<?php
if (!defined('ABSPATH')) {
    exit;
}

class TSAI_Modal {

    private static $instance = null;
    private $needed = false;
    private $preload_url = '';

    public static function instance() {
        if (self::$instance === null) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
        add_action('wp_footer', array($this, 'render_modal'), 99);
        add_action('wp_head', array($this, 'render_resource_hints'), 5);
    }

    /**
     * Mark that at least one modal shortcode is on this page.
     * Optionally records the first URL so the iframe can be preloaded
     * before the user clicks a trigger.
     */
    public function set_needed($url = '') {
        $this->needed = true;
        if ($url && !$this->preload_url) {
            $this->preload_url = $url;
        }
    }

    /**
     * Emit preconnect / preload hints for the SAS app host so the bundle
     * is fetched as early as possible on pages that have a SAS modal.
     */
    public function render_resource_hints() {
        if (!$this->needed || !$this->preload_url) {
            return;
        }
        $parts = wp_parse_url($this->preload_url);
        if (empty($parts['scheme']) || empty($parts['host'])) {
            return;
        }
        $origin = $parts['scheme'] . '://' . $parts['host'];
        printf(
            '<link rel="preconnect" href="%s" crossorigin>' . "\n",
            esc_url($origin)
        );
    }

    /**
     * Inject the shared modal container in the footer (only if needed).
     * The iframe is preloaded with the first SAS URL on the page so the
     * first click is an immediate show, not a fresh bootstrap.
     */
    public function render_modal() {
        if (!$this->needed) {
            return;
        }
        $src = $this->preload_url ? esc_url($this->preload_url) : '';
        ?>
        <div id="tsai-modal-backdrop"></div>
        <div id="tsai-modal-container">
            <button id="tsai-modal-close">&times;</button>
            <iframe id="tsai-modal-frame" src="<?php echo $src; ?>" data-tsai-current-url="<?php echo $src; ?>"></iframe>
        </div>
        <?php
    }
}

// Initialize singleton
TSAI_Modal::instance();