<?php
/**
 * Request input helpers.
 *
 * 1. Public URL parameters (front end). The route finder's filter/view state
 *    lives in shareable URLs (?distance_min=50&u=i, ?rfcc_route=12 ...). These
 *    are registered as WordPress query vars and read back through
 *    rfcc_url_param(), so WordPress itself parses them from the request and no
 *    front-end template reads $_GET directly. They only ever select what is
 *    displayed; nothing is saved from them.
 *
 *    Our own (non-core) vars are removed from the main query's vars in the
 *    'request' filter, after being captured here, so that WordPress never
 *    treats them as part of the post lookup (which would otherwise turn a
 *    static front page into the blog index, or a page into a CPT lookup).
 *
 * 2. rfcc_sanitize_json_data(): type-preserving recursive sanitizer applied to
 *    the result of every json_decode() of request input.
 *
 * @package Route_Finder
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Every public URL parameter the plugin's front end reads.
 *
 * @return string[]
 */
function rfcc_url_param_names() {
	return array(
		// Route / group / view selection.
		'rfcc_route', 'rfcc_group_name', 'rfcc_group_ids', 'route', 'route_id', 'route_ids',
		'group', 'view', 'embed', 'dmap', 'destination', 'rfcc_view_group', 'action',
		// Display preferences.
		'u', 'line_style', 'graph_style', 'sort', 'group_similar', 'group_by_activity_type',
		'main_destination_only',
		// Filters.
		'search', 'search_scope', 'club_groups', 'activity_type', 'directions',
		'distance_min', 'distance_max', 'ascent_min', 'ascent_max', 'duration_min', 'duration_max',
		'climbing', 'region', 'rsc', 'difficulty', 'tags', 'grades',
		'near_lat', 'near_lng', 'near_radius', 'orderby', 'order',
		// Public GPX download endpoint (see rfcc_maybe_serve_gpx_proxy()).
		'rfcc_gpx_proxy', 'gpx', 'post_id',
	);
}

/**
 * Internal store of the captured URL parameters.
 *
 * @param array|null $set Replace the store (only used by the 'request' filter).
 * @return array
 */
function rfcc_url_params_store( $set = null ) {
	static $store = array();
	if ( is_array( $set ) ) {
		$store = $set;
	}
	return $store;
}

/**
 * Names that WordPress core already registers as public query vars; these are
 * captured but left in place, so core behaviour (e.g. /post/embed/) is unchanged.
 *
 * @param string[]|null $set Set once from the 'query_vars' filter.
 * @return string[]
 */
function rfcc_url_params_core_names( $set = null ) {
	static $core = array();
	if ( is_array( $set ) ) {
		$core = $set;
	}
	return $core;
}

add_filter( 'query_vars', 'rfcc_register_url_query_vars' );
/**
 * Register the plugin's public URL parameters as query vars.
 *
 * @param string[] $vars Public query vars.
 * @return string[]
 */
function rfcc_register_url_query_vars( $vars ) {
	$ours = rfcc_url_param_names();
	rfcc_url_params_core_names( array_values( array_intersect( $ours, $vars ) ) );
	return array_values( array_unique( array_merge( $vars, $ours ) ) );
}

add_filter( 'request', 'rfcc_capture_url_query_vars', 1 );
/**
 * Capture the plugin's URL parameters from the parsed request and keep the
 * plugin-only ones out of the main query.
 *
 * @param array $query_vars Parsed query vars.
 * @return array
 */
function rfcc_capture_url_query_vars( $query_vars ) {
	$store = array();
	$core  = rfcc_url_params_core_names();
	foreach ( rfcc_url_param_names() as $name ) {
		if ( ! array_key_exists( $name, $query_vars ) ) {
			continue;
		}
		$store[ $name ] = wp_unslash( $query_vars[ $name ] );
		if ( ! in_array( $name, $core, true ) ) {
			unset( $query_vars[ $name ] );
		}
	}
	rfcc_url_params_store( $store );
	return $query_vars;
}

/**
 * Raw (unslashed, NOT sanitized) value of a public URL parameter.
 * Callers sanitize/validate for their own context.
 *
 * @param string $name    Parameter name (must be listed in rfcc_url_param_names()).
 * @param mixed  $default Returned when the parameter is absent.
 * @return mixed String or array of strings, or $default.
 */
function rfcc_url_param( $name, $default = null ) {
	$store = rfcc_url_params_store();
	return array_key_exists( $name, $store ) ? $store[ $name ] : $default;
}

/**
 * Whether a public URL parameter is present.
 *
 * @param string $name Parameter name.
 * @return bool
 */
function rfcc_has_url_param( $name ) {
	return array_key_exists( $name, rfcc_url_params_store() );
}

/**
 * Sanitized text value of a public URL parameter ('' when absent or an array).
 *
 * @param string $name Parameter name.
 * @return string
 */
function rfcc_url_param_text( $name ) {
	$value = rfcc_url_param( $name, '' );
	return is_scalar( $value ) ? sanitize_text_field( (string) $value ) : '';
}

/**
 * Set a URL parameter's value for the rest of this request (used where
 * shortcode attributes act as defaults for absent URL parameters).
 *
 * @param string $name  Parameter name.
 * @param mixed  $value Value (already sanitized by the caller).
 */
function rfcc_set_url_param( $name, $value ) {
	$store          = rfcc_url_params_store();
	$store[ $name ] = $value;
	rfcc_url_params_store( $store );
}

/**
 * Admin screens: view-state links (tabs, list-table filters, selected route,
 * post-redirect notices) carry an 'rfcc_view_nonce' for action
 * 'rfcc_admin_view'. Each screen verifies it with wp_verify_nonce() in the
 * function that reads the parameters, and falls back to the default view
 * when it is missing or expired.
 *
 * @param string $url Admin URL.
 * @return string URL with the view nonce added.
 */
function rfcc_admin_view_url( $url ) {
	return add_query_arg( 'rfcc_view_nonce', wp_create_nonce( 'rfcc_admin_view' ), $url );
}

/**
 * Hidden view-nonce field for admin GET forms (list-table filters etc.).
 */
function rfcc_admin_view_nonce_field() {
	wp_nonce_field( 'rfcc_admin_view', 'rfcc_view_nonce', false );
}

/**
 * Recursively sanitize data decoded from JSON request input, preserving
 * types: strings through sanitize_text_field(), ints/floats/bools/null kept,
 * keys through sanitize_text_field(). Anything else is dropped.
 *
 * @param mixed $data Output of json_decode( ..., true ).
 * @return mixed
 */
function rfcc_sanitize_json_data( $data ) {
	if ( is_array( $data ) ) {
		$clean = array();
		foreach ( $data as $key => $value ) {
			$clean_key           = is_int( $key ) ? $key : sanitize_text_field( (string) $key );
			$clean[ $clean_key ] = rfcc_sanitize_json_data( $value );
		}
		return $clean;
	}
	if ( is_string( $data ) ) {
		return sanitize_text_field( $data );
	}
	if ( is_int( $data ) || is_float( $data ) || is_bool( $data ) || null === $data ) {
		return $data;
	}
	return null;
}