tr>";

            return new WP_Error('create_failed', __('This isn\'t a valid image format. Please try again.', 'ml-slider'), array('status' => 409));
        }

        $slide_id = $this->insert_slide($data['id'], $data['type'], $slideshow_id);
        if (is_wp_error($slide_id)) {
            return $slide_id;
        }


        // TODO refactor these and investigate why they are needed (legacy?)
        $this->set_slide($slide_id);
        $this->set_slider($slideshow_id);
        $this->tag_slide_to_slider();

        // set default inherit values
        $this->set_field_inherited('title', true);
        $this->set_field_inherited('alt', true);

        // TODO investigate if this is really needed
        $this->settings['width'] = 0;
        $this->settings['height'] = 0;

        // Return the html object
        return array('slide_id' => $slide_id, 'html' => $this->get_admin_slide());
    }

    /**
     * Ajax wrapper to create multiple slides.
     * TODO: deprecate this in favor of only allowing single slide creation
     *
     * @return string The status message and if success, the count of slides added
     */
    public function ajax_create_image_slides()
    {
        if (! isset($_REQUEST['_wpnonce']) || ! wp_verify_nonce(sanitize_key($_REQUEST['_wpnonce']), 'metaslider_create_slide')) {
            wp_send_json_error(array(
                'message' => __('The security check failed. Please refresh the page and try again.', 'ml-slider')
            ), 401);
        }

        $capability = apply_filters('metaslider_capability', MetaSliderPlugin::DEFAULT_CAPABILITY_EDIT_SLIDES);
        if (! current_user_can($capability)) {
            wp_send_json_error(
                [
                    'message' => __('Access denied. Sorry, you do not have permission to complete this task.', 'ml-slider')
                ],
                403
            );
        }

        if (! isset($_POST['slider_id']) || ! isset($_POST['selection'])) {
            wp_send_json_error(
                [
                    'message' => __('Bad request', 'ml-slider'),
                ],
                400
            );
        }

        $capability = apply_filters('metaslider_capability', MetaSliderPlugin::DEFAULT_CAPABILITY_EDIT_SLIDES);
        if (! current_user_can($capability)) {
            wp_send_json_error(
                [
                    'message' => __('Access denied. Sorry, you do not have permission to complete this task.', 'ml-slider')
                ],
                403
            );
        }

        if(empty($_POST['slider_id'])) {
            $slider_id = MetaSlider_Slideshows::create();
        } else {
            $slider_id = absint($_POST['slider_id']);
        }

        $slides = $this->create_slides(
            $slider_id,
            array_map(array($this, 'make_image_slide_data'), $_POST['selection']) // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
        );

        if (is_wp_error($slides)) {
            wp_send_json_error(array(
                'messages' => $slides->get_error_messages()
            ), 409);
        }

        if(empty($_POST['slider_id'])) {
            $response = $slider_id;
        } else {
            $response = $slides;
        }
        
        wp_send_json_success($response, 200);
    }

    /**
     * Adds the type and image id to an array
     *
     * @param  int $image_id Image ID
     * @return array
     */
    public function make_image_slide_data($image_id)
    {
        return array(
            'type' => 'image',
            'id'   => absint($image_id)
        );
    }

    /**
     * Updates the slide data.
     *
     * @param int $slide_id     The id of the slide being updated
     * @param int $image_id     The id of the new image to use
     * @param int $slideshow_id The id of the slideshow
     *
     * @return array|WP_error The status message and if success, details
     */
    public function update_slide($slide_id, $image_id, $slideshow_id = null)
    {
        // Currently only the image
        $image_data = $this->update_slide_image($slide_id, $image_id, $slideshow_id);
        if (is_wp_error($image_data)) {
            return $image_data;
        }

        return array(
            'image' => $image_data
        );
    }

    /**
     * Ajax wrapper to create new cropped images.
     *
     * @return string The status message
     */
    public function ajax_resize_slide()
    {
        if (! isset($_REQUEST['_wpnonce']) || ! wp_verify_nonce(sanitize_key($_REQUEST['_wpnonce']), 'metaslider_resize')) {
            wp_send_json_error(array(
                'message' => __('The security check failed. Please refresh the page and try again.', 'ml-slider')
            ), 401);
        }

        $capability = apply_filters('metaslider_capability', MetaSliderPlugin::DEFAULT_CAPABILITY_EDIT_SLIDES);
        if (! current_user_can($capability)) {
            wp_send_json_error(
                [
                    'message' => __('Access denied. Sorry, you do not have permission to complete this task.', 'ml-slider')
                ],
                403
            );
        }

        if (! isset($_POST['slider_id']) || ! isset($_POST['slide_id'])) {
            wp_send_json_error(
                [
                    'message' => __('Bad request', 'ml-slider'),
                ],
                400
            );
        }

        $slideshow_id = absint($_POST['slider_id']);
        $slide_id = absint($_POST['slide_id']);
        $settings = get_post_meta($slideshow_id, 'ml-slider_settings', true);
        if (empty($settings) || !is_array($settings)) {
            $settings = array();
        }

        $result = $this->resize_slide($slide_id, $slideshow_id, $settings);

        do_action("metaslider_ajax_resize_image_slide", $slide_id, $slideshow_id, $settings);

        if (is_wp_error($result)) {
            wp_send_json_error(array(
                'messages' => $result->get_error_messages()
            ), 409);
        }

        wp_send_json_success($result, 200);
    }

    /**
     * Function to create new cropped images.
     *
     * @param string $slide_id     - The id of the slide being cropped
     * @param string $slideshow_id - The id of the slideshow
     * @param array  $settings     - The settings for the slideshow
     *
     * @return array
     */
    public function resize_slide($slide_id, $slideshow_id, $settings = array())
    {

        // Required for the eventual cropping to take place
        $this->set_slide($slide_id);
        $this->set_slider($slideshow_id);

        // Use what's provided, or grab it from the database. If settings is false, set it as an empty array
        $settings = empty($settings) ? get_post_meta($slideshow_id, 'ml-slider_settings', true) : $settings;
        if (!$settings) {
            $settings = array();
        }

        // Create a copy of the correct sized image
        $imageHelper = new MetaSliderImageHelper(
            $slide_id,
            isset($settings['width']) ? $settings['width'] : 0,
            isset($settings['height']) ? $settings['height'] : 0,
            isset($settings['smartCrop']) ? $settings['smartCrop'] : 'false',
            $this->use_wp_image_editor()
        );

        $url = $imageHelper->get_image_url(true);

        do_action("metaslider_resize_image_slide", $slide_id, $slideshow_id, $settings);
        return array('img_url' => $url);
    }

    public function duplicate_slide($slideshow_id, $slide_id)
    {
        $old_slide = get_post($slide_id);
        if (!$old_slide) {
            return 0;
        }
        $title = $old_slide->post_title;
        $post_excerpt = '';
        if(isset($old_slide->post_excerpt)){
            $post_excerpt = $old_slide->post_excerpt;
        }
        $new_slide = [
            'post_title'  => $title,
            'post_name'   => sanitize_title($title),
            'post_status' => 'publish',
            'post_type'   => $old_slide->post_type,
            'post_excerpt'   => $post_excerpt
        ];
        $new_slide_id = wp_insert_post($new_slide);
        $slide_meta = get_post_custom($slide_id);
        foreach ($slide_meta as $key => $values) {
            foreach ($values as $value) {
                add_post_meta($new_slide_id, $key, maybe_unserialize($value));
            }
        }
        $taxonomies = get_post_taxonomies($slide_id);
        foreach ($taxonomies as $taxonomy) {
            $term_ids = wp_get_object_terms($slide_id, $taxonomy, ['fields' => 'ids']);
            wp_set_object_terms($new_slide_id, $term_ids, $taxonomy);
        }

        $this->set_slide($new_slide_id);
        $this->set_slider($slideshow_id);

        return array('slide_id' => $new_slide_id, 'html' => $this->get_admin_slide());
    }

    public function ajax_duplicate_slide()
    {
        if (! isset($_REQUEST['_wpnonce']) || ! wp_verify_nonce(sanitize_key($_REQUEST['_wpnonce']), 'metaslider_duplicate_slide')) {
            wp_send_json_error(array(
                'message' => __('The security check failed. Please refresh the page and try again.', 'ml-slider')
            ), 401);
        }

        $capability = apply_filters('metaslider_capability', MetaSliderPlugin::DEFAULT_CAPABILITY_EDIT_SLIDES);
        if (! current_user_can($capability)) {
            wp_send_json_error(
                [
                    'message' => __('Access denied', 'ml-slider')
                ],
                403
            );
        }


        if (! isset($_POST['slide_id']) || ! isset($_POST['slider_id'])) {
            wp_send_json_error(
                [
                    'message' => __('Bad request', 'ml-slider'),
                ],
                400
            );
        }

        $result = $this->duplicate_slide(
            absint($_POST['slider_id']),
            absint($_POST['slide_id'])
        );

        wp_send_json_success($result, 200);
    }

    /**
     * Return the HTML used to display this slide in the admin screen
     *
     * @return string slide html
     */
    protected function get_admin_slide()
    {

        // get some slide settings
        $slide_label    = apply_filters("metaslider_image_slide_label", esc_html__("Image Slide", "ml-slider"), $this->slide, $this->settings);
        $attachment_id  = $this->get_attachment_id();

        ob_start();
        echo $this->get_delete_button_html(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
        echo $this->get_update_image_button_html(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
        echo $this->get_duplicate_slide_button_html(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
        do_action('metaslider-slide-edit-buttons', 'image', $this->slide->ID, $attachment_id);
        $edit_buttons = ob_get_clean();

        // slide row HTML
        $row  = "<tr id='slide-" . esc_attr($this->slide->ID) . "' class='slide image flex responsive nivo coin' data-attachment-id='" . esc_attr($attachment_id) . "'>
                    <td class='col-1'>
                        <div class='metaslider-ui-controls ui-sortable-handle rtl:pl-0 rtl:pr-3'>
                        <h4 class='slide-details'>" . esc_html($slide_label) . " | ID: ". esc_html($this->slide->ID) ."</h4>";
        if (metaslider_this_is_trash($this->slide)) {
            $row .= '<div class="row-actions trash-btns">';
            $row .= "<span class='untrash'>{$this->get_undelete_button_html()}</span>";
            $row .= ' | ';
            $row .= "<span class='delete'>{$this->get_permanent_delete_button_html()}</span>";
            $row .= '</div>';
        } else {
            $row .= $edit_buttons;
        }
        $row .=         "</div>
                    </td>
					<td class='col-2'>" .
                    // For now this is the entry point for a slide since you cant wrap around table elements.
                    "<metaslider-slide id='" . esc_attr($this->slide->ID) . "' inline-template>
                        <div class='metaslider-ui-inner flex flex-col h-full'>
                            " . $this->get_admin_slide_tabs_html() . "
                            <input type='hidden' name='attachment[" . esc_attr($this->slide->ID) . "][type]' value='image' />
                            <input type='hidden' class='menu_order' name='attachment[" . esc_attr($this->slide->ID) . "][menu_order]' value='" . esc_attr($this->slide->menu_order) . "' />
                            <input type='hidden' name='resize_slide_id' data-slide_id='" . esc_attr($this->slide->ID) . "' data-width='" . esc_attr($this->settings['width']) . "' data-height='" . esc_attr($this->settings['height']) . "' />
						</div>
					</metaslider-slide>
                    </td>
                </tr>";

        return $row;
    }

    /**
     * Build an array of tabs and their titles to use for the admin slide.
     */
    public function get_admin_tabs()
    {
        $slide_id       = absint( $this->slide->ID );
        $attachment_id  = $this->get_attachment_id();
        $attachment     = get_post( $attachment_id );

        // alt
        $alt = esc_attr(get_post_meta($slide_id, '_wp_attachment_image_alt', true));
        $image_alt = esc_attr(get_post_meta($attachment_id, '_wp_attachment_image_alt', true));
        $inherit_image_alt_check = false; // Converted from string to bool @since 3.60 
        $inherit_image_alt_class = '';
        if ($this->is_field_inherited('alt')) {
            $inherit_image_alt_check = true; // Converted from string to bool @since 3.60 
            $inherit_image_alt_class = ' inherit-from-image';
        }
        // title
        $title = esc_attr(get_post_meta($slide_id, 'ml-slider_title', true));
        $image_title = esc_attr($attachment->post_title);
        $inherit_image_title_check = false; // Converted from string to bool @since 3.60 
        $inherit_image_title_class = '';
        if ($this->is_field_inherited('title')) {
            $inherit_image_title_check = true; // Converted from string to bool @since 3.60 
            $inherit_image_title_class = ' inherit-from-image';
        }

        // alt link
        $link_alt = get_post_meta($slide_id, 'ml-slider_link-alt', true);

        // URL and target
        $url    = get_post_meta( $slide_id, 'ml-slider_url', true );
        $target = get_post_meta( $slide_id, 'ml-slider_new_window', true );

        ob_start();
        include METASLIDER_PATH . 'admin/views/slides/tabs/general.php';
        $general_tab = ob_get_clean();

        if (!$this->is_valid_image()) {
            $message = __("Warning: The image data does not exist. Please re-upload the image.", "ml-slider");

            $general_tab = "<div class='warning'>{$message}</div>" . $general_tab;
        }

        ob_start();
        include METASLIDER_PATH . 'admin/views/slides/tabs/link.php';
        $link_tab = ob_get_clean();

        ob_start();
        include METASLIDER_PATH . 'admin/views/slides/tabs/seo.php';
        $seo_tab = ob_get_clean();

        $tabs = array(
            'general' => array(
                'title' => __("General", "ml-slider"),
                'content' => $general_tab
            ),
            'link' => array(
                'title' => __( "Link", "ml-slider" ),
                'content' => $link_tab
            ),
            'seo' => array(
                'title' => __("SEO", "ml-slider"),
                'content' => $seo_tab
            )
        );

        $ms_slider = new MetaSliderPlugin();
        $global_settings = $ms_slider->get_global_settings();
        if (
            !isset($global_settings['mobileSettings']) ||
            (isset($global_settings['mobileSettings']) && true == $global_settings['mobileSettings'])
        ) {
            ob_start();
            include METASLIDER_PATH . 'admin/views/slides/tabs/mobile.php';
            $mobile_tab = ob_get_clean();

            $tabs['mobile'] = array(
                'title' => __("Mobile", "ml-slider"),
                'content' => $mobile_tab
            );
        }

        if (version_compare(get_bloginfo('version'), 3.9, '>=')) {
            $crop_position = get_post_meta($slide_id, 'ml-slider_crop_position', true);

            if (!$crop_position) {
                $crop_position = 'center-center';
            }

            ob_start();
            include METASLIDER_PATH . 'admin/views/slides/tabs/crop.php';
            $crop_tab = ob_get_clean();

            $tabs['crop'] = array(
                'title' => __("Crop", "ml-slider"),
                'content' => $crop_tab
            );
        }

        // Adds schedule tab
        ob_start();
        include METASLIDER_PATH . 'admin/views/slides/tabs/schedule.php';
        $schedule_tab = ob_get_contents();
        ob_end_clean();

        $tabs['schedule'] = array(
            'title' => __('Schedule', 'ml-slider'),
            'content' => $schedule_tab
        );

        return apply_filters("metaslider_image_slide_tabs", $tabs, $this->slide, $this->slider, $this->settings);
    }


    /**
     * Check to see if metadata exists for this image. Assume the image is
     * valid if metadata and a size exists for it (generated during initial
     * upload to WordPress).
     *
     * @return bool, true if metadata and size exists.
     */
    public function is_valid_image()
    {
        if (get_post_type($this->slide->ID) === 'attachment') {
            $image_id = $this->slide->ID;
        } else {
            $image_id = get_post_thumbnail_id($this->slide->ID);
        }

        $meta = wp_get_attachment_metadata($image_id);

        $is_valid = isset($meta['width'], $meta['height']);

        return apply_filters('metaslider_is_valid_image', $is_valid, $this->slide);
    }


    /**
     * Disable/enable image editor
     *
     * @return bool
     */
    public function use_wp_image_editor()
    {
        return apply_filters('metaslider_use_image_editor', $this->is_valid_image(), $this->slide);
    }


    /**
     * Returns the HTML for the public slide
     *
     * @return string slide html
     */
    protected function get_public_slide()
    {

        // get the image url (and handle cropping)
        // disable wp_image_editor if metadata does not exist for the slide
        $imageHelper = new MetaSliderImageHelper(
            $this->slide->ID,
            $this->settings['width'],
            $this->settings['height'],
            isset($this->settings['smartCrop']) ? $this->settings['smartCrop'] : 'false',
            $this->use_wp_image_editor()
        );

        $thumb = $imageHelper->get_image_url();
        $attachment_id = get_post_thumbnail_id($this->slide->ID);
        $attachment = get_post($attachment_id);

        // Leave this here as the caption used to be inhereted
        if ($this->is_field_inherited('caption')) {
            $caption = $attachment->post_excerpt;
        } else {
            $caption_source = get_post_meta($this->slide->ID, 'ml-slider_caption_source', true);
            switch ($caption_source) {
                case 'image-caption':
                    $caption = $attachment->post_excerpt;
                    break;
                case 'image-description':
                    $caption = $attachment->post_content;
                    break;
                default:
                    $caption = $this->slide->post_excerpt;
                    break;
            }
        }

        if ($this->detect_self_metaslider_shortcode($this->slide->post_excerpt)) {
            $caption = str_replace(array("[metaslider", "[ml-slider"), "[metaslider-disabled", $this->slide->post_excerpt);
        }

        if ($this->is_field_inherited('title')) {
            $title = $attachment->post_title;
        } else {
            $title = get_post_meta($this->slide->ID, 'ml-slider_title', true);
        }

        if ($this->is_field_inherited('alt')) {
            $alt = get_post_meta($attachment_id, '_wp_attachment_image_alt', true);
        } else {
            $alt = get_post_meta($this->slide->ID, '_wp_attachment_image_alt', true);
        }

        $link_alt = get_post_meta($this->slide->ID, 'ml-slider_link-alt', true);


        // store the slide details
        $slide = array(
            'id' => $this->slide->ID,
            'url' => get_post_meta($this->slide->ID, 'ml-slider_url', true),
            'title' => $title,
            'target' => get_post_meta($this->slide->ID, 'ml-slider_new_window', true) ? '_blank' : '_self',
            'src' => $thumb,
            'thumb' => $thumb, // backwards compatibility with Vantage
            'width' => $this->settings['width'],
            'height' => $this->settings['height'],
            'alt' => $alt,
            'link-alt' => $link_alt,
            'caption' => html_entity_decode(do_shortcode($caption), ENT_NOQUOTES, 'UTF-8'),
            'caption_raw' => do_shortcode($caption),
            'class' => "slider-{$this->slider->ID} slide-{$this->slide->ID}",
            'rel' => "",
            'data-thumb' => ""
        );

        // Remove unsafe html but let users that rely on this to override
        if (apply_filters('metaslider_filter_unsafe_html', true, $slide, $this->slider->ID, $this->settings) && $slide['caption']) {
            try {
                if (!class_exists('HTMLPurifier')) {
                    require_once(METASLIDER_PATH . 'lib/htmlpurifier/library/HTMLPurifier.auto.php');
                }
                $config = HTMLPurifier_Config::createDefault();
                // How to filter:
                // add_filter('metaslider_html_purifier_config', function($config) {
                //     $config->set('HTML.Allowed', 'a[href|target]');
                //     $config->set('Attr.AllowedFrameTargets', array('_blank'));
                //     return $config;
                // });
                $config = apply_filters('metaslider_html_purifier_config', $config, $slide, $this->slider->ID, $this->settings);
                $purifier = new HTMLPurifier($config);
                $slide['caption'] = $purifier->purify($slide['caption']);
            } catch (Exception $e) {
                // If something goes wrong then escape
                $slide['caption'] = htmlspecialchars(do_shortcode($caption), ENT_NOQUOTES, 'UTF-8');
            }
        }

        // fix slide URLs
        if (strpos($slide['url'], 'www.') === 0) {
            $slide['url'] = 'http://' . $slide['url'];
        }

        $slide = apply_filters('metaslider_image_slide_attributes', $slide, $this->slider->ID, $this->settings);

        // return the slide HTML
        switch ($this->settings['type']) {
            case "coin":
                return $this->get_coin_slider_markup($slide);
            case "flex":
                return $this->get_flex_slider_markup($slide);
            case "nivo":
                return $this->get_nivo_slider_markup($slide);
            case "responsive":
                return $this->get_responsive_slides_markup($slide);
            default:
                return $this->get_flex_slider_markup($slide);
        }
    }

    /**
     * Generate nivo slider markup
     *
     * @param  string $slide html
     * @return string slide html
     */
    private function get_nivo_slider_markup($slide)
    {
        $attributes = apply_filters('metaslider_nivo_slider_image_attributes', array(
                'src' => $slide['src'],
                'height' => $slide['height'],
                'width' => $slide['width'],
                'data-caption' => htmlentities( apply_filters( 'metaslider_image_caption', $slide['caption_raw'] ), ENT_QUOTES, 'UTF-8'),
                'data-thumb' => $slide['data-thumb'],
                'title' => $slide['title'],
                'alt' => $slide['alt'],
                'rel' => $slide['rel'],
                'class' => $slide['class']
            ), $slide, $this->slider->ID);

        $html = $this->build_image_tag($attributes);

        $anchor_attributes = apply_filters('metaslider_nivo_slider_anchor_attributes', array(
                'href' => $slide['url'],
                'target' => $slide['target']
            ), $slide, $this->slider->ID);

        if (strlen($anchor_attributes['href'])) {
            $html = $this->build_anchor_tag($anchor_attributes, $html);
        }

        return apply_filters('metaslider_image_nivo_slider_markup', $html, $slide, $this->settings);
    }

    /**
     * Generate flex slider markup
     *
     * @param  string $slide html
     * @return string slide html
     */
    private function get_flex_slider_markup($slide)
    {
        $image_attributes = array(
            'src' => $slide['src'],
            'height' => $slide['height'],
            'width' => $slide['width'],
            'alt' => $slide['alt'],
            'rel' => $slide['rel'],
            'class' => $slide['class'],
            'title' => $slide['title']
        );

        if ($this->settings['smartCrop'] == 'disabled_pad') {
            $image_attributes['style'] = $this->flex_smart_pad($image_attributes, $slide);
        }

        $attributes = apply_filters('metaslider_flex_slider_image_attributes', $image_attributes, $slide, $this->slider->ID);

        $html = $this->build_image_tag($attributes);

        $anchor_attributes = apply_filters('metaslider_flex_slider_anchor_attributes', array(
                'href' => $slide['url'],
                'target' => $slide['target'],
                'aria-label' => $slide['link-alt'],
                'class' => 'metaslider_image_link'
            ), $slide, $this->slider->ID);

        if (strlen($anchor_attributes['href'])) {
            $html = $this->build_anchor_tag($anchor_attributes, $html);
        }

        //add class for mobile setting
        $device = array('smartphone', 'tablet', 'laptop', 'desktop');
        $mobile_class = '';
        foreach ($device as $value) {
            $hidden_slide = get_post_meta( $this->slide->ID , 'ml-slider_hide_slide_' . $value, true );
            if(!empty($hidden_slide)) {
              $mobile_class .= 'hidden_' . $value . ' ';
            }
        }
        
        // add caption
        if (strlen($slide['caption'])) {
            $html .= '<div class="caption-wrap"><div class="caption">' . 
                apply_filters( 'metaslider_image_caption', apply_shortcodes( $slide['caption'] ) )  . 
            '</div></div>';
        }

        $attributes = apply_filters('metaslider_flex_slider_list_item_attributes', array(
                'data-thumb' => isset($slide['data-thumb']) ? $slide['data-thumb'] : "",
                'style' => "display: none; width: 100%;",
                'class' => "slide-{$this->slide->ID} ms-image {$mobile_class}",
                'aria-roledescription' => "slide",
                'aria-label' =>"slide-{$this->slide->ID}"
            ), $slide, $this->slider->ID);

        $li = "<li";

        foreach ($attributes as $att => $val) {
            if (strlen($val)) {
                $li .= " " . $att . '="' . esc_attr($val) . '"';
            }
        }

        $li .= ">" . $html . "</li>";

        $html = $li;


        return apply_filters('metaslider_image_flex_slider_markup', $html, $slide, $this->settings);
    }

    /**
     * Calculate the correct width (for vertical alignment) or top margin (for horizontal alignment)
     * so that images are never stretched above the height set in the slideshow settings
     *
     * @param  array $atts  Attributes
     * @param  array $slide Slide details
     * @return string
     */
    private function flex_smart_pad($atts, $slide)
    {
        if (get_post_type($slide['id']) === 'attachment') {
            $slide_id = $slide['id'];
        } else {
            $slide_id = get_post_thumbnail_id($slide['id']);
        }

        $meta = wp_get_attachment_metadata($slide_id);
        $default_settings = MetaSlider_Slideshow_Settings::defaults();

        if (isset($meta['width'], $meta['height'])) {
            $image_width = $meta['width'];
            $image_height = $meta['height'];

            //if slider width and height is empty, get default settings and cast to int
            if ( !empty( $this->settings['height'] )) {
                $container_height = (int)$this->settings['height'];
            } else {
                $container_height = (int)$default_settings['height'];
            }

            if ( !empty( $this->settings['width'] )) {
                $container_width = (int)$this->settings['width'];
            } else {
                $container_width = (int)$default_settings['width'];
            }
            
            $new_image_height = $image_height * ($container_width / $image_width);

            if ($new_image_height < $container_height) {
                $margin_top_in_px = ($container_height - $new_image_height) / 2;
                $margin_top_in_percent = ($margin_top_in_px / $container_width) * 100;
                return 'margin-top: ' . $margin_top_in_percent . '%';
            } else {
                return 'margin: 0 auto; width: ' . ($container_height / $new_image_height) * 100 . '%';
            }
        }

        return "";
    }


    /**
     * Generate coin slider markup
     *
     * @param  string $slide html
     * @return string slide html
     */
    private function get_coin_slider_markup($slide)
    {
        $attributes = apply_filters('metaslider_coin_slider_image_attributes', array(
                'src' => $slide['src'],
                'height' => $slide['height'],
                'width' => $slide['width'],
                'alt' => $slide['alt'],
                'rel' => $slide['rel'],
                'class' => $slide['class'],
                'title' => $slide['title'],
                'style' => 'display: none;'
            ), $slide, $this->slider->ID);

        $html = $this->build_image_tag($attributes);

        if (strlen($slide['caption'])) {
            $html .= "<span>". 
                apply_filters( 'metaslider_image_caption', apply_shortcodes( $slide['caption'] ) )  .
            "</span>";
        }

        $attributes = apply_filters('metaslider_coin_slider_anchor_attributes', array(
                'href' => strlen($slide['url']) ? $slide['url'] : 'javascript:void(0)',
                'target' => strlen($slide['url']) ? $slide['target'] : '_self'
            ), $slide, $this->slider->ID);

        $html = $this->build_anchor_tag($attributes, $html);

        return apply_filters('metaslider_image_coin_slider_markup', $html, $slide, $this->settings);
    }

    /**
     * Generate responsive slides markup
     *
     * @param  string $slide html
     * @return string slide html
     */
    private function get_responsive_slides_markup($slide)
    {
        $attributes = apply_filters('metaslider_responsive_slider_image_attributes', array(
                'src' => $slide['src'],
                'height' => $slide['height'],
                'width' => $slide['width'],
                'alt' => $slide['alt'],
                'rel' => $slide['rel'],
                'class' => $slide['class'],
                'title' => $slide['title']
            ), $slide, $this->slider->ID);

        $html = $this->build_image_tag($attributes);

        if (strlen($slide['caption'])) {
            $html .= '<div class="caption-wrap"><div class="caption">' . 
                apply_filters( 'metaslider_image_caption', apply_shortcodes( $slide['caption'] ) )  . 
            '</div></div>';
        }

        $anchor_attributes = apply_filters('metaslider_responsive_slider_anchor_attributes', array(
                'href' => $slide['url'],
                'target' => $slide['target']
            ), $slide, $this->slider->ID);

        if (strlen($anchor_attributes['href'])) {
            $html = $this->build_anchor_tag($anchor_attributes, $html);
        }

        return apply_filters('metaslider_image_responsive_slider_markup', $html, $slide, $this->settings);
    }

    /**
     * Allow '_blank' as target value in HTML. Only in use for captions for now.
     * 
     * @since 3.90.1
     */
    public function html_purifier_config($config)
    {
        $config->set('Attr.AllowedFrameTargets', array('_blank'));
        
        return $config;
    }

    /**
     * Save
     *
     * @param  array $fields Fields to save
     */
    protected function save($fields)
    {
        $args = array(
            'ID' => $this->slide->ID,
            'menu_order' => $fields['menu_order']
        );

        // This textarea might be hidden, so only update it if it exists
        if (isset($fields['post_excerpt'])) {
            $args['post_excerpt'] = $fields['post_excerpt'];
        }

        wp_update_post($args);

        $this->add_or_update_or_delete_meta($this->slide->ID, 'url', $fields['url']);
        $this->add_or_update_or_delete_meta($this->slide->ID, 'title', $fields['title']);
        $this->add_or_update_or_delete_meta($this->slide->ID, 'crop_position', $fields['crop_position']);
        $this->add_or_update_or_delete_meta($this->slide->ID, 'caption_source', $fields['caption_source']);

        $this->set_field_inherited('title', isset($fields['inherit_image_title']) && $fields['inherit_image_title'] === 'on');
        $this->set_field_inherited('alt', isset($fields['inherit_image_alt']) && $fields['inherit_image_alt'] === 'on');

        if (isset($fields['alt'])) {
            update_post_meta($this->slide->ID, '_wp_attachment_image_alt', $fields['alt']);
        }

        if (isset($fields['link-alt'])) {
            $this->add_or_update_or_delete_meta($this->slide->ID, 'link-alt', $fields['link-alt']);
        }

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'new_window',
            isset($fields['new_window']) && $fields['new_window'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_slide_smartphone',
            isset($fields['hide_slide_smartphone']) && $fields['hide_slide_smartphone'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_slide_tablet',
            isset($fields['hide_slide_tablet']) && $fields['hide_slide_tablet'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_slide_laptop',
            isset($fields['hide_slide_laptop']) && $fields['hide_slide_laptop'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_slide_desktop',
            isset($fields['hide_slide_desktop']) && $fields['hide_slide_desktop'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_caption_smartphone',
            isset($fields['hide_caption_smartphone']) && $fields['hide_caption_smartphone'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_caption_tablet',
            isset($fields['hide_caption_tablet']) && $fields['hide_caption_tablet'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_caption_laptop',
            isset($fields['hide_caption_laptop']) && $fields['hide_caption_laptop'] === 'on'
        );

        $this->add_or_update_or_delete_meta(
            $this->slide->ID,
            'hide_caption_desktop',
            isset($fields['hide_caption_desktop']) && $fields['hide_caption_desktop'] === 'on'
        );

    }

    /**
     * Gets the inheritn parameter of a field
     *
     * @param string $field Field to check
     * @return bool
     */
    private function is_field_inherited($field)
    {
        return (bool) get_post_meta($this->slide->ID, 'ml-slider_inherit_image_' . $field, true);
    }

    /**
     * Sets the inherit parameter of a field.
     *
     * @param string $field Field to set
     * @param bool   $value Value is currently isset($fields['checkbox_parameter'])
     * @return mixed Returns meta_id if the meta doesn't exist, otherwise returns true on success and false on failure. NOTE: If the meta_value passed to this function is the same as the value that is already in the database, this function returns false.
     */
    private function set_field_inherited($field, $value)
    {
        // TODO eventually I would like to handle errors / successful updates to the database even if just sending it to a log file
        return update_post_meta($this->slide->ID, 'ml-slider_inherit_image_' . $field, (bool) $value);
    }
}
