<?php
    $previews = isset($this->config->Content->previews)
        ? explode(',', $this->config->Content->previews) : [];
    if (!empty($previews)) {
        $idClasses = $this->record($this->driver)->getPreviewIds();

        // If we found at least one identifier, we can insert the data
        $html = '';
        if (!empty($idClasses)) {
            // Convert to string:
            $idClasses = implode(' ', $idClasses);

            // Loop through configured options and build appropriate HTML:
            foreach ($previews as $current) {
                switch (trim(strtolower($current))) {
                case 'google':
                    $spanClass = 'googlePreviewSpan';
                    // specify link vs. tab
                    $link_options = '';
                    if ($this->config->Content->GoogleOptions->link ?? false) {
                        $link_options = 'link:' . strtolower(
                            str_replace(
                                ' ',
                                '',
                                $this->config->Content->GoogleOptions->link
                            )
                        );
                    }
                    $tab_options = '';
                    if ($this->config->Content->GoogleOptions->tab ?? false) {
                        $tab_options = 'tab:' . strtolower(
                            str_replace(
                                ' ',
                                '',
                                $this->config->Content->GoogleOptions->tab
                            )
                        );
                    }
                    $options = ($link_options && $tab_options)
                        ? "$link_options;$tab_options"
                        : "$link_options$tab_options";
                    // maintain previous behavior and default
                    if (!$link_options && !$tab_options) {
                        $options = 'link:full,partial';
                        if (is_string($this->config->Content->GoogleOptions ?? null)) {
                            $options = 'link:' . strtolower(
                                str_replace(
                                    ' ',
                                    '',
                                    $this->config->Content->GoogleOptions
                                )
                            );
                        }
                    }
                    break;
                case 'openlibrary':
                    $spanClass = 'olPreviewSpan';
                    $options = isset($this->config->Content->OpenLibraryOptions)
                        ? str_replace(' ', '', $this->config->Content->OpenLibraryOptions)
                        : 'full,partial';
                    break;
                case 'hathitrust':
                    $spanClass = 'hathiPreviewSpan';
                    $options = isset($this->config->Content->HathiRights)
                        ? str_replace(' ', '', $this->config->Content->HathiRights)
                        : 'pd,ic-world';
                    break;
                default:
                    $spanClass = $options = false;
                    break;
                }
                if ($spanClass) {
                    $html .= '<span class="' . $spanClass . '__' . $options . '"></span>';
                }
            }

            // If we built some HTML, we should load the supporting Javascript and
            // add the necessary identifier code:
            if (!empty($html)) {
                $html .= '<span class="previewBibkeys ' . $idClasses . '"></span>';
                $this->headScript()->appendFile('preview.js');
                echo $html;
            }
        }
    }