<?php
namespace FrontGlut\Support;

defined( 'ABSPATH' ) || exit;

/**
 * Recursive sanitising for array / JSON input (imports, admin forms, AJAX requests).
 * Callers may still apply stricter, field-specific sanitising afterwards.
 */
class Sanitize {

	/**
	 * Sanitise a value of any depth.
	 *
	 * @param mixed  $value Raw (already unslashed) value.
	 * @param string $mode  'text' strips all tags (keeps line breaks), 'html' keeps post HTML only, 'key' uses sanitize_key().
	 * @return mixed
	 */
	public static function deep( $value, $mode = 'text' ) {
		if ( is_array( $value ) ) {
			$out = array();
			foreach ( $value as $k => $v ) {
				$out[ is_int( $k ) ? $k : self::key( $k ) ] = self::deep( $v, $mode );
			}
			return $out;
		}
		if ( is_bool( $value ) || is_int( $value ) || is_float( $value ) || null === $value ) {
			return $value;
		}
		if ( ! is_scalar( $value ) ) {
			return '';
		}
		$value = (string) $value;
		switch ( $mode ) {
			case 'html':
				return wp_kses_post( $value );
			case 'key':
				return sanitize_key( $value );
			default:
				return sanitize_textarea_field( $value );
		}
	}

	/** Array keys: letters, numbers, underscore, dash and dot only. */
	public static function key( $key ) {
		return preg_replace( '/[^A-Za-z0-9_\-\.]/', '', (string) $key );
	}

	/**
	 * Decode a JSON string and sanitise every value in it.
	 *
	 * @return array Empty array when the JSON is invalid.
	 */
	public static function json( $raw, $mode = 'text' ) {
		$d = is_string( $raw ) ? json_decode( $raw, true ) : null;
		return is_array( $d ) ? self::deep( $d, $mode ) : array();
	}

	/**
	 * Read, unslash, decode and sanitise a JSON string from $_POST.
	 * The caller must verify the nonce and capability first.
	 */
	public static function post_json( $key, $mode = 'text' ) {
		if ( ! isset( $_POST[ $key ] ) || ! is_string( $_POST[ $key ] ) ) { // phpcs:ignore WordPress.Security.NonceVerification -- verified by the caller.
			return array();
		}
		return self::json( wp_unslash( $_POST[ $key ] ), $mode ); // phpcs:ignore WordPress.Security.NonceVerification, WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- sanitised recursively by json().
	}

	/** Read, unslash and sanitise an array from $_POST. The caller must verify the nonce and capability first. */
	public static function post_array( $key, $mode = 'text' ) {
		if ( ! isset( $_POST[ $key ] ) ) { // phpcs:ignore WordPress.Security.NonceVerification -- verified by the caller.
			return array();
		}
		return (array) self::deep( wp_unslash( $_POST[ $key ] ), $mode ); // phpcs:ignore WordPress.Security.NonceVerification, WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- sanitised recursively by deep().
	}

	/** A Y-m-d date filter from the query string, or $default. Only read with a valid view nonce (see Request). */
	public static function get_date( $key, $default = '' ) {
		return Request::filter( $key, 'date', $default );
	}
}