<?php
/**
 * Admin Functionality
 *
 * @package Max_Interactive_Maps
 */

// Exit if accessed directly
if (!defined('ABSPATH')) {
    exit;
}

/**
 * Class MXIMAP_Admin
 * Handles admin interface and map builder
 */
class MXIMAP_Admin
{

    /**
     * Single instance of the class
     */
    private static $instance = null;

    /**
     * Invalid pin submissions awaiting the normal post-save redirect.
     */
    private $rejected_pin_saves = array();

    private $conflicted_map_saves = array();
    private $editor_states = array();

    /**
     * Get single instance
     */
    public static function get_instance()
    {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Constructor
     */
    private function __construct()
    {
        add_action('add_meta_boxes', array($this, 'add_meta_boxes'), 10, 2);
        add_action('save_post_' . MXIMAP_Post_Type::POST_TYPE, array($this, 'save_meta'), 10, 2);
        add_action('admin_enqueue_scripts', array($this, 'enqueue_assets'));
        add_action('admin_footer', array($this, 'add_pin_templates'));
        add_filter('redirect_post_location', array($this, 'add_pin_save_warning_to_redirect'), 10, 2);
        add_action('admin_notices', array($this, 'render_pin_save_warning'));
        add_filter('redirect_post_location', array($this, 'add_map_conflict_to_redirect'), 10, 2);
        add_action('admin_notices', array($this, 'render_map_conflict'));
    }

    /**
     * Enqueue admin assets
     */
    public function enqueue_assets($hook)
    {
        global $post_type;

        // Only load on our CPT edit screens
        if (('post.php' === $hook || 'post-new.php' === $hook) && MXIMAP_Post_Type::POST_TYPE === $post_type) {
            // WordPress built-in dependencies
            wp_enqueue_style('wp-color-picker');
            wp_enqueue_script('jquery-ui-draggable');
            wp_enqueue_script('wp-color-picker');

            // Plugin styles
            wp_enqueue_style(
                'mximap-admin',
                MXIMAP_PLUGIN_URL . 'admin/css/mximap-admin.css',
                array(),
                MXIMAP_VERSION
            );

            // Plugin scripts
            wp_enqueue_script(
                'mximap-admin',
                MXIMAP_PLUGIN_URL . 'admin/js/mximap-admin.js',
                array('jquery', 'jquery-ui-draggable', 'wp-color-picker'),
                MXIMAP_VERSION,
                true
            );

            // Localize script
            wp_localize_script('mximap-admin', 'mximapAdmin', array(
                'ajaxUrl' => admin_url('admin-ajax.php'),
                'nonce' => wp_create_nonce('mximap_admin_nonce'),
                'pinStyles' => $this->get_pin_styles(),
                'defaultPin' => MXIMAP_Post_Type::get_default_pin(),
                'i18n' => array(
                    'addPin' => __('Add Pin', 'max-interactive-maps'),
                    'deletePin' => __('Delete', 'max-interactive-maps'),
                    'editPin' => __('Edit Pin Settings', 'max-interactive-maps'),
                    /* translators: %s: pin label. */
                    'editNamedPin' => __('Edit pin: %s', 'max-interactive-maps'),
                    /* translators: %d: pin number. */
                    'editNumberedPin' => __('Edit pin %d', 'max-interactive-maps'),
                    /* translators: 1: horizontal percentage, 2: vertical percentage. */
                    'pinPosition' => __('Position: %1$s percent from left, %2$s percent from top.', 'max-interactive-maps'),
                    'pinUrl' => __('Target URL', 'max-interactive-maps'),
                    'pinLabel' => __('Label (Tooltip)', 'max-interactive-maps'),
                    'pinStyle' => __('Icon Style', 'max-interactive-maps'),
                    'pinColor' => __('Pin Color', 'max-interactive-maps'),
                    'save' => __('Save', 'max-interactive-maps'),
                    'cancel' => __('Cancel', 'max-interactive-maps'),
                    'confirmDelete' => __('Are you sure you want to delete this pin?', 'max-interactive-maps'),
                ),
            ));
        }
    }

    /**
     * Get available pin styles
     */
    private function get_pin_styles()
    {
        return array(
            'dot' => __('Simple Dot', 'max-interactive-maps'),
            'teardrop' => __('Teardrop', 'max-interactive-maps'),
            'star' => __('Star', 'max-interactive-maps'),
            'flag' => __('Flag', 'max-interactive-maps'),
            'pushpin' => __('Pushpin', 'max-interactive-maps'),
        );
    }

    /**
     * Add meta boxes
     */
    public function add_meta_boxes($post_type = null, $post = null)
    {
        if ($post instanceof WP_Post && MXIMAP_Post_Type::POST_TYPE === $post_type) {
            // All map controls and their signature must describe the same read.
            $this->editor_states[$post->ID] = $this->read_map_state($post->ID);
        }
        // Map Builder Meta Box
        add_meta_box(
            'mximap_map_builder',
            __('Map Builder', 'max-interactive-maps'),
            array($this, 'render_map_builder'),
            MXIMAP_Post_Type::POST_TYPE,
            'normal',
            'high'
        );

        // Shortcode Display Meta Box
        add_meta_box(
            'mximap_shortcode',
            __('Shortcode', 'max-interactive-maps'),
            array($this, 'render_shortcode_box'),
            MXIMAP_Post_Type::POST_TYPE,
            'side',
            'high'
        );

        // Map Settings Meta Box
        add_meta_box(
            'mximap_map_settings',
            __('Map Colors', 'max-interactive-maps'),
            array($this, 'render_settings_box'),
            MXIMAP_Post_Type::POST_TYPE,
            'side',
            'default'
        );
    }

    /**
     * Render the Map Builder interface
     */
    public function render_map_builder($post)
    {
        // Get saved data
        $state = $this->editor_states[$post->ID] ?? $this->read_map_state($post->ID);
        $pins = $state['pins'];
        $pins_editable = $this->can_edit_pins($state);
        $pins = $pins_editable && is_array($pins) ? $pins : array();

        // Nonce field
        wp_nonce_field('mximap_save_map', 'mximap_map_nonce');
        echo '<input type="hidden" name="mximap_map_version" value="' . esc_attr($this->sign_map_state($post->ID, $state)) . '">';
        ?>
        <?php if (!$pins_editable): ?>
            <div id="mximap-stored-pins-warning" class="notice notice-error inline" role="alert"><p>
                <?php esc_html_e('Pin editing is disabled because this map contains damaged pin records, missing or duplicate pin IDs, or multiple stored pin lists. Stored pins are preserved, and Update will not replace them. The title and any enabled map colors can still be saved. Public maps show only safely readable markers. Ask the site maintainer to inspect a backup before any manual repair; no pins have been repaired or renumbered.', 'max-interactive-maps'); ?>
            </p></div>
        <?php endif; ?>
        <div class="mximap-map-builder">
            <div class="mximap-toolbar">
                <button type="button" id="mximap-add-pin" <?php disabled(!$pins_editable); ?> class="button button-primary" aria-haspopup="dialog" aria-controls="mximap-pin-dialog">
                    <span class="dashicons dashicons-plus-alt2" aria-hidden="true"></span>
                    <?php esc_html_e('Add Pin', 'max-interactive-maps'); ?>
                </button>
                <span class="mximap-toolbar-info" id="mximap-pin-instructions">
                    <?php esc_html_e('Drag pins or use arrow keys to position them (Shift for larger steps). Double-click or use Enter or Space to edit settings.', 'max-interactive-maps'); ?>
                </span>
            </div>
            <p class="screen-reader-text" id="mximap-pin-position-status" role="status" aria-live="polite"></p>

            <div class="mximap-map-container" id="mximap-map-container">
                <div class="mximap-map-wrapper" id="mximap-map-wrapper">
                    <?php
                    // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- SVG is from trusted plugin file
                    echo $this->get_world_map_svg();
                    ?>
                    <div class="mximap-pins-layer" id="mximap-pins-layer">
                        <!-- Pins will be rendered here via JavaScript -->
                    </div>
                </div>
            </div>

            <!-- Hidden input to store pins data -->
            <input type="hidden" id="mximap-pins-data" name="mximap_pins_data" value="<?php echo esc_attr(wp_json_encode($pins)); ?>" <?php disabled(!$pins_editable); ?>>
        </div>

        <!-- Pin Edit Modal -->
        <div class="mximap-modal" id="mximap-pin-modal" style="display: none;">
            <div class="mximap-modal-overlay"></div>
            <div class="mximap-modal-content" id="mximap-pin-dialog" role="dialog" aria-modal="true" aria-labelledby="mximap-pin-modal-title" tabindex="-1">
                <div class="mximap-modal-header">
                    <h3 id="mximap-pin-modal-title"><?php esc_html_e('Edit Pin Settings', 'max-interactive-maps'); ?></h3>
                    <button type="button" class="mximap-modal-close" aria-label="<?php esc_attr_e('Close pin settings', 'max-interactive-maps'); ?>"><span aria-hidden="true">&times;</span></button>
                </div>
                <div class="mximap-modal-body">
                    <input type="hidden" id="mximap-modal-pin-id" value="">

                    <div class="mximap-form-row">
                        <label for="mximap-pin-url"><?php esc_html_e('Target URL', 'max-interactive-maps'); ?></label>
                        <input type="url" id="mximap-pin-url" class="widefat" placeholder="https://example.com/page">
                    </div>

                    <div class="mximap-form-row">
                        <label for="mximap-pin-label"><?php esc_html_e('Label (Tooltip)', 'max-interactive-maps'); ?></label>
                        <input type="text" id="mximap-pin-label" class="widefat"
                            placeholder="<?php esc_attr_e('e.g., Paris Office', 'max-interactive-maps'); ?>">
                    </div>

                    <div class="mximap-form-row mximap-form-row-inline">
                        <div class="mximap-form-col">
                            <label for="mximap-pin-style"><?php esc_html_e('Icon Style', 'max-interactive-maps'); ?></label>
                            <select id="mximap-pin-style" class="widefat">
                                <?php foreach ($this->get_pin_styles() as $value => $label): ?>
                                    <option value="<?php echo esc_attr($value); ?>"><?php echo esc_html($label); ?></option>
                                <?php endforeach; ?>
                            </select>
                        </div>
                        <div class="mximap-form-col">
                            <label for="mximap-pin-color"><?php esc_html_e('Pin Color', 'max-interactive-maps'); ?></label>
                            <input type="text" id="mximap-pin-color" class="mximap-color-picker" value="#e74c3c">
                        </div>
                    </div>

                    <div class="mximap-form-row mximap-form-row-inline">
                        <div class="mximap-form-col">
                            <label
                                for="mximap-pin-font-style"><?php esc_html_e('Label Font Style', 'max-interactive-maps'); ?></label>
                            <select id="mximap-pin-font-style" class="widefat">
                                <option value="normal"><?php esc_html_e('Normal', 'max-interactive-maps'); ?></option>
                                <option value="bold"><?php esc_html_e('Bold', 'max-interactive-maps'); ?></option>
                                <option value="italic"><?php esc_html_e('Italic', 'max-interactive-maps'); ?></option>
                                <option value="uppercase"><?php esc_html_e('Uppercase', 'max-interactive-maps'); ?></option>
                            </select>
                        </div>
                        <div class="mximap-form-col">
                            <label
                                for="mximap-pin-font-size"><?php esc_html_e('Label Font Size', 'max-interactive-maps'); ?></label>
                            <select id="mximap-pin-font-size" class="widefat">
                                <option value="small"><?php esc_html_e('Small (10px)', 'max-interactive-maps'); ?></option>
                                <option value="medium" selected><?php esc_html_e('Medium (12px)', 'max-interactive-maps'); ?>
                                </option>
                                <option value="large"><?php esc_html_e('Large (14px)', 'max-interactive-maps'); ?></option>
                            </select>
                        </div>
                    </div>
                </div>
                <div class="mximap-modal-footer">
                    <button type="button" class="button mximap-modal-delete" style="color: #a00;">
                        <?php esc_html_e('Delete Pin', 'max-interactive-maps'); ?>
                    </button>
                    <button type="button" class="button mximap-modal-cancel">
                        <?php esc_html_e('Cancel', 'max-interactive-maps'); ?>
                    </button>
                    <button type="button" class="button button-primary mximap-modal-save">
                        <?php esc_html_e('Save Changes', 'max-interactive-maps'); ?>
                    </button>
                </div>
            </div>
        </div>
        <?php
    }

    /**
     * Render the shortcode box
     */
    public function render_shortcode_box($post)
    {
        if ('publish' === $post->post_status) {
            $shortcode = '[mximap_map id="' . $post->ID . '"]';
            ?>
            <div class="mximap-shortcode-box">
                <input type="text" readonly value="<?php echo esc_attr($shortcode); ?>" class="widefat" onclick="this.select();">
                <p class="description">
                    <?php esc_html_e('Copy and paste this shortcode to embed your map.', 'max-interactive-maps'); ?>
                </p>
            </div>
            <?php
        } else {
            ?>
            <p class="description"><?php esc_html_e('Publish this map to get the shortcode.', 'max-interactive-maps'); ?></p>
            <?php
        }
    }

    /**
     * Render the settings box
     */
    public function render_settings_box($post)
    {
        $state = $this->editor_states[$post->ID] ?? $this->read_map_state($post->ID);
        $settings = $state['settings'];
        $settings_editable = count($state['settings_rows']) <= 1;
        $settings = MXIMAP_Post_Type::resolve_settings($settings);
        ?>
        <?php if (!$settings_editable): ?>
            <div id="mximap-stored-settings-warning" class="notice notice-error inline" role="alert"><p>
                <?php esc_html_e('Map color editing is disabled because this map has multiple stored color records. Update will preserve all color records. Ask the site maintainer to inspect a backup before any manual repair.', 'max-interactive-maps'); ?>
            </p></div>
        <?php endif; ?>
        <div class="mximap-settings-box">
            <div class="mximap-form-row">
                <label for="mximap-land-color"><?php esc_html_e('Land Color', 'max-interactive-maps'); ?></label>
                <input type="text" id="mximap-land-color" name="mximap_settings[land_color]" class="mximap-color-picker"
                    value="<?php echo esc_attr($settings['land_color']); ?>" <?php disabled(!$settings_editable); ?>>
            </div>

            <div class="mximap-form-row">
                <label for="mximap-water-color"><?php esc_html_e('Water/Background Color', 'max-interactive-maps'); ?></label>
                <input type="text" id="mximap-water-color" name="mximap_settings[water_color]" class="mximap-color-picker"
                    value="<?php echo esc_attr($settings['water_color']); ?>" <?php disabled(!$settings_editable); ?>>
            </div>

            <div class="mximap-form-row">
                <label for="mximap-border-color"><?php esc_html_e('Border Color', 'max-interactive-maps'); ?></label>
                <input type="text" id="mximap-border-color" name="mximap_settings[border_color]" class="mximap-color-picker"
                    value="<?php echo esc_attr($settings['border_color']); ?>" <?php disabled(!$settings_editable); ?>>
            </div>
        </div>
        <?php
    }

    /**
     * Save meta data
     */
    public function save_meta($post_id, $post)
    {
        unset($this->rejected_pin_saves[$post_id]);
        unset($this->conflicted_map_saves[$post_id], $this->editor_states[$post_id]);

        // Verify nonce
        if (!isset($_POST['mximap_map_nonce']) || !wp_verify_nonce(sanitize_text_field(wp_unslash($_POST['mximap_map_nonce'])), 'mximap_save_map')) {
            return;
        }

        // Check autosave
        if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {
            return;
        }

        // Check permissions
        if (!current_user_can('edit_post', $post_id)) {
            return;
        }

        if (!isset($_POST['mximap_pins_data']) && !(isset($_POST['mximap_settings']) && is_array($_POST['mximap_settings']))) {
            return;
        }

        // A content comparison alone races with a second request. Serialize this
        // plugin's writes first, then read uncached metadata and compare the form.
        $lock = $this->acquire_map_save_lock($post_id);
        if (!$lock) {
            $this->conflicted_map_saves[$post_id] = true;
            return;
        }
        try {
            wp_cache_delete($post_id, 'post_meta');
            $state = $this->read_map_state($post_id);
            $version = $_POST['mximap_map_version'] ?? null;
            if (!is_string($version) || !hash_equals($this->sign_map_state($post_id, $state), wp_unslash($version))) {
                $this->conflicted_map_saves[$post_id] = true;
                return;
            }

            $this->save_map_fields($post_id, $state);
        } finally {
            $this->release_map_save_lock($post_id, $lock);
        }
    }

    /** Existing field validation/sanitization; called only after the save guard. */
    private function save_map_fields($post_id, $state)
    {

        // Save pins data
        if (isset($_POST['mximap_pins_data'])
            && $this->can_edit_pins($state)) {
            // Decode before field sanitization so encoded URLs are not text-filtered.
            // Keep objects distinct from lists: only a JSON list of pin objects is valid.
            $pins = is_string($_POST['mximap_pins_data']) ? json_decode(wp_unslash($_POST['mximap_pins_data'])) : null;
            $valid_pins = false;

            if (is_array($pins)) {
                // Sanitize each pin
                $sanitized_pins = array();
                $valid_pins = true;
                foreach ($pins as $pin) {
                    if (!is_object($pin)) {
                        $valid_pins = false;
                        break;
                    }

                    $pin = (array) $pin;
                    foreach (array('id', 'x', 'y', 'url', 'style', 'color', 'label', 'fontStyle', 'fontSize', 'latitude', 'longitude') as $field) {
                        if (isset($pin[$field]) && !is_scalar($pin[$field])) {
                            // Reject the whole list rather than partially replacing saved pins.
                            $valid_pins = false;
                            break 2;
                        }
                    }

                    $sanitized_pins[] = array(
                        'id' => sanitize_text_field($pin['id'] ?? ''),
                        'x' => floatval($pin['x'] ?? 50),
                        'y' => floatval($pin['y'] ?? 50),
                        'url' => esc_url_raw($pin['url'] ?? ''),
                        'style' => sanitize_key($pin['style'] ?? 'dot'),
                        'color' => sanitize_hex_color($pin['color'] ?? '#e74c3c'),
                        'label' => sanitize_text_field($pin['label'] ?? ''),
                        'fontStyle' => sanitize_key($pin['fontStyle'] ?? 'normal'),
                        'fontSize' => sanitize_key($pin['fontSize'] ?? 'medium'),
                        'latitude' => floatval($pin['latitude'] ?? 0),
                        'longitude' => floatval($pin['longitude'] ?? 0),
                    );
                }
                if ($valid_pins) {
                    // WordPress unslashes meta values; protect literal backslashes in text.
                    update_post_meta($post_id, '_mximap_pins', wp_slash($sanitized_pins));
                }
            }
            if (!$valid_pins) {
                $this->rejected_pin_saves[$post_id] = true;
            }
        }

        // Save settings
        if (isset($_POST['mximap_settings']) && is_array($_POST['mximap_settings']) && count($state['settings_rows']) <= 1) {
            // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Sanitized below
            $raw_settings = wp_unslash($_POST['mximap_settings']);
            $settings = array(
                'land_color' => sanitize_hex_color($raw_settings['land_color'] ?? ''),
                'water_color' => sanitize_hex_color($raw_settings['water_color'] ?? ''),
                'border_color' => sanitize_hex_color($raw_settings['border_color'] ?? ''),
            );
            update_post_meta($post_id, '_mximap_settings', $settings);
        }
    }

    private function read_map_state($post_id)
    {
        $pins = get_post_meta($post_id, '_mximap_pins', false);
        $settings = get_post_meta($post_id, '_mximap_settings', false);
        // Include every row in the signature: a second record must not be hidden
        // by get_post_meta(..., true), then overwritten by update_post_meta().
        return array('pins' => $pins ? $pins[0] : '', 'settings' => $settings ? $settings[0] : '', 'pin_rows' => $pins, 'settings_rows' => $settings);
    }

    private function can_edit_pins($state)
    {
        return empty($state['pin_rows']) || (1 === count($state['pin_rows']) && MXIMAP_Post_Type::pins_are_editable($state['pins']));
    }

    private function sign_map_state($post_id, $state)
    {
        return hash_hmac('sha256', serialize(array((int) $post_id, get_current_user_id(), $state)), wp_salt('nonce'));
    }

    /**
     * Atomic private option-row mutex, like WordPress's upgrader lock. Do not
     * use a cached transient for mutual exclusion. No saved map fields are added.
     */
    private function acquire_map_save_lock($post_id)
    {
        global $wpdb;
        $name = 'mximap_save_lock_' . (int) $post_id;
        $old = $wpdb->get_var($wpdb->prepare("SELECT option_value FROM $wpdb->options WHERE option_name = %s", $name));
        if (is_string($old) && preg_match('/^([0-9]+):[a-f0-9]{32}$/D', $old, $match) && (int) $match[1] < time() - 10 * MINUTE_IN_SECONDS) {
            // Reclaim only the exact abandoned lease we observed, never a successor.
            $wpdb->query($wpdb->prepare("DELETE FROM $wpdb->options WHERE option_name = %s AND option_value = %s", $name, $old));
        }
        $value = time() . ':' . bin2hex(random_bytes(16));
        $inserted = $wpdb->query($wpdb->prepare("INSERT IGNORE INTO $wpdb->options (option_name, option_value, autoload) VALUES (%s, %s, 'no')", $name, $value));
        return 1 === $inserted ? $value : false;
    }

    private function release_map_save_lock($post_id, $value)
    {
        global $wpdb;
        $wpdb->query($wpdb->prepare("DELETE FROM $wpdb->options WHERE option_name = %s AND option_value = %s", 'mximap_save_lock_' . (int) $post_id, $value));
    }

    public function add_map_conflict_to_redirect($location, $post_id)
    {
        if (MXIMAP_Post_Type::POST_TYPE !== get_post_type($post_id)) {
            return $location;
        }
        $location = remove_query_arg('mximap_map_conflict', $location);
        if (empty($this->conflicted_map_saves[$post_id]) || !current_user_can('edit_post', $post_id)) {
            return $location;
        }
        unset($this->conflicted_map_saves[$post_id]);
        $token = wp_generate_password(32, false, false);
        $key = 'mximap_map_conflict_' . get_current_user_id() . '_' . $post_id . '_' . $token;
        if (!set_transient($key, 'conflict', 5 * MINUTE_IN_SECONDS)) {
            return $location;
        }
        return add_query_arg('mximap_map_conflict', $token, $location);
    }

    public function render_map_conflict()
    {
        global $post;
        $screen = get_current_screen();
        if (!$screen || 'post' !== $screen->base || MXIMAP_Post_Type::POST_TYPE !== $screen->post_type
            || !($post instanceof WP_Post) || MXIMAP_Post_Type::POST_TYPE !== $post->post_type
            || !current_user_can('edit_post', $post->ID)
            || !isset($_GET['mximap_map_conflict']) || !is_string($_GET['mximap_map_conflict'])) {
            return;
        }
        $token = wp_unslash($_GET['mximap_map_conflict']);
        if (!preg_match('/^[A-Za-z0-9]{32}$/D', $token)) {
            return;
        }
        $key = 'mximap_map_conflict_' . get_current_user_id() . '_' . $post->ID . '_' . $token;
        if ('conflict' !== get_transient($key)) {
            return;
        }
        delete_transient($key);
        echo '<div id="mximap-map-save-conflict" class="notice notice-error" role="alert"><p>';
        esc_html_e('Your pins and map colors were not saved because the editor is out of date or another map save is in progress. The previously saved map was kept. Reload the editor, review the latest map, and reapply your changes. Other post changes may have been saved.', 'max-interactive-maps');
        echo '</p></div>';
    }

    /**
     * Carry a guarded rejection to the submitting user's map editor once.
     */
    public function add_pin_save_warning_to_redirect($location, $post_id)
    {
        if (MXIMAP_Post_Type::POST_TYPE !== get_post_type($post_id)) {
            return $location;
        }

        $location = remove_query_arg('mximap_pins_rejected', $location);
        if (empty($this->rejected_pin_saves[$post_id]) || !current_user_can('edit_post', $post_id)) {
            return $location;
        }

        unset($this->rejected_pin_saves[$post_id]);
        $token = wp_generate_password(32, false, false);
        if (!set_transient($this->get_pin_save_notice_key($post_id, $token), 'rejected', 5 * MINUTE_IN_SECONDS)) {
            return $location;
        }

        return add_query_arg('mximap_pins_rejected', $token, $location);
    }

    /**
     * Show feedback only on the matching authorized editor, without pin data.
     */
    public function render_pin_save_warning()
    {
        global $post;
        $screen = get_current_screen();
        if (!$screen || 'post' !== $screen->base || MXIMAP_Post_Type::POST_TYPE !== $screen->post_type
            || !($post instanceof WP_Post) || MXIMAP_Post_Type::POST_TYPE !== $post->post_type
            || !current_user_can('edit_post', $post->ID)
            || !isset($_GET['mximap_pins_rejected']) || !is_string($_GET['mximap_pins_rejected'])) {
            return;
        }

        $token = wp_unslash($_GET['mximap_pins_rejected']);
        if (!preg_match('/^[A-Za-z0-9]{32}$/D', $token)) {
            return;
        }
        $key = $this->get_pin_save_notice_key($post->ID, $token);
        if ('rejected' !== get_transient($key)) {
            return;
        }
        delete_transient($key);

        echo '<div id="mximap-pins-save-rejected" class="notice notice-error" role="alert"><p>';
        esc_html_e('Pin changes were not saved because the submitted pin data was invalid. Previously saved pins were kept. Other map changes may have been saved. Reload the map editor, check your pins, and try again.', 'max-interactive-maps');
        echo '</p></div>';
    }

    /**
     * Keep independent save events separate without writing map metadata.
     */
    private function get_pin_save_notice_key($post_id, $token)
    {
        return 'mximap_pin_rejected_' . get_current_user_id() . '_' . $post_id . '_' . $token;
    }

    /**
     * Get the World Map SVG
     */
    private function get_world_map_svg()
    {
        $svg_path = MXIMAP_PLUGIN_DIR . 'assets/svg/world-map.svg';

        if (file_exists($svg_path)) {
            return preg_replace('/<svg\b/', '<svg aria-hidden="true" focusable="false"', file_get_contents($svg_path), 1);
        }

        // Fallback: Generate a simple placeholder
        return '<svg aria-hidden="true" focusable="false" viewBox="0 0 1000 500" class="mximap-world-map" id="mximap-world-map">
            <rect class="mximap-water" x="0" y="0" width="100%" height="100%"/>
            <text x="50%" y="50%" text-anchor="middle" fill="#666">World Map SVG</text>
        </svg>';
    }

    /**
     * Add pin SVG templates to footer
     */
    public function add_pin_templates()
    {
        global $post_type;

        if (MXIMAP_Post_Type::POST_TYPE !== $post_type) {
            return;
        }
        ?>
        <script type="text/template" id="mximap-pin-template">
                                                            <div class="mximap-pin" data-pin-id="{{id}}" style="left: {{x}}%; top: {{y}}%;">
                                                                <div class="mximap-pin-icon mximap-pin-{{style}}" style="color: {{color}};">
                                                                    {{icon}}
                                                                </div>
                                                            </div>
                                                        </script>
        <?php
    }
}