<?php
/**
 * Front end: the form, submission (normal post or AJAX), emails and the quote button.
 *
 * @package BYLTCommerce
 */

defined( 'ABSPATH' ) || exit;

class Bylt_Forms_Render {

	const HONEYPOT = 'bylt_hp_website';

	/** Faster than this after the page loaded = a bot. */
	const MIN_SECONDS = 3;

	/** A page older than this (open in a tab for days, or cached) is asked to submit again. */
	const MAX_AGE = WEEK_IN_SECONDS;

	/** Rate-limit window. */
	const WINDOW = 600;

	const MIN_PASSWORD = 8;

	/** @var Bylt_Forms */
	private $forms;

	/** @var array form_id => result of the last non-AJAX submission this request. */
	private $results = array();

	private $assets = false;

	public function __construct( Bylt_Forms $forms ) {
		$this->forms = $forms;
	}

	public function init() {
		add_shortcode( 'bylt_form', array( $this, 'shortcode' ) );
		add_action( 'init', array( $this, 'register_block' ) );
		add_action( 'template_redirect', array( $this, 'preview' ), 4 );
		add_action( 'template_redirect', array( $this, 'handle_post' ), 5 );
		add_action( 'wp_ajax_bylt_form_submit', array( $this, 'ajax' ) );
		add_action( 'wp_ajax_nopriv_bylt_form_submit', array( $this, 'ajax' ) );
		add_action( 'woocommerce_single_product_summary', array( $this, 'quote_button' ), 35 );
	}

	/* ---------------------------------------------------------------------
	 * Output
	 * ------------------------------------------------------------------- */

	public function register_block() {
		if ( ! function_exists( 'register_block_type' ) ) {
			return;
		}
		wp_register_script( 'bylt-form-block', $this->forms->url( 'assets/forms-block.js' ), array( 'wp-blocks', 'wp-element', 'wp-components', 'wp-block-editor', 'wp-server-side-render', 'wp-i18n' ), BYLT_VERSION, true );
		register_block_type(
			'bylt/form',
			array(
				'api_version'     => 2,
				'editor_script'   => 'bylt-form-block',
				'attributes'      => array(
					'formId' => array( 'type' => 'number', 'default' => 0 ),
				),
				'render_callback' => function ( $atts ) {
					return $this->render( isset( $atts['formId'] ) ? (int) $atts['formId'] : 0 );
				},
			)
		);
		if ( is_admin() ) {
			$list = array();
			foreach ( Bylt_Forms_Store::all() as $f ) {
				$list[] = array( 'value' => $f['id'], 'label' => $f['name'] );
			}
			wp_localize_script( 'bylt-form-block', 'byltFormsBlock', array( 'forms' => $list, 'adminUrl' => Bylt_Forms_Admin::url() ) );
		}
	}

	public function shortcode( $atts ) {
		$atts = shortcode_atts( array( 'id' => 0 ), $atts, 'bylt_form' );
		return $this->render( (int) $atts['id'] );
	}

	private function enqueue() {
		if ( $this->assets ) {
			return;
		}
		$this->assets = true;
		wp_enqueue_style( 'bylt-forms', $this->forms->url( 'assets/forms.css' ), array(), BYLT_VERSION );
		wp_enqueue_script( 'bylt-forms', $this->forms->url( 'assets/forms.js' ), array(), BYLT_VERSION, true );
		wp_localize_script(
			'bylt-forms',
			'byltForms',
			array(
				'ajax'    => admin_url( 'admin-ajax.php' ),
				'sending' => __( 'Sending…', 'byltcommerce-toolkit' ),
				'error'   => __( 'Something went wrong. Please try again.', 'byltcommerce-toolkit' ),
				'preview' => __( 'Preview: everything checks out. Nothing was sent or saved.', 'byltcommerce-toolkit' ),
				/* translators: %s: size like "5 MB" */
				'tooBig'  => sprintf( __( 'That file is too big. The limit is %s.', 'byltcommerce-toolkit' ), size_format( Bylt_Forms_Files::max_bytes() ) ),
			)
		);
	}

	private static function current_url() {
		$uri = isset( $_SERVER['REQUEST_URI'] ) ? esc_url_raw( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '/';
		return remove_query_arg( array( 'bylt_sent' ), home_url( $uri ) );
	}

	/** Value to show in a field: posted value after an error, else URL parameter, else default. */
	private static function initial( array $f, $posted ) {
		if ( null !== $posted && isset( $posted[ $f['key'] ] ) ) {
			return $posted[ $f['key'] ];
		}
		// phpcs:ignore WordPress.Security.NonceVerification -- prefill only.
		if ( $f['param'] && isset( $_GET[ $f['param'] ] ) ) {
			$v = wp_unslash( $_GET[ $f['param'] ] ); // phpcs:ignore WordPress.Security.NonceVerification, WordPress.Security.ValidatedSanitizedInput
			return is_array( $v ) ? array_map( 'sanitize_text_field', $v ) : sanitize_text_field( $v );
		}
		if ( 'checkboxes' === $f['type'] ) {
			return '' === $f['default'] ? array() : array_map( 'trim', explode( ',', $f['default'] ) );
		}
		return $f['default'];
	}

	public function render( $id ) {
		$form = Bylt_Forms_Store::get( $id );
		if ( ! $form ) {
			return current_user_can( 'edit_pages' ) ? '<p><em>' . esc_html__( 'Choose a form in the block settings (Forms).', 'byltcommerce-toolkit' ) . '</em></p>' : '';
		}
		return $this->render_form( $form );
	}

	/**
	 * Signed load time: "time.signature". Bots that skip it, change it, or
	 * post faster than a person can type are caught in process().
	 */
	public static function token( $form_id, $time = null ) {
		$time = null === $time ? time() : (int) $time;
		return $time . '.' . substr( hash_hmac( 'sha256', $time . '|' . (int) $form_id, wp_salt( 'nonce' ) ), 0, 20 );
	}

	/** @return string ok | bad | fast | old */
	public static function check_token( $form_id, $token ) {
		$parts = explode( '.', (string) $token );
		if ( 2 !== count( $parts ) || ! ctype_digit( $parts[0] ) || ! hash_equals( self::token( $form_id, (int) $parts[0] ), (string) $token ) ) {
			return 'bad';
		}
		$age = time() - (int) $parts[0];
		if ( $age < self::MIN_SECONDS ) {
			return 'fast';
		}
		return $age > self::MAX_AGE ? 'old' : 'ok';
	}

	/** What the page's script puts in the JS-check field (the signature, reversed). */
	public static function js_answer( $token ) {
		$parts = explode( '.', (string) $token );
		return isset( $parts[1] ) ? strrev( $parts[1] ) : '';
	}

	/**
	 * Output one form.
	 *
	 * @param array $form Form (id, name, fields, settings).
	 * @param array $args preview (bool): no submit, nothing sent; as (guest|user|''): show the form as this visitor would see it.
	 */
	public function render_form( array $form, array $args = array() ) {
		$args    = wp_parse_args( $args, array( 'preview' => false, 'as' => '' ) );
		$preview = (bool) $args['preview'];
		$this->enqueue();
		$s         = $form['settings'];
		$logged_in = '' === $args['as'] ? is_user_logged_in() : 'user' === $args['as'];

		if ( ! $preview ) {
			$instead = apply_filters( 'bylt_form_before_render', null, $form );
			if ( is_string( $instead ) ) {
				return $instead;
			}
			// phpcs:ignore WordPress.Security.NonceVerification -- display only.
			if ( isset( $_GET['bylt_sent'] ) && (int) $_GET['bylt_sent'] === $form['id'] ) {
				$msg = get_transient( 'bylt_form_msg_' . md5( self::client_key( $form['id'] ) ) );
				return '<div class="bylt-form-done" role="status">' . esc_html( $msg ? $msg : $s['success'] ) . '</div>';
			}
		}

		$result = ! $preview && isset( $this->results[ $form['id'] ] ) ? $this->results[ $form['id'] ] : null;
		$errors = $result ? $result['errors'] : array();
		$posted = $result ? $result['values'] : null;

		// phpcs:ignore WordPress.Security.NonceVerification -- prefill only.
		$product_id = isset( $_GET['quote_product_id'] ) ? absint( $_GET['quote_product_id'] ) : 0;
		$classes    = trim( 'bylt-form bylt-form-' . $s['kind'] . ' ' . $s['css_class'] );
		$has_file   = false;
		foreach ( $form['fields'] as $f ) {
			$has_file = $has_file || ( 'file' === $f['type'] && Bylt_Forms_Store::field_live( Bylt_Forms_Store::with_defaults( $f ), $logged_in ) );
		}

		ob_start();
		echo '<form class="' . esc_attr( $classes ) . '" method="post" action="' . esc_url( $preview ? '#' : self::current_url() ) . '" data-form="' . (int) $form['id'] . '"' . ( $has_file ? ' enctype="multipart/form-data"' : '' ) . ( $preview ? ' data-preview="1"' : '' ) . '>';
		if ( ! $preview ) {
			echo '<input type="hidden" name="bylt_form_id" value="' . (int) $form['id'] . '">';
			echo '<input type="hidden" name="bylt_form_t" value="' . esc_attr( self::token( $form['id'] ) ) . '">';
			if ( is_user_logged_in() ) {
				// Logged-in visitors get a nonce too: their submission can update their account.
				wp_nonce_field( 'bylt_form_' . (int) $form['id'], 'bylt_form_nonce' );
			}
			echo '<input type="hidden" name="bylt_form_js" value="">';
			echo '<input type="hidden" name="bylt_form_page" value="' . esc_attr( self::current_url() ) . '">';
			if ( $product_id ) {
				echo '<input type="hidden" name="bylt_product_id" value="' . (int) $product_id . '">';
			}
			echo '<div class="bylt-hp" aria-hidden="true"><label>' . esc_html__( 'Leave this empty', 'byltcommerce-toolkit' ) . ' <input type="text" name="' . esc_attr( self::HONEYPOT ) . '" value="" tabindex="-1" autocomplete="off"></label></div>';
		}
		echo '<div class="bylt-form-errors" role="alert">' . ( isset( $errors['_form'] ) ? '<p>' . esc_html( $errors['_form'] ) . '</p>' : '' ) . '</div>';
		$initial = array();
		foreach ( $form['fields'] as $f ) {
			$f                       = Bylt_Forms_Store::with_defaults( $f );
			$initial[ $f['key'] ]    = in_array( $f['type'], array( 'password', 'file' ), true ) ? '' : self::initial( $f, $posted );
		}
		$shown = Bylt_Forms_Store::visible( $form['fields'], $initial, $logged_in );
		echo '<div class="bylt-form-fields">';
		foreach ( $form['fields'] as $f ) {
			$f = Bylt_Forms_Store::with_defaults( $f );
			if ( ! Bylt_Forms_Store::field_live( $f, $logged_in ) ) {
				continue;
			}
			$html = $this->field( $form['id'], $f, $initial[ $f['key'] ], isset( $errors[ $f['key'] ] ) ? $errors[ $f['key'] ] : '' );
			echo self::with_cond( $html, $f, ! empty( $shown[ $f['key'] ] ) ); // phpcs:ignore WordPress.Security.EscapeOutput -- built from escaped parts.
		}
		echo '</div>';
		$fp = $preview ? null : $this->forms->protection( $form );
		if ( $fp ) {
			$fp->widget( 'bylt_form' );
		}
		echo '<p class="bylt-form-submit"><button type="submit" class="wp-element-button button">' . esc_html( $s['submit_label'] ) . '</button></p>';
		echo '</form>';
		return ob_get_clean();
	}

	/**
	 * Mark a field's outer element for forms.js: its key, its conditions, and
	 * hidden (with its inputs off, so they aren't required or sent) when the
	 * conditions don't match the starting values.
	 */
	private static function with_cond( $html, array $f, $shown ) {
		$attrs = ' data-key="' . esc_attr( $f['key'] ) . '"';
		if ( ! empty( $f['cond']['rules'] ) ) {
			$attrs .= ' data-cond="' . esc_attr( (string) wp_json_encode( $f['cond'] ) ) . '"';
			if ( ! $shown ) {
				$attrs .= ' hidden';
				$html   = preg_replace( '/<(input|select|textarea)\b/', '<$1 disabled', $html );
			}
		}
		return (string) preg_replace( '/^<(div|input)\b/', '<$1' . $attrs, (string) $html, 1 );
	}

	private function field( $form_id, array $f, $value, $error ) {
		$id    = 'bylt-f-' . $form_id . '-' . $f['key'];
		$name  = 'bylt_f[' . $f['key'] . ']';
		$req   = $f['required'] ? ' required' : '';
		$star  = $f['required'] ? ' <span class="bylt-req" aria-hidden="true">*</span>' : '';
		$ph    = $f['placeholder'] ? ' placeholder="' . esc_attr( $f['placeholder'] ) . '"' : '';
		$desc  = $f['help'] && 'html' !== $f['type'] ? '<small class="bylt-help" id="' . esc_attr( $id ) . '-help">' . esc_html( $f['help'] ) . '</small>' : '';
		$aria  = ( $f['help'] ? ' aria-describedby="' . esc_attr( $id ) . '-help"' : '' ) . ( $error ? ' aria-invalid="true"' : '' );
		$value = is_array( $value ) ? $value : (string) $value;
		$class = trim( 'bylt-field bylt-field-' . $f['type'] . ' bylt-w-' . $f['width'] . ( $error ? ' bylt-has-error' : '' ) . ' ' . $f['css'] );
		$err   = '<span class="bylt-error" data-for="' . esc_attr( $f['key'] ) . '">' . esc_html( $error ) . '</span>';

		switch ( $f['type'] ) {
			case 'html':
				return '<div class="' . esc_attr( trim( 'bylt-field bylt-field-html bylt-w-full ' . $f['css'] ) ) . '">' . ( $f['label'] ? '<h3>' . esc_html( $f['label'] ) . '</h3>' : '' ) . wp_kses_post( wpautop( $f['help'] ) ) . '</div>';
			case 'hidden':
				return '<input type="hidden" name="' . esc_attr( $name ) . '" value="' . esc_attr( is_array( $value ) ? implode( ', ', $value ) : $value ) . '">';
			case 'file':
				if ( ! $f['help'] ) {
					$desc = '<small class="bylt-help" id="' . esc_attr( $id ) . '-help">' . esc_html( Bylt_Forms_Files::hint() ) . '</small>';
					$aria = ' aria-describedby="' . esc_attr( $id ) . '-help"' . ( $error ? ' aria-invalid="true"' : '' );
				}
				$input = '<input type="file" id="' . esc_attr( $id ) . '" name="' . esc_attr( $name ) . '" accept="' . esc_attr( Bylt_Forms_Files::accept() ) . '" data-max="' . (int) Bylt_Forms_Files::max_bytes() . '"' . $req . $aria . '>';
				break;
			case 'password':
				$input = '<input type="password" id="' . esc_attr( $id ) . '" name="' . esc_attr( $name ) . '" value="" autocomplete="new-password" minlength="' . (int) self::MIN_PASSWORD . '"' . $req . $ph . $aria . '>';
				break;
			case 'textarea':
				$input = '<textarea id="' . esc_attr( $id ) . '" name="' . esc_attr( $name ) . '" rows="5"' . $req . $ph . $aria . '>' . esc_textarea( is_array( $value ) ? implode( "\n", $value ) : $value ) . '</textarea>';
				break;
			case 'select':
				$input = '<select id="' . esc_attr( $id ) . '" name="' . esc_attr( $name ) . '"' . $req . $aria . '><option value="">' . esc_html( $f['placeholder'] ? $f['placeholder'] : __( 'Choose…', 'byltcommerce-toolkit' ) ) . '</option>';
				foreach ( $f['options'] as $o ) {
					$input .= '<option value="' . esc_attr( $o ) . '" ' . selected( $value, $o, false ) . '>' . esc_html( $o ) . '</option>';
				}
				$input .= '</select>';
				break;
			case 'radio':
			case 'checkboxes':
				$multi = 'checkboxes' === $f['type'];
				$input = '<fieldset id="' . esc_attr( $id ) . '"' . $aria . '><legend>' . esc_html( $f['label'] ) . $star . '</legend>';
				foreach ( $f['options'] as $i => $o ) {
					$on     = $multi ? in_array( $o, (array) $value, true ) : $value === $o;
					$input .= '<label class="bylt-choice"><input type="' . ( $multi ? 'checkbox' : 'radio' ) . '" name="' . esc_attr( $name . ( $multi ? '[]' : '' ) ) . '" value="' . esc_attr( $o ) . '"' . checked( $on, true, false ) . ( ! $multi && $f['required'] && 0 === $i ? ' required' : '' ) . '> ' . esc_html( $o ) . '</label>';
				}
				$input .= '</fieldset>';
				return '<div class="' . esc_attr( $class ) . '">' . $input . $desc . $err . '</div>';
			case 'consent':
				return '<div class="' . esc_attr( $class ) . '"><label class="bylt-choice"><input type="checkbox" id="' . esc_attr( $id ) . '" name="' . esc_attr( $name ) . '" value="yes"' . checked( 'yes' === $value || '1' === $value, true, false ) . $req . $aria . '> ' . esc_html( $f['label'] ) . $star . '</label>' . $desc . $err . '</div>';
			default:
				$type  = in_array( $f['type'], array( 'email', 'tel', 'number', 'date', 'url' ), true ) ? $f['type'] : 'text';
				$auto  = array( 'email' => 'email', 'tel' => 'tel', 'url' => 'url' );
				$input = '<input type="' . esc_attr( $type ) . '" id="' . esc_attr( $id ) . '" name="' . esc_attr( $name ) . '" value="' . esc_attr( is_array( $value ) ? implode( ', ', $value ) : $value ) . '"' . $req . $ph . $aria . ( isset( $auto[ $type ] ) ? ' autocomplete="' . esc_attr( $auto[ $type ] ) . '"' : '' ) . ( 'number' === $type ? ' step="any"' : '' ) . '>';
		}
		return '<div class="' . esc_attr( $class ) . '"><label for="' . esc_attr( $id ) . '">' . esc_html( $f['label'] ) . $star . '</label>' . $input . $desc . $err . '</div>';
	}

	public function quote_button() {
		global $product;
		if ( ! $product || ! is_object( $product ) ) {
			return;
		}
		foreach ( Bylt_Forms_Store::all() as $form ) {
			$s = $form['settings'];
			if ( 'quote' !== $s['kind'] || 'no' === $s['product_button'] || ! $s['page_id'] || 'publish' !== get_post_status( $s['page_id'] ) ) {
				continue;
			}
			if ( 'cats' === $s['product_button'] && ! array_intersect( $s['button_cats'], wc_get_product_term_ids( $product->get_id(), 'product_cat' ) ) ) {
				continue;
			}
			$url = add_query_arg(
				array(
					'quote_product'    => rawurlencode( $product->get_name() ),
					'quote_product_id' => $product->get_id(),
				),
				get_permalink( $s['page_id'] )
			);
			echo '<p class="bylt-quote-button"><a class="button alt wp-element-button" href="' . esc_url( $url ) . '">' . esc_html( $s['button_label'] ) . '</a></p>';
			return;
		}
	}

	/* ---------------------------------------------------------------------
	 * Preview (Forms → editor → Preview): the editor posts its unsaved
	 * fields here, into an iframe, so the form shows with the theme's styles.
	 * ------------------------------------------------------------------- */

	public function preview() {
		// phpcs:disable WordPress.Security.ValidatedSanitizedInput -- cleaned by the store below.
		if ( empty( $_POST['bylt_pv'] ) || ! is_array( $_POST['bylt_pv'] ) ) {
			return;
		}
		$nonce = isset( $_POST['bylt_pv_nonce'] ) ? sanitize_key( wp_unslash( $_POST['bylt_pv_nonce'] ) ) : '';
		if ( ! wp_verify_nonce( $nonce, 'bylt_form_preview' ) || ! class_exists( 'Bylt_Admin' ) || ! current_user_can( Bylt_Admin::cap() ) ) {
			wp_die( esc_html__( 'The preview expired. Reload the editor and try again.', 'byltcommerce-toolkit' ), '', array( 'response' => 403 ) );
		}
		$pv = wp_unslash( $_POST['bylt_pv'] );
		$as = isset( $_POST['bylt_pv_as'] ) && 'user' === $_POST['bylt_pv_as'] ? 'user' : 'guest';
		// phpcs:enable
		$settings = Bylt_Forms_Store::clean_settings( isset( $pv['settings'] ) ? (array) $pv['settings'] : array() );
		$form     = array(
			'id'       => isset( $pv['id'] ) ? absint( $pv['id'] ) : 0,
			'name'     => isset( $pv['name'] ) ? sanitize_text_field( $pv['name'] ) : '',
			'fields'   => Bylt_Forms_Store::clean_fields( Bylt_Forms_Admin::fields_from_post( isset( $pv['fields'] ) ? (array) $pv['fields'] : array() ), $settings['kind'] ),
			'settings' => $settings,
		);
		show_admin_bar( false );
		nocache_headers();
		header( 'X-Frame-Options: SAMEORIGIN' );
		header( 'X-Robots-Tag: noindex' );
		$html = $this->render_form( $form, array( 'preview' => true, 'as' => $as ) );
		?>
<!doctype html>
<html <?php language_attributes(); ?>>
<head>
<meta charset="<?php bloginfo( 'charset' ); ?>">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="robots" content="noindex">
		<?php
		wp_register_style( 'bylt-form-preview', false, array(), BYLT_VERSION );
		wp_enqueue_style( 'bylt-form-preview' );
		wp_add_inline_style( 'bylt-form-preview', 'html{margin-top:0!important}body.bylt-form-preview{margin:0;padding:32px 24px 48px}.bylt-form-preview .bylt-pv-wrap{max-width:var(--wp--style--global--content-size,760px);margin:0 auto}.bylt-pv-note{margin:16px 0 0;padding:12px 16px;border-radius:6px;background:#f0f6fc;border:1px solid #c5d9ed;color:#1d2327;font:14px/1.4 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}' );
		wp_head();
		?>
</head>
<body <?php body_class( 'bylt-form-preview' ); ?>>
<main class="bylt-pv-wrap entry-content">
		<?php
		echo $html; // phpcs:ignore WordPress.Security.EscapeOutput -- built from escaped parts.
		?>
</main>
		<?php wp_footer(); ?>
</body>
</html>
		<?php
		exit;
	}

	/* ---------------------------------------------------------------------
	 * Submission
	 * ------------------------------------------------------------------- */

	public function handle_post() {
		// phpcs:disable WordPress.Security.NonceVerification -- verified in process(): a WordPress nonce for logged-in visitors; guests (often on cached pages, where nonces go stale) get a signed time token, honeypot and optional Turnstile/reCAPTCHA. Guest submissions never change existing data.
		if ( empty( $_POST['bylt_form_id'] ) || 'POST' !== ( isset( $_SERVER['REQUEST_METHOD'] ) ? $_SERVER['REQUEST_METHOD'] : '' ) ) { // phpcs:ignore WordPress.Security.ValidatedSanitizedInput
			return;
		}
		$id     = absint( $_POST['bylt_form_id'] );
		$result = $this->process( $id, wp_unslash( $_POST ), self::posted_files() ); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput -- sanitized per field.
		// phpcs:enable
		if ( $result['ok'] ) {
			$to = $result['redirect'] ? $result['redirect'] : add_query_arg( 'bylt_sent', $id, self::current_url() );
			wp_safe_redirect( $to, 303 );
			exit;
		}
		$this->results[ $id ] = $result;
	}

	public function ajax() {
		// phpcs:disable WordPress.Security.NonceVerification -- verified in process(); see handle_post().
		$id     = isset( $_POST['bylt_form_id'] ) ? absint( $_POST['bylt_form_id'] ) : 0;
		$result = $this->process( $id, wp_unslash( $_POST ), self::posted_files() ); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput
		// phpcs:enable
		unset( $result['values'] );
		wp_send_json( $result );
	}

	private static function ip() {
		return Bylt_Forms::client_ip();
	}

	/** Uploads for bylt_f[...] as key => array( name, tmp_name, size, error ). */
	private static function posted_files() {
		// phpcs:ignore WordPress.Security.NonceVerification, WordPress.Security.ValidatedSanitizedInput -- checked per file in Bylt_Forms_Files::check().
		$f = isset( $_FILES['bylt_f'] ) && is_array( $_FILES['bylt_f'] ) ? $_FILES['bylt_f'] : array();
		$out = array();
		if ( empty( $f['name'] ) || ! is_array( $f['name'] ) ) {
			return $out;
		}
		foreach ( array_keys( $f['name'] ) as $k ) {
			foreach ( array( 'name', 'tmp_name', 'size', 'error' ) as $p ) {
				$out[ $k ][ $p ] = isset( $f[ $p ][ $k ] ) && ! is_array( $f[ $p ][ $k ] ) ? $f[ $p ][ $k ] : '';
			}
		}
		return $out;
	}

	/** Visitor + form, for the rate limit and the thank-you message. */
	private static function client_key( $form_id ) {
		return (int) $form_id . '|' . self::ip();
	}

	/** Only staff skip the rate limit (they test forms a lot). */
	private static function staff() {
		return class_exists( 'Bylt_Admin' ) && current_user_can( Bylt_Admin::cap() );
	}

	/** Links in the visitor's text (Website fields don't count). */
	public static function count_links( array $form, array $data ) {
		$n = 0;
		foreach ( $form['fields'] as $f ) {
			if ( 'url' === $f['type'] || ! isset( $data[ $f['key'] ] ) ) {
				continue;
			}
			$n += preg_match_all( '#https?://|www\.|\[url|<a\s#i', Bylt_Forms_Mailer::text( $data[ $f['key'] ] ) );
		}
		return $n;
	}

	/**
	 * Validate, store and email one submission.
	 *
	 * @return array{ok: bool, errors: array, message: string, redirect: string, values: array, entry_id: int}
	 */
	public function process( $id, array $post, array $files = array() ) {
		$form = Bylt_Forms_Store::get( $id );
		$out  = array( 'ok' => false, 'errors' => array(), 'message' => '', 'redirect' => '', 'values' => array(), 'entry_id' => 0 );
		if ( ! $form ) {
			$out['errors']['_form'] = __( 'This form is no longer available.', 'byltcommerce-toolkit' );
			return $out;
		}
		$s    = $form['settings'];
		$fake = $out;  // What a bot gets: looks like it worked.
		$fake['ok']      = true;
		$fake['message'] = $s['success'];

		// Logged-in visitors: a nonce, so another site can't submit (and update their account) on their behalf.
		$nonce = isset( $post['bylt_form_nonce'] ) ? sanitize_key( $post['bylt_form_nonce'] ) : '';
		if ( is_user_logged_in() && ! wp_verify_nonce( $nonce, 'bylt_form_' . (int) $form['id'] ) ) {
			$out['errors']['_form'] = __( 'This page has expired. Please reload it and send the form again.', 'byltcommerce-toolkit' );
			return $out;
		}

		// Bots: filled the hidden field, skipped or forged the signed load time, or posted faster than a person could.
		$token = isset( $post['bylt_form_t'] ) ? (string) $post['bylt_form_t'] : '';
		$check = self::check_token( $form['id'], $token );
		if ( ! empty( $post[ self::HONEYPOT ] ) || 'bad' === $check || 'fast' === $check ) {
			do_action( 'bylt_form_spam', $form, $post, ! empty( $post[ self::HONEYPOT ] ) ? 'honeypot' : $check );
			return $fake;
		}
		if ( 'old' === $check ) {
			$out['errors']['_form'] = __( 'This page was open for a long time. Please press the button again to send.', 'byltcommerce-toolkit' );
			$out['token']           = self::token( $form['id'] );
			return $out;
		}
		if ( 'yes' === $s['spam_js'] && ( ! isset( $post['bylt_form_js'] ) || ! hash_equals( self::js_answer( $token ), (string) $post['bylt_form_js'] ) ) ) {
			do_action( 'bylt_form_spam', $form, $post, 'no_js' );
			$out['errors']['_form'] = __( 'Your browser didn\'t finish loading this form. Please make sure JavaScript is on, reload the page and try again.', 'byltcommerce-toolkit' );
			return $out;
		}

		$raw    = isset( $post['bylt_f'] ) && is_array( $post['bylt_f'] ) ? $post['bylt_f'] : array();
		$data   = array();
		$secret = array();  // Passwords: handed to bylt_form_handle, never saved or emailed.
		$errors = array();
		$uploads = array(); // key => checked file, stored once everything else is valid.

		// Conditional logic: fields the visitor couldn't see aren't required, checked or saved.
		$seen = array();
		foreach ( $form['fields'] as $f ) {
			if ( 'file' === $f['type'] ) {
				$seen[ $f['key'] ] = isset( $files[ $f['key'] ]['name'] ) && is_string( $files[ $f['key'] ]['name'] ) ? sanitize_file_name( $files[ $f['key'] ]['name'] ) : '';
			} elseif ( isset( $raw[ $f['key'] ] ) ) {
				$seen[ $f['key'] ] = is_array( $raw[ $f['key'] ] ) ? array_map( 'sanitize_text_field', array_filter( $raw[ $f['key'] ], 'is_scalar' ) ) : sanitize_text_field( (string) $raw[ $f['key'] ] );
			}
		}
		$shown = Bylt_Forms_Store::visible( $form['fields'], $seen );

		foreach ( $form['fields'] as $f ) {
			if ( 'html' === $f['type'] || empty( $shown[ $f['key'] ] ) ) {
				continue;
			}
			if ( 'file' === $f['type'] ) {
				$chk = Bylt_Forms_Files::check( isset( $files[ $f['key'] ] ) ? (array) $files[ $f['key'] ] : array() );
				if ( is_wp_error( $chk ) ) {
					$errors[ $f['key'] ] = $chk->get_error_message();
				} elseif ( null === $chk && $f['required'] ) {
					/* translators: %s: field label */
					$errors[ $f['key'] ] = sprintf( __( '%s is required.', 'byltcommerce-toolkit' ), $f['label'] );
				} elseif ( $chk ) {
					$uploads[ $f['key'] ] = $chk;
					$data[ $f['key'] ]    = $chk['name'];
				} else {
					$data[ $f['key'] ] = '';
				}
				continue;
			}
			$k   = $f['key'];
			$val = isset( $raw[ $k ] ) ? $raw[ $k ] : ( 'checkboxes' === $f['type'] ? array() : '' );
			list( $val, $err ) = self::validate( $f, $val );
			if ( 'password' === $f['type'] ) {
				$secret[ $k ] = $val;
			} else {
				$data[ $k ] = $val;
			}
			if ( $err ) {
				$errors[ $k ] = $err;
			}
		}
		$out['values'] = $data;

		if ( ! $errors ) {
			$fp = $this->forms->protection( $form );
			if ( $fp && ! $fp->passes( 'bylt_form' ) ) {
				$errors['_form'] = __( 'Please confirm you\'re human and try again.', 'byltcommerce-toolkit' );
			}
		}
		$errors = apply_filters( 'bylt_form_errors', $errors, $form, $data );

		// Same visitor, too many entries in a few minutes.
		$rate_key = 'bylt_form_rate_' . md5( self::client_key( $form['id'] ) );
		$rate     = get_transient( $rate_key );
		$rate     = is_array( $rate ) && isset( $rate['n'], $rate['t'] ) && $rate['t'] > time() - self::WINDOW ? $rate : array( 'n' => 0, 't' => time() );
		if ( ! $errors && $s['spam_rate'] > 0 && $rate['n'] >= $s['spam_rate'] && ! self::staff() ) {
			do_action( 'bylt_form_spam', $form, $post, 'rate' );
			$errors['_form'] = __( 'You\'ve sent this form several times in the last few minutes. Please wait a little and try again.', 'byltcommerce-toolkit' );
		}
		if ( $errors ) {
			if ( ! isset( $errors['_form'] ) ) {
				$errors['_form'] = __( 'Please check the highlighted fields.', 'byltcommerce-toolkit' );
			}
			$out['errors'] = $errors;
			return $out;
		}

		// The same entry again (double click, back button, bot replay): don't save or email it twice.
		$dup_key = 'bylt_form_dup_' . md5( $form['id'] . '|' . wp_json_encode( $data ) );
		if ( get_transient( $dup_key ) ) {
			return $fake;
		}

		$email      = self::first_email( $form, $data );
		$product_id = isset( $post['bylt_product_id'] ) ? absint( $post['bylt_product_id'] ) : 0;
		$page       = isset( $post['bylt_form_page'] ) ? esc_url_raw( $post['bylt_form_page'] ) : '';
		$page       = $page && wp_validate_redirect( $page, '' ) ? $page : '';
		$is_spam    = $s['spam_links'] > 0 && self::count_links( $form, $data ) > $s['spam_links'];

		// Files: stored only now that the entry is valid; spam keeps the names but not the files.
		$stored = array();
		if ( ! $is_spam ) {
			foreach ( $uploads as $k => $info ) {
				$rel = Bylt_Forms_Files::store( $info, 'forms' );
				if ( is_wp_error( $rel ) ) {
					foreach ( $stored as $r ) {
						Bylt_Forms_Files::delete( $r );
					}
					$out['errors'] = array( $k => $rel->get_error_message(), '_form' => __( 'Please check the highlighted fields.', 'byltcommerce-toolkit' ) );
					return $out;
				}
				$stored[ $k ] = $rel;
			}
			if ( $stored ) {
				$data['_files'] = $stored;
			}
		}

		$user_id = get_current_user_id();
		$message = $s['success'];
		if ( ! $is_spam ) {
			$handled = apply_filters( 'bylt_form_handle', null, $form, $data, $secret );
			if ( is_wp_error( $handled ) ) {
				foreach ( $handled->get_error_codes() as $code ) {
					$k            = in_array( $code, wp_list_pluck( $form['fields'], 'key' ), true ) ? $code : '_form';
					$errors[ $k ] = $handled->get_error_message( $code );
				}
				if ( ! isset( $errors['_form'] ) ) {
					$errors['_form'] = __( 'Please check the highlighted fields.', 'byltcommerce-toolkit' );
				}
				foreach ( $stored as $r ) {
					Bylt_Forms_Files::delete( $r );
				}
				$out['errors'] = $errors;
				return $out;
			}
			if ( is_array( $handled ) ) {
				$user_id = ! empty( $handled['user_id'] ) ? (int) $handled['user_id'] : $user_id;
				$message = ! empty( $handled['message'] ) ? (string) $handled['message'] : $message;
			}
			if ( $user_id ) {
				self::save_to_customer( $user_id, $form, $data );
			}
		}

		$entry_id = 0;
		if ( 'yes' === $s['store'] || $is_spam ) {
			$entry_id = Bylt_Forms_Store::add_entry(
				array(
					'form_id'    => $form['id'],
					'status'     => $is_spam ? 'spam' : 'new',
					'email'      => $email,
					'data'       => $data,
					'user_id'    => $user_id,
					'product_id' => $product_id,
					'page_url'   => $page,
					'ip'         => self::ip(),
				)
			);
		}
		set_transient( $dup_key, 1, self::WINDOW );
		if ( $is_spam ) {
			do_action( 'bylt_form_spam', $form, $post, 'links' );
			return $fake;
		}
		set_transient( $rate_key, array( 'n' => $rate['n'] + 1, 't' => $rate['t'] ), self::WINDOW );
		$this->forms->mailer()->notify( $form, $data, $entry_id, $email, $product_id, $page );
		do_action( 'bylt_form_submitted', $entry_id, $form, $data );

		if ( $message !== $s['success'] ) {
			set_transient( 'bylt_form_msg_' . md5( self::client_key( $form['id'] ) ), $message, 60 );
		}
		$out['ok']       = true;
		$out['entry_id'] = $entry_id;
		$out['message']  = $message;
		$out['redirect'] = $s['redirect'] ? wp_validate_redirect( $s['redirect'], '' ) : '';
		return $out;
	}

	/** Copy fields marked "Save to customer" onto the customer's account. */
	public static function save_to_customer( $user_id, array $form, array $data ) {
		$targets = Bylt_Forms::map_targets();
		foreach ( $form['fields'] as $f ) {
			if ( empty( $f['map'] ) || ! isset( $targets[ $f['map'] ] ) || ! isset( $data[ $f['key'] ] ) || '' === Bylt_Forms_Mailer::text( $data[ $f['key'] ] ) ) {
				continue;
			}
			// File targets, and targets a module saves itself (e.g. wholesale certificates).
			if ( 0 === strpos( $f['map'], 'file:' ) || apply_filters( 'bylt_form_map_handled', false, $f['map'], $user_id, $data[ $f['key'] ], $f ) ) {
				continue;
			}
			$v = Bylt_Forms_Mailer::text( $data[ $f['key'] ] );
			if ( 'billing_country' === $f['map'] ) {
				$v = strtoupper( substr( preg_replace( '/[^A-Za-z]/', '', $v ), 0, 2 ) );
			}
			update_user_meta( $user_id, $f['map'], $v );
		}
	}

	public static function first_email( array $form, array $data ) {
		foreach ( $form['fields'] as $f ) {
			if ( 'email' === $f['type'] && ! empty( $data[ $f['key'] ] ) ) {
				return $data[ $f['key'] ];
			}
		}
		return '';
	}

	/**
	 * @return array{0: mixed, 1: string} Cleaned value, and an error message or ''.
	 */
	public static function validate( array $f, $val ) {
		$label = $f['label'];
		if ( 'checkboxes' === $f['type'] ) {
			$val = array_values( array_intersect( array_map( 'sanitize_text_field', (array) $val ), $f['options'] ) );
			return array( $val, $f['required'] && ! $val ? __( 'Please choose at least one.', 'byltcommerce-toolkit' ) : '' );
		}
		if ( 'password' === $f['type'] ) {
			$val = is_string( $val ) ? substr( $val, 0, 200 ) : '';
			if ( '' === $val ) {
				/* translators: %s: field label */
				return array( '', $f['required'] ? sprintf( __( '%s is required.', 'byltcommerce-toolkit' ), $label ) : '' );
			}
			if ( strlen( $val ) < self::MIN_PASSWORD ) {
				/* translators: %d: number of characters */
				return array( '', sprintf( __( 'Please use at least %d characters.', 'byltcommerce-toolkit' ), self::MIN_PASSWORD ) );
			}
			$rule = (string) apply_filters( 'bylt_password_error', '', $val ); // Site Tweaks → Password rules.
			return '' !== $rule ? array( '', $rule ) : array( $val, '' );
		}
		if ( is_array( $val ) ) {
			$val = implode( ', ', $val );
		}
		$val = 'textarea' === $f['type'] ? sanitize_textarea_field( $val ) : sanitize_text_field( $val );
		$val = mb_substr( $val, 0, 'textarea' === $f['type'] ? 10000 : 500 );
		if ( '' === $val ) {
			/* translators: %s: field label */
			return array( '', $f['required'] ? ( 'consent' === $f['type'] ? __( 'Please tick this box to continue.', 'byltcommerce-toolkit' ) : sprintf( __( '%s is required.', 'byltcommerce-toolkit' ), $label ) ) : '' );
		}
		switch ( $f['type'] ) {
			case 'email':
				return is_email( $val ) ? array( sanitize_email( $val ), '' ) : array( $val, __( 'Please enter a valid email address.', 'byltcommerce-toolkit' ) );
			case 'url':
				$u = esc_url_raw( preg_match( '#^https?://#i', $val ) ? $val : 'https://' . $val );
				return $u ? array( $u, '' ) : array( $val, __( 'Please enter a valid web address.', 'byltcommerce-toolkit' ) );
			case 'number':
				return is_numeric( $val ) ? array( $val, '' ) : array( $val, __( 'Please enter a number.', 'byltcommerce-toolkit' ) );
			case 'date':
				return preg_match( '/^\d{4}-\d{2}-\d{2}$/', $val ) && strtotime( $val ) ? array( $val, '' ) : array( $val, __( 'Please enter a date.', 'byltcommerce-toolkit' ) );
			case 'tel':
				return preg_match( '/^[0-9 +().\-extEXT#*]{5,40}$/', $val ) ? array( $val, '' ) : array( $val, __( 'Please enter a valid phone number.', 'byltcommerce-toolkit' ) );
			case 'select':
			case 'radio':
				return in_array( $val, $f['options'], true ) ? array( $val, '' ) : array( '', __( 'Please choose an option.', 'byltcommerce-toolkit' ) );
			case 'consent':
				return array( 'yes', '' );
		}
		return array( $val, '' );
	}
}