<?php
/**
 * AJAX controller for Booking Form Builder (BFB) FormConfig.
 *
 * Responsibilities:
 * - Save Builder structure (+ exported shortcodes) into booking_form_structures table.
 * - Load FormConfig (DB first, legacy options fallback) for the Builder UI.
 *
 * This file exposes AJAX endpoints:
 * - WPBC_AJX_BFB_SAVE_FORM_CONFIG   -> wpbc_bfb_ajax_save_form_config()
 * - WPBC_AJX_BFB_LOAD_FORM_CONFIG   -> wpbc_bfb_ajax_load_form_config()
 * - WPBC_AJX_BFB_CREATE_FORM_CONFIG -> wpbc_bfb_ajax_create_form_config()
 * - WPBC_AJX_BFB_LIST_FORMS         -> wpbc_bfb_ajax_list_forms()
 * - WPBC_AJX_BFB_DELETE_FORM_CONFIG -> wpbc_bfb_ajax_delete_form_config()
 * - WPBC_AJX_BFB_DELETE_TEMPLATE_CONFIG -> wpbc_bfb_ajax_delete_template_config()
 *
 * Both endpoints work with the normalized FormConfig structure defined in
 * bfb-form-manager.php.
 *
 * @package     Booking Calendar.
 * @subpackage  Form Builder
 *
 * @since 11.0.0
 * @file        ../includes/page-form-builder/ajax/bfb-ajax.php
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * OR separator for template search queries (UI + AJAX).
 *
 * Used by wpbc_bfb_ajax_list_forms() to support multi-keyword searches:
 *    "time|duration|slots"
 *
 * NOTE:
 * - This separator is for AJAX search (POST) and UI input.
 * - Do NOT use it in URLs. Some server configs can block "|" in URLs.
 * - For URLs, use WPBC_BFB_TEMPLATE_SEARCH_OR_SEPARATOR_URL (default "^").
 *
 * @since 11.0.0
 */
if ( ! defined( 'WPBC_BFB_TEMPLATE_SEARCH_OR_SEPARATOR' ) ) {
	define( 'WPBC_BFB_TEMPLATE_SEARCH_OR_SEPARATOR', '|' );
}

/**
 * OR separator for template search queries in URLs only.
 *
 * Used for redirects like:
 *   &auto_open_template=service^duration
 *
 * @since 11.0.0
 */
if ( ! defined( 'WPBC_BFB_TEMPLATE_SEARCH_OR_SEPARATOR_URL' ) ) {
	define( 'WPBC_BFB_TEMPLATE_SEARCH_OR_SEPARATOR_URL', '^' );
 }

// == Helpers == =======================================================================================================

/**
 * Get capability required to manage booking forms in the Builder.
 *
 * Resolves to a WordPress capability based on the plugin setting
 * booking_user_role_settings. This keeps Form Builder access aligned with the
 * rest of the Booking Calendar admin UI.
 *
 * Mapping example:
 * - administrator -> activate_plugins
 * - editor        -> publish_pages
 * - author        -> publish_posts
 * - contributor   -> edit_posts
 * - subscriber    -> read
 *
 * If the configured role is not recognized, falls back to manage_options.
 *
 * @since 11.0.0
 *
 * @return string Capability name.
 */
function wpbc_bfb_get_manage_cap() {

	$min_user_role = get_bk_option( 'booking_user_role_settings' );

	$capability = array(
		'administrator' => 'activate_plugins',
		'editor'        => 'publish_pages',
		'author'        => 'publish_posts',
		'contributor'   => 'edit_posts',
		'subscriber'    => 'read',
	);

	if ( isset( $capability[ $min_user_role ] ) ) {
		return $capability[ $min_user_role ];
	}

	// Fallback: admins only.
	return 'manage_options';
}

/**
 * Extend the list of safe inline CSS properties for BFB-generated markup.
 *
 * Callback for the safe_style_css filter. It ensures that BFB-specific inline
 * styles (including CSS custom properties used by the layout engine) pass
 * through wp_kses() sanitization.
 *
 * The base list of allowed properties is provided by core; this function
 * appends additional properties if they are not already present.
 *
 * You can modify the final list via the wpbc_bfb_safe_style_props filter.
 *
 * @since 11.0.0
 *
 * @param string[] $styles Array of allowed CSS properties from core.
 *
 * @return string[] Modified array including BFB-specific properties.
 */
function wpbc_bfb_safe_style_props_filter( $styles ) {

	$extra_css_props = array(
		'display',
		'clear',        // used in wizard hidden_style (optional, but safe)
		'flex-basis',   // IMPORTANT: exported per-column layout width
		// Optional but often useful if you ever output them:
		'flex',
		'flex-grow',
		'flex-shrink',
		'width',
		'min-width',
		'max-width',
		'box-sizing',

		'transform',
		'align-self',
		'--wpbc-bfb-col-dir',
		'--wpbc-bfb-col-wrap',
		'--wpbc-bfb-col-jc',
		'--wpbc-bfb-col-ai',
		'--wpbc-bfb-col-gap',
		'--wpbc-bfb-col-ac',
		'--wpbc-bfb-col-aself',
		'--wpbc-bfb-col-padding',
		'--wpbc-bfb-col-margin',
		'--wpbc-bfb-col-padding-top',
		'--wpbc-bfb-col-padding-right',
		'--wpbc-bfb-col-padding-bottom',
		'--wpbc-bfb-col-padding-left',
		'--wpbc-bfb-col-margin-top',
		'--wpbc-bfb-col-margin-right',
		'--wpbc-bfb-col-margin-bottom',
		'--wpbc-bfb-col-margin-left',
		'--wpbc-bfb-col-max-width',
		'--wpbc-bfb-col-max-height',
		'--wpbc-bfb-col-overflow',
		'--wpbc-bfb-col-overflow-x',
		'--wpbc-bfb-col-overflow-y',
		'--wpbc-bfb-form-background',
		'--wpbc-bfb-form-border-color',
		'--wpbc-bfb-form-border-width',
		'--wpbc-bfb-form-border-radius',
		'--wpbc-bfb-form-padding',
		'--wpbc-bfb-form-box-shadow',
		'--wpbc-col-min',
	);

	/**
	 * Filter extra safe CSS properties for BFB inline styles.
	 *
	 * @since 11.0.0
	 *
	 * @param string[] $extra_css_props List of extra CSS properties.
	 */
	$extra_css_props = apply_filters( 'wpbc_bfb_safe_style_props', $extra_css_props );

	foreach ( $extra_css_props as $prop ) {
		if ( ! in_array( $prop, $styles, true ) ) {
			$styles[] = $prop;
		}
	}

	return $styles;
}

/**
 * Allow STRICT ONLY: transform: translate(... , ...) with numeric/% values
 *
 * @param $allow
 * @param $css_test_string
 *
 * @return bool|mixed
 */
function wpbc_bfb_allow_transform_translate_only( $allow, $css_test_string ) {
	if ( $allow ) {
		return $allow;
	}

	$css_test_string = trim( (string) $css_test_string );

	// Allow ONLY: transform: translate(... , ...) with numeric/% values. Also allow px (common for translate), still STRICT.
	if ( preg_match( '/^transform\s*:\s*translate(?:3d|x|y)?\(\s*-?\d+(?:\.\d+)?(?:%|px)?\s*,\s*-?\d+(?:\.\d+)?(?:%|px)?\s*(?:,\s*-?\d+(?:\.\d+)?(?:%|px)?\s*)?\)\s*$/i', $css_test_string ) ) {
		return true;
	}

	return false;
}

/**
 * Sanitize advanced/content booking form text coming from the Builder.
 *
 * @since 11.0.0
 *
 * @param string $form_value Raw form markup (may be slashed).
 *
 * @return string Sanitized form markup.
 */
function wpbc_bfb_sanitize_form_text( $form_value ) {

	$form_value = (string) $form_value;

	if ( '' === $form_value ) {
		return '';
	}

	// Make function self-contained for all call-sites.
	$form_value = wp_unslash( $form_value );
	$form_value = wp_kses_no_null( $form_value );

	// Optional but recommended: avoid comment encoding artifacts.
	// Remove this if you must preserve comments in DB exactly as-is.
	$form_value = preg_replace( '/<!--[\s\S]*?-->/', '', $form_value );

	// Start with WP default allowed tags, then extend with our custom tags (custom wins).
	$allowed_tags = array_merge(
		wp_kses_allowed_html( 'post' ),
		wpbc_get_allowed_simple_html_tags__for_wp_kses()     // Custom short tags used in legacy / advanced markup. 	// FixIn: 10.15.5.6.
	);

	// Allow 'name' on <p> (if used by legacy markup).
	if ( isset( $allowed_tags['p'] ) ) {
		$allowed_tags['p']['name'] = true;
	}

	// Extra attributes for layout/structure wrappers.
	foreach ( array( 'div', 'span', 'hr' ) as $tag ) {
		if ( ! isset( $allowed_tags[ $tag ] ) ) {
			$allowed_tags[ $tag ] = array();
		}
		$allowed_tags[ $tag ]['data-bfb-type']    = true;
		$allowed_tags[ $tag ]['data-orientation'] = true;
		$allowed_tags[ $tag ]['name']             = true;
		$allowed_tags[ $tag ]['aria-orientation'] = true;
	}

	// Appointment Form Builder control: permit only its declarative action.
	if ( ! isset( $allowed_tags['button'] ) ) {
		$allowed_tags['button'] = array();
	}
	$allowed_tags['button']['type']                         = true;
	$allowed_tags['button']['class']                        = true;
	$allowed_tags['button']['id']                           = true;
	$allowed_tags['button']['data-wpbc-appointment-action'] = true;

	// Temporarily allow extra inline style properties for BFB.
	add_filter( 'safe_style_css', 'wpbc_bfb_safe_style_props_filter', 10, 1 );

	// Allow ONLY transform: translate*(...) patterns (your strict validator).
	add_filter( 'safecss_filter_attr_allow_css', 'wpbc_bfb_allow_transform_translate_only', 10, 2 );

	$sanitized = wp_kses( $form_value, $allowed_tags );

	remove_filter( 'safecss_filter_attr_allow_css', 'wpbc_bfb_allow_transform_translate_only', 10 );
	remove_filter( 'safe_style_css', 'wpbc_bfb_safe_style_props_filter', 10 );

	return $sanitized;
}

/**
 * Sanitize a form slug/key.
 *
 * Allows: a-z, 0-9, underscore, dash.
 *
 * @param string $raw
 *
 * @return string
 */
function wpbc_bfb__sanitize_form_slug( $raw ) {

	$raw = strtolower( trim( sanitize_text_field( (string) $raw ) ) );

	// Replace spaces with underscore for readability.
	$raw = preg_replace( '/\s+/', '_', $raw );

	// Keep only: a-z 0-9 _ -
	$raw = preg_replace( '/[^a-z0-9_\-]/', '_', $raw );

	// Collapse multiple separators.
	$raw = preg_replace( '/[_\-]{2,}/', '_', $raw );

	// Trim separators.
	$raw = trim( $raw, '_-' );

	return $raw;
}

/**
 * Read form_details from POST (array or JSON string) and sanitize values.
 *
 * Keys:
 * - form_name
 * - title
 * - description
 * - picture_url
 *
 * IMPORTANT: We keep "presence" checks with array_key_exists() in the caller,
 * so UI can intentionally clear values by sending empty string.
 *
 * @param mixed $raw
 *
 * @return array
 */
function wpbc_bfb__normalize_form_details_from_post( $raw ) {

	if ( is_string( $raw ) && '' !== $raw ) {
		$tmp = json_decode( $raw, true );
		if ( is_array( $tmp ) ) {
			$raw = $tmp;
		}
	}

	if ( ! is_array( $raw ) ) {
		return array();
	}

	$out = array();

	if ( array_key_exists( 'form_name', $raw ) ) {
		$out['form_name'] = sanitize_text_field( $raw['form_name'] );
	}

	if ( array_key_exists( 'title', $raw ) ) {
		$out['title'] = sanitize_text_field( (string) $raw['title'] );
	}

	if ( array_key_exists( 'description', $raw ) ) {
		$out['description'] = sanitize_textarea_field( (string) $raw['description'] );
	}

	if ( array_key_exists( 'picture_url', $raw ) ) {
		$out['picture_url'] = esc_url_raw( (string) $raw['picture_url'] );
	}

	return $out;
}

/**
 * Split a search string into OR-terms by configured separator.
 *
 * Example (default "~"):
 * - "time~duration~slots" => array( 'time', 'duration', 'slots' )
 * - " time ~ duration "   => array( 'time', 'duration' )
 *
 * @since 11.0.0
 *
 * @param string $search_raw Raw search string.
 * @param int    $max_terms  Max number of terms allowed (anti-abuse).
 *
 * @return array List of unique, trimmed terms.
 */
function wpbc_bfb__split_search_terms_by_or_separator( $search_raw, $max_terms = 5 ) {

	$search_raw = trim( (string) $search_raw );

	if ( '' === $search_raw ) {
		return array();
	}

	$max_terms = absint( $max_terms );
	if ( $max_terms <= 0 ) {
		$max_terms = 5;
	}


	$sep = ( defined( 'WPBC_BFB_TEMPLATE_SEARCH_OR_SEPARATOR' ) ) ? (string) WPBC_BFB_TEMPLATE_SEARCH_OR_SEPARATOR : '|';
	if ( '' === $sep ) {
		$sep = '|';
	}

	$pattern = '/\s*' . preg_quote( $sep, '/' ) . '\s*/';
	$parts   = preg_split( $pattern, $search_raw );

	if ( ! is_array( $parts ) ) {
		return array();
	}

	$terms = array();

	foreach ( $parts as $p ) {
		$t = trim( (string) $p );
		if ( '' === $t ) {
			continue;
		}
		$terms[] = $t;
		if ( count( $terms ) >= $max_terms ) {
			break;
		}
	}

	$terms = array_values( array_unique( $terms ) );

	return $terms;
}

/**
* Normalize settings into array() and ensure ONLY supported schema exists:
 * {
 *   options     : {},
 *   css_vars    : [],
 *   bfb_options : { advanced_mode_source: 'builder'|'advanced'|'auto' }
 * }
 *
 * @param mixed $settings
 *
 * @return array
 */
function wpbc_bfb__normalize_settings_array( $settings ) {

	if ( is_string( $settings ) && '' !== $settings ) {
		$tmp = json_decode( $settings, true );
		if ( is_array( $tmp ) ) {
			$settings = $tmp;
		}
	}

	if ( ! is_array( $settings ) ) {
		$settings = array();
	}

	if ( empty( $settings['options'] ) || ! is_array( $settings['options'] ) ) {
		$settings['options'] = array();
	}

	if ( function_exists( 'wpbc_bfb_settings__strip_form_style_options_from_form_settings' ) ) {
		$settings = wpbc_bfb_settings__strip_form_style_options_from_form_settings( $settings );
	}

	if ( empty( $settings['css_vars'] ) || ! is_array( $settings['css_vars'] ) ) {
		$settings['css_vars'] = array();
	}

	if ( empty( $settings['bfb_options'] ) || ! is_array( $settings['bfb_options'] ) ) {
		$settings['bfb_options'] = array();
	}

	$src = isset( $settings['bfb_options']['advanced_mode_source'] ) ? strtolower( trim( (string) $settings['bfb_options']['advanced_mode_source'] ) ) : 'auto';
	if ( ! in_array( $src, array( 'builder', 'advanced', 'auto' ), true ) ) {
		$src = 'auto';
	}
	$settings['bfb_options']['advanced_mode_source'] = $src;

	return $settings;
}

/**
 * Normalize preview-only global Form Style override.
 *
 * @param mixed $preview_form_style Raw JSON string or array.
 * @return array
 */
function wpbc_bfb__normalize_preview_form_style( $preview_form_style ) {

	if ( is_string( $preview_form_style ) && '' !== trim( $preview_form_style ) ) {
		$decoded = json_decode( $preview_form_style, true );
		if ( is_array( $decoded ) ) {
			$preview_form_style = $decoded;
		}
	}

	if ( ! is_array( $preview_form_style ) ) {
		return array();
	}

	$style = isset( $preview_form_style['booking_form_style'] ) ? $preview_form_style['booking_form_style'] : '';
	$style = function_exists( 'wpbc_bfb_settings__sanitize_form_style' )
		? wpbc_bfb_settings__sanitize_form_style( $style )
		: sanitize_key( (string) $style );

	$custom_options = function_exists( 'wpbc_bfb_settings__get_custom_form_style_options' )
		? wpbc_bfb_settings__get_custom_form_style_options( $preview_form_style )
		: array();
	$accent_options = function_exists( 'wpbc_bfb_settings__get_form_accent_options' )
		? wpbc_bfb_settings__get_form_accent_options( $preview_form_style )
		: array();

	return array_merge(
		array(
			'booking_form_style' => $style,
		),
		$custom_options,
		$accent_options
	);
}

/**
 * Check whether template key means "blank form".
 *
 * @param string $template_form_name
 *
 * @return bool
 */
function wpbc_bfb__is_blank_template_key( $template_form_name ) {

	$template_form_name = (string) $template_form_name;

	return ( '' === $template_form_name || '__blank__' === $template_form_name || 'blank' === $template_form_name );
}

/**
 * Get blank Builder structure seed.
 *
 * @return array
 */
function wpbc_bfb__get_blank_structure_seed() {

	return array(
		array(
			'page'    => 1,
			'content' => array(),
		),
	);
}

/**
 * Resolve BFB form/template picture URL.
 *
 * Rules:
 * - If value is already an absolute URL, return as is.
 * - If value is only a file name, first try local bundled templates image folder:
 *   ../includes/page-form-builder/save-load/../assets/template-img/
 * - If local file does not exist, use external fallback base URL.
 *
 * @param string $picture_url Raw picture_url value from DB.
 *
 * @return string
 */
function wpbc_bfb_resolve_picture_url( $picture_url ) {

	$picture_url = trim( (string) $picture_url );

	if ( '' === $picture_url ) {
		return '';
	}

	// Already absolute URL or protocol-relative URL.
	if (
		( false !== strpos( $picture_url, '://' ) ) ||
		( 0 === strpos( $picture_url, '//' ) )
	) {
		return $picture_url;
	}

	// If path contains directories, treat it as already prepared relative path.
	// This helper is intended mainly for simple file names like "template_appointments_01.png".
	if (
		( false !== strpos( $picture_url, '/' ) ) ||
		( false !== strpos( $picture_url, '\\' ) )
	) {
		return $picture_url;
	}

	$file_name = sanitize_file_name( wp_basename( $picture_url ) );
	if ( '' === $file_name ) {
		return '';
	}

	$local_dir_path = trailingslashit( plugin_dir_path( __FILE__ ) ) . '../assets/template-img/';
	$local_file_path = $local_dir_path . $file_name;

	if ( file_exists( $local_file_path ) ) {
		return trailingslashit( plugin_dir_url( __FILE__ ) ) . '../assets/template-img/' . rawurlencode( $file_name );
	}

	$fallback_base_url = apply_filters( 'wpbc_bfb_template_picture_fallback_base_url', 'https://wpbookingcalendar.com/assets/template-img/' );

	return trailingslashit( $fallback_base_url ) . rawurlencode( $file_name );
}

/**
 * Verify AJAX delete nonce for BFB delete operations.
 *
 * Preferred nonce:
 * - wpbc_bfb_form_delete
 *
 * Backward-compatible fallback:
 * - wpbc_bfb_form_list
 *
 * This fallback allows template deletion from the Apply Template modal
 * even if only nonce_list is localized in older builder pages.
 *
 * @since 11.0.0
 *
 * @return bool
 */
function wpbc_bfb__verify_delete_request_nonce() {

	if ( check_ajax_referer( 'wpbc_bfb_form_delete', 'nonce', false ) ) {
		return true;
	}

	if ( check_ajax_referer( 'wpbc_bfb_form_list', 'nonce', false ) ) {
		return true;
	}

	return false;
}

/**
 * Check whether a listed template can be deleted in the current owner context.
 *
 * Rules:
 * - Only rows with status=template are deletable.
 * - Reserved/default templates are never deletable.
 * - In MU regular-user context, only own templates are deletable.
 * - In global/admin context, only global templates are deletable.
 *
 * @since 11.0.0
 *
 * @param string $form_slug              Template slug.
 * @param int    $row_owner_user_id      Owner of listed row.
 * @param int    $current_owner_user_id  Current owner context.
 * @param int    $is_default             Default flag.
 * @param string $status                 Row status.
 *
 * @return bool
 */
function wpbc_bfb__can_delete_template_in_current_context( $form_slug, $row_owner_user_id, $current_owner_user_id, $is_default, $status ) {

	if ( 'template' !== (string) $status ) {
		return false;
	}

	if ( 'standard' === (string) $form_slug ) {
		return false;
	}

	if ( 1 === absint( $is_default ) ) {
		return false;
	}

	$row_owner_user_id = absint( $row_owner_user_id );
	$current_owner_user_id = absint( $current_owner_user_id );

	if ( $current_owner_user_id > 0 ) {
		return ( $row_owner_user_id === $current_owner_user_id );
	}

	return ( 0 === $row_owner_user_id );
}

// == AJAX == ==========================================================================================================


/**
 * Handle AJAX request: save FormConfig from the Form Builder.
 *
 * Security:
 * - Verifies wpbc_bfb_form_save nonce (sent as 'nonce').
 * - Requires current_user_can( wpbc_bfb_get_manage_cap() ).
 *
 * Expects POST:
 * - nonce          : string  Nonce for 'wpbc_bfb_form_save'.
 * - form_name      : string  'standard' or custom key (optional, default 'standard').
 * - engine         : string  Engine name, usually 'bfb' (optional, default 'bfb').
 * - engine_version : string  Engine version (optional, default '1.0').
 * - structure      : string  JSON string (Builder structure).
 * - settings       : string  JSON string (extra settings, optional).
 * - advanced_form  : string  Shortcodes / markup for booking form (optional).
 * - content_form   : string  Shortcodes / markup for "Content of booking fields data" (optional).
 *
 * On success:
 * - Persists FormConfig via wpbc_form_config_save() (which writes to
 *   booking_form_structures and optionally syncs legacy options).
 *
 * Response (JSON):
 * - success: true|false
 * - data: {
 *     booking_form_id: int,
 *     form_name:       string,
 *     engine:          string
 *   }
 *
 * @since 11.0.0
 *
 * @return void
 */
function wpbc_bfb_ajax_save_form_config() {
	global $wpdb;

	if ( ! check_ajax_referer( 'wpbc_bfb_form_save', 'nonce', false ) ) {
		wp_send_json_error( array( 'code' => 'invalid_nonce', 'message' => __( 'Security check failed.', 'booking' ) ) );
	}

	if ( ! current_user_can( wpbc_bfb_get_manage_cap() ) ) {
		wp_send_json_error( array( 'code' => 'forbidden', 'message' => __( 'You are not allowed to save booking forms.', 'booking' ) ) );
	}

	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$form_name = isset( $_POST['form_name'] ) ? wpbc_bfb__sanitize_form_slug( wp_unslash( $_POST['form_name'] ) ) : '';
	if ( '' === $form_name ) {
		$form_name = 'standard';
	}

	$status = isset( $_POST['status'] ) ? sanitize_key( wp_unslash( $_POST['status'] ) ) : 'published';
	$allowed_statuses = array( 'published', 'preview', 'template' );
	if ( ! in_array( $status, $allowed_statuses, true ) ) {
		$status = 'published';
	}

	// Preview context ID (calendar/resource) used ONLY to build preview URL + render shortcode.                        It is NOT saved into FormConfig in BFB mode !
	$preview_form_id = isset( $_POST['preview_form_id'] ) ? absint( wp_unslash( $_POST['preview_form_id'] ) ) : 0;
	if ( $preview_form_id <= 0 ) {
		$preview_form_id = 1;
	}
	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$return_preview_url = ( isset( $_POST['return_preview_url'] ) && '1' === (string) wp_unslash( $_POST['return_preview_url'] ) );

	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$engine         = isset( $_POST['engine'] ) ? sanitize_text_field( wp_unslash( $_POST['engine'] ) ) : 'bfb';
	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$engine_version = isset( $_POST['engine_version'] ) ? sanitize_text_field( wp_unslash( $_POST['engine_version'] ) ) : '1.0';

	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$structure_raw = isset( $_POST['structure'] ) ? wp_unslash( $_POST['structure'] ) : '';
	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$settings_raw  = isset( $_POST['settings'] ) ? wp_unslash( $_POST['settings'] ) : '';
	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$preview_form_style_raw = isset( $_POST['preview_form_style'] ) ? wp_unslash( $_POST['preview_form_style'] ) : '';

	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$content_form_raw = isset( $_POST['content_form'] ) && is_scalar( $_POST['content_form'] )
		? wp_unslash( $_POST['content_form'] )
		: '';
	$content_form     = wpbc_bfb_sanitize_form_text( $content_form_raw );

	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$advanced_form_raw = isset( $_POST['advanced_form'] ) && is_scalar( $_POST['advanced_form'] )
		? wp_unslash( $_POST['advanced_form'] )
		: '';
	$advanced_form     = wpbc_bfb_sanitize_form_text( $advanced_form_raw );


	// Validate structure JSON.
	$structure_arr = json_decode( $structure_raw, true );
	if ( ! is_array( $structure_arr ) ) {
		wp_send_json_error( array( 'code' => 'invalid_structure', 'message' => __( 'Form structure is not a valid JSON object.', 'booking' ) ) );
	}
	$preview_structure_arr = $structure_arr;

	/**
	 * Filter and sanitize a decoded Form Builder structure before persistence.
	 *
	 * Field packs may normalize only their own stored properties. Callbacks must
	 * return the complete structure and must not perform persistence or output.
	 *
	 * @since 11.8.4
	 *
	 * @param array $structure_arr Decoded Form Builder structure.
	 */
	$structure_arr = apply_filters( 'wpbc_bfb_sanitize_structure_before_save', $structure_arr );

	if ( ! is_array( $structure_arr ) ) {
		wp_send_json_error( array( 'code' => 'invalid_structure', 'message' => __( 'Form structure could not be normalized.', 'booking' ) ) );
	}

	// Settings JSON (normalized to the ONLY supported schema).
	$settings_arr = wpbc_bfb__normalize_settings_array( $settings_raw );
	$preview_form_style = wpbc_bfb__normalize_preview_form_style( $preview_form_style_raw );
	// $advanced_mode_source = ( isset( $settings_arr['bfb_options']['advanced_mode_source'] ) ) ? (string) $settings_arr['bfb_options']['advanced_mode_source'] : 'builder';

	// Check if owner of this form  is "Regular User" in MU.
	$owner_user_id = WPBC_FE_Custom_Form_Helper::wpbc_mu__get_current__owner_user_id();

	$form_config = array(
		'form_name'           => $form_name,
		'engine'              => $engine,
		'engine_version'      => $engine_version,
		'structure_json'      => wpbc_form_config__encode_json( $structure_arr ),
		'settings'            => $settings_arr,
		'advanced_form'       => $advanced_form,
		'content_form'        => $content_form,
		'owner_user_id'       => $owner_user_id,
		'scope'               => ( $owner_user_id > 0 ) ? 'user' : 'global',
		'status'              => $status,
		'is_default' => ( ( 'standard' === $form_name ) && ( 'template' !== $status ) ) ? 1 : 0,
		'booking_resource_id' => null,
	);

	// ---------------------------------------------------------------------
	// Form Details (title/description/picture) coming from UI.
	// - Preserve existing values unless UI explicitly sent a key.
	// ---------------------------------------------------------------------

	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$form_details_raw = isset( $_POST['form_details'] ) ? wp_unslash( $_POST['form_details'] ) : null;
	$form_details     = wpbc_bfb__normalize_form_details_from_post( $form_details_raw );

	$existing_cfg = wpbc_form_config_load( $form_name, $owner_user_id );

	// Optional: rename slug/key (save by booking_form_id to avoid creating a duplicate).
	if ( array_key_exists( 'form_name', $form_details ) && '' !== $form_details['form_name'] ) {

		$new_form_name = (string) $form_details['form_name'];

		// Block reserved.
		if ( 'standard' === $new_form_name && 'standard' !== $form_name ) {
			wp_send_json_error( array( 'code' => 'reserved', 'message' => __( 'This form key is reserved.', 'booking' ) ) );
		}

		// If slug changed, ensure no collision.
		if ( $new_form_name !== $form_name ) {

			$is_fallback_to_legacy = false;
			$collision             = wpbc_form_config_load( $new_form_name, $owner_user_id, 'published', $is_fallback_to_legacy );

			$existing_id  = ( is_array( $existing_cfg ) && isset( $existing_cfg['id'] ) ) ? absint( $existing_cfg['id'] ) : 0;
			$collision_id = ( is_array( $collision ) && isset( $collision['id'] ) ) ? absint( $collision['id'] ) : 0;

			if ( ! empty( $collision ) && $collision_id !== $existing_id ) {
				wp_send_json_error( array( 'code' => 'already_exists', 'message' => __( 'Form key already exists. Please choose another.', 'booking' ) ) );
			}

			// Save by ID (so wpbc_form_config_save updates this row).
			if ( $existing_id > 0 ) {
				$form_config['booking_form_id'] = $existing_id;
			}

			$form_name = $new_form_name;

			// Keep flags consistent.
			$form_config['form_name']  = $form_name;
			$form_config['is_default'] = ( 'standard' === $form_name ) ? 1 : 0;
		}
	}


	$existing_title = ( is_array( $existing_cfg ) && isset( $existing_cfg['title'] ) ) ? (string) $existing_cfg['title'] : '';
	$existing_desc  = ( is_array( $existing_cfg ) && isset( $existing_cfg['description'] ) ) ? (string) $existing_cfg['description'] : '';
	$existing_pic   = ( is_array( $existing_cfg ) && isset( $existing_cfg['picture_url'] ) ) ? (string) $existing_cfg['picture_url'] : '';

	// Default: keep existing if set, otherwise fallback.
	$form_title = ( '' !== trim( $existing_title ) ) ? $existing_title : ( ( 'standard' === $form_name ) ? __( 'Standard', 'booking' ) : $form_name );
	$form_desc  = $existing_desc;
	$form_pic   = $existing_pic;

	// 1) Preferred: override from form_details if key exists (supports clearing).
	if ( array_key_exists( 'title', $form_details ) ) {
		$form_title = (string) $form_details['title'];
	}

	if ( array_key_exists( 'description', $form_details ) ) {
		$form_desc = (string) $form_details['description'];
	}

	if ( array_key_exists( 'picture_url', $form_details ) ) {
		$form_pic = (string) $form_details['picture_url'];
	}

	// 2) Backward compatibility: keep your old options override (if still used elsewhere).
	if ( ! empty( $settings_arr['options'] ) && is_array( $settings_arr['options'] ) ) {

		$options = $settings_arr['options'];

		if ( array_key_exists( 'booking_form_title', $options ) && ! array_key_exists( 'title', $form_details ) ) {
			$form_title = sanitize_text_field( $options['booking_form_title'] );
		}

		if ( array_key_exists( 'booking_form_description', $options ) && ! array_key_exists( 'description', $form_details ) ) {
			$form_desc = sanitize_textarea_field( $options['booking_form_description'] );
		}
	}

	// Store final meta into columns.
	$form_config['title']       = $form_title;
	$form_config['description'] = $form_desc;
	$form_config['picture_url'] = $form_pic;

	// Apply (possibly adjusted) settings back into form_config (important).
	$form_config['settings'] = wpbc_bfb__normalize_settings_array( $settings_arr );

	// We do not need to update options: 'booking_form', etc... in BFB!
	$sync_legacy = false;
	// == One Saving point ==
	$booking_form_id = wpbc_form_config_save( $form_config, array( 'sync_legacy' => (bool) $sync_legacy ) );

	if ( ! $booking_form_id ) {

		wp_send_json_error(
			array(
				'code'    => 'save_failed',
				'message' => __( 'Error saving booking form.', 'booking' ) . ( ! empty( $wpdb->last_error ) ? ' ' . $wpdb->last_error : '' ),
			)
		);
	}


	$preview_url   = '';
	$preview_token = '';

	if ( $return_preview_url && 'preview' === $status && class_exists( 'WPBC_BFB_Preview_Service' ) ) {

		$preview_service = WPBC_BFB_Preview_Service::get_instance();

		$res = $preview_service->create_preview_session(
			$preview_form_id,
			get_current_user_id(),
			$preview_structure_arr,
			$form_name,
			$advanced_form_raw,
			$content_form_raw,
			$preview_form_style
		);

		if ( is_array( $res ) && ! empty( $res['preview_url'] ) ) {
			$preview_url   = (string) $res['preview_url'];
			$preview_token = ! empty( $res['token'] ) ? (string) $res['token'] : '';
		}
	}

	wp_send_json_success(
		array(
			'booking_form_id' => $booking_form_id,
			'form_name'       => $form_name,
			'engine'          => $engine,
			'status'          => $status,
			'preview_url'     => $preview_url,
			'token'           => $preview_token,
			'title'          => isset( $form_config['title'] ) ? (string) $form_config['title'] : '',
			'description'    => isset( $form_config['description'] ) ? (string) $form_config['description'] : '',
			'picture_url'    => isset( $form_config['picture_url'] ) ? (string) $form_config['picture_url'] : '',
		)
	);

}
add_action( 'wp_ajax_' . 'WPBC_AJX_BFB_SAVE_FORM_CONFIG', 'wpbc_bfb_ajax_save_form_config' );


/**
 * Handle AJAX request: save FormConfig as TEMPLATE.
 *
 * This is a minimal wrapper around wpbc_bfb_ajax_save_form_config().
 * It forces status='template' and reuses all validations/sanitizers.
 *
 * @since 11.0.0
 *
 * @return void
 */
function wpbc_bfb_ajax_save_form_config_template() {

	// Force template status (listing expects status='template').
	$_POST['status'] = 'template';

	// Reuse main save logic.
	wpbc_bfb_ajax_save_form_config();
}
add_action( 'wp_ajax_' . 'WPBC_AJX_BFB_SAVE_FORM_CONFIG_TEMPLATE', 'wpbc_bfb_ajax_save_form_config_template' );


/**
 * Handle AJAX request: load FormConfig for the Form Builder.
 *
 * Security:
 * - Verifies wpbc_bfb_form_load nonce (sent as 'nonce').
 * - Requires current_user_can( wpbc_bfb_get_manage_cap() ).
 *
 * Expects POST:
 * - nonce     : string  Nonce for 'wpbc_bfb_form_load'.
 * - form_name : string  'standard' or custom key (optional, default 'standard').
 *
 * Behaviour:
 * - Loads FormConfig via wpbc_form_config_load().
 * - For engine = 'bfb', decodes structure_json into 'structure' array.
 * - For engine = 'legacy_*', returns a simple "notice" structure in Builder canvas.
 *
 * @since 11.0.0
 *
 * @return void
 */
function wpbc_bfb_ajax_load_form_config() {

	if ( ! check_ajax_referer( 'wpbc_bfb_form_load', 'nonce', false ) ) {
		wp_send_json_error(
			array(
				'code'    => 'invalid_nonce',
				'message' => __( 'Security check failed.', 'booking' ),
			)
		);
	}

	if ( ! current_user_can( wpbc_bfb_get_manage_cap() ) ) {
		wp_send_json_error(
			array(
				'code'    => 'forbidden',
				'message' => __( 'You are not allowed to load booking forms.', 'booking' ),
			)
		);
	}

	$form_name = isset( $_POST['form_name'] ) ? sanitize_text_field( wp_unslash( $_POST['form_name'] ) ) : '';
	if ( '' === $form_name ) {
		$form_name = 'standard';
	}

	$status           = isset( $_POST['status'] ) ? sanitize_key( wp_unslash( $_POST['status'] ) ) : 'published';
	$allowed_statuses = array( 'published', 'preview', 'template' );
	if ( ! in_array( $status, $allowed_statuses, true ) ) {
		$status = 'published';
	}


	// Check if owner of this form  is "Regular User" in MU.
	$user_id = WPBC_FE_Custom_Form_Helper::wpbc_mu__get_current__owner_user_id();

	if ( ! empty( $user_id ) ) {
		make_bk_action( 'check_multiuser_params_for_client_side_by_user_id', $user_id );   // == MU ==  // FixIn: 2026-03-06 11:57.
	}

	$form_config = wpbc_form_config_load( $form_name, $user_id, $status );

	if ( ! empty( $user_id ) ) {
		make_bk_action( 'finish_check_multiuser_params_for_client_side', null );          // == MU ==   // FixIn: 2026-03-06 11:57.
	}

	if ( empty( $form_config ) || ( ! is_array( $form_config ) ) ) {
		wp_send_json_error(
			array(
				'code'    => 'not_found',
				'message' => __( 'Booking form configuration not found.', 'booking' ),
			),
			404
		);
	}

	$engine    = isset( $form_config['engine'] ) ? (string) $form_config['engine'] : '';
	$structure = array();

	if ( ! empty( $form_config['structure_json'] ) ) {
		$tmp = json_decode( $form_config['structure_json'], true );
		if ( is_array( $tmp ) ) {
			$structure = $tmp;
		}
	}

	// Advanced Mode notice only when no visual Builder structure exists.
	if ( empty( $structure ) && 'advanced_mode' === $engine ) {

		$structure = array(
			array(
				'page'    => 1,
				'content' => array(
					array(
						'type' => 'field',
						'data' => array(
							'id'             => 'static_text_legacy_notice_1',
							'type'           => 'static_text',
							'usage_key'      => 'static_text',
							'text'           => __( 'This imported form is currently configured in Advanced Form mode only.', 'booking' ),
							'tag'            => 'p',
							'align'          => 'center',
							'bold'           => 1,
							'italic'         => 0,
							'html_allowed'   => 0,
							'nl2br'          => 1,
							'name'           => 'static_text_legacy_notice_1',
							'html_id'        => '',
							'cssclass_extra' => '',
							'label'          => 'Static_text',
						),
					),
					array(
						'type' => 'field',
						'data' => array(
							'id'             => 'static_text_legacy_notice_2',
							'type'           => 'static_text',
							'usage_key'      => 'static_text',
							'text'           => __( 'Nothing is broken - the form was imported and can be edited in Advanced Mode. You can also start building visually by dragging fields from Add Fields onto this canvas.', 'booking' ),
							'tag'            => 'p',
							'align'          => 'center',
							'bold'           => 0,
							'italic'         => 0,
							'html_allowed'   => 0,
							'nl2br'          => 1,
							'name'           => 'static_text_legacy_notice_2',
							'html_id'        => '',
							'cssclass_extra' => '',
							'label'          => 'Static_text',
						),
					),
				),
			),
		);
	}

	$settings_out = wpbc_bfb__normalize_settings_array( isset( $form_config['settings'] ) ? $form_config['settings'] : array() );

	wp_send_json_success(
		array(
			'form_name'      => isset( $form_config['form_name'] ) ? (string) $form_config['form_name'] : $form_name,
			'engine'         => $engine,
			'engine_version' => isset( $form_config['engine_version'] ) ? (string) $form_config['engine_version'] : '',
			'structure'      => $structure,
			'settings'       => $settings_out,
			'advanced_form'  => isset( $form_config['advanced_form'] ) ? (string) $form_config['advanced_form'] : '',
			'content_form'   => isset( $form_config['content_form'] ) ? (string) $form_config['content_form'] : '',
			'title'          => isset( $form_config['title'] ) ? (string) $form_config['title'] : '',
			'description'    => isset( $form_config['description'] ) ? (string) $form_config['description'] : '',
			'picture_url'    => isset( $form_config['picture_url'] ) ? (string) $form_config['picture_url'] : '',
		)
	);
}
add_action( 'wp_ajax_' . 'WPBC_AJX_BFB_LOAD_FORM_CONFIG', 'wpbc_bfb_ajax_load_form_config' );


/**
 * Handle AJAX request: create new FormConfig by cloning a template form,
 * or creating a blank form when template is not selected / not available.
 *
 * Expects POST:
 * - nonce
 * - form_name          (new form key / slug)
 * - template_form_name (optional; '' or '__blank__' => blank form)
 * - title              (optional)
 * - description        (optional)
 * - image_url          (optional)
 */
function wpbc_bfb_ajax_create_form_config() {

	if ( ! check_ajax_referer( 'wpbc_bfb_form_create', 'nonce', false ) ) {
		wp_send_json_error(
			array(
				'code'    => 'invalid_nonce',
				'message' => __( 'Security check failed.', 'booking' ),
			)
		);
	}

	if ( ! current_user_can( wpbc_bfb_get_manage_cap() ) ) {
		wp_send_json_error(
			array(
				'code'    => 'forbidden',
				'message' => __( 'You are not allowed to create booking forms.', 'booking' ),
			)
		);
	}

	// New form key.
	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$form_name = isset( $_POST['form_name'] ) ? wpbc_bfb__sanitize_form_slug( wp_unslash( $_POST['form_name'] ) ) : '';
	if ( '' === $form_name ) {
		wp_send_json_error(
			array(
				'code'    => 'invalid_form_name',
				'message' => __( 'Form key is required.', 'booking' ),
			)
		);
	}
	if ( 'standard' === $form_name ) {
		wp_send_json_error( array( 'code' => 'reserved', 'message' => __( 'This form key is reserved.', 'booking' ) ) );
	}

	// Template key (optional).
	$template_form_name = isset( $_POST['template_form_name'] ) ? sanitize_text_field( wp_unslash( $_POST['template_form_name'] ) ) : '';

	$is_blank = wpbc_bfb__is_blank_template_key( $template_form_name );

	// Meta.
	$title       = isset( $_POST['title'] ) ? sanitize_text_field( wp_unslash( $_POST['title'] ) ) : '';
	$description = isset( $_POST['description'] ) ? sanitize_textarea_field( wp_unslash( $_POST['description'] ) ) : '';
	$image_url   = isset( $_POST['image_url'] ) ? esc_url_raw( wp_unslash( $_POST['image_url'] ) ) : '';

	if ( '' === $title ) {
		$title = $form_name;
	}

	// MU owner logic.
	$owner_user_id = WPBC_FE_Custom_Form_Helper::wpbc_mu__get_current__owner_user_id();

	// Ensure new form does not already exist.
	$is_fallback_to_legacy = false;
	$existing              = wpbc_form_config_load( $form_name, $owner_user_id, 'published', $is_fallback_to_legacy );
	if ( ! empty( $existing ) ) {
		wp_send_json_error(
			array(
				'code'    => 'already_exists',
				'message' => __( 'Form key already exists. Please choose another.', 'booking' ),
			)
		);
	}

	$template     = array();
	$structure_arr = array();
	$settings_arr  = array();
	$engine        = 'bfb';
	$engine_version = '1.0';
	$advanced_form = '';
	$content_form  = '';

	// Try to load template only when requested.
	if ( ! $is_blank ) {

		// 1) Prefer user-owned template (MU) if exists.
		if ( $owner_user_id > 0 ) {
			$template = wpbc_form_config_load( $template_form_name, $owner_user_id, 'template' );
		}

		// 2) Fallback to global template.
		if ( empty( $template ) ) {
			$template = wpbc_form_config_load( $template_form_name, 0, 'template' );
		}

		// 3) If still missing (template deleted), fallback to standard if it exists.
		if ( empty( $template ) ) {
			$template = wpbc_form_config_load( 'standard', $owner_user_id );
		}

		// If still nothing, create blank.
		if ( empty( $template ) ) {
			$is_blank = true;
		}
	}

	if ( $is_blank ) {

		// Blank form seed.
		$structure_arr = wpbc_bfb__get_blank_structure_seed();
		$settings_arr  = wpbc_bfb__normalize_settings_array( array() );

		// IMPORTANT: blank forms start in Builder sync mode (Builder -> Advanced).
		if ( empty( $settings_arr['bfb_options'] ) || ! is_array( $settings_arr['bfb_options'] ) ) {
			$settings_arr['bfb_options'] = array();
		}
		$settings_arr['bfb_options']['advanced_mode_source'] = 'builder';

		$engine         = 'bfb';
		$engine_version = '1.0';
		$advanced_form  = '';
		$content_form   = '';

	} else {

		// Clone structure from template.
		if ( ! empty( $template['structure_json'] ) ) {
			$tmp = json_decode( $template['structure_json'], true );
			if ( is_array( $tmp ) ) {
				$structure_arr = $tmp;
			}
		}

		// Clone settings from template.
		$settings_arr = wpbc_bfb__normalize_settings_array( isset( $template['settings'] ) ? $template['settings'] : array() );

		$engine         = ! empty( $template['engine'] ) ? (string) $template['engine'] : 'bfb';
		$engine_version = ! empty( $template['engine_version'] ) ? (string) $template['engine_version'] : '1.0';

		$advanced_form = isset( $template['advanced_form'] ) ? (string) $template['advanced_form'] : '';
		$content_form  = isset( $template['content_form'] ) ? (string) $template['content_form'] : '';
	}

	$form_config = array(
		'form_name'      => $form_name,
		'engine'         => $engine,
		'engine_version' => $engine_version,
		'structure_json' => wpbc_form_config__encode_json( $structure_arr ),
		'settings'       => $settings_arr,
		'advanced_form'  => $advanced_form,
		'content_form'   => $content_form,
		'owner_user_id'  => $owner_user_id,

		'title'          => $title,
		'description'    => $description,
		'picture_url'    => $image_url,

		'scope'               => ( $owner_user_id > 0 ) ? 'user' : 'global',
		'status'              => 'published',
		'is_default'          => 0,
		'booking_resource_id' => null,
	);

	$sync_legacy = false;

	$booking_form_id = wpbc_form_config_save( $form_config, array( 'sync_legacy' => (bool) $sync_legacy ) );

	if ( ! $booking_form_id ) {
		wp_send_json_error(
			array(
				'code'    => 'create_failed',
				'message' => __( 'Error creating booking form.', 'booking' ),
			)
		);
	}

	wp_send_json_success(
		array(
			'booking_form_id' => $booking_form_id,
			'form_name'       => $form_name,
		)
	);
}
add_action( 'wp_ajax_' . 'WPBC_AJX_BFB_CREATE_FORM_CONFIG', 'wpbc_bfb_ajax_create_form_config' );


/**
 * Build optional adjacency-aware ordering for the template library.
 *
 * Domains may register stable before/after slug pairs through
 * `wpbc_bfb_template_library_adjacencies`. The list endpoint keeps every pair
 * together at the existing target template's chronological position without
 * placing domain slugs or other business knowledge in the shared controller.
 *
 * @param string $table_name Trusted Booking Form structures table name.
 *
 * @return array SQL fragments and ordered prepare arguments.
 */
function wpbc_bfb_get_template_library_order_clauses( $table_name ) {

	$adjacencies = apply_filters( 'wpbc_bfb_template_library_adjacencies', array() );

	if ( ! is_array( $adjacencies ) ) {
		$adjacencies = array();
	}

	$effective_updated_at_cases = array();
	$adjacency_rank_cases       = array();
	$effective_updated_at_args  = array();
	$adjacency_rank_args        = array();

	foreach ( $adjacencies as $adjacency ) {
		if ( ! is_array( $adjacency ) ) {
			continue;
		}

		$before_slug = isset( $adjacency['before'] ) ? sanitize_title( (string) $adjacency['before'] ) : '';
		$after_slug  = isset( $adjacency['after'] ) ? sanitize_title( (string) $adjacency['after'] ) : '';

		if ( '' === $before_slug || '' === $after_slug || $before_slug === $after_slug ) {
			continue;
		}

		$effective_updated_at_cases[] = "WHEN form_slug = %s THEN COALESCE(
			( SELECT MAX( wpbc_adjacent_target.updated_at )
			  FROM {$table_name} AS wpbc_adjacent_target
			  WHERE wpbc_adjacent_target.form_slug = %s
			    AND wpbc_adjacent_target.status = 'template'
			    AND ( wpbc_adjacent_target.owner_user_id = 0 OR wpbc_adjacent_target.owner_user_id IS NULL ) ),
			updated_at
		)";
		$effective_updated_at_args[]  = $before_slug;
		$effective_updated_at_args[]  = $after_slug;

		$adjacency_rank_cases[] = 'WHEN form_slug = %s THEN 2 WHEN form_slug = %s THEN 1';
		$adjacency_rank_args[]  = $before_slug;
		$adjacency_rank_args[]  = $after_slug;
	}

	if ( empty( $effective_updated_at_cases ) ) {
		return array(
			'effective_updated_at_sql' => 'updated_at',
			'adjacency_rank_sql'       => '',
			'args'                     => array(),
		);
	}

	return array(
		'effective_updated_at_sql' => 'CASE ' . implode( ' ', $effective_updated_at_cases ) . ' ELSE updated_at END',
		'adjacency_rank_sql'       => 'CASE ' . implode( ' ', $adjacency_rank_cases ) . ' ELSE 0 END',
		'args'                     => array_merge( $effective_updated_at_args, $adjacency_rank_args ),
	);
}

/**
 * Handle AJAX request: list booking forms for current user (and optionally global ones).
 *
 * Security:
 * - Verifies wpbc_bfb_form_list nonce (sent as 'nonce').
 * - Requires current_user_can( wpbc_bfb_get_manage_cap() ).
 *
 * Expects POST:
 * - nonce          : string  Nonce for 'wpbc_bfb_form_list'.
 * - include_global : 0|1     If 1, include global forms (owner_user_id=0/NULL) in addition to user-owned.
 * - status         : string  Default 'published'. Allowed: published|preview|draft|archived|template
 * - search         : string  Optional filter by title/slug/description
 * - limit          : int     Optional max rows (default 20, max 500)
 * - page           : int     Optional page number, starts from 1
 *
 * Response (JSON):
 * - success: true|false
 * - data: { forms: [ ... ] }
 *
 * @since 11.0.0
 *
 * @return void
 */

function wpbc_bfb_ajax_list_forms() {

	global $wpdb;

	if ( ! check_ajax_referer( 'wpbc_bfb_form_list', 'nonce', false ) ) {
		wp_send_json_error( array(
			'code'    => 'invalid_nonce',
			'message' => __( 'Security check failed.', 'booking' ),
		) );
	}

	if ( ! current_user_can( wpbc_bfb_get_manage_cap() ) ) {
		wp_send_json_error( array(
			'code'    => 'forbidden',
			'message' => __( 'You are not allowed to list booking forms.', 'booking' ),
		) );
	}

	// Allow global forms ONLY when listing templates.
	// Templates usually live as global rows (owner_user_id = 0 / NULL).
	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$include_global = ( isset( $_POST['include_global'] ) && '1' === (string) wp_unslash( $_POST['include_global'] ) );

	// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
	$status = isset( $_POST['status'] ) ? sanitize_key( wp_unslash( $_POST['status'] ) ) : 'published';
	if ( '' === $status ) {
		$status = 'published';
	}

	$allowed_statuses = array( 'published', 'preview', 'draft', 'archived', 'template' );
	if ( ! in_array( $status, $allowed_statuses, true ) ) {
		$status = 'published';
	}

	// Security policy: include_global is allowed only for templates.
	if ( 'template' !== $status ) {
		$include_global = false;
	}

	$search = isset( $_POST['search'] ) ? sanitize_text_field( wp_unslash( $_POST['search'] ) ) : '';

	// Pagination.
	$page = isset( $_POST['page'] ) ? absint( wp_unslash( $_POST['page'] ) ) : 1;
	if ( $page <= 0 ) {
		$page = 1;
	}

	$limit = isset( $_POST['limit'] ) ? absint( wp_unslash( $_POST['limit'] ) ) : 20;
	if ( $limit <= 0 ) {
		$limit = 20;
	}
	if ( $limit > 500 ) {
		$limit = 500;
	}

	$offset = ( $page - 1 ) * $limit;
	if ( $offset < 0 ) {
		$offset = 0;
	}

	// MU owner logic (same as save/load/create).
	$owner_user_id = WPBC_FE_Custom_Form_Helper::wpbc_mu__get_current__owner_user_id();

	$table = $wpdb->prefix . 'booking_form_structures';

	// Base WHERE.
	$where_sql  = " WHERE status = %s ";
	$where_args = array( $status );

	// Owner/global logic.
	if ( $owner_user_id > 0 ) {
		if ( $include_global ) {
			$where_sql .= " AND ( owner_user_id = %d OR owner_user_id = 0 OR owner_user_id IS NULL ) ";
			$where_args[] = $owner_user_id;
		} else {
			$where_sql .= " AND owner_user_id = %d ";
			$where_args[] = $owner_user_id;
		}
	} else {
		// Non-MU (or super admin context): treat as global rows.
		$where_sql .= " AND ( owner_user_id = 0 OR owner_user_id IS NULL ) ";
	}

	// Search filter. Supports OR search by configured separator (default "~"): "time~duration~slots"
	if ( '' !== $search ) {

		$terms = wpbc_bfb__split_search_terms_by_or_separator( $search, 5 );

		if ( empty( $terms ) ) {
			// No usable terms after splitting.
		} elseif ( 1 === count( $terms ) ) {

			$like = '%' . $wpdb->esc_like( $terms[0] ) . '%';
			$where_sql .= " AND ( form_slug LIKE %s OR title LIKE %s OR description LIKE %s ) ";
			$where_args[] = $like;
			$where_args[] = $like;
			$where_args[] = $like;

		} else {

			$or_groups = array();

			foreach ( $terms as $term ) {

				$or_groups[] = "( form_slug LIKE %s OR title LIKE %s OR description LIKE %s )";

				$like = '%' . $wpdb->esc_like( $term ) . '%';
				$where_args[] = $like;
				$where_args[] = $like;
				$where_args[] = $like;
			}

			$where_sql .= " AND ( " . implode( ' OR ', $or_groups ) . " ) ";
		}
	}

	// Order:
	// - prefer user-owned rows first (when include_global + owner_user_id > 0)
	// - default forms first
	// - preserve registered template adjacency at the target template's position
	// - newest first
	$template_order_clauses = array(
		'effective_updated_at_sql' => 'updated_at',
		'adjacency_rank_sql'       => '',
		'args'                     => array(),
	);

	if ( 'template' === $status ) {
		$template_order_clauses = wpbc_bfb_get_template_library_order_clauses( $table );
	}

	$effective_updated_at_sql = $template_order_clauses['effective_updated_at_sql'];
	$adjacency_rank_order_sql = '' !== $template_order_clauses['adjacency_rank_sql']
		? ', ' . $template_order_clauses['adjacency_rank_sql'] . ' DESC'
		: '';
	$order_sql               = " ORDER BY is_default DESC, {$effective_updated_at_sql} DESC{$adjacency_rank_order_sql}, version DESC, booking_form_id DESC ";

	if ( $owner_user_id > 0 && $include_global ) {
		$order_sql = " ORDER BY ( owner_user_id = " . intval( $owner_user_id ) . " ) DESC, is_default DESC, {$effective_updated_at_sql} DESC{$adjacency_rank_order_sql}, version DESC, booking_form_id DESC ";
	}

	$query_args = array_merge( $where_args, $template_order_clauses['args'] );

	$limit_plus_one = $limit + 1;

	$sql = "SELECT booking_form_id, form_slug, title, description, picture_url, updated_at, owner_user_id, status, scope, is_default, version
			FROM {$table}
			{$where_sql}
			{$order_sql}
			LIMIT " . intval( $limit_plus_one ) . ' OFFSET ' . intval( $offset );

	// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
	$rows = $wpdb->get_results( $wpdb->prepare( $sql, $query_args ) );

	$has_more = ( count( (array) $rows ) > $limit );
	if ( $has_more ) {
		$rows = array_slice( (array) $rows, 0, $limit );
	}

	$forms = array();

	// If include_global + owner_user_id > 0: dedupe by slug, prefer owner over global.
	$seen_by_slug = array();

	foreach ( (array) $rows as $r ) {

		$slug = isset( $r->form_slug ) ? (string) $r->form_slug : '';
		if ( '' === $slug ) {
			continue;
		}

		if ( $owner_user_id > 0 && $include_global ) {
			if ( isset( $seen_by_slug[ $slug ] ) ) {
				continue;
			}
			$seen_by_slug[ $slug ] = true;
		}


		$row_owner_user_id = isset( $r->owner_user_id ) ? absint( $r->owner_user_id ) : 0;
		$row_status        = isset( $r->status ) ? (string) $r->status : '';
		$row_is_default    = isset( $r->is_default ) ? absint( $r->is_default ) : 0;

		$raw_picture_url = isset( $r->picture_url ) ? (string) $r->picture_url : '';

		$final_picture_url = ( 'template' === $row_status ) ? wpbc_bfb_resolve_picture_url( $raw_picture_url ) : $raw_picture_url;

		$can_delete = wpbc_bfb__can_delete_template_in_current_context(
			$slug,
			$row_owner_user_id,
			$owner_user_id,
			$row_is_default,
			$row_status
		);

		$forms[] = array(
			'booking_form_id' => isset( $r->booking_form_id ) ? (int) $r->booking_form_id : 0,
			'form_slug'       => $slug,
			'title'           => isset( $r->title ) ? (string) $r->title : '',
			'description'     => isset( $r->description ) ? (string) $r->description : '',
			'picture_url'     => $final_picture_url,
			'updated_at'      => isset( $r->updated_at ) ? (string) $r->updated_at : '',
			'owner_user_id'   => $row_owner_user_id,
			'status'          => $row_status,
			'scope'           => isset( $r->scope ) ? (string) $r->scope : '',
			'is_default'      => $row_is_default,
			'version'         => isset( $r->version ) ? (int) $r->version : 0,
			'can_delete'      => $can_delete ? 1 : 0,
		);
	}

	wp_send_json_success( array(
		'forms'    => $forms,
		'count'    => count( $forms ),
		'page'     => $page,
		'limit'    => $limit,
		'has_more' => $has_more,
	) );
}
add_action( 'wp_ajax_' . 'WPBC_AJX_BFB_LIST_FORMS', 'wpbc_bfb_ajax_list_forms' );


/**
 * Handle AJAX request: delete a TEMPLATE FormConfig.
 *
 * Security:
 * - Verifies wpbc_bfb_form_delete nonce (or list nonce fallback).
 * - Requires current_user_can( wpbc_bfb_get_manage_cap() ).
 *
 * Expects POST:
 * - nonce     : string  Nonce for delete/list action.
 * - form_name : string  Template slug/key to delete.
 *
 * Behaviour:
 * - Deletes ONLY template rows for the given slug.
 * - In MultiUser mode: a regular user can delete ONLY their own templates.
 * - Global templates shown to regular MU users are NOT deletable.
 *
 * Response (JSON):
 * - success: true|false
 * - data: {
 *     form_name: string,
 *     deleted:   int
 *   }
 *
 * @since 11.0.0
 *
 * @return void
 */
function wpbc_bfb_ajax_delete_template_config() {
	global $wpdb;

	if ( ! wpbc_bfb__verify_delete_request_nonce() ) {
		wp_send_json_error(
			array(
				'code'    => 'invalid_nonce',
				'message' => __( 'Security check failed.', 'booking' ),
			)
		);
	}

	if ( ! current_user_can( wpbc_bfb_get_manage_cap() ) ) {
		wp_send_json_error(
			array(
				'code'    => 'forbidden',
				'message' => __( 'You are not allowed to delete templates.', 'booking' ),
			)
		);
	}

	// phpcs:ignore WordPress.Security.NonceVerification.Recommended, WordPress.Security.NonceVerification.Missing
	$form_name = isset( $_POST['form_name'] ) ? sanitize_text_field( wp_unslash( $_POST['form_name'] ) ) : '';
	if ( '' === $form_name ) {
		wp_send_json_error(
			array(
				'code'    => 'invalid_form_name',
				'message' => __( 'Template key is required.', 'booking' ),
			)
		);
	}

	if ( 'standard' === $form_name ) {
		wp_send_json_error(
			array(
				'code'    => 'reserved',
				'message' => __( 'This template cannot be deleted.', 'booking' ),
			)
		);
	}

	$owner_user_id = WPBC_FE_Custom_Form_Helper::wpbc_mu__get_current__owner_user_id();

	/**
	 * Filter whether deletion of a specific template is allowed.
	 *
	 * @since 11.0.0
	 *
	 * @param bool   $is_allowed    Default true.
	 * @param string $form_name     Template slug/key.
	 * @param int    $owner_user_id Owner user id in MU (0 for global).
	 */
	$is_allowed = apply_filters( 'wpbc_bfb_delete_template_is_allowed', true, $form_name, $owner_user_id );
	if ( ! $is_allowed ) {
		wp_send_json_error(
			array(
				'code'    => 'not_allowed',
				'message' => __( 'Deletion is not allowed for this template.', 'booking' ),
			)
		);
	}

	$table = $wpdb->prefix . 'booking_form_structures';

	$where_sql  = " WHERE form_slug = %s AND status = %s ";
	$where_args = array( $form_name, 'template' );

	if ( $owner_user_id > 0 ) {
		$where_sql .= " AND owner_user_id = %d ";
		$where_args[] = $owner_user_id;
	} else {
		$where_sql .= " AND ( owner_user_id = 0 OR owner_user_id IS NULL ) ";
	}

	$sql = "SELECT booking_form_id, is_default, owner_user_id
			FROM {$table}
			{$where_sql}
			ORDER BY updated_at DESC, version DESC, booking_form_id DESC
			LIMIT 1";

	// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
	$row = $wpdb->get_row( $wpdb->prepare( $sql, $where_args ) );

	if ( empty( $row ) ) {
		wp_send_json_error(
			array(
				'code'    => 'not_found',
				'message' => __( 'Template not found.', 'booking' ),
			)
		);
	}

	if ( 1 === absint( $row->is_default ) ) {
		wp_send_json_error(
			array(
				'code'    => 'reserved',
				'message' => __( 'This template cannot be deleted.', 'booking' ),
			)
		);
	}

	$delete_sql = "DELETE FROM {$table} {$where_sql}";

	// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
	$deleted = $wpdb->query( $wpdb->prepare( $delete_sql, $where_args ) );

	if ( false === $deleted ) {
		wp_send_json_error(
			array(
				'code'    => 'delete_failed',
				'message' => __( 'Error deleting template.', 'booking' ) . ( ! empty( $wpdb->last_error ) ? ' ' . $wpdb->last_error : '' ),
			)
		);
	}

	wp_send_json_success(
		array(
			'form_name' => $form_name,
			/* translators: 1: template name */
			'message' => sprintf( __( 'Template %s deleted.', 'booking' ), "'" . $form_name . "'" ) . ' [' . absint( $deleted ) . ']',
			'deleted' => absint( $deleted ),
		)
	);
}
add_action( 'wp_ajax_' . 'WPBC_AJX_BFB_DELETE_TEMPLATE_CONFIG', 'wpbc_bfb_ajax_delete_template_config' );


/**
 * Handle AJAX request: delete a custom FormConfig.
 *
 * Security:
 * - Verifies wpbc_bfb_form_delete nonce (sent as 'nonce').
 * - Requires current_user_can( wpbc_bfb_get_manage_cap() ).
 *
 * Expects POST:
 * - nonce     : string  Nonce for 'wpbc_bfb_form_delete'.
 * - form_name : string  Custom form slug/key to delete (required).
 *
 * Behaviour:
 * - Blocks deletion of reserved/default forms (e.g. 'standard' or is_default=1).
 * - In MultiUser mode: a regular user can delete ONLY their own forms.
 * - Deletes ALL rows for this form_slug (all statuses/versions), excluding scope='template'.
 *
 * Response (JSON):
 * - success: true|false
 * - data: {
 *     form_name: string,
 *     deleted:   int
 *   }
 *
 * @since 11.0.0
 *
 * @return void
 */
function wpbc_bfb_ajax_delete_form_config() {
	global $wpdb;

	if ( ! wpbc_bfb__verify_delete_request_nonce() ) {
		wp_send_json_error(
			array(
				'code'    => 'invalid_nonce',
				'message' => __( 'Security check failed.', 'booking' ),
			)
		);
	}

	if ( ! current_user_can( wpbc_bfb_get_manage_cap() ) ) {
		wp_send_json_error(
			array(
				'code'    => 'forbidden',
				'message' => __( 'You are not allowed to delete booking forms.', 'booking' ),
			)
		);
	}

	// phpcs:ignore WordPress.Security.NonceVerification.Recommended, WordPress.Security.NonceVerification.Missing
	$form_name = isset( $_POST['form_name'] ) ? sanitize_text_field( wp_unslash( $_POST['form_name'] ) ) : '';
	if ( '' === $form_name ) {
		wp_send_json_error(
			array(
				'code'    => 'invalid_form_name',
				'message' => __( 'Form key is required.', 'booking' ),
			)
		);
	}

	// Block reserved key.
	if ( 'standard' === $form_name ) {
		wp_send_json_error(
			array(
				'code'    => 'reserved',
				'message' => __( 'This form cannot be deleted.', 'booking' ),
			)
		);
	}

	// MU owner logic (same approach as save/load/create/list).
	$owner_user_id = WPBC_FE_Custom_Form_Helper::wpbc_mu__get_current__owner_user_id();

	/**
	 * Filter whether deletion of a specific form is allowed.
	 *
	 * @since 11.0.0
	 *
	 * @param bool   $is_allowed    Default true.
	 * @param string $form_name     Form slug/key.
	 * @param int    $owner_user_id Owner user id in MU (0 for global).
	 */
	$is_allowed = apply_filters( 'wpbc_bfb_delete_form_is_allowed', true, $form_name, $owner_user_id );
	if ( ! $is_allowed ) {
		wp_send_json_error(
			array(
				'code'    => 'not_allowed',
				'message' => __( 'Deletion is not allowed for this form.', 'booking' ),
			)
		);
	}

	$table = $wpdb->prefix . 'booking_form_structures';

	// ---------------------------------------------------------------------------------
	// Check existence + protect default/template.
	// ---------------------------------------------------------------------------------
	$where_sql  = " WHERE form_slug = %s ";
	$where_args = array( $form_name );

	if ( $owner_user_id > 0 ) {
		$where_sql .= " AND owner_user_id = %d ";
		$where_args[] = $owner_user_id;
	} else {
		$where_sql .= " AND ( owner_user_id = 0 OR owner_user_id IS NULL ) ";
	}

	// Exclude template scope rows from selection checks as well.
	$where_sql .= " AND ( scope IS NULL OR scope <> %s ) ";
	$where_args[] = 'template';

	// Exclude template scope rows from selection checks as well.
	$where_sql .= " AND ( status IS NULL OR status <> %s ) ";
	$where_args[] = 'template';

	$sql = "SELECT booking_form_id, is_default, scope, status
			FROM {$table}
			{$where_sql}
			ORDER BY updated_at DESC, version DESC, booking_form_id DESC
			LIMIT 1";

	// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, PluginCheck.Security.DirectDB.UnescapedDBParameter
	$row = $wpdb->get_row( $wpdb->prepare( $sql, $where_args ) );

	if ( empty( $row ) ) {
		wp_send_json_error(
			array(
				'code'    => 'not_found',
				'message' => __( 'Booking form not found.', 'booking' ),
			)
		);
	}

	$is_default = isset( $row->is_default ) ? absint( $row->is_default ) : 0;
	if ( 1 === $is_default ) {
		wp_send_json_error(
			array(
				'code'    => 'reserved',
				'message' => __( 'This form cannot be deleted.', 'booking' ),
			)
		);
	}

	$scope  = isset( $row->scope ) ? (string) $row->scope : '';
	$status = isset( $row->status ) ? (string) $row->status : '';
	if ( ( 'template' === $scope ) || ( 'template' === $status ) ) {
		wp_send_json_error(
			array(
				'code'    => 'reserved',
				'message' => __( 'Template forms cannot be deleted.', 'booking' ),
			)
		);
	}

	// ---------------------------------------------------------------------------------
	// Delete ALL rows for this slug/owner (all statuses/versions), excluding templates.
	// ---------------------------------------------------------------------------------
	$delete_where_sql  = " WHERE form_slug = %s ";
	$delete_where_args = array( $form_name );

	if ( $owner_user_id > 0 ) {
		$delete_where_sql .= " AND owner_user_id = %d ";
		$delete_where_args[] = $owner_user_id;
	} else {
		$delete_where_sql .= " AND ( owner_user_id = 0 OR owner_user_id IS NULL ) ";
	}

	$delete_where_sql .= " AND ( scope IS NULL OR scope <> %s ) ";
	$delete_where_args[] = 'template';
	$delete_where_sql .= " AND ( status IS NULL OR status <> %s ) ";
	$delete_where_args[] = 'template';

	$delete_sql = "DELETE FROM {$table} {$delete_where_sql}";

	// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.DirectDatabaseQuery.NoCaching, PluginCheck.Security.DirectDB.UnescapedDBParameter
	$deleted = $wpdb->query( $wpdb->prepare( $delete_sql, $delete_where_args ) );

	if ( false === $deleted ) {
		wp_send_json_error(
			array(
				'code'    => 'delete_failed',
				'message' => __( 'Error deleting booking form.', 'booking' ) . ( ! empty( $wpdb->last_error ) ? ' ' . $wpdb->last_error : '' ),
			)
		);
	}

	wp_send_json_success(
		array(
			'form_name' => $form_name,
			/* translators: 1: template name */
			'message'   => sprintf( __( 'Booking form %s deleted.', 'booking' ), "'" . $form_name . "'" ) . ' [' . absint( $deleted ) . ']',
			'deleted'   => absint( $deleted ),
		)
	);
}
add_action( 'wp_ajax_' . 'WPBC_AJX_BFB_DELETE_FORM_CONFIG', 'wpbc_bfb_ajax_delete_form_config' );